Quarkonium production in CMS Hyunchul Kim (Korea University For the CMS collaboration
Content CMS detector@lhc Quarkonia physics motivation Result from CMS Charmonia : J/ψ Bottomonia : ϒ Summary HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University
LHC (Large Hadron Collider CMS FRANCE ALICE HIM@Pyeongchang, Korea, // LHCb ALAS proton : Accelerate 99.999999% of speed of light From surface ~m SWIZERLAND Hyunchul Kim (Korea University 3
LHC (Large Hadron Collider 7 km in circumference CMS LHCb FRANCE ALICE ALAS SWIZERLAND HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 4
CMS (Compact Muon Solenoid detector Superconducting Solenoid B=3.8, 6m internal diameter Muon system racking Barrel : Drift ube (D Endcap : Cathode Strip Chamber (CSC rigger (Barrel, Endcap Resistive Plate Chamber (RPC 8.7m Inner tracker Silicon pixel( 5 µm, ~66M channels Microstrips(8~8 µm, ~9.6M channels p resolution at barrel.5%, p <GeV/c 5.m otal weight : 4 t HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 5
Muon reconstruction mechanism in CMS With information from inner tracker and muon stations, global muons reconstructed Because of the magnetic field and energy loss(~3 GeV in the iron yoke, Global muons need p 3~5 GeV to reach the muon stations, (depending on eta Further muon ID based on track quality (χ, # of hits, HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 6
Dimuon mass plot by the CMS experiment At, the integrated luminosity used in the HI analysis corresponds to 7.8 µb for.76 ev PbPb and 5 nb for.76 ev pp collisions Events/(GeV/c 3 J/! "(,,3S CMS Preliminary PbPb =.76 ev L int = 7.8 µb Z m µµ (GeV/c Cover from low mass to high mass region Good dimuon resolution thanks to the tracking p > 4. GeV/c : to remove background around the upsilon mass region p µ > 4. GeV/c Invariant mass spectrum of + pairs over the mass range. m HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 7
Quarkonia candidate in PbPb at CMS µ + µ! pair: mass:" 9.46 GeV/c p:" ".6 GeV/c rapidity:"!.33 µ + : p" =" 4.74 GeV/c η" ="!.39 µ! : p" =" 4.7 GeV/c η" ="!.8 HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 8
Physics motivation of quarkonia study ( Quarkonium : flavorless meson whose constituents are a quark and its own antiquark Charmonium(c-cbar, Bottomonium(b-bbar Suppression of quarkonium states : Good candidates to probe the QGP in Heavy-Ion collisions Because of their large mass (mc~.7 GeV, mb~4.9 GeV, heavy quarks are produced in parton-parton collisions with large momentum transfer Q, at the initial stage of the reaction. < d, heavy quark pair make strongly bound resonance. > d, by Debye screening of the heavy quark binding potential no resonance can be formed. d is depend on the binding energy and radius of the resonance. Sequential suppression of the resonances thermometer for the temperature reached in the HI collisions. State Υ (S J/Ψ (S Χ b (P Χ c (P Υ (3S Ψ (S ΔE (GeV/c 9.46 3..6 3.53.36 3.68 R (fm.8.5.68.7.78.9 HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 9
