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Carmine Elvezio Pagliarone INFN Pisa

The CDF II Tau Physics Program. Carmine Elvezio Pagliarone INFN Pisa. ( on behalf of the CDF Collaboration & the t Group & Lepton+Track WG ). the CDFII Collaboration. Fermilab Tevatron Collider.  p source. Main Injector and Recycler. The Fermilab Accelerator Complex.

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Carmine Elvezio Pagliarone INFN Pisa

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  1. The CDF II Tau Physics Program Carmine Elvezio Pagliarone INFN Pisa (on behalf of the CDF Collaboration & the t Group&Lepton+Track WG)

  2. the CDFII Collaboration

  3. Fermilab Tevatron Collider p source Main Injector and Recycler

  4. The Fermilab Accelerator Complex • Main Injector (150 GeV proton storage ring) replaces Main Ring (the original accelerator); • Completely revamped stochastic cooling system for antiprotons; • A new permanent magnet Recycler storage ring for antiprotons; • Increased number of p and p-bar bunches : 6  36 (396 ns) • Higher center of mass energy 2 TeV achived increasing the beam Energies 900  980 GeV

  5. Np NBNp Total Antiprotons p per bunch Tevatron Collider Improvements Physics Opportunites • Top • Higgs • QCD • Electroweak • B Physics • New Phenomena ? ? ? ?

  6. Tevatron Run I History Discovered: Top, Bc, diffractive… Measured: MW, Mtop, stt, sin2b, … Ltot= 110 pb-1 ~ 1 yr to get x 10 Steady progress after that… Run 1B (1994-1996) Run 1A (1992-1993)

  7. Tevatron Performances vs Expected Luminosity 5 x 1032 cm-2 s-1 2 x 1032 cm-2 s-1 2 fb-1 15 fb-1 2000 2002 2004 2006 2008

  8. Present Tevatron Luminosity Performance Tevatron Peak Luminosity 4.7●1031 peak luminosity average luminosity integrateed luminosity Tevatron Integrated Luminosity 240 pb-1

  9. Present CDF/D0 Luminosity Status CDF Integrated Luminosity

  10. Short term Luminosity Prospects • Massive effort put into understanding and improving Luminosity • Fixed Accumulator  MI optics • Much work on stabilizing tunes in injection and low beta squeeze • Fight large antiproton emittances • Work on accumulator lattice to reduce beam heating • Max luminosity achievable without Recycler ~8x1031 • Need recycler to get to 2x1032 • full benefits of Recycler later on Peak Luminosity: 4.7●1031

  11. Long term Luminosity Profile by Year 2009 previous estimate (5.5  9.5 fb-1) (4.5  5.5 fb-1) without electron cooling in the Recycler with electron cooling in the Recycler

  12. Si tracking CDF II CMX • Endplug Calorimeter • Tracking • Layer 00 • SVX II • ISL • COT • Front End Electronics • Trigger (pipelined) • DAQ System • Muon Systems • Luminosity Monitors • TOF • Offline Software IMU COT CMP CMX Miniskirt

  13. The CDFII Tracking System • Central Outer Tracker (COT): • open cell drift chamber • maximum drift time 100ns • Small cell size, Fast gas • single hit resolution ~200 mm • excellent pattern recognition • improved stereo capabilities • Silicon Tracker System: • increased z coverage (length ~ 1m) •  coverage up to |  | < 2 • 3-D track reconstruction • impact parameter resolution •  < 30 m • z < 60 m • 3 different detectors: ≈750,000 channels • L00:inner most, R= 2.5 cm, rad-hard, SS • SVXII:5 layers, 3<R<10 cm, DS (90 and sas) • ISL:2 layers, 10<R<20 cm and large h, DS COT into CDFII Trigger System: two main improvements • XFT: Track reconstruction at L1 • SVT: Displaced track triggering at L2

  14. CDF II Silicon Detectors

  15. CDF II Layer 0

  16. SVX II Detector CDF II

  17. ISL provides one space point to improve track matching between SVX II & COT. • Total Length  2 m; • 1 central layer covering||<1 (r= 20 cm) • 2 layers covering 1<||< 2 (r= 20&28 cm) • sPT/P2T=9·10-4(GeV/c)-1for (||<1,PT=10GeV/c) • In the forward region ISL&SVXII constitue a standalone 3D silicon tracker with up to 7 axial + 7 stereo measurements out to ||  2 • Carbon fiber structure: Max. rigidity & min. material • Beryllium support for ladders • 6th layer: 28 ladd/barrel • 7th layer: 36 ladd/barrel. ISL 3 Double side p-n sensors axial+stereo (1.2º) 4 SVX3 Chips on each side The hybrid is placed at the end of the ladder top anti top Event Ladder length~25 cm

