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Report from

( ). *. ( ) still a conventional name !. *. Report from. A. Passeri. Expression of Interest Physics goals Detector developments Collaboration setup. http://www.lnf.infn.it/lnfadmin/direzione/KLOE2-LoI.pdf. 72 physicists. 12 institutions. Expression of Interest.

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  1. ( ) * ( )still a conventional name ! * Report from A. Passeri • Expression of Interest • Physics goals • Detector developments • Collaboration setup A.Passeri: KLOE-2 Report

  2. http://www.lnf.infn.it/lnfadmin/direzione/KLOE2-LoI.pdf 72 physicists 12 institutions A.Passeri: KLOE-2 Report

  3. Expression of Interest • Vast physics program both at the f peak and in the range 1< s < 2.5 GeV • RequireʃLdt 50 fb-1in a 34 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 L∼1032cm-2s-1 . • Expect to start experimental program in 2011 • Plan to use the KLOE detector with some important upgrades A.Passeri: KLOE-2 Report

  4. Physics goals at the f peak Kaon 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 Bell’s inequality. Improve, where possible, all KLOE BR measurements  Vus Search for LFV effects in Ke2 decays h, h’ physics: extensive cPT tests, very sensitive to hadron structure, light quark masses and couplings: h(h’)3p , h’hpp Radiative decays: h(h’)gg, p+p-g, p+p-e+e- , hp0gg C,CP violation: hpp, ggg, p0p0g,p0l+l-h’l+l-h • Light scalars: Investigate the nature of the established scalars f0(980), a0(980) • measure their s-quark couplings via f(f0+a0)gKKg • Search for the controversial lighter scalars s(600) and K*(800) • via gg process. A.Passeri: KLOE-2 Report

  5. Physics goals in the region 1≤s≤ 2.5 GeV 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. Vector meson spectroscopy: study r, , f recurrencies and their place in hadron multiplets. Understand the nature of r(1900) (glueball?). gg physics: Study h’, f0, a0 production and their gg width (related to the quark structure of the hadron). 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.Bini’s talk. A.Passeri: KLOE-2 Report

  6. G(K  pℓn(g))  |Vus f+K0p-(0) |2 I(lt) SEW(1 + dEM + dSU(2) ) The KLOE heritage: Vus CKM matrix unitarity test can be refined by 1 order of magnitude. |Vud|2 + |Vus|2 + |Vub|2~ |Vud|2 + |Vus|2  1 – D = 0.9997 ± 0.0013 Presently: Vud from superallowed Fermi transition Vus dominated by KLOE measurements of K semileptonic decays: Precision limited by hadronic corrections KLOE does alsoextract |Vus| from (K())/(()) ratio. Precision limited by the theoretical uncertainity on the fK/f evaluation. Recent progress in lattice QCDseems to open the possibility of lowering the theoretical uncertainty to ∼0.1% Considering the actual KLOE performances and assuming that systematics will scale with statistics, a factor of 100 more statistics is needed to match the theoretical precision, i.e. 40 fb-1 A.Passeri: KLOE-2 Report

  7. Lepton universality test In 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 that 50 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. A.Passeri: KLOE-2 Report

  8. CPT violation tests Violation 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 Bell’s inequality. A.Passeri: KLOE-2 Report

  9. CPTV I : KS semileptonic decayasymmetry _ G(KS,L  p-e+n) - G(KS,L  p+e-n) AS,L = _ G(KS,L  p-e+n) + G(KS,L  p+e-n) CPT in mixing CPT in decay S Q and CPT CP AS  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: AL KTeV-’02 AS KLOE 400pb-1 With 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 A.Passeri: KLOE-2 Report

  10. CPTV II : Bell-Steinberger relation From unitarity conditions: Im(d) ≠ 0 can be only due to CPTV, unitarity violation or exotic states. After KLOE measurement of BR(KS3p0) : Im(d) = (1.2 ±3.0) 10-5 The next limiting inputs to B.S. are h+- and h00 A.Passeri: KLOE-2 Report

  11. f1 t1 t2 KS,L f KL,S Dt=t1- t2 f2 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)<tS •  quest for an improvement of inner tracking! • several QG models predict CPTV terms in the • interference time evolution I(Dt) f1,f2 = p±l∓n large Dt: Semileptonic decays give access to dK small Dt: Dt/tS A.Passeri: KLOE-2 Report

  12. 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. • 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 KLOE2 figure of merit: constant line is CPLEAR VDET means svtx∼tS/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 10-4 level. KLOE2 can go up to 10-5 A.Passeri: KLOE-2 Report