Physics motivation of quarkonia study ( Inclusive J/ψ Direct J/ψ Prompt J/ψ Feed-down from ψ and χ c Non-Prompt J/ψ from B decays Prompt J/ includes the information of the initial state of hot-dense matter. Owing to the long lifetime of the b hadrons, compared to the QGP lifetime, non-prompt J/ should not suffer from color screening, but instead may reflect the b-quark energy loss in the medium. Energy loss would lead to a reduction of the b-hadron yield at high p in PbPb collisions compared to the binary-collision-scaled pp yield. HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University
J/ψ in pp at s = 7 ev irect J/ Inclusive J/ψ Inclusive J/ Prompt J/ψ Non- Non-Prompt J/ J/ψ Prompt J/ Feed-down from B from decays B from ψ and χ c decays Direct J/ψ Feed-down from c Reconstruct µ + µ - vertex Simultaneous D unbinned maximum likelihood fit of µ + µ - mass and pseudo-proper decay length (l J/ψ B L xy J/ µ + µ.5.6.7.8.9 3 3. 3. 3.3 3.4 3.5 - µ + µ invariant mass (GeV/c EPJC 7:55 ( HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University Events / (. GeV/c CMS - s = 7 ev L = 37 pb data 8 total fit background Events / (.6 mm Fit pull 6 4 < p < 5 GeV/c.9 < y <. CMS - χ /n DoF s = 7 ev L = 37 pb = 45.5/44 data total fit prompt non-prompt background < p < 5 GeV/c.6 < y <.4 4 -.5.5.5 3 - -3-4 -.5.5.5 (mm l ψ(s
J/ψ in pp at s = 7 ev dy (nb/(gev/c /dp 3 - prompt J/ψ µ + µ, corrected for acceptance CMS s = 7 ev L = 37 pb. < y <.9 ( 65.9 < y <. ( 5. < y <.6 ( 5.6 < y <. ( 5. < y <.4 ( prompt NLO NRQCD dy (nb/(gev/c /dp - non-prompt J/ψ µ + µ, corrected for acceptance CMS s = 7 ev L = 37 pb. < y <.9 ( 65.9 < y <. ( 5. < y <.6 ( 5.6 < y <. ( 5. < y <.4 ( FONLL J/ψ σ d J/ψ σ d B - Luminosity and polarization uncertainties not shown B Luminosity uncertainty not shown 6 7 8 9 3 4 5 p (GeV/c 6 7 8 9 3 4 5 p (GeV/c Prompt J/ψ well described by NRQCD Non-prompt J/ψ fall faster at high p than expected from FONLL HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University arxiv :.557 (accepted by JHEP
ψ(s in pp at s = 7 ev dy (nb/(gev/c /dp ψ(s σ d B - + - prompt ψ(s µ µ, corrected for acceptance CMS s = 7 ev L = 37 pb. < y <. ( 5. < y <.6 ( 5.6 < y <.4 ( prompt NLO NRQCD dy (nb/(gev/c /dp ψ(s σ d B - + - non-prompt ψ(s µ µ, corrected for acceptance CMS s = 7 ev L = 37 pb. < y <. ( 5. < y <.6 ( 5.6 < y <.4 ( FONLL -3 Luminosity and polarization uncertainties not shown -3 Luminosity uncertainty not shown 6 7 8 9 3 p (GeV/c Prompt ψ(s well described by NRQCD Non-prompt ψ(s overestimated by FONLL (however, large uncertainty on BR(B ψ(sx falls faster with p than expected from FONLL 6 7 8 9 3 p (GeV/c arxiv :.557 (accepted by JHEP HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 3
