Heavy flavour measurements with ALICE. heavy ion collisions & QGP heavy flavours & QGP ALICE detector overview selected physics channels

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1 Heavy flavour measurements with ALICE heavy ion collisions & QGP heavy flavours & QGP ALICE detector overview selected physics channels Excited QCD09, Zakopane, 09/02/09 1

2 The QCD phase diagram µ B = 0: T c = 173 ± 15 MeV ε c = 0.7 ± 0.3 GeV/fm 3 crossover -like transition µ B > 0: large uncertainties order of transition unknown existence of a critical point chiral sym. rest. coincides with deconf. the QGP is not an ideal gas µ B >> 0: color superconductivity (not shown) Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 2

3 Exploring the QCD phase diagram with heavy ion collisions pressure + heat QGP key parameters: bombarding energy, collision centrality, particle transverse momentum Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 3

4 Schematic space-time evolution of a heavy ion collision 4 main distinct phases strategy: use produced particles as probes of the medium Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 4

5 QGP signatures modification of lowmass resonances suppression of high-mass resonances photon production hard probes based on particles produced in the early stage soft probes based on particles produced in the late stage strangeness enhancement flow profile jet quenching..etc?? direct info from the medium Excited QCD09, Zakopane, 09/02/09? non-direct info from the medium

6 Heavy flavours in heavy ion collisions open heavy flavour quenching probe medium density parton energy loss via medium-induced gluon radiation proportional to ε, L & C R with C R = 4/3(3) for q(g) and to m Q (gluon radiation suppressed at Θ < m Q /E Q ) Eg > Ec~q > Eb expected Q quarkonia (final) yield probe medium temperature debye screening suppresses QQbar bound states A. Mocsy but non-correlated quarks can recombine in the QGP observable: nuclear modification factor R AA = Yield in AA Yield in pp N coll if no hot nuclear effects average number of NN collision in an AA collision note: only effects in final state here, for effects in initial state, see M. Malek talk on Friday Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 6

7 : 34 years of heavy-ion collisions BEVALAC (LBL) fixed target s < 2.4 GeV 2 experiments ~ 100 physicists Saturne II (Saclay) fixed target s < 2.4 GeV 1 experiment ~ 30 physicists SIS (GSI) fixed target s < 2.7 GeV 4 experiments ~ 200 physicists FAIR (GSI) fixed target s < 9 GeV 1 experiment ~ 300 physicists Synchro (JINR) fixed target s < 3 GeV x experiments ~ xxx physicists AGS (BNL) fixed target s < 5 GeV 4 experiments ~ 400 physicists RHIC (BNL) collider s < 200 GeV 4 experiments ~ 1000 physicists SPS (CERN) fixed target s < 20 GeV 7 experiments ~ 600 physicists LHC (CERN) collider s < 5500 GeV 3 experiments ~ 1000 physicists NICA (JINR) collider s < 9 GeV 1 experiment ~ xxx physicists s from ~2 GeV in 1975 to 5500 GeV in 2009 Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 7

8 SPS & RHIC results on heavy flavours in 4 plots SPS: J/ψ suppression in central PbPb debye screening not a unique scenario models cannot reproduce data in InIn collisions RHIC: J/ψ suppression in central AuAu large uncertainties in cold nuclear effects larger suppression at forward angles? mid-rapidity forward rapidity RHIC: charm quenching ~ light hadron quenching non-photonic electron vs. hadron R AA a challenge for models experiments disagree on charm x-section Phys. Lett. B477 (2000) 28, Phys. Rev. Lett. 98 (2007) , Phys. Rev. C 77 (2008) Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 8

9 Heavy ion collisions & LHC the biggest step in energy in the history of heavy-ion collisions machine SPS RHIC LHC s (GeV) τ 0 QGP N ch (fm/c) T/T c (τ 0 QGP ) ε[1 fm/c] (GeV/fm 3 ) τ QGP (fm/c) τ f (fm/c) ~ V f (fm 3 ) ~ 10 3 ~ 10 4 ~ 10 5 µ B (MeV) processes soft semi-hard hard = 0.18 mj faster hotter denser longer bigger cleaner harder ε, vol. & τ QGP 10(4) from SPS(RHIC) to LHC...the LHC will become the ideal facility for a systematic exploration and quantitative confirmation of the insights obtained at RHIC, aided by the plentiful abundance of hard probes. B. Müller, hep-ph/ J. Schukraft, Nucl. Phys. A 698 (2002) 287 Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 9

