Report from Expression of Interest

Physics goals

Detector developments

Collaboration setupA. Passeri

72 physicists12 institutionshttp://www.lnf.infn.it/lnfadmin/direzione/KLOE2-LoI.pdf

Expression of Interest Vast physics program both at the f peak and in the range 1< s < 2.5 GeV

Require Ldt 50 fb-1 in a 34 years running period at the f peak (i.e. 5 x 1010 KSKL events and 7.5 x1010 K+K- events), in order to reach significant sensitivities for the study of neutral kaon interferometry, KS rare decays, lepton universality test and h, h program.

Require to run also at higher energies to accomplish the multihadronic cross section measurement and the gg program. Energy scan highly recommended, with average L1032cm-2s-1 .

Expect to start experimental program in 2011

Plan to use the KLOE detector with some important upgrades

Physics goals at the f peakKaon physics: KS rare decays pen, pmn, 3p0, p+p-p0, p0l+l- Study neutral kaon interference: search for CPT violation, quantum decoherence, EPR phenomena, test Bells inequality. Improve, where possible, all KLOE BR measurements Vus Search for LFV effects in Ke2 decaysh, h physics: extensive cPT tests, very sensitive to hadron structure, light quark masses and couplings: h(h)3p , hhpp Radiative decays: h(h)gg, p+p-g, p+p-e+e- , hp0gg C,CP violation: hpp, ggg, p0p0g, p0l+l- hl+l-h Light scalars: Investigate the nature of the established scalars f0(980), a0(980) measure their s-quark couplings via f(f0+a0)gKKg Search for the controversial lighter scalars s(600) and K*(800) via gg process.

Physics goals in the region 1s 2.5 GeVgg physics: Study h, f0, a0 production and their gg width (related to the quark structure of the hadron). Vector meson spectroscopy: study r, , f recurrencies and their place in hadron multiplets. Understand the nature of r(1900) (glueball?).Hadronic cross section: Provide R measurement for am and aem determination. Perform an accurate energy scan. Improve by a factor of 10 the present BABAR exclusive cross section measurements. Afford the only inclusive shad measurement since 80s. The program is wide and spread over many topics. All together they offer a rich experimental field.In the following I will briefly discuss mainly the kaon part.The rest will be addressed in C.Binis talk.

The KLOE heritage: Vus|Vud|2 + |Vus|2 + |Vub|2 ~ |Vud|2 + |Vus|2 1 D = 0.9997 0.0013CKM matrix unitarity test can be refined by 1 order of magnitude.Vud from superallowed Fermi transitionVus dominated by KLOE measurements of K semileptonic decays:Recent progress in lattice QCD seems to open the possibility of lowering the theoretical uncertainty to 0.1% KLOE does also extract |Vus| from (K())/(()) ratio. Precision limited by the theoretical uncertainity on the fK/f evaluation.Precision limited by hadronic correctionsConsidering the actual KLOE performances and assuming thatsystematics will scale with statistics, a factor of 100 more statisticsis needed to match the theoretical precision, i.e. 40 fb-1 Presently:

Lepton universality testIn extended SUSY models large contributions to Ke2 decay are expected from LFV terms:First studies are going on in KLOE: need to fully exploit calorimeter for e/m separation. A reasonable guess, based on present detector, is that50 fb-1 would push relative error around 0.5%.But : efficiency could improve dramatically with an increased calo granularity and with a better inner tracking stage.

CPT violation testsViolation expected in QG models. No obvious scale predictions.The f-factory environment provides a unique opportunity to test the existence of such effect, in 3 different ways:

The comparison of KS and KL semileptonic decay charge asymmetries

Via the Bell-Steinberger relation

By studying the quantum interference between entangled kaon pairs produced in f decays. This is also allow to perform tests of quantum coherence, EPR paradox and Bells inequality.