as projections onto the mass and J/ψ axes. Integrated over centrality, the numbers of prompt and non-prompt J/ψ mesons with y <.4 and 6.5 < p < 3 GeV/c are 37 ± and 9 ± 3, respectively. J/ψ in PbPb at =.76 ev Events / (. GeV/c CMS PbPb =.76 ev 8 6 = 7.8 µb L int Cent. -%, y <.4 6.5 < p < 3 GeV/c data total fit bkgd + non-prompt background! = 34 MeV/c Events / (.88 mm 3 Events / (.88 mm CMS CMS PbPb PbPb = s.76 NN =.76 ev ev 3 Lint = 7.8 Lint = µb 7.8 µb Cent. -%, Cent. -%, y <.4 y <.4 6.5 < p6.5 < < 3 p GeV/c < 3 GeV/c data data total fittotal fit bkgd + bkgd non-prompt + non-prompt background background 4.6.7.8.9 3 3. 3. 3.3 3.4 3.5 -.5 -.5.5.5.5.5 (mm (mm 3 4 4 CMS CMS PbPb PbPb s = s.76 NN =.76 ev ev 3 CMS PbPb = s.76 arxiv =.76 ev : ev.569 CMS PbPb NN (submitted NN by JHEP 35 L = 7.8 µb 35 L = 7.8 Same mechanism int µb int Lint = 7.8 Lint = µb 7.8 µb Cent. -%, Cent. -%, y <.4 y <.4 used as in pp Cent. -%, Cent. -%, y <.4 y <.4 6.5 < p6.5 < < 3 p GeV/c < 3 GeV/c For 3 the 3 6.5 < first p6.5 < < 3 p GeV/c < time, 3 GeV/cprompt! = 34! MeV/c = 34 and MeV/cnon-prompt J/ψ have been separated data data total fittotal fit in heavy-ion data data collisions Events / (. GeV/c Events / (. GeV/c 5 5 m µµ (GeV/c total fittotal fit bkgd + bkgd non-prompt + non-prompt background background Events / (.88 mm HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 4 Events / (.88 mm l J/! l J/! bkgd + bkgd non-prompt + non-prompt background background
Prompt J/ψ R AA vs p, y Prompt J 5 5 5 3 p (GeV/c R AA.4..8.6.4 PbPb AuAu =.76 ev CMS: prompt J/! Cent. -%, y <.4 = GeV PHENIX: J/! ( y <.35 PHENIX: J/! (.< y <. (both PRL 98 (7 33 SAR: J/! (preliminary Cent. -6%, y <. R AA.4 PbPb =.76 ev..8.6.4 CMS Preliminary PbPb AuAu CMS: prompt J/! Cent. -% 6.5 < p < 3 GeV/c Prompt J/! =.76 ev = GeV PHENIX: J/! y <.35 ( y <.35 PHENIX: J/! (.< y <. (both PRL 98, (7 3333 (7. 5 5 5 3 p (GeV/c RHIC : lower p, but R AA increase with p CMS : factor 3 suppression for p > 6.5 GeV/c AuAu almost no p dependence PHENIX: J/! ( y <.35 (do not seem to be PHENIX: observed J/! (.< y <. by RHIC (both PRL 98 (7 33 arxiv :.569 (submitted by JHEP HIM@Pyeongchang, Korea, //. -% 6.5 < p < 3. GeV/c -.5 - -.5 -.5.5.5.5 PHENIX : stronger suppression in forward range CMS : less suppression in forward range Increasing R AA going towards ALICE y range Hyunchul Kim (Korea University 5 y
Prompt J/ψ R AA vs N part R AA.4..8.6 PbPb AuAu =.76 ev CMS: prompt J/! y <.4 6.5 < p < 3 GeV/c = GeV PHENIX: J/! ( y <.35 PHENIX: J/! (.< y <. (both PRC 84 ( 549 ~% : suppressed by factor 5 with respect to pp 5~% : suppressed by factor.6 remains Similar suppression seen at PHENIX though CMS is high p while PHENIX is low p.4. 5 5 5 3 35 4 N part arxiv :.569 (submitted by JHEP HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 6
Prompt J/ψ R AA vs N part R AA.4..8.6.4 PbPb AuAu = GeV SAR: J/! (preliminary > 5 GeV/c, y <. p =.76 ev CMS: prompt J/! y <.4 6.5 < p < 3 GeV/c ~% : suppressed by factor 5 with respect to pp 5~% : suppressed by factor.6 remains Similar suppression seen at PHENIX though CMS is high p while PHENIX is low p SAR measured less suppression at high p. 5 5 5 3 35 4 N part HIM@Pyeongchang, arxiv :.569 Korea, (submitted // by JHEP Hyunchul Kim (Korea University 7
