Measurement of quarkonium production at the LHC: from pp to Pb Pb collisions with insight into the Quark-Gluon Plasma

Transcription

1 Measurement of quarkonium production at the LHC: from pp to Pb Pb collisions with insight into the Quark-Gluon Plasma A. Andronic GSI Darmstadt Quarkonium production in pp and p Pb collisions Quarkonium production in Pb Pb collisions Summary and outlook MU Programmtag 6 - Mainz, -3 Dec. 6

2 dy (µb/gev/c) Charmonium production in pp collisions A.Andronic /dp σ J/ψ d + ALICE e e, y <.9 ALICE µ + µ,.5<y<4. CMS, y <. ALAS, y <.75 LHCb,.5<y<4. s=7 ev ALICE, PLB 74 () 44 pp p (GeV/c) (µb) dσ/dy pp - ALICE preliminary, L = 3. pb ± 3.4%, p < 3 GeV/c int - LHCb, JHEP(5)7, L = 3. pb ± 3.9%, p < 4 GeV/c int Systematic uncertainty BR uncert.:.6 % s = 3 ev, inclusive J/ψ y ALI-PREL-869 Observable to test models (non-perturbative QCD) Reference for measurements in p Pb, Pb Pb collisions R AA = dn AA/dp dy N AA coll dn pp/dp dy

3 pp collisions 3 A.Andronic

4 pp collisions 4 A.Andronic

5 J/ψ production vs. multiplicity 5 A.Andronic dn J/ψ /dy /dy J/ψ dn ALICE pp J/ψ µ + µ J/ψ e + e s = 7 ev (.5 < y < 4) ( y <.9) 5 Normalization uncert.:.5% 4 dn ch /dη dn /dη ch ALICE, PLB 7 () 65

6 J/ψ production vs. multiplicity 6 A.Andronic dn J/ψ /dy /dy J/ψ dn 5 ALICE pp J/ψ µ + µ J/ψ e + e s = 7 ev (.5 < y < 4) ( y <.9) Normalization uncert.:.5% 4 dn ch /dη dn /dη ch ALICE, PLB 7 () 65 N/dydp ) / d N/dydp (d N/dydp ) / d N/dydp (d ALICE pp s = 7 ev D meson B feed down and normalization uncertainties not shown < p < GeV/c 4 < p < 8 GeV/c (dn ch /dη) / dn /dη ch ALICE, JHEP 9 (5) Percolation, p > EPOS 3.99 EPOS Hydro PYHIA 8.57 < p < 4 GeV/c 8 < p < GeV/c (dn ch /dη) / dn /dη ch

7 J/ψ production in p Pb collisions 7 A.Andronic R ppb.4 ALICE (JHEP (4) 73): inclusive J/ψ µ + µ, <p <5 GeV/ c. p Pb = 5. ev L int ( 4.46<y <.96)= 5.8 nb, L (.3<y cms int ALICE (JHEP 6 (5) 55): inclusive J/ψ e L int (.37<y <.43)= 5 µb cms cms + <3.53)= 5. nb e, p > global uncertainty = 3.4% ALI DER EPS9 NLO (Vogt) CGC + CEM (Fujii et al.) CGC + CEM (Ducloue et al.) CGC + NRQCD (Ma et al.) ELoss, q =.75 GeV /fm (Arleo et al.) EPS9 NLO + ELoss, q =.55 GeV /fm (Arleo et al.) y cms ALICE, JHEP (4) 73, 6 (5) 55 Shadowing describes data, not that well though...more sophistications needed? Precision to improve significantly with data just acquired (Nov.-Dec. 6)

8 ψ(s) production in p Pb collisions 8 A.Andronic R ppb.8.6 ALICE, p Pb J/ψ ψ(s) = 5. ev, inclusive J/ψ, + ψ(s) µ µ EPS9 NLO (Vogt) ELoss with q =.75 GeV /fm (Arleo et al.) EPS9 NLO + ELoss with q =.55 GeV /fm (Arleo et al.) y cms ALICE, JHEP (4) 73 (at least in first order) models give same result for ψ(s) as for J/ψ difference predominant at low p

9 ψ(s) production in p Pb collisions 9 A.Andronic R ppb LHCb ppb p = 5 ev < 4 GeV/c LHCb, inclusive ψ(s) LHCb, inclusive J/ ψ ALICE, inclusive ψ(s) y LHCb, arxiv:6.7878

10 Lattice QCD predicts a phase transition (at µ B =) A.Andronic 6 non-int. limit (ideal gas) HRG quarks and gluons ε qg / 4 = (3 + N f ) π c 3p/ 4 ε/ 4 3s/4 3 hadrons (pions) ε had / 4 = π [MeV] of crossover type, Y. Aoki et al., Nature 443 (6) 675 c MeV, ε c (.8.5) GeV/fm 3, or (.-3.)ε nuclear