  13. Rare KS decays BR(KSpen)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(KSpmn) same as the above, but more difficult. Expected error at 0.4%. BR(KSgg) test of cPT at o(p4). NA48 measurement 30% apart from calculations. Current error is 2.7%. KLOE2 can go below 1% BR(KSp+p-p0) another test of cPT, predictions around 10-7. KLOE2 expected precision around 15%. Would benefit from B field reduction. BR(KS3p0) CP and CPT test. Expected at 10-9, present limit at 10-7. KLOE2 can aim to observe the signal. BR(KSp0l+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. A.Passeri: KLOE-2 Report

  14. R measurement and energy scan Hadronic contribution to aem(MZ) is very important in the region 1<s<2.5 GeV If not measuredat few % levelis going to be the limiting factor for future precision calculation (linear collider physics). B factories are already doing it ! Radiative return with 2 fb-1 at 2.4 GeV Energy scan 20 pb-1 per point BABAR now BABAR full stat KLOE2 A.Passeri: KLOE-2 Report

  15. The KLOE detector EmC DC Lead/scintillating fiber 4880 PMTs 98% coverage of solid angle 4 m diameter × 3.75 m length 90% helium, 10% isobutane 12582/52140 sense/total wires All-stereo geometry E/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 m z = 2 mm solenoidal 0.5 T magnetic field A.Passeri: KLOE-2 Report

  16. Calorimeter: Drift Chamber: Full angular coverage Good momentum resolution Large tracking volume Exceptional timing capabilities Minimization of materials Large lever arm The KLOE concept: Excellent e/ separation based on t.o.f. Good 0 reconstruction capabilities Full kinematical reconstruction of events The 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. A.Passeri: KLOE-2 Report

  17. KLOE detector “weaknesses” for DAFNE2 physics: • 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± tagger • Physics and background rate could be an issue for DAQ and trigger 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 A.Passeri: KLOE-2 Report

  18. 5 KGauss 4 Kgauss 3 KGauss Muon momentum in K± CM (MeV) p(MeV) B field (KGauss) B field: from 5  3 KGauss ? • Increase acceptance for low momentum tracks • coming from I.P. • Reduction of spiralizing tracks  less tails in • momentum resolution KSp+p-p0 Simulated Km2 events Drawback:sp worsening for tracks at higher 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 increase in Km2 events A.Passeri: KLOE-2 Report

  19. 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 3040 hits /plane/ms • easy: using straw tubes layers. Very light. • Electronics and mechanics “standard”. • challenging: cylindrical GEM. Expertise exists at LNF, • but detector shape is totally new. considered solutions: A.Passeri: KLOE-2 Report

  20. Courtesy of G.Bencivenni Conversion & Principle of operation of a GEM detector The GEM (Gas Electron Multiplier) (F.Sauli, NIM A386 (1997) 531) is a thin (50mm) 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. LHCb GEM configuration A Triple-GEM detector is built by inserting three GEM foils between two planar electrodes, which act as the cathode and the anode. A.Passeri: KLOE-2 Report

  21. LNF Detector Development Group F.Anulli, G.Bencivenni, D.Domenici, G.Felici, F.Murtas Cylindrical GEM development • 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 frame First prototype for mechanical test successfully produced A.Passeri: KLOE-2 Report

  22. GEM vs KLOE2 requirements : • Cylindrical GEM can be assembled in 5 detector layers at 10<R<25 cm • providing 3D spatial measurements for a total surface of 33000 cm2and • 27000 readout channels (for a 400 mm pitch). • Hit resolution around 170 mm. • Thickness grand total for 5 layers: between 0.92% and 1.57% X0 • (depending on copper coat thickness). • Sustainable rate up to 50 MHz/cm2 (measured in planar GEM). • Time resolution ∼45 ns. A.Passeri: KLOE-2 Report

  23.  Data MC KS 30 80 60 40 20  0 0 10 20 30 40 Calorimeter readout granularity: why refine it ? Avoid cluster splitting…. …and merging …and on top of that.. Improve e/m/p separation via cluster shape variables 6 g events After kinematic fit c2 cut 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 A.Passeri: KLOE-2 Report

  24. Standard KLOE calorimeter behaviour well reproduced for photons: sE/E sz Energy and spatial resolutions compared to measured ones FLUKA ….. Data resol Eg (MeV) Eg (MeV) Cluster depth and rms compared to p+p- g events centroid rms (cm) centroid depth (cm) Eg (MeV) Eg (MeV) A.Passeri: KLOE-2 Report

  25. planes (depth) Columns () Granularity tests with 1000 events with two 200 MeV electrons preliminary 4.4x4.4cm2 Digitized cells KLOE granularity Generated energy release Energy 2x2cm2 1x1cm2 KLOE granularity x 16 KLOE granularity x 4 A.Passeri: KLOE-2 Report