Non-prompt J/ψ R AA R AA.4. CMS PbPb Prompt J/! Non-prompt J/! =.76 ev.8.6 -% -%.4. y <.4 6.5 < p < 3 GeV/c 5 5 5 3 35 4 N part Suppression of non-prompt J/ψ observed in minimum bias and central PbPb collisions, no centrality dependence First indications of high-p b-quark quenching like light quarks arxiv :.569 (submitted by JHEP HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 8
b fraction compared with earlier results b fraction.9.8 CMS PbPb =.76 ev ( y <.4 CMS PbPb =.76 ev (.6< y <.4 CMS pp s =.76 ev ( y <.4 CMS pp s =.76 ev (.6< y <.4.7 CMS pp s = 7 ev (.6 < y <.4 CMS pp s = 7 ev (. < y <.6.6 CMS pp s = 7 ev ( y <. CDF pp s =.96 ev ( y <.6.5.4.3.. ion of J/ 5 5 5 3 p (GeV/c production in pp and PbPb collisions at Good agreement within uncertainties, between the earlier results at other collision energies and the present measurements. arxiv :.569 (submitted by JHEP HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 9
ϒ(nS in pp at s = 7 ev Events / (.7 GeV/c 8 6 4 Events / (.7 GeV/c S 8 6 4 CMS Preliminary, S s = 7 ev CMS Preliminary, s = 7 ev L int = 4 pb µ L int = 4 pb! < µ! < " = 67 MeV/c " = 67 MeV/c 8 8.5 9 9.5.5.5 µ + µ - mass (GeV/c ϒ(nS in pp at s = 7 ev 3S 8 8.5 9 9.5.5.5 µ + µ - mass (GeV/c dy! BR(µµ (nb/(gev/c "/dp "/dp s 5= 7 ev, L 5 = 3 pb 5 3 py (GeV/c Separation of the 3! states with good mass resolution 5Phys. Rev. D 835( 4 PYHIA agrees in shape, but not in normalization p d - -3 #(S CMS data CMS data PYHIA (norma PYHIA (normalized # # y < y < Y (G Separation of the 3 ϒ states with good mass resolution he normalized otal cross p section overestimated by about a factor -spectrum prediction from PYHIA is Phys. consistent Rev. D 83 with ( the measurements dy! BR(µµ (nb/(gev/c d - -3 #(S s = 7 ev, L = 3 pb 7 HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University
ϒ(nS in PbPb at =.76 ev arxiv :.569 (submitted by JHEP Events / (.4 GeV/c 6 5 4 3 p µ data fit > 4 GeV/c CMS Preliminary PbPb =.76 ev -%,. < y <.4 < p < GeV/c = 7.8 µb L int! = 9 MeV/c 7 8 9 3 4 m µµ (GeV/c (fixed to MC Extended unbinned maximum likelihood fit Signal Resolution fixed from MC simulation Efficiency.9 Peak separation PYHIA+EvtGen+HYDJE(Bass fixed to!(s.8 Background.7.6 Second order polynomial.5 Obvious Upsilon(S.4.3.. PDG CMS Simulation PbPb =.76 ev 5 5 5 3 p (GeV/c 5 HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University
ϒ(S+3S Suppression ϒ(S+3S/ϒ(S suppression arxiv : 5.4894 PRL 7 ( 53 8 8 data data CMS pp CMS spp =.76 s = ev.76 ev Events / (.4 GeV/c 7 6 5 4 7 µ p6> 4 pgev/c > 4 GeV/c 5 4 fit µ fit y <.4 y <.4 < p L int < < p GeV/c < GeV/c = 3 = nb3 nb L int! = 9! MeV/c = 9 MeV/c (fixed (fixed to MC to MC N Υ (S N Υ (S = = ± ± Events / (.4 GeV/c 6 5 4 3 Events / (.4 GeV/c 6 pp shape pp shape < p < < p GeV/c < GeV/c 5 µ µ p > 4 pgev/c > 4 GeV/c = 7.8 = µb 7.8 µb 4 3 data data CMS PbPb CMS PbPb =.76 = ev.76 ev PbPb PbPb fit fit Cent. Cent. -%, -%, y <.4 y <.4 L int L int! = 9! MeV/c = 9 MeV/c (fixed (fixed to MC to MC N Υ (S N Υ (S = 86 = ± 86 ± 3 3 7 78 89 9 3 34 4 m µµ (GeV/c (GeV/c m µµ (S+3S suppression m µµ (GeV/c m µµ (GeV/c 7 78 89 9 3 34 (S Υ + (S 3S/Υ + 3S/Υ (S (S (S+3S pp =.78 +.6.4 ±. Υ (S + 3S/Υ (S PbPb =.4 +.3 pp =.78 +.6 production.4 ±. relative Υ (S + to 3S/Υ (S (S in pp and PbPb =.4 PbPb Measure ϒ(S+3S production relative to ϒ(S production +.3.. ±. ± easure Simultaneous!