CPTV I : KS semileptonic decay asymmetryAS AL 0 implies CPT AS = 2(Re K Re K Re b/a Re d*/a) AL = 2(Re K Re K Re b/a Re d*/a)Present results:ALASKTeV-02KLOE 400pb-1With a 50 fb-1 sample: s(AS)10-3

But: acceptance can be increased up to a factor of 2 just by lowering the B field

CPTV II : Bell-Steinberger relationFrom unitarity conditions:Im(d) 0 can be only due to CPTV, unitarity violation or exotic states.After KLOE measurement of BR(KS3p0) : Im(d) = (1.2 3.0) 10-5The next limiting inputs to B.S. are h+- and h00

CPTV III :Quantum interference interference pattern I(Dt) for different final states f1,f2 give access to different parameters a good vtx resolution is required: s(Dt)

In the EHNS model the interference pattern contains 3 CPTV parameters: a, b, g o (MK2/MPlanck) 10-20 GeV KLOE measurements still worse than CPLEAR Generic quantum decoherence (which can also signal CPTV) is introduced via a parameter z . KLOE already measured: 50fb-1 more would reduce error by 10.KLOE2 figure of merit: constant line is CPLEAR VDET means svtxtS/4 in BMP model CPTV modifies the concept of antiparticle and KSKL state deviates from Bose statistics via a parameter :Preliminary KLOE measurement is already at 10-4level. KLOE2 can go up to 10-5

Rare KS decaysBR(KSpen) is still the limiting factor in the test of DS=DQ rule by 3 error reduction on Re(x+) provided systematics scales with stat BR(KSpmn) same as the above, but more difficult. Expected error at 0.4%.

BR(KSgg) test of cPT at o(p4). NA48 measurement 30% apart from calculations. Current error is 2.7%. KLOE2 can go below 1%

BR(KSp+p-p0) another test of cPT, predictions around 10-7. KLOE2 expected precision around 15%. Would benefit from B field reduction.

BR(KS3p0) CP and CPT test. Expected at 10-9, present limit at 10-7. KLOE2 can aim to observe the signal.

BR(KSp0l+l-) very important to evaluate the CPV via mixing contribution to the rare analogous decay of KL. Present NA48 measurement based on 7+6 events. With conservative efficiency estimate KLOE2 expects to perform a measurement at the same level.

R measurement and energy scan Hadronic contribution to aem(MZ) is very important in the region 1

The KLOE detectorE/E = 5.7% / E(GeV) t = 54 ps / E(GeV) 50 ps(finite bunch-length contribution subtracted)p/p = 0.4 % (tracks with > 45)= 150 mz = 2 mm4 m diameter 3.75 m length90% helium, 10% isobutane12582/52140 sense/total wiresAll-stereo geometryLead/scintillating fiber4880 PMTs98% coverage of solid angleEmCDCsolenoidal 0.5 T magnetic field

The KLOE concept:Good 0 reconstruction capabilitiesExcellent e/ separation based on t.o.f. Full kinematical reconstruction of eventsThe focus in KLOE design was mainly on efficiency for long-lived particles (K ,KL), but the detector provides as well acceptable efficiency and resolution for prompt particles.

KLOE ( K LONG Experiment ) was not fully optimized to detect low momentum tracks coming from IP (KS, h decay products)Tracking starts at 25 cm from IP: both tracking and vertex efficiency affected Calorimeter readout granularity does not prevent cluster merging and is not sufficient for a a shower-shape pid.at f peak, gg physics impossible without small angle e taggerPhysics and background rate could be an issue for DAQ and triggerKLOE detector weaknesses for DAFNE2 physics:Proposed upgrades: Lower B field from 0.5 T to 0.3 T (at least at f peak) Add an inner tracker at 10< R < 25 cm refine calorimeter readout granularity Small Angle Tagger for gg events placed downstream Trigger and DAQ upgrades

B field: from 5 3 KGauss ? KSp+p-p0Simulated Km2 events Increase acceptance for low momentum tracks coming from I.P. Reduction of spiralizing tracks less tails in momentum resolutionDrawback: sp worsening for tracks athigher pT (>150 MeV/c)However: other effects, depending on the channel, may partially compensate According to simulation 40% B field reduction produce only a 15% sp increasein Km2 events

Inner tracker: requirements It must start at R 20 tS , to avoid spoiling the KSKL interference path To maximize acceptance it must extend up to q=30o

It must be able to provide independent tracking, i.e. must measure at least 4 or 5 3D-spatial points. It must be very light, not to spoil sP: a total material 1% X0 is acceptable hit resolution: lS is only upper limit from physics but for independent tracking we must ensure that contribution to sP is better than M.S. shit 200 mm is enough for 10 cm track length

it must sustain a very high rate: extrapolation from KLOE machine background monitors yields a pessimistic figure od 3040 hits /plane/msconsidered solutions: easy: using straw tubes layers. Very light. Electronics and mechanics standard. challenging: cylindrical GEM. Expertise exists at LNF, but detector shape is totally new.