10 Heavy-flavour LHC σ c (LHC) = σ c (RHIC) 10 σ b (LHC) = σ b (RHIC) 100 σ W (LHC) = σ ϒ (RHIC) 10 σ Z (LHC) = σ ϒ (RHIC) K. Safarik Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 10

11 A closer look at heavy-quark cross-section 14 TeV charm bottom σ(14 TeV) / σ(5.5 TeV) NLO predictions for LHC: a factor ~ 2 uncertainty σ(14 TeV) / σ(5.5 TeV) ~ 10% measuring σ(c,b) in 14TeV is top priority hep-ph/ , J. Phys. G 32 (2006) 1295 Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 11

12 Quarkonia LHC quarkonium dissociation temperatures A. Mocsy & P. Petreczky, Phys. Rev. Lett. 99 (2007) hard gluon induced quarkonium breakup hep-ph/ LHC RHIC whether J/ψ melts or RHIC it will be strongly either suppressed or LHC 5.5 TeV use ϒ(2S) to unravel J/ψ sup. vs. reco. ϒ reco. is small: L. Grandchamp et al., PRC 73 (2006) ϒ(1S) melts significantly only at LHC additional suppression by hard gluons relevance of quarkonium ratios vs. p t R. Vogt in J. Phys. G 35 (2008) Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 12

13 Charmonium LHC peculiar centrality dependence 2. predictions strongly depend on σ cc 3. (re-)dissociation by comovers 4. regeneration smaller <p 2 t > 4. note: N(B J/ψ) / N(direct J/ψ) ~ 20% in 4π A. Andronic et al., Phys. Lett. B 652 (2007) 259, J. Phys. G 35 (2008) , A. Capella et al., Eur. Phys. J. C58 (2008) 437, R. Thews et al., J. Phys. G 35 (2008) Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 13

14 Heavy quark LHC: new ratios E > E > E R < R < g q c b h AA D AA R B AA R D( B)/ h = R D( B) AA R h AA R = R B / D AA B AA R D AA R D/h probes color charge dep. of E R B/h probes mass dep. of E isolate mass dep. of E sensitivity disappears at large p t lower sensitivity to qhat N. Armesto et al., Phys. Rev. D 71 (2005) , J. Phys. G 35 (2008) Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 14

15 Heavy LHC CMS ALICE ATLAS Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 15

16 ALICE (A Large Ion Colider Experiment) 7(4) SPS(RHIC) experiments in one 18 sub-detectors tons 16 x 26 m 150 MCH 1000 members 109 institutes 31 countries Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 16

17 Heavy flavours with ALICE ITS, TPC, TRD, ToF ( η <0.9) (di-)electrons: J/ψ, ψ, ϒ, ϒ,ϒ, open charm, open bottom, W ±, Z 0 muon spectrometer (-2.5<η<-4) (di-)muons: J/ψ, ψ, ϒ, ϒ,ϒ, open charm, open bottom, W ±, Z 0 ITS, TPC, TRD, ToF ( η <0.9) hadrons: D 0, D ±, electron-muon coincidences: open charm & bottom no 2 nd vertex 2 nd vertex Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 17

18 Selected physics channels Quarkonia B from single leptons D 0 Kπ Heavy flavour quenching published results only Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 18

19 Quarkonia: expected statistics in muon channel 1 LHC year = 7 months pp (10 7 s, cm -2 s -1 ) + 1 month AA (10 6 s, cm -2 s -1 ) PbPb MB 5.5 TeV pp 14 TeV J/ψ ψ ϒ ϒ ϒ S ( 10 3 ) S/B S/ S+B S ( 10 3 ) S/B S/ S+B from PbPb MB to pp, a factor ~ 10 more stat. J/ψ: large stat., good significance ψ : small S/B ϒ: good stat., S/B > 1, good significance ϒ : good stat., S/B > 1, good significance ϒ : low statistics similar expected statistics in the electron channel J. Phys. G 30 (2004) 1517, x-sections from CERN , hep-ph/ , with shadowing & feed-down, w/o nuclear absorption/suppression/regeneration Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 19

20 Observables with bottomonia suppression 1: T C = 270 MeV, T D /T C = 4.0 (1.4) for ϒ(ϒ ) suppression 2: T C = 190 MeV, T D /T C = 2.9 (1.1) for ϒ(ϒ ) statistics: one month 5.5 TeV large sensitivity to dissociation temperatures and medium size ALICE: J. Phys. G 32 (2006) 1295 Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 20

