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K physics at a high-intensity future machine. Marco S.Sozzi Scuola Normale Superiore and INFN – Pisa for INFN fixed-target working group. SPSC Meeting Villars September 26 th 2004. Outline. Where are we now? Very well defined (data in previous talks) - PowerPoint PPT Presentation
Citation preview
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K physics at a high-intensity future
machine
Marco SSozziScuola Normale Superiore
and INFN ndash Pisafor INFN fixed-target working group
SPSC MeetingVillars
September 26th 2004
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outline
bull Where are we nowndash Very well defined (data in previous talks)
bull Where will we be in say 10 years from nowndash Pretty hard question (hopes in previous talks)
bull What will we want to do thenndash Rather hopeless question (this talk)
bull Stillhellip a few things are quite clear
Try to give a sampler of opportunities
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
CaveatsbullSmall working group set up by the particle physics branch of INFN to assess the interest for fixed-target experiments at possible high-intensity proton machines in the mid-long term future bullVery difficult to extrapolate to the long term future quite some wishful thinking and wild guessesSteps and milestones are fundamentalbullThe big issue relevance of what we can learn from kaons in 10 years from nowbullWhat this talk IS NOT
A specification for a projectA design of an experiment
Only high-energy physics with K covered (no hyper-nuclei πhellip)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon decays map1 CP CPT measurements (well known decays)
Kplusmnrarr πplusmnπplusmnπplusmn Kplusmnrarr πplusmnπ0π0 Kplusmnrarr πplusmnπ0γ KSrarr3π0 KSrarrπℓν +ndash 00
2 Long-distance modes (tests of low-energy effective th) Kplusmnrarrπplusmnℓ+ℓndash KLrarrℓ+ℓndash
3 ldquoNew physicsrdquo decays (SM = 0)LFV (KL rarr μe KLKplusmn rarr πμe)
4 Precision measurements (SM = small NP window)Transverse μ polarization (K+ rarr πμν K+ rarr μνγ)
5 Short-distance modes (SM = precise)KLrarrπ0ℓ+ℓndash KLrarrπ0νν Kplusmnrarrπplusmnνν
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
1 CP CPT violationbullNew (direct) CP asymmetries [NA482 OKA starting 2005]Krarr3π slopes and Krarrππγ spectra SM level (10-5)
bullNew CP violation KSrarr3π0 at hadron machines with KS-KL interference close to target (see NA481) KSrarrπ+πndashπ0 (Dalitz plot analysis)
bullCPT test at Planck scale (~1019 GeV)Compare +ndash to SW asymp (ε) at very high precision [CPT proposal 25 GeV] Need +ndash at 005deg and (ε) from precise ancillary measurements (semileptonics 3π Δm τS interf close to target) KTeV-1997 +ndash - SW = (061 plusmn 062 plusmn 101)deg 00 - +ndash = (039 plusmn 022 plusmn 045)degSyst limited acceptance regeneration physics π0π0 reconstrPure beam flux calorimetry vacuum interference (5-20 τS) ie pure K0K0 shielding Also Bell-Steinberger CPT test CPV in KLrarrπ+πndashγAmbitious wide-ranging project
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 Lepton-flavour violationStringent limits reached
Further progress hindered by fluxes but also backgrounds
No longer very competitive with μ system (but complementary)
Byproducts limits on direct decays to exotic (s-)particles Higgs
No new experiments planned
KLrarrμe
A-exchange
P-exchange
New results still expected from high-flux experiments
Decay mode
BR limit (90 CL)
K+ ++endash 28 10ndash11
K+ +ndashe+ 52 10ndash10
K+ ndashe+e+ 64 10ndash10
K+ ndash++ 30 10ndash9
K+ ndash+e+ 50 10ndash10
KL e 47 10ndash12
KL ee 412 10ndash11
KL 0e 62 10ndash9
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
4 PT measurements
PT() = (-17 23 11) 10-
3Also 105 decays (complementary sensitivity to New Physics higher FSI)
PT() in 3-body decays (T-odd correlation) Tiny (10-6) FSI (EM) in SM sensitive to New PhysicsStopped K experiments systematics from detector mis-alignment magnetic fields asymmetries and (large) in-plane polarization
bullJ-PARC LoI Stopped K+ 107 K+s (1 year) 600-700 MeVc plusmn 2 2-stage DC-separated Goal lt 10-4 on PT
bullThere was a BNL proposal for 10-4 on PT with decay in-flight from 2 GeV separated beam
Window of opportunity open Difficult systematics hard to extrapolate more than x10
KEK-E246 (1996-98 8middot106 decays)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
5 K ℓℓExperimental problemsBR 10-11 few (or no) kinematic constraints backgrounds with BR x 107
Dedicated experiments required
KL 0e+e (37 plusmn 10) middot10-11 (CPVdir 1-2 middot10-11)
lt 28 middot10-10
(FNAL KTeV)CPC+CPV eeγγ bkg3 ev (205 bkg)
KL 0μ+μ (15 plusmn 03) middot 10-11 (CPVdir 1-5middot10-12)
lt 38 middot10-10
(FNAL KTeV)CPC+CPV2 ev (087 bkg)
K+ + (80 plusmn 10) middot 10-11 (at 7) No CP
147+130ndash089 middot 10-
10 (BNL E787+E949)
Dedicated expt3 evt (bkg 045)
KL 0 (30 plusmn 06) middot 10-11 (at 2)
lt 59 middot10-7 (KTeV Dalitz decay)
Pure CPV dirldquoNothing to nothingrdquo
Phenomenological
advantageswell known
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ε εrsquo
Unitarity triangle from K
In some cases (π0ℓ+ℓndash) precision ancillary measurements required to fully extract the
short-distance (CKM) information
BR asymp O(10-4 ndash 10-9)
BR asymp O(10-
11)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Aside a super-DaФneKLOE at Frascati reached L = 1032 cm-2 s-1 Need 10-20 fb-1 (exp 2 fb-1 in 2004) for significant improvement on KSrarrπ0ℓ+ℓndash (non-optimal acceptance)
Can a high-luminosity -factory contribute (tagged K known momentum)
[Workshop on e+e- in the 1-2 GeV range (Sett 2003)][F Bossi et al EPJ C6 (1999) 109]
Required luminosity for πνν experiments 1035 cm-2 s-1(Assuming ldquorealisticrdquo detector and vetos)
