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Heavy Flavour in ALICE

Heavy Flavour in ALICE. Federico Antinori (INFN Padova & CERN) for the ALICE Collaboration. Contents. The LHC, Heavy Flavours and ALICE Expected performance (examples) D 0  K - p + D +  K - p + p + B  e + X B  µ + X B  J/ y + X … Coming up: proton-proton Conclusion.

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Heavy Flavour in ALICE

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  1. Heavy Flavour in ALICE Federico Antinori (INFN Padova & CERN) for the ALICE Collaboration F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  2. Contents • The LHC, Heavy Flavours and ALICE • Expected performance (examples) • D0 K-p+ • D+ K-p+ p+ • B  e + X • B  µ + X • B  J/y + X • … • Coming up: proton-proton • Conclusion F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  3. The LHC, Heavy Flavours and ALICE(or “ALICE in Wonderland”) F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  4. LHC • Running conditions: • + other ions (Sn, Kr, O) & energies (e.g.: pp @ 5.5 TeV) *Lmax (ALICE) = 1031 ** Lint (ALICE) ~ 0.5 nb-1/year F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  5. Heavy Flavour @ LHC system shadowing NN x-sect (mb) total multiplicity pp 14 TeV 11.2/0.5 1/1 0.16/0.007 Pb-Pb 5.5 TeV (5% cent) 6.6 /0.2 0.65 /0.85 115 /4.6 • cc and bb rates • ALICE PPR (NTLO + shadowing) cc bb PbPb/pp PbPb/pp PbPb PbPb pp pp F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  6. Exploring the low-x region… • Shadowing, saturation, … • p-A essential!

  7. Probing the medium... • study medium with probes of known colour charge and mass • e.g.: energy loss by gluon radiation expected to be: • parton-specific: stronger for gluons than quarks (colour charge ratio = 9/4) • flavour-specific: stronger for lighter than for heavier quarks (dead-cone effect) • study effect of medium on fragmentation (no extra production of c, b at hadronization) • independent string fragmentation vs recombination • e.g.: D+s/D+ • + measurement important for quarkonium physics • open QQ production natural normalization for quarkonium studies • B meson decays non negligible source of non-prompt J/y at LHC F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  8. Large suppression at RHIC! scaled to M. Cacciari et al., hep-ph/0502203 non phot. el. [J.Bielcik @QM05] • n.p. electrons ~ as suppressed as expected for c only (no b) • yet, region above 3-4 GeV expected to be dominated by beauty... [Xin Dong@QM05] • disentangling c/b is a must • full reconstruction of D vertices! F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  9. By the way: the factor 9/4? • energy loss should be proportional to: CR = 4/3 for q, = 3 for g • at RHIC, at 6-8 GeV pT: x ~ 10-1 • large quark contribution also for light flavours? • at LHC, at same pT: x ~ a few 10-4 • quark contribution negligible F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  10. ALICE Set-up Size: 16 x 26 meters Weight: 10,000 tons TOF TRD HMPID ITS PMD Muon Arm PHOS TPC

  11. Inner Tracking System (ITS) longitudinal coverage: |h| < 1 (tracking), |h|<2 (multiplicity) F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  12. ITS and TPC

  13. rf: 50 mm z: 425 mm PIXEL CELL  9.8 M Two layers: r = 4 cm r = 7 cm Silicon Pixel Detector (SPD) F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  14. Expected resolution on track impact parameter • track impact parameter (d0) F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  15. Expected performance(examples) F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  16. D0 K-p+ statistical. systematic. • expected ALICE performance • S/B ≈ 10 % • S/(S+B) ≈ 40 (1 month Pb-Pb running) pT - differential F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  17. D+ K-p+p+ • Performance comparable to that for D0K-p+ Pb-Pb significance ~ 30 (1 month) p-p F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  18. Beauty to electrons • Expected ALICE performance (1 month Pb-Pb) • e± identification from TRD and dE/dx in TPC • impact parameter from ITS S/(S+B) S per 107 central Pb-Pb events F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  19. Electrons (from b) pt spectrum Error composition stat  syst error stat error 11% from overall normalization not included F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  20. Expected performance on D, B RAA mb = 4.8 GeV mass dependence colour charge dependence • should help clarify the heavy flavour quenching story! D0 K-p+ B  e + X 1 year at nominal luminosity (107 central Pb-Pb events, 109 pp events) F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  21. Beauty to single muons • expected in the muon arm  very high statistics and heavy flavour purity expected F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  22. Beauty to dimuons µ-+ X X + µ+ B B B µ+ + D + X µ-+ X • Two main sources: “BDSAME” “BBDIFF” F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  23. high mass mm low mass mm • consistency check! F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  24. B  J/y + X • More “exclusive” than B  e/µ + X • better handle on B momentum distribution • Preliminarypp study: pseudoproper decay time (à la CDF) CDF (data) pT>0 ALICE (prelim. simulation) F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  25. Many more under study… F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  26. Coming up: pp F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  27. Example: D0 in pp • D0 K-p+ • 1 year run  ~ 109 events • ~ 20 shifts, 10 hrs each  a few 107 events • reach out to 12 GeV or so F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  28. Example: B  e + X in pp F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  29. LHC Cooldown F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  30. Detector Status Today & for First Beam 1/5 PHOS, 4/18 TRD, 18/18 TOF HMPID 0/6 EMCAL ALICE Status

  31. ALICE Status • Startup configuration: • complete: ITS, TPC, TOF, HMPID, muon arm, trigger detectors (V0, T0, ZDC, Acorde) • partially complete: PHOS (1/5), TRD (4/18), PMD (6/48), DAQ/HLT (20-30%) • Timeline: • Global commissioning/cosmic runs I and II in Dec 2007 & Feb 2008 • Cosmic run III under way • LHC will close end July  first injection expected shortly after • commissioning run in 2008 • “long run” in 2009 • followed by first Pb-Pb run (√s = 5.5 TeV, L = 5·1025 cm-2s-1) F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  32. Taking data! F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  33. ALICE sees particles! • TPC • TPC + ITS • ITS F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  34. ITS alignment with cosmics • 2198 sensitive modules X6d.o.f. each = 13188alignment parametersto be determined! F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  35. SPD alignment QA plots (first sample of 940, 4P tracks) Adam Jacholkowski

  36. AliMillepede re-alignment(first test) Adam Jacholkowski

  37. First particles from LHC! • TI2 injection test (15/6): muons from beam dump F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  38. First particles from LHC! • Seen from an SPD half-sector: inner layer outer layer transversal tracks! F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

  39. Conclusion • With heavy flavours, Nature kindly provides us with a beautiful tool to study the properties of the strongly interacting medium produced in ultra-relativistic nucleus-nucleus collisions • At LHC •  very high rates •  very extended pT range •  well developed jets • ALICE is very well equipped for this physics • The FUN is just starting! F Antinori - 417th WE-Heraeus-Seminar - Bad Honnef - June 2008

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