11 Heavy quarks and deconfined matter A.Andronic q q pairs produced early in pqcd processes Open heavy-flavor hadrons are at high energies abundant probes of high density stages (thermalization and energy loss) Quarkonium formation is hindered with a screened potential Matsui & Satz, Phys. Lett. B 78 (986) 78 If high energy heavy-ion collisions lead to the formation of a hot quark-gluon-plasma, then color screening prevents c c binding in the deconfined interior of the interaction region. no q q state if r q q ( ) > λ D /(g( ) ) (Debye length in QGP) via binding E of different states, quarkonia constitute a thermometer of deconfined medium Main observable (vs. N part and p ): he nuclear modification factor, R AA = hot QCD / binary-scaled pp

12 Nucleus-nucleus collisions at the LHC A.Andronic a picture (with 5 mil. pixels) of a central collision (about 3 primary tracks)

13 D-meson production 3 A.Andronic Nuclear modification factor ALICE Average D, D, D* ALICE, JHEP 3 (6) 8 + Pb Pb, =.76 ev, y <.5 % with pp p extrap. reference 3 5% p Pb, = 5. ev,.96 <y <.4 cms + p (GeV/c) R AA D pb (5. ev pp) + 44 µb (5. ev PbPb) CMS Preliminary AA and lumi. uncertainty Centrality -% y < p CMS, CMS-PAS-HIN-6- (GeV/c) Large suppression of charmed mesons, due to quark energy loss in QGP R AA D R AA charged hadrons M. Djordjevic CUJE3. D S. Cao et al. PHSD w/ shadowing PHSD w/o shadowing I.Vitev (g=.8-.) Heavy quarks also experience collective flow (similar magnitude as lighter siblings)

14 J/ψ R AA Charmonium data at RHIC and the LHC 4 A.Andronic. ALICE (.5<y<4., ±5% syst.), PHENIX (.<y<., ±9% syst.), =.76 ev =. ev suppression at RHIC dramatically different at the LHC forward rapidity dn ch /dη η= dn ch /dη ε (>6 GeV/fm 3, for dn ch /dη 5)...

15 J/ψ R AA Charmonium data at RHIC and the LHC 5 A.Andronic..8 ALICE (.5<y<4., ±5% syst.), PHENIX (.<y<., ±9% syst.), lines: Statistical Hadronization Model dσ cc =.76 ev =. ev /dy=.5 mb suppression at RHIC dramatically different at the LHC Statistical Hadronization Model N J/ψ (N dir c c ).6.4. dσ cc /dy=.5 mb forward rapidity dn ch /dη η= dn ch /dη ε (>6 GeV/fm 3, for dn ch /dη 5) Predictions: AA et al., PLB 65 (7) 59 What is so different at the LHC? (compared to RHIC) σ c c : x, Volume:.x J/ψ is another observable (charm) for the phase boundary calculations are for =56 MeV

16 Charmonium production at the LHC 6 A.Andronic J/ψ R AA. Pb-Pb, =.76 ev,.5 < y < 4. ALICE (±5% syst. unc.) J/ψ R AA. Pb-Pb, = 5. ev,.5 < y < 4. ALICE (±8% syst. unc.) Statistical Hadronization Model. dσ cc /dy =.6 mb dσ cc /dy ±.35 mb N part. Statistical Hadronization Model dσ cc /dy =.3 mb dσ cc /dy ±.55 mb N part the generic prediction by the model is confirmed by data arxiv: establishes charmonium as a powerful new observable of the phase boundary

17 J/ψ production at 5 ev 7 A.Andronic R AA.4 ALICE, Pb Pb = 5. ev. Inclusive J/ψ.5 < y µ + µ < 4,.3 < p < 8 GeV/c ransport, p >.3 GeV/c (M, Du and Rapp) ransport (M, Zhou et al.) Statistical hadronization (Andronic et al.) Co movers (Ferreiro) N part ALICE, arxiv:66.897

18 J/ψ production vs. p 8 A.Andronic, R PbPb backw x R ppb.4. ALICE inclusive J/ψ µ + µ forw R ppb (.3<y <3.53) x cms backw R ppb ( 4.46<y <.96), cms R PbPb (.5<y <4), =.76 ev, 9% cms (Phys. Lett. B734 (4) 34) = 5. ev forw R ppb ALICE, (GeV/c) JHEP 6 (5) 55 distinct differences between Pb Pb and p Pb, further support that low-p J/ψ are from (re)generation (while at high-p outcome of charm energy loss) p