Discussions for a future (5 years) -factory for KS physics Extrapolating known approaches L = 1033 to 1034 20-100 KSrarrπ0ℓ+ℓndash events can be collectedldquoConventionalrdquo 05 GeV (4π detector) or ldquoLarge crossing-anglerdquo 1 GeV (forward detector) options
Not on the horizon
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outline
bull Where are we nowndash Very well defined (data in previous talks)
bull Where will we be in say 10 years from nowndash Pretty hard question (hopes in previous talks)
bull What will we want to do thenndash Rather hopeless question (this talk)
bull Stillhellip a few things are quite clear
Try to give a sampler of opportunities
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
CaveatsbullSmall working group set up by the particle physics branch of INFN to assess the interest for fixed-target experiments at possible high-intensity proton machines in the mid-long term future bullVery difficult to extrapolate to the long term future quite some wishful thinking and wild guessesSteps and milestones are fundamentalbullThe big issue relevance of what we can learn from kaons in 10 years from nowbullWhat this talk IS NOT
A specification for a projectA design of an experiment
Only high-energy physics with K covered (no hyper-nuclei πhellip)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon decays map1 CP CPT measurements (well known decays)
Kplusmnrarr πplusmnπplusmnπplusmn Kplusmnrarr πplusmnπ0π0 Kplusmnrarr πplusmnπ0γ KSrarr3π0 KSrarrπℓν +ndash 00
2 Long-distance modes (tests of low-energy effective th) Kplusmnrarrπplusmnℓ+ℓndash KLrarrℓ+ℓndash
3 ldquoNew physicsrdquo decays (SM = 0)LFV (KL rarr μe KLKplusmn rarr πμe)
4 Precision measurements (SM = small NP window)Transverse μ polarization (K+ rarr πμν K+ rarr μνγ)
5 Short-distance modes (SM = precise)KLrarrπ0ℓ+ℓndash KLrarrπ0νν Kplusmnrarrπplusmnνν
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
1 CP CPT violationbullNew (direct) CP asymmetries [NA482 OKA starting 2005]Krarr3π slopes and Krarrππγ spectra SM level (10-5)
bullNew CP violation KSrarr3π0 at hadron machines with KS-KL interference close to target (see NA481) KSrarrπ+πndashπ0 (Dalitz plot analysis)
bullCPT test at Planck scale (~1019 GeV)Compare +ndash to SW asymp (ε) at very high precision [CPT proposal 25 GeV] Need +ndash at 005deg and (ε) from precise ancillary measurements (semileptonics 3π Δm τS interf close to target) KTeV-1997 +ndash - SW = (061 plusmn 062 plusmn 101)deg 00 - +ndash = (039 plusmn 022 plusmn 045)degSyst limited acceptance regeneration physics π0π0 reconstrPure beam flux calorimetry vacuum interference (5-20 τS) ie pure K0K0 shielding Also Bell-Steinberger CPT test CPV in KLrarrπ+πndashγAmbitious wide-ranging project
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 Lepton-flavour violationStringent limits reached
Further progress hindered by fluxes but also backgrounds
No longer very competitive with μ system (but complementary)
Byproducts limits on direct decays to exotic (s-)particles Higgs
No new experiments planned
KLrarrμe
A-exchange
P-exchange
New results still expected from high-flux experiments
Decay mode
BR limit (90 CL)
K+ ++endash 28 10ndash11
K+ +ndashe+ 52 10ndash10
K+ ndashe+e+ 64 10ndash10
K+ ndash++ 30 10ndash9
K+ ndash+e+ 50 10ndash10
KL e 47 10ndash12
KL ee 412 10ndash11
KL 0e 62 10ndash9
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
4 PT measurements
PT() = (-17 23 11) 10-
3Also 105 decays (complementary sensitivity to New Physics higher FSI)
PT() in 3-body decays (T-odd correlation) Tiny (10-6) FSI (EM) in SM sensitive to New PhysicsStopped K experiments systematics from detector mis-alignment magnetic fields asymmetries and (large) in-plane polarization
bullJ-PARC LoI Stopped K+ 107 K+s (1 year) 600-700 MeVc plusmn 2 2-stage DC-separated Goal lt 10-4 on PT
bullThere was a BNL proposal for 10-4 on PT with decay in-flight from 2 GeV separated beam
Window of opportunity open Difficult systematics hard to extrapolate more than x10
KEK-E246 (1996-98 8middot106 decays)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
5 K ℓℓExperimental problemsBR 10-11 few (or no) kinematic constraints backgrounds with BR x 107
Dedicated experiments required
KL 0e+e (37 plusmn 10) middot10-11 (CPVdir 1-2 middot10-11)
lt 28 middot10-10
(FNAL KTeV)CPC+CPV eeγγ bkg3 ev (205 bkg)
KL 0μ+μ (15 plusmn 03) middot 10-11 (CPVdir 1-5middot10-12)
lt 38 middot10-10
(FNAL KTeV)CPC+CPV2 ev (087 bkg)
K+ + (80 plusmn 10) middot 10-11 (at 7) No CP
147+130ndash089 middot 10-
10 (BNL E787+E949)
Dedicated expt3 evt (bkg 045)
KL 0 (30 plusmn 06) middot 10-11 (at 2)
lt 59 middot10-7 (KTeV Dalitz decay)
Pure CPV dirldquoNothing to nothingrdquo
Phenomenological
advantageswell known
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ε εrsquo
Unitarity triangle from K
In some cases (π0ℓ+ℓndash) precision ancillary measurements required to fully extract the
short-distance (CKM) information
BR asymp O(10-4 ndash 10-9)
BR asymp O(10-
11)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Aside a super-DaФneKLOE at Frascati reached L = 1032 cm-2 s-1 Need 10-20 fb-1 (exp 2 fb-1 in 2004) for significant improvement on KSrarrπ0ℓ+ℓndash (non-optimal acceptance)
Can a high-luminosity -factory contribute (tagged K known momentum)
[Workshop on e+e- in the 1-2 GeV range (Sett 2003)][F Bossi et al EPJ C6 (1999) 109]
Required luminosity for πνν experiments 1035 cm-2 s-1(Assuming ldquorealisticrdquo detector and vetos)
Discussions for a future (5 years) -factory for KS physics Extrapolating known approaches L = 1033 to 1034 20-100 KSrarrπ0ℓ+ℓndash events can be collectedldquoConventionalrdquo 05 GeV (4π detector) or ldquoLarge crossing-anglerdquo 1 GeV (forward detector) options
Not on the horizon
