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Heavy flavours & quarkonia @ LHC

Heavy flavours & quarkonia @ LHC. motivations selected physics channels quarkonia, B-hadron x-section, « hadronic » charm, heavy flavour quenching. Philippe.Crochet@clermont.in2p3.fr.

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Heavy flavours & quarkonia @ LHC

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  1. Heavy flavours & quarkonia @ LHC • motivations • selected physics channels • quarkonia, B-hadron x-section, « hadronic » charm, heavy flavour quenching Philippe.Crochet@clermont.in2p3.fr

  2. Heavy-flavour x-sections @ LHC c(LHC) = c(RHIC) × 10 b(LHC) = b(RHIC) × 100 W(LHC) = (RHIC) × 10 Z(LHC) = (RHIC) K. Safarik

  3.  (pb) s (GeV) Dileptons @ LHC world data on total x-section of e+e- hadrons (PDG06) a similar plot is accessible in Pb-Pb @ LHC within a few weeks typical number of reconstructed resonances in min-bias PbPb @ 5.5 TeV (1 month)

  4. charm bottom W± Single leptons @ LHC pp @ 14 TeV expected number of measured muons in min-bias PbPb @ 5.5 TeV (1 month) simulation by Z. Conesa del Valle

  5. pp @ 14 TeV PbPb @ 5.5 TeV charm bottom (14 TeV) / (5.5 TeV) A closer look at heavy-quark cross-section charm thermal production ~ 25% (assumes large medium temperature) • NLO predictions for pp @ LHC: a factor ~ 2 uncertainty • (14 TeV) / (5.5 TeV) ~ 10% •  measuring (c,b) in pp @ 14TeV is top priority hep-ph/0601164, J. Phys. G 32 (2006) 1295, J. Phys. G 35 (2008) 054001

  6. hard gluon induced quarkonium breakup hep-ph/0311048 PbPb @ 5.5 TeV RHIC LHC Quarkonia suppression @ LHC quarkonium dissociation temperatures A. Mocsy & P. Petreczky, Phys. Rev. Lett. 99 (2007) 211602 • whether J/ melts or not @ RHIC it will be strongly either suppressed or regenerated @ LHC • use (2S) to unravel J/ sup. vs. reco.  reco. is small: L. Grandchamp et al., PRC 73 (2006) 064906 • (1S) melts significantly only at LHC • additional suppression by hard gluons • relevance of quarkonium ratios vs. pt R. Vogt in J. Phys. G 35 (2008) 054001

  7. 1. 2. 3. 4. Charmonium regeneration @ LHC • peculiar centrality dependence • predictions strongly depend on cc • (re-)dissociation by comovers • regeneration  smaller <p2t> • note: N(B  J/) / N(direct J/) ~ 20% in 4 A. Andronic et al., Phys. Lett. B 652 (2007) 259, J. Phys. G 35 (2008) 054001, A. Capella et al., arXiv:0712.4331 [hep-ph], R. Thews et al., J. Phys. G 35 (2008) 054001

  8. isolate mass dep. of E • sensitivity disappears at large pt • lower sensitivity to qhat • RD/h probes color charge dep. of E • RB/h probes mass dep. of E Heavy quark quenching @ LHC: new ratios available N. Armesto et al., Phys. Rev. D 71 (2005) 054027, J. Phys. G 35 (2008) 054001

  9. Heavy quark quenching @ LHC: new reference available • heavy quark energy loss: • shifts down the (c,b)/W crossing point by ~ 5-7 GeV/c • suppresses muon yield by a factor 2-5 for 2 < pt < 20 GeV/c • W affected by shadowing only Z. Conesa del Valle et al., Phys. Lett. B 663 (2008) 202, J. Phys. G 35 (2008) 054001

  10. Heavy flavour flow @ LHC • resonance interactions increase v2 • v2 quantitatively similar at RHIC & LHC H. van Hess et al., Phys. Rev. C 73 (2006) 034913, J. Phys. G 35 (2008) 054001 more details in “Heavy Ion Collisions at the LHC, Last Call for Predictions”, May-June 2007, CERN proceedings: J. Phys. G 35 (2008) 054001