19 Connection to the phase diagram of QCD 9 A.Andronic (MeV) LHC RHIC SPS AGS GSI Lattice QCD Borsanyi et al. Kaczmarek et al., Bazavov et al. hermal fits (central collisions) Cleymans et al. Andronic et al. Manninen, Becattini SAR (BES prelim.) 3 µ B (MeV) phenomenological link (at low µ B ), chemical freeze-out of u,d,shadrons Lattice QCD, µ B = : crossover =45-65 MeV Borsanyi et al., JHEP 9 () 73, JHEP 8 () 53 HotQCD, PRD 9 (4) 9453, PRD 83, 454 ()

20 Charmonium and the phase boundary A.Andronic...an important connection, but not decisive (yet) (recall that only σ c c is a new parameter in the statistical model, besides, V )...as transport models describe data equally well (and predict R AA (p ) and v ) assuming continuous dissociation and formation during the whole lifetime of QGP is there a way to make the distinction?

21 ψ(s) production at the LHC A.Andronic pp / (ψ(s)/j/ψ) (ψ(s)/j/ψ) PbPb % CL - - PbPb 35 µb, pp 8. pb (5. ev) = 5. ev =.76 ev (PRL3 (4) 63).6 < y <.4, 3 < p < 3 GeV/c Prompt only 95% CL CMS Cent. -% A A [ψ(s) / J/ψ] ALICE =.76eV,.5<y<4, <p <3 GeV/c ALICE =.76eV,.5<y<4, 3<p <8 GeV/c NA5 =.7 ev, <y<, p > GeV/c SHM, p > GeV/c 95%CL 95%CL 95%CL CMS, arxiv:6.438 N part N part ALICE, JHEP 5 (6) 79 at the SPS, the thermal value (SHM) was reached for central Pb Pb (p > ) LHC: uncertainties large, no conclusion yet...run and Run 3 data crucial

22 he weight of the ψ(s) measurement A.Andronic R < expected in both models, different magnitudes predicted (p -integrated) ransport model: Zhao, Rapp, NPA 859 () 4 and priv. comm. see Du, Rapp, arxiv:54.67 J/ψ /R AA ψ(s) R AA pp (N ) scaling coll transport model ( =.76 ev) (dashed: w. shadowing) statistical model symbols: expected ALICE data ( y <.9) N part Central Barrel: measurement possible only with upgrade ( nb ) Muon Spectrometer: a first glimpse with baseline data ( nb ), a real measurement only with upgraded ALICE ALICE, JPG 4 (4) 87

23 Υ production 3 A.Andronic CMS, arxiv:6.5 Υ(S) supression interpreted as effect of feed-down from Υ(S, 3S), which were fully dissociated ( sequential suppression )

24 Υ production 4 A.Andronic ransport model predicts a small fraction of regenerated Υ (more at y = ) Primordial : assumes that 6% of Υ(S) originates from feed-down

25 Υ production 5 A.Andronic R AA. ALICE, Inclusive Pb-Pb + - ϒ(S) µ µ, centrality -9% = 5. ev, Preliminary global sys.= ± 3% Pb-Pb =.76 ev, (PLB 738 (4) 36-37) global sys.= ± 7% open: reflected ALI-PREL an intriguing result...even if, considering uncertainties, not a large effect expectation from the sequential melting (Debye screening): R 5. do we see substantial (re)generation? (in QGP/at phase boundary?) y AA R.76 AA

26 Υ production (relative) 6 A.Andronic Υ(S) / Υ(S) CMS data pp p Pb Pb Pb s=.76 ev, y <.93 cms =5. ev, y =.76 ev, y <.93 cms <.4 cms he data approach the thermal limit for central Pb-Pb coll. (the trend itself is interesting and not well understood).5..5 thermal model (=59 MeV) with corona w/o corona 3 dn ch /dη η= fair description by model [also for R AA of Υ(S)]

27 Summary and outlook 7 A.Andronic A wealth of data on quarkonium production in pp and p Pb collisions interesting observations on multiplicity dependence Everybody agrees that we see (re)combination of charm quarks at the LHC...a new observable for the QCD phase boundary Interesting (sequential?) disappearance pattern in the bottom (Υ) sector do bottom quarks also thermalize at the LHC? will Υ add more weight to the phase boundary? A larger data sample available in Pb Pb (5 ev) and p-pb (5, 8 ev) in Run Ambitious plans for Run 3, 4...characterization of deconfined medium (ALICE and LHCb upgrades targeted/crucial for p/pb Pb)