21 More with quarkonia polarization pp: test production mechanisms AA: probe QGP formation dn/dy in pp probe gluon distribution at low x ϒ(α gen - α rec ) vs. p t 14 TeV 14 TeV: J/ψ & ϒ pol. vs. p t 5.5TeV: J/ψ pol. vs. centrality, ϒ pol. needs 2-3 runs R. Analdi, E. Scomparin, D. Stocco Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 21

22 Open charm & bottom: accessible channels charm: exclusive hadronic channels charm & bottom: semi-inclusive leptonic channels D 0 Kπ (tested in pp & PbPb) D + Kππ (tested in pp & PbPb) D ± s KKπ (under study) D* D 0 π (under study) D 0 Kπππ (under study) Λ c pkπ (under study) c l + X (à la CDF & D0) b l + X (à la CDF & D0) b J/ψ + X (à la CDF & D0) bbbar J/ψ + l (under study) bbbar 3µ (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 eµ, b > 5 prongs, Λ b J/ψ + X, etc Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 22

23 B-hadron cross-section from single leptons First step: extract N l B w/o 2 nd vertex: unfold lepton dn/dp t via combined fit large statistics constrains fit with 2 nd vertex: cut on dca & subtract remaining background large purity of lepton sample 14 TeV B µ+x 5.5 TeV B e+x pp evts (1 year) p t > 2 GeV/c µ ± from B 10 7 PbPb (5%) evts (1 month) p t > 2 GeV/c, 200 < d0 < 600 µm e ± from B, S/(S+B) = 80% J. Phys. G 32 (2006) 1295, DIMUONnet Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 23

24 B-hadron cross-section from single leptons Second step: correct for efficiency, acceptance & decay kinematics total number of l B σ N 1 ε ( p σ > p ( Φ ) B B B B min l B t ( pt > pt ) = B l Ldt σ min t ) MC integrated luminosity lepton global detection efficiency J. Phys. G 32 (2006) 1295, DIMUONnet Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 24

25 B-hadron cross-section from single leptons Third step: the inclusive differential B-hadron cross-section w/o 2 nd vertex with 2 nd vertex B semi-muonic decays pp, s = 14 TeV method widely used (UA1, CDF, D0) large p t reach (~ 80% of the total cross-section is reconstructed) large η reach (central and forward regions) (very) small statistical errors, systematics ~ 10-15% allows to get B-hadron R AA (p t ) (and D-hadron R AA (p t ) simultaneously) J. Phys. G 32 (2006) 1295, DIMUONnet Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 25

26 Hadronic charm cos(θ pointing ) > 0.98 d 0 K d 0 π < µm 2 increase S/B by 10 3 D 0 K π (3.8%) cτ = 123 µm 10 7 central PbPb (5%) S ~ S/B ~ 10 % S/ (S+B) ~ 40 background assumes dn/dη = η = 0 J. Phys. G 32 (2006) 1295 Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 26

27 Hadronic charm differential x-section system pp ppb PbPb s (TeV) trig MB MB CC N evt time (months) p min t (GeV/c) E stat (%) E syst (%) the most precise measurement of the total charm x-section in pp LHC J. Phys. G 32 (2006) 1295 Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 27

28 Testing QCD with hadronic charm in pp 14 TeV m c, µ F /µ 0, µ R /µ 0, PDF bars: quadratic sum of statistical & systematic errors expected experimental errors are much smaller than theoretical uncertainties J. Phys. G 32 (2006) 1295 Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 28

29 Heavy quark quenching: traditional ratios 1 nominal year: 10 7 central Pb-Pb events, 10 9 pp events statistics: bars, systematics: bands R D AA 1 dn / dp 1 dn / dp D e = AA t e AA t R D AA = e Ncoll dn pp / dpt Ncoll dn pp / dpt sensitivity to shadowing for p t <~ 7 GeV/c & to energy loss for p t >~ 7GeV/c J. Phys. G 32 (2006) 1295 Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 29

30 Heavy quark quenching: more ratios 1 nominal year: 10 7 central Pb-Pb events, 10 9 pp events statistics: bars, systematics: bands R R / D / h = D AA R h AA R = R R e from B e from D B / D AA AA sensitivity to color charge dependence sensitivity to mass dependence J. Phys. G 32 (2006) 1295 Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 30

31 Waiting for data first collisions expected in August TeV in ALICE Philippe.Crochet@clermont.in2p3.fr Excited QCD09, Zakopane, 09/02/09 31