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
CaveatsbullSmall working group set up by the particle physics branch of INFN to assess the interest for fixed-target experiments at possible high-intensity proton machines in the mid-long term future bullVery difficult to extrapolate to the long term future quite some wishful thinking and wild guessesSteps and milestones are fundamentalbullThe big issue relevance of what we can learn from kaons in 10 years from nowbullWhat this talk IS NOT
A specification for a projectA design of an experiment
Only high-energy physics with K covered (no hyper-nuclei πhellip)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon decays map1 CP CPT measurements (well known decays)
Kplusmnrarr πplusmnπplusmnπplusmn Kplusmnrarr πplusmnπ0π0 Kplusmnrarr πplusmnπ0γ KSrarr3π0 KSrarrπℓν +ndash 00
2 Long-distance modes (tests of low-energy effective th) Kplusmnrarrπplusmnℓ+ℓndash KLrarrℓ+ℓndash
3 ldquoNew physicsrdquo decays (SM = 0)LFV (KL rarr μe KLKplusmn rarr πμe)
4 Precision measurements (SM = small NP window)Transverse μ polarization (K+ rarr πμν K+ rarr μνγ)
5 Short-distance modes (SM = precise)KLrarrπ0ℓ+ℓndash KLrarrπ0νν Kplusmnrarrπplusmnνν
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
1 CP CPT violationbullNew (direct) CP asymmetries [NA482 OKA starting 2005]Krarr3π slopes and Krarrππγ spectra SM level (10-5)
bullNew CP violation KSrarr3π0 at hadron machines with KS-KL interference close to target (see NA481) KSrarrπ+πndashπ0 (Dalitz plot analysis)
bullCPT test at Planck scale (~1019 GeV)Compare +ndash to SW asymp (ε) at very high precision [CPT proposal 25 GeV] Need +ndash at 005deg and (ε) from precise ancillary measurements (semileptonics 3π Δm τS interf close to target) KTeV-1997 +ndash - SW = (061 plusmn 062 plusmn 101)deg 00 - +ndash = (039 plusmn 022 plusmn 045)degSyst limited acceptance regeneration physics π0π0 reconstrPure beam flux calorimetry vacuum interference (5-20 τS) ie pure K0K0 shielding Also Bell-Steinberger CPT test CPV in KLrarrπ+πndashγAmbitious wide-ranging project
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 Lepton-flavour violationStringent limits reached
Further progress hindered by fluxes but also backgrounds
No longer very competitive with μ system (but complementary)
Byproducts limits on direct decays to exotic (s-)particles Higgs
No new experiments planned
KLrarrμe
A-exchange
P-exchange
New results still expected from high-flux experiments
Decay mode
BR limit (90 CL)
K+ ++endash 28 10ndash11
K+ +ndashe+ 52 10ndash10
K+ ndashe+e+ 64 10ndash10
K+ ndash++ 30 10ndash9
K+ ndash+e+ 50 10ndash10
KL e 47 10ndash12
KL ee 412 10ndash11
KL 0e 62 10ndash9
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
4 PT measurements
PT() = (-17 23 11) 10-
3Also 105 decays (complementary sensitivity to New Physics higher FSI)
PT() in 3-body decays (T-odd correlation) Tiny (10-6) FSI (EM) in SM sensitive to New PhysicsStopped K experiments systematics from detector mis-alignment magnetic fields asymmetries and (large) in-plane polarization
bullJ-PARC LoI Stopped K+ 107 K+s (1 year) 600-700 MeVc plusmn 2 2-stage DC-separated Goal lt 10-4 on PT
bullThere was a BNL proposal for 10-4 on PT with decay in-flight from 2 GeV separated beam
Window of opportunity open Difficult systematics hard to extrapolate more than x10
KEK-E246 (1996-98 8middot106 decays)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
5 K ℓℓExperimental problemsBR 10-11 few (or no) kinematic constraints backgrounds with BR x 107
Dedicated experiments required
KL 0e+e (37 plusmn 10) middot10-11 (CPVdir 1-2 middot10-11)
lt 28 middot10-10
(FNAL KTeV)CPC+CPV eeγγ bkg3 ev (205 bkg)
KL 0μ+μ (15 plusmn 03) middot 10-11 (CPVdir 1-5middot10-12)
lt 38 middot10-10
(FNAL KTeV)CPC+CPV2 ev (087 bkg)
K+ + (80 plusmn 10) middot 10-11 (at 7) No CP
147+130ndash089 middot 10-
10 (BNL E787+E949)
Dedicated expt3 evt (bkg 045)
KL 0 (30 plusmn 06) middot 10-11 (at 2)
lt 59 middot10-7 (KTeV Dalitz decay)
Pure CPV dirldquoNothing to nothingrdquo
Phenomenological
advantageswell known
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ε εrsquo
Unitarity triangle from K
In some cases (π0ℓ+ℓndash) precision ancillary measurements required to fully extract the
short-distance (CKM) information
BR asymp O(10-4 ndash 10-9)
BR asymp O(10-
11)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Aside a super-DaФneKLOE at Frascati reached L = 1032 cm-2 s-1 Need 10-20 fb-1 (exp 2 fb-1 in 2004) for significant improvement on KSrarrπ0ℓ+ℓndash (non-optimal acceptance)
Can a high-luminosity -factory contribute (tagged K known momentum)
[Workshop on e+e- in the 1-2 GeV range (Sett 2003)][F Bossi et al EPJ C6 (1999) 109]
Required luminosity for πνν experiments 1035 cm-2 s-1(Assuming ldquorealisticrdquo detector and vetos)
Discussions for a future (5 years) -factory for KS physics Extrapolating known approaches L = 1033 to 1034 20-100 KSrarrπ0ℓ+ℓndash events can be collectedldquoConventionalrdquo 05 GeV (4π detector) or ldquoLarge crossing-anglerdquo 1 GeV (forward detector) options
Not on the horizon
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon decays map1 CP CPT measurements (well known decays)
Kplusmnrarr πplusmnπplusmnπplusmn Kplusmnrarr πplusmnπ0π0 Kplusmnrarr πplusmnπ0γ KSrarr3π0 KSrarrπℓν +ndash 00
2 Long-distance modes (tests of low-energy effective th) Kplusmnrarrπplusmnℓ+ℓndash KLrarrℓ+ℓndash
3 ldquoNew physicsrdquo decays (SM = 0)LFV (KL rarr μe KLKplusmn rarr πμe)
4 Precision measurements (SM = small NP window)Transverse μ polarization (K+ rarr πμν K+ rarr μνγ)
5 Short-distance modes (SM = precise)KLrarrπ0ℓ+ℓndash KLrarrπ0νν Kplusmnrarrπplusmnνν
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
