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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 1
CDF hot topicsCDF hot topics
Sandro De CeccoSandro De Cecco
FNAL & INFN Roma 1FNAL & INFN Roma 1
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 2
OutlineOutline
• Tevatron performances
• Recent and new results:– Bs mixing– b-hadrons Lifetimes & s/s
– b modes– Charmless Bd,s decays– Rare decays
• Summary and perspectives
• CDF detector and B physics triggers
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 3
Tevatron performancesTevatron performances
•CDF II has collected so far ~ 0.8 fb-1 out of >1 fb-1 delivered by Tevatron.
•Record peak luminosity is ~ 1.3∙1032 cm-2s-1
•Around 600 pb-1 are available for B physics (good tracking detector conditions)
•Current analyses use 180 - 350 pb-1 of integrated luminosity
1 fb-1 !
Right on the track of stretched TeV plans
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 4
The CDF II detectorThe CDF II detector
CDF Tracking System
Particle ID
•dE/dX in COT
•Time Of Flight detector
Lepton ID
Muons: CMU, CMP, CMX 1.1)Electrons: CEM (EM calorimeter) CPR (pre-shower detector)
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 5
B Physics at B Physics at pp colliderpp collider•All B species produced:
Bu,Bd,Bs,Bc,b, b…
•With production fractions:
fu : fd : fs : f ≈ 4 : 4 : 1 : 1
•Acceptance for other B is 20-40%
BUT: (bb) << (pp) (~65 mb) B have to be selected with specific Triggers
Primary Vertex
Secondary Vertex
Impact Parameter ( ~100m)
Lxy ~ 1 mm
B decay
•b production is so large (~300 Hz @ 1032 cm-2 Hz) that we could not even cope with writing it all to tape! trigger quasi-exclusively on specific decay modes
Example: the Secondary Vertex Trigger SVT
•Online (L2) selection of displaced tracks
based on Silicon detector hits.
see talk by Mauro Dell’Orso
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 6
B physics triggers at CDF IIB physics triggers at CDF II
1-Displaced track + lepton (e, )
120 m < I.P.(trk) < 1mm
PT(lepton) > 4 GeV
Semileptonic modes
2-Displaced tracks
PT(trk) > 2 GeV
120 m < I.P.(trk) < 1mm
pT > 5.5 GeV
fully hadronic modes
Di-Muon (J/)
Pt() > 1.5 GeV
J/ modes down to low Pt(J/)~0 (Run II)
Conventional at colliders (Run I)
+
With SVT trigger
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 8
WA experimental limit:ms > 14.5 ps-1 (95%CL)
(LEP+SLD+CDF 1)
BBss Mixing Mixing
Fit with all constraints (winter 05):ρ = 0.190 ± 0.044
η = 0.349 ± 0.024
2
2
22
2
2
2
td
ts
Bd
Bs
td
ts
BdBd
BsBs
Bd
Bs
d
s
V
V
m
m
V
V
Bf
Bf
m
m
m
m
but: |Vts|>>|Vtd| ms>>md
Measuring ms/md determines |Vts|/|Vtd| Lattice calculation error O(5%)
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 9
Δms = 20.5 ± 3.2 ps-1
[14.4, 27.1] @ 95% CL
ms = 18.9 ± 1.6 ps-1
[15.7, 23.0] @ 95% CL
SM CKM-fit prediction for SM CKM-fit prediction for mms s
If ms > 30 ps-1 New Physics @ 3
(with all constraints)(Δms not used)
compatibility plot
SM New Physics modelscan allow high ms
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 10
Analysis StrategyAnalysis Strategy
• Bs signal reconstruction– Flavour specific states
• Bs decay time– proper time reconstruction – Lifetime measurement
• Initial flavour of the Bs
– Flavour tagging techniques
– calibrate on Bd mixing
mtSDAeL ttsig cos1
1 /
A
B0 Mixing perform a “Blind AMPLITUDE SCAN”:
B0 A-scan
md = 0.5ps-1 ↔ A =1
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 11
Two different BTwo different Bss signatures: signatures:Fully reconstructed HADRONIC modes:
SEMILEPTONIC modes:
D
P.V.B
,e
ss
D
P.V.
