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Quarkonia in heavy ion collisions @ LHC

Quarkonia in heavy ion collisions @ LHC. heavy flavors & (di)leptons @ LHC detector performances selected physics channels. Philippe.Crochet@clermont.in2p3.fr. central AA. hard gluon induced quarkonium breakup hep-ph/0311048. RHIC. LHC. Heavy flavors: what is different @ the LHC.

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Quarkonia in heavy ion collisions @ LHC

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  1. Quarkonia in heavy ion collisions @ LHC • heavy flavors & (di)leptons @ LHC • detector performances • selected physics channels Philippe.Crochet@clermont.in2p3.fr

  2. central AA hard gluon induced quarkonium breakup hep-ph/0311048 RHIC LHC Heavy flavors: what is different @ the LHC • large primary production • melting of (1S) by color screening • none of the primary J/ survives the (PbPb)QGP • a lot of charmonia from b hadron decay • large secondary production of charmonia • statistical hadronization, kinetic recombination, DD annhililation Philippe.Crochet@clermont.in2p3.fr

  3.  in ALICE Z. Conesa del Valle (2005) pp @ 14TeV (di)leptons: what is different @ the LHC dimuons in ALICE, pt > 2 GeV/c unlike-sign total unlike-sign from bottom unlike-sign from charm like-sign from bottom charm pure NLO S. Grigoryan (2004) • large & complex combinatorial background • dileptons from b decay dominate the spectrum below  & J/ • large yield of secondary J/ from b decay • dileptons from b decay have different origin at low & high mass • sizeable yield of like-sign correlated dileptons from b decay • W stick out from single lepton spectra with large statistics Philippe.Crochet@clermont.in2p3.fr

  4. J/ from b decay in central PbPb @ 5.5 TeV • b  J/ (1S) anything : 1.16  0.10% (PDG) • N(direct J/) in central (5%) PbPb @ 5.5 TeV : 0.49* • N(bb pairs) in central (5%) PbPb @ 5.5 TeV : 4.56# •  N(b  J/) / N(direct J/) ~ 20% in 4 (22% in pp @ 14 TeV) • (with shadowing & feed-down, w/o nuclear absorption, suppression, regeneration…) • this is a lot! • no obvious way to disentangle prompt & secondary J/ from pt dist. (only 2nd vertexing or b measurement can help) *from CERN-2004-009, hep-ph/0311048, CEM, underpredicts CDF data by a factor 2 #from ALICE PPR VII, CERN/LHCC 2005-030, uncertainty: a factor 2-3 (mQ, F, R, PDF) Philippe.Crochet@clermont.in2p3.fr

  5. J/ suppression & regeneration? • c suppression (J/ TD > 1.5 Tc)? enhanced regeneration H. Satz, CERN Heavy Ion Forum, 09/06/05 enhanced suppression 30 SPS RHIC LHC One physics case: on the relevance of measuring  in heavy ion collisions at the LHC using (2s) to unravel J/ suppression vs. regeneration • TLHC >> J/ TD ~ (2s) TD • C.-Y. Wong, PRC 72 034906 • W.M. Alberico et al., PRD 72 114011 •  regeneration is small • L. Grandchamp et al., hep-ph/0507314

  6. CMS: strong heavy ion program ATLAS: heavy ion LOI (2004) M.Rosati Tuesday parallel II Heavy ions @ the LHC D.d’Enterria Tuesday parallel II ALICE: the dedicated heavy ion experiment

  7. ALICE (A Large Ion Collider Experiment) TOF DIPOLE MAGNET TRD HMPID ACORDE L3 MAGNET PMD FMD ITS MUON TRIGGER CHAMBERS TPC PHOS MUON FILTER ABSORBER MUON TRACKING CHAMBERS

  8. How LHC detectors measure quarkonia • nice complementarity between the 3 experiments • ATLAS & CMS acceptance is large in  & limited to high pt • ALICE acceptance covers low pt & high • ATLAS, CMS & ALICE-electron have inner tracking

  9. LHC inner trackers expected performances • (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

  10. Transverse momentum acceptance for quarkonia measurements CMS J/ ALICE J/  e+e- acceptance || < 2.4 barrel • ALICE can measure J/ down to 0 pt (unique @ LHC) • ATLAS acceptance similar to CMS acceptance for J/ in central barrel • ALICE, ATLAS & CMS can measure  down to 0 pt • note: ≠ trigger & reconstruction efficiencies (expected statistics doesn’t scale with geo. acc.!) w/o trigger with trigger ALICE J/  µ+µ- ALICE: PPRVII, CERN/LHCC 2005-030, CMS: NOTE 2006/089