1 CP CPT violationbullNew (direct) CP asymmetries [NA482 OKA starting 2005]Krarr3π slopes and Krarrππγ spectra SM level (10-5)
bullNew CP violation KSrarr3π0 at hadron machines with KS-KL interference close to target (see NA481) KSrarrπ+πndashπ0 (Dalitz plot analysis)
bullCPT test at Planck scale (~1019 GeV)Compare +ndash to SW asymp (ε) at very high precision [CPT proposal 25 GeV] Need +ndash at 005deg and (ε) from precise ancillary measurements (semileptonics 3π Δm τS interf close to target) KTeV-1997 +ndash - SW = (061 plusmn 062 plusmn 101)deg 00 - +ndash = (039 plusmn 022 plusmn 045)degSyst limited acceptance regeneration physics π0π0 reconstrPure beam flux calorimetry vacuum interference (5-20 τS) ie pure K0K0 shielding Also Bell-Steinberger CPT test CPV in KLrarrπ+πndashγAmbitious wide-ranging project
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 Lepton-flavour violationStringent limits reached
Further progress hindered by fluxes but also backgrounds
No longer very competitive with μ system (but complementary)
Byproducts limits on direct decays to exotic (s-)particles Higgs
No new experiments planned
KLrarrμe
A-exchange
P-exchange
New results still expected from high-flux experiments
Decay mode
BR limit (90 CL)
K+ ++endash 28 10ndash11
K+ +ndashe+ 52 10ndash10
K+ ndashe+e+ 64 10ndash10
K+ ndash++ 30 10ndash9
K+ ndash+e+ 50 10ndash10
KL e 47 10ndash12
KL ee 412 10ndash11
KL 0e 62 10ndash9
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
4 PT measurements
PT() = (-17 23 11) 10-
3Also 105 decays (complementary sensitivity to New Physics higher FSI)
PT() in 3-body decays (T-odd correlation) Tiny (10-6) FSI (EM) in SM sensitive to New PhysicsStopped K experiments systematics from detector mis-alignment magnetic fields asymmetries and (large) in-plane polarization
bullJ-PARC LoI Stopped K+ 107 K+s (1 year) 600-700 MeVc plusmn 2 2-stage DC-separated Goal lt 10-4 on PT
bullThere was a BNL proposal for 10-4 on PT with decay in-flight from 2 GeV separated beam
Window of opportunity open Difficult systematics hard to extrapolate more than x10
KEK-E246 (1996-98 8middot106 decays)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
5 K ℓℓExperimental problemsBR 10-11 few (or no) kinematic constraints backgrounds with BR x 107
Dedicated experiments required
KL 0e+e (37 plusmn 10) middot10-11 (CPVdir 1-2 middot10-11)
lt 28 middot10-10
(FNAL KTeV)CPC+CPV eeγγ bkg3 ev (205 bkg)
KL 0μ+μ (15 plusmn 03) middot 10-11 (CPVdir 1-5middot10-12)
lt 38 middot10-10
(FNAL KTeV)CPC+CPV2 ev (087 bkg)
K+ + (80 plusmn 10) middot 10-11 (at 7) No CP
147+130ndash089 middot 10-
10 (BNL E787+E949)
Dedicated expt3 evt (bkg 045)
KL 0 (30 plusmn 06) middot 10-11 (at 2)
lt 59 middot10-7 (KTeV Dalitz decay)
Pure CPV dirldquoNothing to nothingrdquo
Phenomenological
advantageswell known
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ε εrsquo
Unitarity triangle from K
In some cases (π0ℓ+ℓndash) precision ancillary measurements required to fully extract the
short-distance (CKM) information
BR asymp O(10-4 ndash 10-9)
BR asymp O(10-
11)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Aside a super-DaФneKLOE at Frascati reached L = 1032 cm-2 s-1 Need 10-20 fb-1 (exp 2 fb-1 in 2004) for significant improvement on KSrarrπ0ℓ+ℓndash (non-optimal acceptance)
Can a high-luminosity -factory contribute (tagged K known momentum)
[Workshop on e+e- in the 1-2 GeV range (Sett 2003)][F Bossi et al EPJ C6 (1999) 109]
Required luminosity for πνν experiments 1035 cm-2 s-1(Assuming ldquorealisticrdquo detector and vetos)
Discussions for a future (5 years) -factory for KS physics Extrapolating known approaches L = 1033 to 1034 20-100 KSrarrπ0ℓ+ℓndash events can be collectedldquoConventionalrdquo 05 GeV (4π detector) or ldquoLarge crossing-anglerdquo 1 GeV (forward detector) options
Not on the horizon
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
1 CP CPT violationbullNew (direct) CP asymmetries [NA482 OKA starting 2005]Krarr3π slopes and Krarrππγ spectra SM level (10-5)
bullNew CP violation KSrarr3π0 at hadron machines with KS-KL interference close to target (see NA481) KSrarrπ+πndashπ0 (Dalitz plot analysis)
bullCPT test at Planck scale (~1019 GeV)Compare +ndash to SW asymp (ε) at very high precision [CPT proposal 25 GeV] Need +ndash at 005deg and (ε) from precise ancillary measurements (semileptonics 3π Δm τS interf close to target) KTeV-1997 +ndash - SW = (061 plusmn 062 plusmn 101)deg 00 - +ndash = (039 plusmn 022 plusmn 045)degSyst limited acceptance regeneration physics π0π0 reconstrPure beam flux calorimetry vacuum interference (5-20 τS) ie pure K0K0 shielding Also Bell-Steinberger CPT test CPV in KLrarrπ+πndashγAmbitious wide-ranging project
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 Lepton-flavour violationStringent limits reached
Further progress hindered by fluxes but also backgrounds
No longer very competitive with μ system (but complementary)
Byproducts limits on direct decays to exotic (s-)particles Higgs
No new experiments planned
KLrarrμe
A-exchange
P-exchange
New results still expected from high-flux experiments
Decay mode
BR limit (90 CL)
K+ ++endash 28 10ndash11
K+ +ndashe+ 52 10ndash10
K+ ndashe+e+ 64 10ndash10
K+ ndash++ 30 10ndash9
K+ ndash+e+ 50 10ndash10
KL e 47 10ndash12
KL ee 412 10ndash11
KL 0e 62 10ndash9
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
4 PT measurements
PT() = (-17 23 11) 10-
3Also 105 decays (complementary sensitivity to New Physics higher FSI)
PT() in 3-body decays (T-odd correlation) Tiny (10-6) FSI (EM) in SM sensitive to New PhysicsStopped K experiments systematics from detector mis-alignment magnetic fields asymmetries and (large) in-plane polarization
bullJ-PARC LoI Stopped K+ 107 K+s (1 year) 600-700 MeVc plusmn 2 2-stage DC-separated Goal lt 10-4 on PT