B
ss
ss DB0
XlDB lss 0
•Good proper time resolution•High Bs mass resolution•Selected by Two Track Trigger (SVT)
•Missing momentum carried by the •Diluted proper time resolution•Selected by dedicated trigger (l+SVT):
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 12
Flavour taggingFlavour taggingOpposite SideOpposite Side Same SideSame Side
Same Side Kaon: for B0s is likely to have close
in DR a K+. High D2 is expected
Soft Lepton (e,) due to bℓXℓ charge correlated to b-flavour
Jet Charge: the sum of charges of the b-Jet trackscorrelated to the b-flavour
Used for today results
NOT yet used
HADRONIC SEMILEPTONIC
md(0.503±0.063±0.015) ps-1 (0.498±0.028±0.015) ps-1
Tot. D2 (1.12±0.23)% (1.43±0.09)%
)( KDXlDB
Muon TagCalibrate the OS taggers on B0 mixing
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 13
BBss Amplitude Scan results Amplitude Scan results
Semileptonic
Hadronic
•Sensitivity: 8.4 ps-1
•Limit: ms > 7.9 ps-1 @ 95% CL
•Sensitivity: 0.4 ps-1
•Limit: ms > 0 ps-1 @ 95% CL
Semileptonic
Hadronic
•Sensitivity: 8.4 ps-1
•Limit: ms > 7.9 ps-1 @ 95% CL
CDF winter ’05 Combined
• World Average + CDF Run II
– Sensitivity: 18.2 18.6 ps-1
– Limit: 14.5 ps-1
see talk by Marco Rescigno
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 14
Near future for Near future for mmss
With the SAME data:
• Add new tagging algorithms Same Side Kaon Tag• Add more channels• Add signals from other triggers• Improve decay time resolution with PV event by event
With NEW data:
• Increased Luminosity (0.8fb-1 on tape!)• Use new trigger strategies
•2 SVT Tracks + tagging muon at trigger level (already in place since summer 2004)
x4 statistics
+20% better ct res.
•Hadronic analysis will begin to lead the sensitivity•Start to “eat” interesting ms range (expect comb. sens. ~ 15ps-1)
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 15
NEWNEW:: additional semileptonic B decays additional semileptonic B decays
From the same data (360 pb-1) usedin mixing analysis:
•Use SVT trigger (2 displaced and 2 GeV tracks)
•Select e and offline
•Allow lower LEPTON PT (42GeV)
•Increase the overall acceptance
of more than X 3
At low Lepton PT, expect more backgrounds from BDDX decays
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 16
more semileptonicmore semileptonic BBss forfor mmss analysisanalysis
+
4GeV-lepton + 1 displaced track trigger
2 displaced track trigger
Additional new sample overlap with the one already used ~ 20%
Effective ~ X 3 more semileptonic Bs yield to be used for MIXING Expect significant sensitivity increase in semileptonic ms search
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 17
b-hadron lifetimes and b-hadron lifetimes and ss//ss
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 18
•Full statistics sample still under study.
Statistical uncertainty expected:
Lifetimes in semileptonic B decaysLifetimes in semileptonic B decays
•Largest statistics B sample
•More complicated background
13,300Signal events
260 pb-1
(B+) = 1.653±0.029±0.032 ps, (B0) = 1.473±0.036±0.054 ps (B+)/(B0) = 1.123±0.040±0.040
http://www-cdf.fnal.gov/physics/new/bottom/050224.blessed-bsemi-life/
B+ 0.017 ps
B0d 0.025 ps
B0s 0.03 ps
b 0.037 ps
@ ~400 pb-1
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 19
Lifetimes in fully reconstructed modesLifetimes in fully reconstructed modes
(B+) = 1.661±0.027±0.013 ps (B0) = 1.511±0.023±0.013 ps(Bs) = 1.598±0.097±0.017 ps
•Test for our ability to understand SVT trigger biases
•Very clean samples
•Prerequisite for mixing fits
KK
CDF ’05 preliminary result
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 20
• Result (260 pb-1)– 1/4 heavy - 3/4 light state– Lifetime - heavy ~ 2 x light
• Lifetime difference measures“same” CKM element as m (oscillation frequency)
• Exciting!! Need more data– ~ 5 % sensitivity by 2009 ms = 10 ps-1 S / S = 7%
• Test still possible CP violation effect in Bs mixing
BBssJ/J/ and andssss
• BS J/ +- K+K-
• BVV decays: Heavy and Light state decay with distinct angular distributions and different lifetimes.