  26. planes (depth) Columns () Granularity tests with 1000 events with two 200 MeV muons Digitized cells KLOE granularity 4.4x4.4cm2 preliminary Generated energy release Energy 2x2cm2 1x1cm2 A.Passeri: KLOE-2 Report

  27. 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. A.Passeri: KLOE-2 Report

  28. Trigger considerations Simple rate scaling shows that KLOE2 Must work well above 10 KHz total rate, depending on machine bckg • DAFNE DANAE •  events300 Hz2500 Hz • Good Bhabhas600 Hz5000 Hz • Residual cosmics600 Hz600 Hz • Machine backgr.500 Hz ? • 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. A.Passeri: KLOE-2 Report

  29. DAQ at KLOE2 • KLOE 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 A tester board has been realized to test the full environment. MVME6100 running Linux with a custom vme driver and the KLOE online sw. Measured sustained rate is 180 Mbyte/s Aloisio,Branchini,Cevenini,Izzo,Loffredo,Lomoro A.Passeri: KLOE-2 Report

  30. Setup of the collaboration For 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 program • By 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 A.Passeri: KLOE-2 Report

  31. Conclusions A sizeable group of experimental physicists has expresses interest in a wide physics program to be performed at the next Frascati e+e- collider, both at the f peak and at higher energy We plan to use the KLOE detector with some important upgrades, for which we have already started developments. A.Passeri: KLOE-2 Report

  32. Spare Slides A.Passeri: KLOE-2 Report

  33. Slopes l+ = 0.02534(30) l+ = 0.00128(3) (Pole model: KLOE, KTeV, and NA48 ave.) l0 = 0.01587(95) (KTeV and Istra+ ave.) From unitarity • f+(0)=0.961(8) • Leutwyler and Roos Z. • [Phys. C25, 91, 1984] • Vud=0.97377(27) • Marciano and Sirlin • [Phys.Rev.Lett.96 032002,2006] Vus×f+(0) = 0.2187(22) Vus from KLOE results (BR’s and tL) c2/dof = 1.9/4 A.Passeri: KLOE-2 Report

  34. Vus f+(0) plot: F.Mescia courtesy From unitarity • f+(0)=0.961(8) • Leutwyler and Roos Z. • [Phys. C25, 91, 1984] • Vud=0.97377(27) • Marciano and Sirlin • [Phys.Rev.Lett.96 032002,2006] Vus×f+(0) = 0.2187(22) Vus and Unitarity • tL = 50.99(20) ns, • average KLOE-PDG • Including all new measurements • for semileptonic kaon decays • (KTeV, NA48, E865, and KLOE) <Vus×f+(0)>WORLD AV. = 0.2164(4) A.Passeri: KLOE-2 Report

  35. The Vus- Vud plane Inputs: Vus = 0.2254  0.0020 Kl3 KLOE, using f+(0)=0.961(8) Vud = 0.97377  0.00027 Marciano and Sirlin Phys.Rev.Lett.96 032002,2006 Vus/Vud = 0.2294  0.0026 Km2 KLOE (K())/(())  |Vus|2/|Vud|2fK2/f2 unitarity Fit 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 A.Passeri: KLOE-2 Report

  36. Ke2 Momentum distribution Red = MC blu = ke2 black data • We 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 inserted • The K+ decay must be reconstructed with vertex in FV • The electron momentun ranges in 200-300 MeV/c region. Same as the muons from K2 Lab momentum SD Mev/c A.Passeri: KLOE-2 Report

  37. p/p p/p pions,muons electrons Silicon 1.5mm muons Silicon 1.5mm muons silicon 1mm silicon 1mm 1% 1% KLOE KLOE P (MeV/c) P (MeV/c) Multiple scattering vs thickness Comparison between MS induced by 2 reference value of silicon thickness (1mm and 1.5 mm) wrt a KLOE-like:≈ 700m 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 A.Passeri: KLOE-2 Report

  38. R O C K R O C K R O C K DATA CONCENTRATOR Level 2 Level 1 16 DAQ FEE boards Trigger V I C AUX bus C P U TS+FIO C-bus Trigger lines VIC VME bus VME bus Vic bus R O C K M F D D I V I C C P U V I C Trigger lines DAQ Chain AUX bus A.Passeri: KLOE-2 Report

  39. In KLOE the link and the switch between fee and farm is based on FDDI IT MUST BE CHANGED A.Passeri: KLOE-2 Report

  40. A.Passeri: KLOE-2 Report

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