bullThere was a BNL proposal for 10-4 on PT with decay in-flight from 2 GeV separated beam
Window of opportunity open Difficult systematics hard to extrapolate more than x10
KEK-E246 (1996-98 8middot106 decays)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
5 K ℓℓExperimental problemsBR 10-11 few (or no) kinematic constraints backgrounds with BR x 107
Dedicated experiments required
KL 0e+e (37 plusmn 10) middot10-11 (CPVdir 1-2 middot10-11)
lt 28 middot10-10
(FNAL KTeV)CPC+CPV eeγγ bkg3 ev (205 bkg)
KL 0μ+μ (15 plusmn 03) middot 10-11 (CPVdir 1-5middot10-12)
lt 38 middot10-10
(FNAL KTeV)CPC+CPV2 ev (087 bkg)
K+ + (80 plusmn 10) middot 10-11 (at 7) No CP
147+130ndash089 middot 10-
10 (BNL E787+E949)
Dedicated expt3 evt (bkg 045)
KL 0 (30 plusmn 06) middot 10-11 (at 2)
lt 59 middot10-7 (KTeV Dalitz decay)
Pure CPV dirldquoNothing to nothingrdquo
Phenomenological
advantageswell known
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ε εrsquo
Unitarity triangle from K
In some cases (π0ℓ+ℓndash) precision ancillary measurements required to fully extract the
short-distance (CKM) information
BR asymp O(10-4 ndash 10-9)
BR asymp O(10-
11)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Aside a super-DaФneKLOE at Frascati reached L = 1032 cm-2 s-1 Need 10-20 fb-1 (exp 2 fb-1 in 2004) for significant improvement on KSrarrπ0ℓ+ℓndash (non-optimal acceptance)
Can a high-luminosity -factory contribute (tagged K known momentum)
[Workshop on e+e- in the 1-2 GeV range (Sett 2003)][F Bossi et al EPJ C6 (1999) 109]
Required luminosity for πνν experiments 1035 cm-2 s-1(Assuming ldquorealisticrdquo detector and vetos)
Discussions for a future (5 years) -factory for KS physics Extrapolating known approaches L = 1033 to 1034 20-100 KSrarrπ0ℓ+ℓndash events can be collectedldquoConventionalrdquo 05 GeV (4π detector) or ldquoLarge crossing-anglerdquo 1 GeV (forward detector) options
Not on the horizon
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 Lepton-flavour violationStringent limits reached
Further progress hindered by fluxes but also backgrounds
No longer very competitive with μ system (but complementary)
Byproducts limits on direct decays to exotic (s-)particles Higgs
No new experiments planned
KLrarrμe
A-exchange
P-exchange
New results still expected from high-flux experiments
Decay mode
BR limit (90 CL)
K+ ++endash 28 10ndash11
K+ +ndashe+ 52 10ndash10
K+ ndashe+e+ 64 10ndash10
K+ ndash++ 30 10ndash9
K+ ndash+e+ 50 10ndash10
KL e 47 10ndash12
KL ee 412 10ndash11
KL 0e 62 10ndash9
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
4 PT measurements
PT() = (-17 23 11) 10-
3Also 105 decays (complementary sensitivity to New Physics higher FSI)
PT() in 3-body decays (T-odd correlation) Tiny (10-6) FSI (EM) in SM sensitive to New PhysicsStopped K experiments systematics from detector mis-alignment magnetic fields asymmetries and (large) in-plane polarization
bullJ-PARC LoI Stopped K+ 107 K+s (1 year) 600-700 MeVc plusmn 2 2-stage DC-separated Goal lt 10-4 on PT
bullThere was a BNL proposal for 10-4 on PT with decay in-flight from 2 GeV separated beam
Window of opportunity open Difficult systematics hard to extrapolate more than x10
KEK-E246 (1996-98 8middot106 decays)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
5 K ℓℓExperimental problemsBR 10-11 few (or no) kinematic constraints backgrounds with BR x 107
Dedicated experiments required
KL 0e+e (37 plusmn 10) middot10-11 (CPVdir 1-2 middot10-11)
lt 28 middot10-10
(FNAL KTeV)CPC+CPV eeγγ bkg3 ev (205 bkg)
KL 0μ+μ (15 plusmn 03) middot 10-11 (CPVdir 1-5middot10-12)
lt 38 middot10-10
(FNAL KTeV)CPC+CPV2 ev (087 bkg)
K+ + (80 plusmn 10) middot 10-11 (at 7) No CP
147+130ndash089 middot 10-
10 (BNL E787+E949)
Dedicated expt3 evt (bkg 045)
KL 0 (30 plusmn 06) middot 10-11 (at 2)
lt 59 middot10-7 (KTeV Dalitz decay)
Pure CPV dirldquoNothing to nothingrdquo
Phenomenological
advantageswell known
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ε εrsquo
Unitarity triangle from K
In some cases (π0ℓ+ℓndash) precision ancillary measurements required to fully extract the
short-distance (CKM) information
BR asymp O(10-4 ndash 10-9)
BR asymp O(10-
11)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Aside a super-DaФneKLOE at Frascati reached L = 1032 cm-2 s-1 Need 10-20 fb-1 (exp 2 fb-1 in 2004) for significant improvement on KSrarrπ0ℓ+ℓndash (non-optimal acceptance)
Can a high-luminosity -factory contribute (tagged K known momentum)
[Workshop on e+e- in the 1-2 GeV range (Sett 2003)][F Bossi et al EPJ C6 (1999) 109]
Required luminosity for πνν experiments 1035 cm-2 s-1(Assuming ldquorealisticrdquo detector and vetos)
Discussions for a future (5 years) -factory for KS physics Extrapolating known approaches L = 1033 to 1034 20-100 KSrarrπ0ℓ+ℓndash events can be collectedldquoConventionalrdquo 05 GeV (4π detector) or ldquoLarge crossing-anglerdquo 1 GeV (forward detector) options
Not on the horizon
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
4 PT measurements
PT() = (-17 23 11) 10-
3Also 105 decays (complementary sensitivity to New Physics higher FSI)
PT() in 3-body decays (T-odd correlation) Tiny (10-6) FSI (EM) in SM sensitive to New PhysicsStopped K experiments systematics from detector mis-alignment magnetic fields asymmetries and (large) in-plane polarization
bullJ-PARC LoI Stopped K+ 107 K+s (1 year) 600-700 MeVc plusmn 2 2-stage DC-separated Goal lt 10-4 on PT
bullThere was a BNL proposal for 10-4 on PT with decay in-flight from 2 GeV separated beam
Window of opportunity open Difficult systematics hard to extrapolate more than x10
KEK-E246 (1996-98 8middot106 decays)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
5 K ℓℓExperimental problemsBR 10-11 few (or no) kinematic constraints backgrounds with BR x 107