01.065.0 25.033.0
s
s
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 22
bb modes modes
http://www-cdf.fnal.gov/physics/new/bottom/050407.blessed-lbbr/
C. Tarantino, hep-ph/0310241 Oct 2003
b c X
•Lifetimes are an important experimental reference:–Overlap with B factories understanding of detector/trigger/analysis biases
–Further test on species not produced at B factories:
b c
NEW:
b Branching ratios:
Exp. Theo.
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 23
bb Updated knowledge Updated knowledge
Mass m = 5619.9 1.7 MeV/c2
(4.1 2.0) x 10-3
c l (5.5 1.8) %
pK + p < 2.2 x 10-5
c(2593) + l
seenc(2625)
+l seenc
++ l
seenc
0 l
seen
c+
seen
b mass
Colors:
- PDG2004
- CDF contribution beyond current PDG2004
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 24
CP violation and charmless B decaysCP violation and charmless B decays
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 25
Charmless BCharmless Bhh’hh’•Difficult competition with B factories for t-dependent tagged measurements
•Interesting B physics measurement of Bs BR and ACP(B0K)
• Signals overlap within mass resolution
• Kinematic and dE/dX to disentangle components in a combined fit:
see talk by Simone Donati
Future: measure Bs lifetimein the CP even mode KK
extract s/s
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 26
Charmless BCharmless BVV decaysVV decays
Bd→K*
~125 events ~44 events
•Measured BR( Bs) with 8 events (180 pb-1)
•Update with 360 pb-1
•Will go soon for Polarization Amplitude analysis
•Expected significance similar to B-factories
Bs→
see talk by Simone Donati
~225 events
Bs→J/
TTT dataoverlap with2 trigger:~20%
Future: measure s/s
in Bs penguin mode
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 27
Search for BSearch for Bs,ds,d see talk by Sinead Farrington
NEW Results (360 pb-1): BR(Bs ) < 1.6×10-7 @ 90% CL < 2.1×10-7 @ 95% CL
BR(Bd ) < 3.9×10-8 @ 90% CL < 5.1×10-8 @ 95% CL
These are currently world best limits
SM: BR(Bs) < 3.8∙10-9
Sensitive to new physics
Ex.:
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 28
… … and also at BEAUTY 05:and also at BEAUTY 05:
• Other VERY INTERESTING results from TEVATRON Heavy Flavour physics on:
– Bc meson at CDF and D0
– X(3872) at CDF and D0
see talk by William Wester
see talk by Ulrich Kerzel
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 29
ConclusionsConclusions
• CDF performed the first Bs mixing analysis in run II
• We foresee a substantial update with new samples, new data collected and improved tagging power for winter 2006
• Working to have world class measurements on b-hadron lifetimes and lifetime difference s/s
• Perform complementary studies in the field of charmless B decays: Bd,shh, Bd,sVV, help digging the penguin sector
• Huge CDF legacy of knowledge in Beauty to next generation B physics experiments.