  18. Central Outer Tracker CDF II

  19. CMX IMU Muon System CMP CMU CMX Mini skirt

  20. 110 ps of average resolution (from preliminary calibration) Getting close to 100 ps goal; TOF System Performance TOF + track informations Cut on TOF info

  21. Level 1 storage pipeline: 42 clock cycles Level 1 Level 1 • 7.6 MHz Synchronous Pipeline • 5544 ns Latency • 50 KHz max Rate L1 Accept Level 2 L2 Accept Level 2 • Asynchronous 2 Stage Pipeline • 20 s Latency • 300 Hz Accepted Rate L3 Farm CDF Trigger system 3 step Trigger System • Tracks available at Level 1 eXtremely Fast Tracker (XFT) › 150 Triggers

  22. CDF-II Status • Detector: • All systems were installed and commissioned by end of 2001; • DAQ and trigger: • Running physics trigger table with > 150 trigger paths since Feb ‘02 • New SVT very successful • Typical running conditions: • L1: 3.5KHz L2: 200 Hz L3: 20 Hz • Data processing: • Reconstruction farm keeps up with data logging • Physics groups skim data: • Observe signals from low and high PT triggers: J/y, D, B, W, Z

  23. Run II detector improvements • Improved z coverage of Silicon tracker +50% of Run I geometrical acceptance (…top) • 3D vertexing capabilities  better fake rejection • Track reconstruction can be extended to 1<h<2 several major effects: • b-tagging(recover ~30% of b’s in tt events) • lepton ID(electrons in Plug calorimeter) • Increased muon system acceptance by 12% affects trigger, ID and SLT efficiency

  24. t Physics at CDFII INFN Pisa, UC Davis, LPNHE Paris, Rutgers, Texas A&M, Waseda U.

  25. t Decays and t signatures • t decay promptly either to leptons or to hadrons; • always 1 or 2 n in the final state; • Leptonic t decays BR= 35.2%; • Hadronic t decaysBR= 64.0%; (40.7% 1-prong, 23.3% 3-prongs) • Leptonic t-decays are difficult to identify: • small impact parameter: ct= 90mm; • low-pT isolated leptons (30% of parent pT); • Hadronic t-decays have a distinct signatures: • narrow isolated jet (no m or e); • low track multiplicity (1 or 3); • M(visible decay product)<Mt ;

  26. Taus in Run II • Many searches with taus in the final state; • Taus were traditionally more “difficult” for both experiments; • Needs of a significant improvement; • CDF Lepton+Track (LT) WG designed and implemented single tau and Ditau Triggers (5): • t + MET, • th + tl (l= e, m) • th th • lepton+Track Trigger • Lepton PT> 8 GeV/c; central-e, central-m, forward-m; • Tau-style isolated 5 GeV/c track; • Targets multilepton final states including taus; • Trigger was Installedand Commissionedin January 2002.

  27. CDF-II Tau Triggers 5 Tau Triggers • Central m + Track • Forward m + Track • Electron + Track • Di-t Trigger • t + ET t  l  t hadrons In the Trigger Table since Jan 2002

  28. t t Lepton+Track Trigger pTseed> 5 GeV/c Tau Cone Isolation Cone • Lepton (e,m) Lower PT Threshold • Isolated track No tracks in 10-300 Cone No prescale with high luminosity !! Z pTl > 8 GeV/c

  29. Offline Tau Cone definition (the new approach) =max[min(0.2 rad,(5 GeV∙rad)/E_tau_vis),0.005 rad]  •  largest separation Angle between the shoulder and the seed traks Visible Energy

  30. Tau ID Cuts (new approach) • TauFinderModulereconstruction parameters • Seed tower ET > 6 GeV • Shoulder tower ET > 1 GeV • Ntowers <= 6 • |Cluster detector eta| < 1.1 • Seed track pT > 4.5 GeV/c • ID cuts • tau cone: a(t)= max[min (0.2 rad, (5 GeV∙rad)/E_tau), 0.005 rad] • No tracks, no p0 in the isolation annulus: a(t) < a < 0.5 • Calorimeter isolation Iso0.4 < 3 GeV • |Seed track Z0| < 60 cm • Anti electron: xi_e = E_HAD/SUM (P) < 0.15 • Anti muon: CMU/P/X stubs in 15 degree cone = 0 • Mass (tracks + p0s) < 1.8 GeV/c**2 • Calo Mass < 5 GeV/c**2 • Extra cuts (still under study) • Cluster width (eta and/or phi) • Number of p0 in cone / isolation annulus • Track(s) impact parameter