Principle of operation of a GEM detectorThe GEM (Gas Electron Multiplier) (F.Sauli, NIM A386 (1997) 531) is a thin (50 mm) metal coated kapton foil, perforated by a high density of holes (70 mm diameter, pitch of 140 mm) standard photo-lithographic technology.By applying 400-500 V between the two copper sides, an electric field as high as ~100 kV/cm is produced into the holes which act as multiplication channels for electrons produced in the gas by a ionizing particle.Gains up to 1000 can be easily reached with a single GEM foil. Higher gains (and/or safer working conditions) are usually obtained by cascading two or three GEM foils.A Triple-GEM detector is built by inserting three GEM foils between two planar electrodes, which act as the cathode and the anode. LHCb GEM configurationCourtesy ofG.Bencivenni

Cylindrical GEM developmentLNF Detector Development GroupF.Anulli, G.Bencivenni, D.Domenici, G.Felici, F.Murtas The basic cylindrical structure can be realized with the straw-tube technology The cylinder is obtained winding a parallelogram-shaped kapton foil. A helicoidal joint line (~3 mm wide) is left: Two consecutive cylindrical electrodes have opposite helicity in order to reduce the overlap of joint lines to only one point (~3x3 mm2). A detector layer is composed by five concentric cylindrical structures: the cathode, the 3 GEM foils, the readout anode. Anode and GEM3-down (where only electron fast signals are present) are equipped with U-V strip readout for stereo view. Strip pitch is 400 mm. The cylindrical electrodes are glued at the ends on circular frames, by which the detector can be hung to the beam pipe, avoiding any internal support frameFirst prototype for mechanical test successfully produced

GEM vs KLOE2 requirements : Cylindrical GEM can be assembled in 5 detector layers at 10

Calorimeter readout granularity: why refine it ?Avoid cluster splitting.and mergingImprove e/m/pseparation viacluster shapevariables6 g eventsAfter kinematicfit c2 cutand on top of that..Started a detailed calorimeter simulation based on FLUKA mc:

lead foils, including 5% Bi glue Bicron BC-600ML, in all components individual fibers: polystirene core + PMMA cladding

Standard KLOE calorimeter behaviour well reproduced for photons:Eg (MeV)Eg (MeV)Eg (MeV)Eg (MeV)sE/Eszcentroid depth (cm)centroid rms (cm)FLUKA..Data resolEnergy and spatialresolutions comparedto measured onesCluster depth and rmscompared top+p- g events

Granularity tests with 1000 events with two 200 MeV electronsGenerated energy releaseDigitized cellsKLOE granularityKLOE granularity x 4KLOE granularity x 161x1cm22x2cm24.4x4.4cm2Energypreliminary

Granularity tests with 1000 events with two 200 MeV muonsGenerated energy releaseDigitized cellsKLOE granularity1x1cm22x2cm24.4x4.4cm2Energypreliminary

Calorimeter granularity refinement: how to implement it ? Still a lot of work to do with simulation and comparison to KLOE data

Light readout could be performed with multi-anode PM tubes, like Hamamatsu R7600-00M4 or 00M16, having very good risetime and QE similar to present PMs. Sample of such devices already purchased, to be tested very soon.

Light guides should be replaced with smaller ones: not an easy job !

Prototyping and testing is mandatory

Granularity could be refined only on first 1 or 2 planes, and eventually only in the barrel region.

FEE should be redesigned for the new cells, while old cells FEE boards can be used as spares for the remaining ones.

Trigger considerations DAFNE DANAE events 300 Hz 2500 Hz Good Bhabhas 600 Hz 5000 Hz Residual cosmics 600 Hz 600 Hz Machine backgr. 500 Hz ? Simple rate scaling shows that KLOE2Must work well above 10 KHz total rate,depending on machine bckg If machine bckg does not increase dramatically, present minimum bias trigger strategy (2 hw lvls + 1 sw) can be mantained, with Bhabha prescaling ON. The 3rd level filter must become more selective, to minimize the fraction of non-interesting events on tape. Most of the present trigger custom boards (11 diferent types) need to be designed, for lack of spares and components obsolescence DC trigger need to be reconsidered: actual thresholds are not easily under control, and may change trigger conditions unexpectedly. A gg physics trigger must be included At high energy multiplicity will increase: trigger should be even more efficient. However threshold tuning will be necessary.