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 31
SVT: the hadronic B triggerSVT: the hadronic B trigger
≈ 47 m ≈ 35 m + 30 m
SVT resolution Beam spot size
Online Impact parameterAvailable at Level 2 trigger (20µs latency)
convolution of transverse size of the beam spot with the impact parameter resolution of the SVT:
Impact Parameter distribution
Offline ~ 45 m
d
beam spot
COT track ( 2 parameters) 5 SVX coordinates
Impact Parameter (transverse projection)
Primary Vertex
Secondary Vertex
Impact Parameter ( ~100m)
Lxy ~ 1 mm
B decay
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 32
HadronicSemileptonic
mmss : systematic Uncertainties : systematic Uncertainties
•Physics background at low ms
•Prompt background at high ms
•Dilution scale factors and templatessystematic limited from control samplestatistics
**Systematic errors are negligible with respect to statistical in both cases**
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 33
Heavy Flavour ProductionHeavy Flavour Production
from HbX in 37 pb-1 of data!PRD 71, 032001 (2005)
Pt >
GeV/c
(y<1)b
D0 5.5 13.30.20.5
D*+ 6.0 5.20.10.8
D+ 6.0 4.30.10.7
Ds 8.0 0.750.050.22
PRL 91, 241804 (2003)
bb
cc with first 6.5 pb-1 !
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 34
Excited Heavy Flavor statesExcited Heavy Flavor states
• B**(L=1) B
– B J/K and D modes
– Important to understand impact for Same Side Kaon tagging mixing
2*2
2
2
*2
Common
45 /m B B MeV cm B B
f f B BB B
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 35
Welcome back to BWelcome back to Bcc
Hep-ex/0505076
http://www-cdf.fnal.gov/physics/new/bottom/050330.blessed-bc-jpsimu/
080.0032.0045.0245.0
/6
/6
KJBBRGeVP
JBRGeVP
tB
ctBc
106 events46.07.3 events
20011.00048.0287.6c
GeVm
•First signal of fully reconstructed Bc
•Direct mass measurement!
•Mode that gave the first evidence of the Bc (CDF Run I)
•Large yield, no clean resonance though!
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 36
Lifetimes: J/Lifetimes: J/ modes modes
This was the starting point:
•Clean unbiased sample
•Precision measurement
•Reference for biased (e.g. displaced track) triggers
•Test for the understanding of:
•Detector
•Analysis technique
•Sample composition ps008.0051.0539.1
ps008.0010.0100.0369.1
http://www-cdf.fnal.gov/physics/new/bottom/040428.blessed-lft2/
ps008.0033.0662.1
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 37
Lifetime in the hadronic Lifetime in the hadronic BBss modes modes
• Decay time
• actually measure transverse quantities:
– Lxy , PT(B)
• Un-binned likelihood fit
• Used: and
p
mLLt c /
Combinatorial background cttemplate from high mass sideband
ss DB0 ss DB0
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 38
Hadronic B-lifetimes resultsHadronic B-lifetimes results
(B+) = 1.66 ± 0.03 ± 0.01 ps (B0) = 1.51 ± 0.02 ± 0.01 ps(Bs) = 1.60 ± 0.10 ± 0.02 ps
Systematic summary
(B+)/(B0) = 1.10 ± 0.02 ± 0.01
(Bs)/(B0) = 1.06 ± 0.07 ± 0.01
± (stat) ± (syst)
(B+) = 1.653 ± 0.014 ps (B0) = 1.534 ± 0.013 ps(Bs) = 1.469 ± 0.059 ps
World Average lifetimes (exp.):
(B+)/(B0) = 1.06 ± 0.02
(Bs)/(B0) = 1.00 ± 0.01
Theory prediction (see Cecilia Tarantino CKM05):
CDF
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 39
Lifetime in the semileptonic Lifetime in the semileptonic BBss modes modes
c = 455.9 11.9 m c = 422.6 25.7 m c = 413.8 20.1 m
Combined ℓ-Ds lifetime result: 445.0 9.5 m (W.A.: 438 17 m)
statistical err .only, NOT for Averages (DØ ’05: 426 13 17 m)
Real Ds backgrounds: prompt and physics
Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma 40
HQET: baryon lifetimes and B momentsHQET: baryon lifetimes and B moments
B lifetimes Vcb
Dominant uncertainty comes from HQET extraction!
CDF can probe HQET and constrain it!
%183.81
0
Bb
b lifetimeC. Tarantino, hep-ph/0310241 Oct 2003
LO NLO 0B
B
0B
Bs
0B
b
LO NLO
LO NLO
http://www-cdf.fnal.gov/physics/new/bottom/030710.blessed-lambdab-lifetime/