Dedicated experiments required
KL 0e+e (37 plusmn 10) middot10-11 (CPVdir 1-2 middot10-11)
lt 28 middot10-10
(FNAL KTeV)CPC+CPV eeγγ bkg3 ev (205 bkg)
KL 0μ+μ (15 plusmn 03) middot 10-11 (CPVdir 1-5middot10-12)
lt 38 middot10-10
(FNAL KTeV)CPC+CPV2 ev (087 bkg)
K+ + (80 plusmn 10) middot 10-11 (at 7) No CP
147+130ndash089 middot 10-
10 (BNL E787+E949)
Dedicated expt3 evt (bkg 045)
KL 0 (30 plusmn 06) middot 10-11 (at 2)
lt 59 middot10-7 (KTeV Dalitz decay)
Pure CPV dirldquoNothing to nothingrdquo
Phenomenological
advantageswell known
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ε εrsquo
Unitarity triangle from K
In some cases (π0ℓ+ℓndash) precision ancillary measurements required to fully extract the
short-distance (CKM) information
BR asymp O(10-4 ndash 10-9)
BR asymp O(10-
11)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Aside a super-DaФneKLOE at Frascati reached L = 1032 cm-2 s-1 Need 10-20 fb-1 (exp 2 fb-1 in 2004) for significant improvement on KSrarrπ0ℓ+ℓndash (non-optimal acceptance)
Can a high-luminosity -factory contribute (tagged K known momentum)
[Workshop on e+e- in the 1-2 GeV range (Sett 2003)][F Bossi et al EPJ C6 (1999) 109]
Required luminosity for πνν experiments 1035 cm-2 s-1(Assuming ldquorealisticrdquo detector and vetos)
Discussions for a future (5 years) -factory for KS physics Extrapolating known approaches L = 1033 to 1034 20-100 KSrarrπ0ℓ+ℓndash events can be collectedldquoConventionalrdquo 05 GeV (4π detector) or ldquoLarge crossing-anglerdquo 1 GeV (forward detector) options
Not on the horizon
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
5 K ℓℓExperimental problemsBR 10-11 few (or no) kinematic constraints backgrounds with BR x 107
Dedicated experiments required
KL 0e+e (37 plusmn 10) middot10-11 (CPVdir 1-2 middot10-11)
lt 28 middot10-10
(FNAL KTeV)CPC+CPV eeγγ bkg3 ev (205 bkg)
KL 0μ+μ (15 plusmn 03) middot 10-11 (CPVdir 1-5middot10-12)
lt 38 middot10-10
(FNAL KTeV)CPC+CPV2 ev (087 bkg)
K+ + (80 plusmn 10) middot 10-11 (at 7) No CP
147+130ndash089 middot 10-
10 (BNL E787+E949)
Dedicated expt3 evt (bkg 045)
KL 0 (30 plusmn 06) middot 10-11 (at 2)
lt 59 middot10-7 (KTeV Dalitz decay)
Pure CPV dirldquoNothing to nothingrdquo
Phenomenological
advantageswell known
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ε εrsquo
Unitarity triangle from K
In some cases (π0ℓ+ℓndash) precision ancillary measurements required to fully extract the
short-distance (CKM) information
BR asymp O(10-4 ndash 10-9)
BR asymp O(10-
11)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Aside a super-DaФneKLOE at Frascati reached L = 1032 cm-2 s-1 Need 10-20 fb-1 (exp 2 fb-1 in 2004) for significant improvement on KSrarrπ0ℓ+ℓndash (non-optimal acceptance)
Can a high-luminosity -factory contribute (tagged K known momentum)
[Workshop on e+e- in the 1-2 GeV range (Sett 2003)][F Bossi et al EPJ C6 (1999) 109]
Required luminosity for πνν experiments 1035 cm-2 s-1(Assuming ldquorealisticrdquo detector and vetos)
Discussions for a future (5 years) -factory for KS physics Extrapolating known approaches L = 1033 to 1034 20-100 KSrarrπ0ℓ+ℓndash events can be collectedldquoConventionalrdquo 05 GeV (4π detector) or ldquoLarge crossing-anglerdquo 1 GeV (forward detector) options
Not on the horizon
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ε εrsquo
Unitarity triangle from K
In some cases (π0ℓ+ℓndash) precision ancillary measurements required to fully extract the
short-distance (CKM) information
BR asymp O(10-4 ndash 10-9)
BR asymp O(10-
11)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Aside a super-DaФneKLOE at Frascati reached L = 1032 cm-2 s-1 Need 10-20 fb-1 (exp 2 fb-1 in 2004) for significant improvement on KSrarrπ0ℓ+ℓndash (non-optimal acceptance)
Can a high-luminosity -factory contribute (tagged K known momentum)
[Workshop on e+e- in the 1-2 GeV range (Sett 2003)][F Bossi et al EPJ C6 (1999) 109]
Required luminosity for πνν experiments 1035 cm-2 s-1(Assuming ldquorealisticrdquo detector and vetos)
Discussions for a future (5 years) -factory for KS physics Extrapolating known approaches L = 1033 to 1034 20-100 KSrarrπ0ℓ+ℓndash events can be collectedldquoConventionalrdquo 05 GeV (4π detector) or ldquoLarge crossing-anglerdquo 1 GeV (forward detector) options
Not on the horizon
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Aside a super-DaФneKLOE at Frascati reached L = 1032 cm-2 s-1 Need 10-20 fb-1 (exp 2 fb-1 in 2004) for significant improvement on KSrarrπ0ℓ+ℓndash (non-optimal acceptance)
Can a high-luminosity -factory contribute (tagged K known momentum)
[Workshop on e+e- in the 1-2 GeV range (Sett 2003)][F Bossi et al EPJ C6 (1999) 109]
Required luminosity for πνν experiments 1035 cm-2 s-1(Assuming ldquorealisticrdquo detector and vetos)
Discussions for a future (5 years) -factory for KS physics Extrapolating known approaches L = 1033 to 1034 20-100 KSrarrπ0ℓ+ℓndash events can be collectedldquoConventionalrdquo 05 GeV (4π detector) or ldquoLarge crossing-anglerdquo 1 GeV (forward detector) options
Not on the horizon
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
SSL aaKBR 611732510)(2120
CPC (th 30 + KL rarr π0γγ)
CPV ind (KS rarr π0μ+μndash)
50
CPV dir 10 CPV int
25
SSL aaeeKBR 2642715310)(2120
CPC (th +
KL rarr π0γγ)
CPV ind (KS rarr π0e+endash)
50
CPV dir 8
CPV int 25
bullError dominated by CPVind need several 100s KSrarrπ0ℓ+ℓndash (and improvement in theory)
bullSign of interference term crucial only from theory (positive favoured)
bullBackground subtraction will be an issue irreducible γγℓ+ℓndash at 15middot104 and 8middot102 hard to reduce below signal Tight cuts rarr acceptance rarr flux
bullee mode requires very good πe separation more material (TRD) μμ mode might turn out to be easier (also more handles small CPC in low mass region )