DAQ at KLOE2KLOE DAQ was designed to sustain 50 Mbyte/s and was tested up to 80 Mbyte/s , divided between 10 similar acquisition chains. Its architecture can be kept, provided we overcome 3 bottlenecks : VME block transfer from 2nd lvl concentrator to CPU, limited at 20 Mbyte/s VME64x protocol, together with the new 2eSST block transfer (Double-edge Source Syncronous Block Transfer) can transmit up to 320 Mbyte/s ! FDDI data transfer from 2nd lvl CPUs to onlinefarm, limited at 12.5 Mbyte/s can be replaced by Gigabit Ethernet 2nd lvl CPUs (old DEC) data framing, limited around 8 Mbyte/s Motorola MVME6100 implements both VME64 and Gigabit Ethernet Aloisio,Branchini,Cevenini,Izzo,Loffredo,LomoroA tester board has been realized to test thefull environment. MVME6100 running Linux with a custom vme driver and the KLOE online sw. Measured sustained rate is 180 Mbyte/s

Setup of the collaborationFor the moment : 72 physicists in 12 institutions

Out of which: 44 are italians 4 are italians 41 are also in KLOE 7 are also in KLOE Doors are open to newcomers who share the same physics programBy end of june a KLOE2 full meeting is planned to:

start giving the collaboration a governing structure

define together the next milestones and start sharing working items

ConclusionsA sizeable group of experimental physicists has expresses interest ina wide physics program to be performed at the next Frascati e+e-collider, both at the f peak and at higher energyWe plan to use the KLOE detector with some important upgrades, for which we have already started developments.

Spare Slides

Vus from KLOE results (BRs and tL)c2/dof = 1.9/4

KL e3KL m3KS e3K e3K m3BR0.4007(15)0.2698(15)7.046(91)10-40.05047(46)0.03310(40)t50.84(23) ns89.58(6) ps12.384(24) ns

Vus and UnitarityWORLD AV. = 0.2164(4) tL = 50.99(20) ns, average KLOE-PDG Including all new measurements for semileptonic kaon decays (KTeV, NA48, E865, and KLOE)

The Vus- Vud planeunitarityFit results, P(c2) = 0.66: Vus = 0.2246 0.0016 Vud = 0.97377 0.00027

Fit result assuming unitarity, P(c2) = 0.23: Vus = 0.2264 0.0009

Ke2 Momentum distributionWe use as starting point a sample of 80000 K+e2 corresponding to 2fb statistic. (IB+SD)MC 2005 was used with the new charged kaon noise insertedThe K+ decay must be reconstructed with vertex in FVThe electron momentun ranges in 200-300 MeV/c region. Same as the muons from K2Red = MCblu = ke2black dataLab momentumMev/cSD

Multiple scattering vs thicknessComparison between MS induced by 2 reference value of silicon thickness (1mm and 1.5 mm) wrt a KLOE-like: 700m of carbon fiber. A thickness larger than 1mm of silicon equivalent ( 1% of X0) can be a limiting factor for the momentum mesurement of low momentum particle coming from IP . Problem can also be given by the conversion of photons from machine

VICVIC C P UFDDIROCKMVICCPUTS+FIOVic busAUX bus VME busVME busTrigger16 DAQ FEE boardsVICC-busTrigger linesDAQ ChainDATA CONCENTRATORAUX busTrigger linesLevel 2Level 1

In KLOE the link and the switch between fee and farm is based onFDDI IT MUST BE CHANGED

SM predictions: GammaS = GammaL, As = AL = 2Re epsilondal Perl di Matt con i numeri di Paolo Franzinifrom Vud and unitarity Vusf0 = 0.21866 +/- 0.00213; from Kl3 Vusf0 = 0.21605 +/- 0.00051; Vus = 0.22482 +/- 0.00195Vusxf+(0) with pole model, Tau_L KLOE = 0.21617(48) i.e 0.2162(5) Using as pole masses: Mv=876.7(5.1 )MeV, Mp=1182(38)MeVQuesta e` quella buona! Average KLOE+KTeV+NA48+E865 Vus(Mescia) =0.2164(4) Vud from Fermi super-allowed beta decays, valore di Vud=.97377(27) verificato in Marciano hep-ph/0510099, pubbl. Phys.Rev.Lett. 96:032002Vus from: Kl3 e tauL KLOE NEW(24feb2006) Vus = 0.22482(195) Kl3 e tauL AVE NEW(24feb2006) Vus = 0.22458(194) Fit1 a due parametri: P(chi2) = 66%Fit2 a un parametro+unitarieta`: P(chi2) = 23%