  11. Heavy ions @ LHC CMS ATLAS ALICE

  12. ITS, TPC, TRD, ToF (||<0.9) (di-)electrons: J/, ’, , ’,’’, open charm, open bottom, W±,Z0 muon spectrometer (-2.5<<-4) (di-)muons: J/, ’, , ’,’’, open charm, open bottom, W±, Z0 electron-muon coincidences: open charm & bottom ITS, TPC, TRD, ToF (||<0.9) hadrons: D0, D±,… Heavy flavours with ALICE

  13. muon spectrometer & silicon tracker in central barrel & end-caps (||<2.5) J/, ’, , ’,’’, open bottom, Z0 studies limited to J/, ’, , ’,’’ reconstruction & b-jet tagging Heavy flavours with CMS & ATLAS

  14. Acceptance for heavy flavour measurements • complementarity between the 3 experiments • ATLAS & CMS acceptance is large in  & limited to high pt • ALICE combines hadrons, electrons, muons & covers low pt & high  • ATLAS, CMS & ALICE-electrons/hadrons have inner tracking • ATLAS & CMS electron/hadron channels not yet investigated

  15. Selected physics channels • Quarkonia • B from secondary J/ • B from dileptons • B from single leptons • D0  K • Heavy flavour quenching • only “published” results

  16. Quarkonia

  17. Expected performances for quarkonia WARNING: different simulation frameworks & different assumptions bkg assumes dN/d = 2500-5000, S & S/S+B: one month min-bias PbPb (CC for ALICE e+e-) • J/,: first detailed studies within one month • ’: difficult (small S/B), ’, ’’: need 2-3 runs From A. Dainese @ HP2006, updated according to ALICE: J. Phys. G 32 (2006) 1295, W. Sommer et al. @ QM2006, CMS: J. Phys. G 34 (2007) 2307, CMS/note-2006/089, ATLAS: L. Rosselet @ HEP2007

  18. Normalization for suppression studies there is no golden normalization

  19. Observables with bottomonia suppression 1: TC = 270 MeV, TD/TC = 4.0 (1.4) for ϒ(ϒ’) suppression 2: TC = 190 MeV, TD/TC = 2.9 (1.1) for ϒ(ϒ’) • statistics: one month PbPb @ 5.5 TeV • large sensitivity to dissociation temperatures and medium size ALICE: J. Phys. G 32 (2006) 1295, CMS: J. Phys. G 34 (2007) 2307

  20. More with quarkonia polarization dN/dy in pp • pp: test production mechanisms • AA: probe QGP formation • probe gluon distribution at low x (gen - rec) vs. pt pp @ 14 TeV • pp @ 14 TeV: J/ &  pol. vs. pt • PbPb @ 5.5TeV: J/  pol. vs. centrality,  pol. needs 2-3 runs R. Analdi, E. Scomparin, D. Stocco

  21. Open charm & bottom: accessible channels • charm: exclusive hadronic channels • D0  K (tested in pp & PbPb) • D+  K (tested in pp & PbPb) • D±s  KK (under study) • D*  D0 (under study) • D0  K (under study) • c  pK (under study) • charm & bottom: semi-inclusive leptonic channels • c  l + X (à la CDF & D0) • b  l + X (à la CDF & D0) • b  J/ + X (à la CDF & D0) • b  J/ + l (under study) • bbbar  3 (should work in pp) • bbbar  l+l-,l-l+ (Bchain & BBdiff) • bbbar  l-l-,l+l+ (Bchain & B osc.) more exotic (and more challenging): QQbar  e, b  > 5 prongs, b  J/ + X, etc

  22. Selected physics channels • Quarkonia • B from secondary J/ • B from dileptons • B from single leptons • D0  K • Heavy flavour quenching • only “published” results

  23. Secondary J/ from B hadron decay N(B  J/) / N(direct J/) ~ 20% in 4 @ LHC • (d0) < 50 µm for pt > 1.5/2/3 GeV/c in ALICE/CMS/ATLAS • disentangle primary & secondary J/ • measure inclusive b cross-section • probe b quark in-medium energy loss ALICE: CERN/LHC 2005-030, CERN/LHCC 99-13, ATLAS: EPJC 33 (2004) s1023, CMS: CMS NOTE 2006/031, 2001/008