bullWith very high fluxes more approaches are available Dalitz plot analysis time evolution (interference) or polarization analysis (μ mode) O(1014 K)
260210081
Sa (NA48)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K+ + BR(SM) ~ 10-10 (3 events)Theoretical uncertainty ~ 7(going down to 2 )
Background from K and beam no kinematic constraints Suppression 1011 limited by physical processes Redundancy particle ID kinematics vacuum live-time VETO
bullStopped K+ approach has limits (stop fraction slow PID solid angle π scatter vetoing)
bullIn-flight approach (new) needs pK measurement no scattering faster better vetoing)
CERN
J-PARCCKM-2
Will have some 10s of events
Proposed
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0
Model independent bound
ldquoDirectrdquo CP-violatingBR ~ 310-11 (or NP) (limit 59middot10-7 bound 17middot10-9)Theoretical uncertainty ~ 1-2
Background from 00γγ mode n flux hyperons vacuum material live-time Very few handles missing pT VETO
bullKOPIO approach (40 events) bullKAMI-(KEK)-JPARC approach large acceptance pencil beam (flux) rate (100-1000 events)Several options (DC energy barrel detectionhellip
Will have few 10s of events
KLOD (Protvino)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New projects startingproposedTps MKs
KL KOPIO (BNL) 2010+ on track 14 33
KL (J-PARC) 2008++ (beam line accidentals)
60 320
KL KLOD (Protvino)
2007+ 11 9
K+ (CERN) After RampD 2009+ (tracking)
02 9
K+ CKM-2 (FNAL) Re-design 2009+ (tracking veto)
2 3()
K+ (J-PARC) 2008+ (improvements)
23 23
K+ OKA (Protvino) 2005+ (Krarr3π) 11 06
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios Experiment the coming generation of experiments will
reach the 10-100 SM events level for πνν decays
Theory existing precision data on K system will become quantitative checks of SM (or constraints to NP) Precision on πℓℓ decays will improve to 1-2-5
(a) K in agreement with SM for both modes 1 order of magnitude to go to close the window for NP
(b) K in disagreement with SM precision measurement O(1000) access to form factor other kinematical regions Dalitz plot time-interference Krarrπℓ+ℓndash
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future scenarios
Impact on unitarity triangle
Buras et al hep-ph0405132
10201x
5201xx
Now
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future machinesA high intensity p driver (gt1014 ppp) would be very valuable
for ldquoultimaterdquo K measurements Sinergies with neutrino physics With LHC injectors
upgradeEnergy in the tens of GeV range slow extraction (high DC)
Intense K+ beam Kplusmn CP asymmetriesIntense K+ RF-separated beam K+ + Tertiary K0 beam CPT tests at Planck scale (K phases)Intense KL beam KL 0 KL 0e+e- KL 0μ+μ- (with several handles) diverse program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Remember KAON at TRIUMFThe ultimate kaon (+ much more) machine1985-1993 RIP
30 GeV - 3MW - 100 μA625 Tps
2 RCS + 3 SR450 MeV rarr 3 GeV rarr 30 GeV + stretcher ring
6 K+ beams 05-21 GeVc1-6 Δpp(06-37) middot 108 K+s
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC at Tokai phase 2Phase I 30 GeV 075 MW9 μA 21014 pspill60 Tps07s342 s (DC 20 )
Start physics 2008
Phase II 50 GeV 4 MW15 μA 331014 pspill94 Tps
Better DC required (otherwise ltIgt = 6xAGS but I = 15xAGS) 5 HEP kaon physics LoI
KL 0 K+ + T-violation BR(K+) Ke3
2 kaon lines initially foreseen 08 - 11 GeV K+ and 2 GeVc KL ()
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
High-intensity upgrades
FNAL 1 MW8 GeV p LINAC
5 x MI flux 120 GeV55 Tps
BNL 02 MWMore booster cycles AGS x
17+ accumulator ring AGS x 34
34-60 Tps
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Kaon production
For indicative purposesMaximum kaon yield per given
power at 30-100 GeV
(Of course several other crucial issues for energy choice)
G Kalmus CERN-TH2001-75
Constant kaon yield
Constant beam power
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
A new proton driverAssume 4 MW accelerator + stretcher ring
Unseparated (πK ~ 10) 30 GeV (75 GeV K) 133μA (830 Tps 20xAGS) 120 GeV (30 GeV K) 33μA (210 Tps 7xMI) 400 GeV (100 GeV K) 10μA (63 Tps 9xSPS)
RF-separated (pK lt 50 GeV O(70) purity)50 GeV machine maximum K+ yield at 12 GeV (048 K+pGeVsr)
Target efficiency 40
Beam momentum 12 GeVc plusmn 1
Beam acceptance 75 μsr
Separator acceptance 50
Duty cycle 30
K+year (107 s) 26 middot 1015
K+ decaysyear (in 30m) 6 middot 1014
3middot108 K+sWith 2 acceptanceeff
1000 K+ rarr πνν eventsyear
(BR at 3 ultimate)
with beam rate 12 GHz
O(few 1010) K+s
THz beams
Ballpark numbers
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
New K beamsMaximum K+ yield at fixed beam momentum p pKp = 023
Naively fixing this beam power and geometry NK = Φ(p) σ(p) Ω(p) (1p) p2 (1p) for unsep beam (1p) p2 (1p4) for sep beam(moreover decays in fixed volume 1p)
1 Intense K+ beam
2 RF-separation needed at high intensities for measurements requiring kaon tracking low energy (pK=30 GeV survival lt 04) compromise with exp technique
3 Production of pure K0 (interference experiments) by charge-exchange at 0ordm (same p and Δpp 80μb CEX cross-section factor ~ 10-3) narrow band or separated () K+ beam
4 Neutral broad band beam need space for sweeping dump shielding (higher E) O(few 109) Ks O(1000) KLrarrπ0νν events
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
(Some more) experimental issuesHigh-intensity beams target halo collimation sweeping neutron absorber collimator scattering secondary productionhellip
Energy choice K yield nγπhyperon yield K survival (separated beams) resolutions and veto capability interactions acceptancehellip
Rates in detectors (E781 20 MHzm2 HyperCP 30 MHzm2 CKM-1 50 MHz)
DAQ live-time monitoringstatistics