  31. Physics at CDFIIseveral analysis underway

  32. Baseline selection: e+th e: 10 GeV, th : 20GeV Transverse mass cut to reduce W+jets events: MT(l,ET) < 25 GeV/c2 Vector Sum pT cut to reduce QCD events pT(l,ET) > 25 GeV/c Example: Run I (e: 10GeV, th :15GeV) Z Event Selection (OS lth + 0 jets) CDF Run I Preliminary

  33. W/Z t+ t- track Multiplicity After Baseline( e /th ), MT, PT cuts Data: 2345 Events Data: 78 Events • Zteth (fit): 46 ± 15 events • QCD (fit): 28 ± 14 events • Zee (fit): 3.7 events Compare s(W)*BR(W->t n) to s(W)*BR(W->e n) gt / ge = 0.99 + 0.04

  34. Z t+ t- After Baseline(e /th ), MT, pT cuts, OS Mass (OS data) Data : 47 events • Zteth(fix): 39 evts • QCD (fit): 11±6 evts • Zee (fix): 2.8 evts Finalizing Z analysis, including them+ m-channel

  35. RPV mSUGRA Search in Decays of Stop Pair h selection (106 pb-1): • h: cluster PT>15 GeV/c, ||<1.0 h ID: number of tracks and o in a narrow cone, isolation energy, etc. • Stop pairs are produced thru RPC • Assuming RPV only in the 3rd generation( ):

  36. Additional Selections: MT(lepton,ET)< 35 GeV/c2 HT(lepton,h,ET)> 70 GeV  2 jets: ET > 15 GeV ALEPH Limit:

  37. Run II Preliminary Results

  38. 2TeV Mass Limit : 122 188GeV/c2 Assuming same efficiency, same background level due to 1 b-tag, naturally not observing the process

  39. Top quark Production Pair production Single top production

  40. SM-SM top decay

  41. Light stop: the theoretical prejudices generate the observed baryon number of the Universe at the EWK phase transition EWK Baryogenesis: Becouse of Yukawa the scalar top squark can be light But there are also arguments that directly favor this ! ! J. M. Cline,hep-ph/9810267 M. Carena et al.,Nucl.Phys. B524 (1998) D. Delepine et al.,Phys.Lett. B386 (1996) LSP is a good candidate for Dark Matter; to get the right relic LSP density we only need: J. Wells & G. Kane,hep-ph/9810267 M. Hosch et al.,Phys.Rev.D58 (1998) G. Malone et al.,Phys.Rev.D55 (1997) J. Sender,Phys.Rev.D54 (1996)

  42. SUSY decays of the top x 2Br(1-Br) SM-SUSY top decay SUSY-SUSY top decay x Br2

  43. SUSY-SUSY top decay (Lepton+jets) SM top decay (Lepton+jets) SM-SUSY top decay (Lepton+jets)

  44. SUSY Parameter Space • The tt decay can be defined in terms of 5 parameters: • Assuming that only SM and SUSY top decays are allowed then: • the BR for the chargino leptonic decay is almost the same in any model: • So we end up with a general SUSY phase space: This is a Model independent Search ! SUSY Space to explore ?

  45. Model Assumptions • In General SUSY Models: • When all the squarks and slepton masses get heavy: • As we are not assuming any GUT Scale Unification: • In most of the models we have: for

  46. Top Kinematic Analysis Cuts Analysis Path • W+ 3 Jets Analysis • Reduce as much as possible QCD BKG • Kinematic Cuts • b-tag (SECVTX) • Discriminate between SM & SM-SUSY • Excluded Br without taking in account QCD

  47. 95 % CL Limit • Result interpreted in general SUSY Model assuming R-Parity conservation; • Model independent search • no GUT Scale unification

  48. Run II SM Higgs Sensitivities maybe forget the discovery ?

  49. Exploring LFV at hadron colliders another Lep+Track signature

  50. Why H t ? • strong evidence in favour of netrino masses and mixing; • Higgs sector is the last constrained; • LFV effects on Higgs sector parametrized as function of the flavor changing coupling parameter:Kij • Surprisingly we don’t have limits on the size of the LFV in the Higgs sector !

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