  24. secondary J/ from B decay in CMS, pt > 5 GeV/c Using secondary J/ from B decay to probe b quark energy loss • energy loss is included in 2 scenarios: • collisional energy loss • collisional + radiative energy loss • with energy loss: • yield reduced by a factor ~ 4 •  distribution gets significantly narrower I.P. Lokhtin & A.M. Snigirev, Eur. Phys. J. C 21(2001)155

  25. B signal from high-mass dimuons with vertexing  from BBbar  from Drell-Yan min-bias PbPb one month r > 50 m suppresses Drell-Yan rate by 2 orders of magnitude with ~ 30% loss of signal J. Phys. G 34 (2007) 2307

  26. B signal from dimuons w/o vertexing unlike-sign total unlike-sign from bottom unlike-sign from charm like-sign from bottom • unfold mass continuum • large statistics is expected • systematics to be estimated central PbPb (5%), one month R. Guernane et al., ALICE-INT-2005-018, J. Phys. G 32 (2006) 1295

  27. First step: extract Nl B w/o 2nd vertex: unfold lepton dN/dpt via combined fit large statistics constrains fit with 2nd vertex: cut on dca & subtract remaining background large purity of lepton sample pp @ 14 TeV B  +X PbPb @ 5.5 TeV B  e+X 2.1·1012 pp evts (1 year) pt > 2 GeV/c 1.7·108  from B 107 PbPb (5%) evts (1 month) pt > 2 GeV/c, 200 < d0 < 600 m 80000 e from B, S/(S+B) = 80% B hadron cross-section from single leptons J. Phys. G 32 (2006) 1295, DIMUONnet

  28. B hadron cross-section from single leptons Second step: correct for efficiency, acceptance & decay kinematics total number of lB integrated luminosity lepton global detection efficiency J. Phys. G 32 (2006) 1295, DIMUONnet

  29. B semi-muonic decays pp, s = 14 TeV B hadron cross-section from single leptons Third step: the B-hadron inclusive differential cross-section w/o 2nd vertex with 2nd vertex • method widely used (UA1, CDF, D0) • large pt reach, (very) small statistical errors, systematics ~ 10-15% • allows to get B RAA(pt), should work for charm as well • similar performances to be expected in ATLAS & CMS J. Phys. G 32 (2006) 1295, DIMUONnet

  30. Hadronic charm cos(pointing) > 0.98 d0K  d0 < - 40 000 m2 increase S/B by 103 D0 K  (3.8%) c = 123 m • 107 central PbPb (5%) • S ~ 13000 • S/B ~ 10 % • S/(S+B) ~ 40 background assumes dN/d = 6000 @  = 0 J. Phys. G 32 (2006) 1295

  31. Hadronic charm differential x-section the most precise measurement of the total charm x-section in pp collisions @ LHC J. Phys. G 32 (2006) 1295

  32. Testing QCD with hadronic charm in pp collisions @ 14 TeV mc, F/0, R/0, PDF bars: quadratic sum of statistical & systematic errors expected experimental errors are much smaller than theoretical uncertainties J. Phys. G 32 (2006) 1295

  33. Heavy quark quenching: traditional ratios 1 nominal year: 107 central Pb-Pb events, 109 pp events statistics: bars, systematics: bands sensitivity toshadowing for pt <~ 7 GeV/c & to energy loss for pt >~ 7GeV/c J. Phys. G 32 (2006) 1295

  34. Heavy quark quenching: more ratios 1 nominal year: 107 central Pb-Pb events, 109 pp events statistics: bars, systematics: bands sensitivity to color charge dependence sensitivity to mass dependence J. Phys. G 32 (2006) 1295

  35. Heavy flavours at the LHC provide a rich physics program more analyses (not discussed here) are under study: heavy flavour flow, charm baryons, e- coincidences, b-tagged jets, Z0, W±,… first collisions in one month! Philippe.Crochet@clermont.in2p3.fr

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