E949 2E12 K dec 700 MeVc DC-sep (πK=3) E787 5E12 K dec 700 MeVc DC-sep (πK=4) NA482 2E11 K dec 60 GeVc unsep (πK=10) KTeV gt2E11 KL dec 100 GeVcKOPIO 1E14 KL dec 700 MeVcE391a 2E11 KL dec 2 GeVcJ-PARC KL 4E14 KL dec 2 GeVc
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Thirsty for flux
bullSensitivity
bullTighter cuts to control background (pencil beam)
bullAbsorber for n targeting angle choice (at 16p angle nK x16 for K yield x06)
bullOther approaches Dalitz plot time-interference analysis polarizations
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Example polarization measurements
Diwan et alPRD 65 (2002) 054020
In the case of KLrarrπ0μ+μndash
longitudinal μ polarization (P-odd) is non-zero only in
presence of direct CPV
Single-muon polarization measurement is sufficient
large effects
This helps reducing background and
disentangling amplitude components at some
price on statistics
Longitudinal μ+ polarization
in K rest frame
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Outlook more fundamental physics with K
bullImportance of K in shaping the SM well known
bullThe increase in flux availability led to beyond-state-of-the-art experiments
bullFlavour physics least understood part of SM rather unique access to SM or NP couplings before the LC era (the high-precision frontier)
bullFlux (not only) required for sensitivity ancillary measurements background suppressions (also improvement in techniques rate handlinghellip)
bullExistence of clean decay modes stimulated world-wide efforts in an active and strong community with several generations of experience
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ConclusionsA few things are clear
The information to be gained from rare K decays is not going to be exhausted with the arrival of LHC
Itrsquos not going to be complete by then either
The focus is on SD precision rare decays (experiments starting now) These experiments are hard enough that they will require double-checks and complementary approaches
The quality of the data is as important as the statistics higher fluxes are crucial for control of backgrounds and systematics
A high-intensity (MWs tens of GeV slow extracted) p machine would give an excellent (unique) opportunity to extract all the rich information available from K decays
Sinergies with neutrino physics program
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Spare slides
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KLOE at Frascati
DAΦNE φ-factory e+e-Low luminosity at start constantly improvingPeak luminosity 81031 cm-2 s-1 in 2002Goal 51032 cm-2 s-1 500 pb-1 (15 109 ) collected until 2002
Currently running
Good prospects for KS interferometry
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KS decays CPVSearch for KS 30 interf KL-KS at hadron machines or Φ factories
BR(KS30) lt 310-7 (90 CL)
Not yet reached indirect CP violation
SM expectation 310-9
(NA481 prel)
m(K0) m(K0) = (17 42) 10-19 GeVc2
Dominates indirect CPT violation limits
S = (-2 9 6) 10-3
KS charge asymmetry (KLOE prel)
( plusmn 410-3 still far from CPT test)
Semileptonic KS decays (KLOE prel 170 pb-
1)BR(KSeν) = (709 007 008) 10-4
BR(KS30) lt 2110-7 (90 CL) (KLOE prel 450 pb-1 4 ev 32 bkg)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
RF-separated beam in preparation at U-70 PS15 GeVc K+ or K- (alternated) detector from ISTRA+ GAMSAsymmetries of Dalitz plot slopes in 3 decays at O(1 10-4)T-odd correlations search for New Physics in Kl2 decays
2003 12 beam line cryogenics slow extraction of 131013 pppFirst physics run in 2005
K decays OKA Protvino
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARC Tokai
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
J-PARCRequested beam lines
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
K at J-PARC
KL follow-up of KEK-E391a100 MHz pencil beam (accidentals rate x500) acceptance ~ 16 high energy (flux resolution acceptance veto efficiency) New calorimeters (CeF3 ) and DAQGoal gt100 SM events (SES 3middot10-14 max limit) in 3 years (2middot1015 KL)
K+ BNL stopped-K technique Low energy (600-800 MeVc) DC-separated (Kπ gt3) beamDecays at rest (gt25 stop)Incremental upgrade (x4) of detector new spectrometerGoal gt50 SM events in 3 years (SES 210-12 E9495)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
ΔS=1
ΔB=2
Comparing K and B
Comparing Vtd from K+ + and
ΔM(Bd) ΔM(Bs)
Comparing β from BR(KL 0) BR(K+ +) and A(BdJψK0)
Constraints from B and K physics (10 BR measurements)
bullErrors on Vtd better from B
bullErrors on sin2 similar to B- factories
bullError on t better from KA Buras hep-ph9905437
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
3 contributions to these decays
KL 0ℓ+ℓ-
KTeV limits (90 CL) BR(KL 0e+e-) lt 2810-10
BR(KL 0+-) lt 3810-10
bull CP-allowed not predictedderived from KL 0γγ (NA48 KTeV)
bull Indirect CP violation not predictedmeasured by KS 0ℓ+ℓ- (NA481)
bull Direct CP violation predicted in terms of CKM phase
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
KL 0ℓ+ℓ-
Isidori et al hep-ph0404127bullKL measurements CP-allowed contribution is small
bullKS measurements indirect CP-violating term dominates
bullSensitivity of BR to CKM phase depends on the (unmeasurable) relative sign of the two CP-violating termsTheoretical predictions constructive interferenceBR(KL 0e+e-)CPV times 1012 asymp 17 (ind) plusmn 9 (interf) + 4 (dir)
BR(KL 0μ+μ-)CPV times 1012 asymp 8 (ind) plusmn 3 (interf) + 2 (dir)
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K
September 26th 2004 M Sozzi ndash K at high intensity SPSC Meeting Villars
Future projects and goals
Main focus on the measurement of ultra-rare
decaystheoretically clean highly sensitive complementary
to B
Also T-violation searches
CP asymmetries in charged K