  11. CMS no bkg || < 0.8  ~ 54 MeV CMS dN/d = 2500 || < 2.4  ~ 90 MeV ATLAS dN/d = 3000 || < 2  ~ 145 MeV ALICE muon background level 1 = 2 HIJING evts with dN/d = 6000 @  = 0 each  mass resolution(  100 MeV @ M ~ 10 GeV is needed to separate the  sub-states) ALICE electron dN/d = 6000 • warning: • ≠ simulation frameworks & inputs • ongoing analyses ALICE: PPRVII, CERN/LHCC 2005-030, ATLAS: CERN/LHCC/2004-009, CMS: NOTE 2006/089

  12. Expected statistics in ALICE-muon 1 LHC year = 7 months pp (107s, 3·1030cm-2s-1) + 1 month AA (106s, 5·1026cm-2s-1) • full simulation including • realistic geometry • trigger efficiency • reconstruction efficiency • tracking efficiency • resolutions • from PbPb MB to pp, a factor ~ 10 more stat. • J/: large stat., good significance • ’: small S/B • : good stat., S/B > 1, good significance • ’: good stat., S/B > 1, good significance • ’’: low statistics ALICE PPR VII, CERN/LHCC 2005-030, x-sections from CERN-2004-009, hep-ph/0311048, with shadowing & feed-down, w/o nuclear absorption/suppression/regeneration…

  13. EPJC 39 (2005) 335 From NA50’s (J/)/DY to ALICE’s /bbbar ALICE PbPb @ 5.5TeV NA50 PbPb @ 17GeV • statistics : one month PbPb • (b) extracted à la UA1, CDF, D0 • statistics of the reference is in 5<M<20GeV ~5 times larger than that of the probe • systematic errors underway ALICE PPRVII, CERN/LHCC 2005-030 dissociation temperatures: C.-Y. Wong, PRC 72 034906 & W.M. Alberico et al., PRD 72 114011

  14. ’/ ratio versus pt J.P. Blaizot & J.Y. Ollitrault, Phys. Lett. B 199(1987)499; F. Karsch & H. Satz, Z. Phys. C 51(1991)209; J.F. Gunion & R. Vogt, Nucl. Phys. B 492(1997)301 • melting depends on • resonance formation time, dissociation temp. & pt • QGP temp., lifetime & size • ratio is flat in ppbar (CDF) • any deviation from the pp (pA) value is a clear evidence for the QGP (nuclear effects cancel-out) • the pt dependence of the ratio is sensitive to the characteristics of the QGP • full & realistic simulation • error bars = 1 month of central PbPb (10%) E. Dumonteil, PhD Thesis (2004), ALICE-INT-2005-002

  15. Using b decays to probe the QGP • a measurement of (J/)/(b) = (2)1% or ’/(J/) = 0.0625 is an evidence for full J/ suppression (& no regeneration!) • no need to disentangle prompt & secondary J/! ALICE PPRVII, CERN/LHCC 2005-030

  16. 2007 2008 Aug. Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May Jun. July 10 weeks pp shut-down pp high L, 1st PbPb… machine closure set-up, injection Instead of a summary, what will happen next year first physics run! Philippe.Crochet@clermont.in2p3.fr

  17. BACKUP

  18. Heavy ion (ALICE) data taking scenario one LHC year = 7 months pp (107s) + 1 month AA (106s), starts in 2007 • 5 first years: • regular pp runs at 14 TeV: commissioning, reference, dedicated pp physics • first PbPb run at low luminosity: global observables, large x-sections • 2 PbPb runs at high luminosity (Lint = 0.5nb-1/year): small x-sections • 1 pA run: structure functions, hadronic reference • 1 light ion run: energy density dependence • later (different options depending on the first results): • pp (or pp-like) at 5.5 TeV • other light or intermediate-mass systems • other systems p-likeA & Ap-like • PbPb at low energy • PbPb at 5.5 TeV & high luminosity ALICE collaboration, J. Phys. G 30 (2004) 1517

  19. Combined momentum resolution at low momentum dominated by - ionization-loss fluctuations - multiple scattering at high momentum determined by - point measurement precision - alignment & calibration (assumed ideal here) resolution ~ 7% at 100 GeV/c excellent performance in hard region! F. Antinori, 06/20/05

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