28 Backup slides

29 Charmonium and deconfined matter 9 A.Andronic the original idea: Matsui & Satz, Phys. Lett. B 78 (986) 78 If high energy heavy-ion collisions lead to the formation of a hot quark-gluon-plasma, then color screening prevents c c binding in the deconfined interior of the interaction region. Debye screening : no J/ψ if r J/ψ > λ D Refinements: sequential suppression : Digal et al., PRD 64 () 75.5 J/ψ Debye length in QGP: λ D /(g( ) ) r () Υ r q q = f( ) (Lattice QCD results).5 q q thermometer of QGP hermal picture (n partons = 5. 3 for 3 flavors) / c for =5 MeV: n p 84/fm 3, mean separation r=. fm < r J/ψ

30 J/ψ production at 5 ev 3 A.Andronic R AA (5. ev)/r AA (.76 ev) ALICE, Pb Pb, inclusive J/ψ.5 < y < 4,.3 < p < 8 GeV/c ransport, p >.3 GeV/c (M, Du and Rapp) ransport (M, Zhou et al.) Statistical hadronization (Andronic et al.) Co movers (Ferreiro) µ + µ N part R AA.76 ev /R AA 5. ev R AA ALICE, inclusive J/ψ µ + µ.5 < y < 4 ransport = 5. ev (M, Du and Rapp) Pb Pb Pb Pb = 5. ev, % =.76 ev, % (GeV/c) p ALICE, arxiv: he current (syst.) uncertainties prevent a firm conclusion, but trend generically predicted by (re)generation models (uncertainties determined by σ c c, 5% here)

31 D-meson nuclear modification 3 A.Andronic pqcd models transport models R AA ALICE % Pb Pb, =.76 ev Average D, D, D* y <.5 with pp p extrap. reference + + Djordjevic WHDG rad+coll Vitev, Rad+dissoc Vitev, Rad CUJE3. R AA ALICE % Pb Pb, =.76 ev + + Average D, D, D* y <.5 with pp p extrap. reference AMU elastic Cao, Qin, Bass MC@sHQ+EPOS POWLANG BAMPS el. BAMPS el.+rad PHSD p ALICE, JHEP 3 (6) 8 (GeV/c) good description of data in theoretical models p (GeV/c)

32 hermal fit at the LHC (Pb Pb, -%) 3 A.Andronic Yield dn/dy 3 Pb-Pb =.76 ev π - π Data, ALICE, -% Statistical model fit (χ /N df =9./8) =56.5 MeV, µ =.7 MeV, V =58 fm B + K - K Ks φ p p Λ Λ - Ξ + Ξ - Ω Ω d d He He ΛH 3 H Λ 4 He π, K ±, K from charm included (.7%,.9%, 3.% for the best fit) = 56.5 ±.5 MeV, µ B =.7 ± 3.8 MeV, V y= = 58 ± 4 fm 3

33 Statistical hadronization of charm: method and inputs 33 A.Andronic hermal model calculation (grand canonical),µ B : n th X N dir c c = g cv ( i nth D i + n th Λ i ) + g cv ( i nth ψ i + n th χ i ) N c c << Canonical (J.Cleymans, K.Redlich, E.Suhonen, Z. Phys. C5 (99) 37): N dir c c = g cn th oc ) oc I (g c N th I (g c N th oc ) + g cnc c th g c (charm fugacity) Outcome: N D = g c V n th D I /I he only new input parameter: N dir c c N J/ψ = g cv n th J/ψ (from experiment or pqcd) Minimal volume for QGP: VQGP min = fm3

34 Charmonium in the statistical hadronization model 34 A.Andronic the model predicts absolute yields (R AA is calculated with the pp reference as for data) (.76) J/ψ (5.) / R J/ψ R AA AA dσ cc /dy(5./.76) - Statistical Hadronization Model.56 (pqcd, FONLL) ± 5% ± % Pb-Pb,.5 < y < 4. ALICE data (±7% syst. unc.) N part.5 < y < 4. σ c c from pp, s=7 ev, LHCb, NPB 87 (3) p < 8 GeV/c,. < y < 4.5 σ c c = 49 ± (stat) ± 6(syst) ± 65(frag) µb energy scaling via FONLL pqcd shadowing calculations (R.Vogt):.7±. V y= :.76 ev: 4 fm 3 ; 5. ev: 55 fm 3 Syst. uncert. of data apply fully-correlated to the model calculations

35 D-meson production vs. multiplicity 35 A.Andronic (dn/dy) / dn/dy PYHIA 8.57 SOFQCD MPI/ FSR/ ISR/ Colour ON diffractive processes included pp s = 7 ev Average D mesons 8 6 First hard process MPI Gluon splitting from hard process ISR/FSR Average B mesons First hard process MPI ISR/FSR 4 N/dydp ) / d N/dydp (d Average D mesons all contributions <p < GeV/c <p <4 GeV/c 4<p <8 GeV/c 8<p < GeV/c <p < GeV/c Average D mesons hard process <p < GeV/c <p <4 GeV/c 4<p <8 GeV/c 8<p < GeV/c <p < GeV/c