(S+3S Simultaneous production fit to pp and relative PbPb fit to to data PbPb!(S at.76 production and ev pp data at.76 ev imultaneous fit to pp and PbPb data at.76 ev PRL 7 ( 53 Υ (S + arxiv: 5.4894 3S/Υ (S PbPb =.3 +.9 Accepted by PR.5 Υ (S + 3S/Υ (S ±.3 HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University pp
ϒ(S R AA vs p, y ϒ(S and NRAA part R AA AA.5.5 CMS PbPb s NN =.76 ev R AA.4 CMS PbPb!(S.!(S.5.5.8 =.76 ev R AA.4 PbPb =.76 ev CMS:!(S..8 y <.4. < p < GeV/c AuAu = GeV SAR:!(S+S+3S y <.5 (preliminary.6.6.5.5 44 66 88 4 4 6 6 8 8 pp (GeV/c Cent. -% y y < <.4.4. Cent. -% < p < GeV/c..4.6.8..4.6.8..4 bpb 6: Left: collisions Υ(S (green yield divided diamonds by as AA ainfunct PbPb collisions (green diamonds as a function ity. he result is compared to the cross section measured in pp collisions (black crosses. bal scale uncertainties on the PbPb data due to AA (5.7% and the pp integrated lumi- Are No obvious ϒ(S rapidity suppressed dependence at high p 6.% are not shown. Right: nuclear modification factor? R AA of Υ(S as a function of. A global CMS: uncertainty!(s of 8.3%, from AA and the integrated luminosity of the pp data, is shown as a grey box at R AA =. Points are plotted at their measured average y. al (systematic uncertainties are shown as bars (boxes. Horizontal bars indicate the bin 8 6!(S suppressed at low p R AA.4 No obvious rapidity dependence within the large statistical uncertainties suppressed by factor ~. in % In CMS, ϒ(S suppressed by factor ~.3 in ~% SAR measures R AA (Υ (S + S + 3S =.56 ±. +.8 (arxiv:9.389 SAR for CMS measures ( %: R AA of ϒ(S+S+3S =.56 for CMS (~% calculated R AA of ϒ(S+S+3S =.43 CMS pp & PbPb =.76 ev.4 CMS PbPb =.76 ev HIM@Pyeongchang, "(S (PbPb (pp Korea, //!(S Hyunchul Kim (Korea University 3. y.6.4. 5 5 5 3 35 4 N part CMS-HIN--6 arxiv:.569 (submitted to JHEP R AA (Υ (S + S + 3S = R AA (Υ (S +Υ (S + 3S/Υ (S PbPb +Υ (S + 3S/Υ (S pp =.6 +.4 arxiv :.569 (submitted by JHEP +.78.43
Summary of the results In pp collisions at s = 7 ev, prompt J/ψ and ϒ(S is well described by models within uncertainties J/ψ from B decays is overestimated by FONLL model In PbPb collisions at =.76 ev, R AA.4..8.6.4 CMS PbPb Prompt J/! Non-prompt J/! "(S -% =.76 ev -% prompt J/ψ and J/ψ from B decays suppressed ϒ(S and ϒ(S+3S with respect to ϒ(S are suppressed. y <.4 J/! 6.5 < p < 3 GeV/c < p < GeV/c 5 5 5 3 35 4 N part arxiv :.569 (submitted by JHEP " HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 4
CMS HI group is analyzing with HI data now! Expect new excited result! HIM@Pyeongchang, Korea, // Hyunchul Kim (Korea University 5