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Upsilon Production in Heavy Ions with STAR and CMS

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Presentation on theme: "Upsilon Production in Heavy Ions with STAR and CMS"— Presentation transcript:

1 Upsilon Production in Heavy Ions with STAR and CMS
HIT Seminar Berkeley Lab September 18, 2012. Manuel Calderón de la Barca Sánchez

2 Manuel Calderón de la Barca Sánchez
Outline Bottomonium in heavy ion collisions Upsilon measurements in: STAR CMS Upsilon cross sections in p+p Upsilon nuclear modification factors Conclusions 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

3 Manuel Calderón de la Barca Sánchez
Quarkonium in the QGP Heavy quarkonia: Heavy quark bound state are probes of the hot QCD medium Debye screening Matsui & Satz, PLB (1986) Sequential Suppression Digal et al., PRD Landau damping: Im V. (e.g. Laine et al., JHEP ) TC<T 0<T<TC T=0 ϒ 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

4 High T: the interaction between the heavy quarks is modified.
Charmonium suppression: longstanding QGP signature Original idea: High T leads to screening Screening prevents heavy quark bound states from forming. J/ysuppression: Matsui and Satz, Phys. Lett. B 178 (1986) 416 lattice calculations, indications of screening Nucl.Phys.Proc.Suppl.129: ,2004 Note: Calculations of internal energy or internal energy O. Kaczmarek, et al., Nucl.Phys.Proc.Suppl.129: ,2004 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

5 The heavy quark potential in QCD
Recent news: Heavy quark potential from (quenched) Lattice QCD A.Rothkopf, et al. PRL 108 (2012) Broadening due to collisions with medium (Im V) possibly more important than screening (Re V). 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

6 Measuring the Temperature
Quarkonia’s suppression pattern  QGP thermometer Lattice QCD Calculations: Dissociation temperatures of quarkonia states hep-ph/ For  production at RHIC and LHC A cleaner probe compared to J/y co-mover absorption → negligible recombination → negligible d-Au: Cold Nuclear Matter Effects Shadowing / Anti-shadowing at y~0 Challenge: low rate, rare probe Large acceptance detector Efficient trigger Why do we measure Y at STAR A .Mocsy, 417th WE-Heraeus-Seminar,2008 Expectation: (1S) no melting (2S) likely to melt (3S) melts 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

7 J/y Puzzles from SPS and RHIC
Similar J/y suppression at the SPS and RHIC! despite 10× higher √sNN Suppression does not increase with local energy density RAA(forward)<RAA(mid) Possible ingredients cold nuclear matter effects sequential melting regeneration What happens for bottomonium? 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

8 Charmonium vs Bottomonium
J/y suppression Hot nuclear matter effects: Suppression? Regeneration? Co-mover absorption? Energy loss? Flow? Bottomonium Expectations Cleaner probe of screening, deconfinement. Regeneration? Not a big role for bottomonium Open bottom: sbb ~ 1.34 – 1.84 mb. Open charm: scc ~ 551 – 1400 mb. Co-mover absorption? Expected to be small for bottomonium Charmonium sabs ~ 3 – 4 mb. Bottmonium sabs ~ 1 mb. Lin & Ko, PLB (2001) 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

9 Manuel Calderón de la Barca Sánchez
Upsilons in STAR Upsilons via Triggering, Calorimetry, Tracking, and matching of tracks to calorimeter towers. 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

10 Manuel Calderón de la Barca Sánchez
The CMS Detector ϒ event in CMS. 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

11 Manuel Calderón de la Barca Sánchez
 in p+p 200 GeV in STAR 2006 2009 Phys. Rev. D 82 (2010) 12004 ∫L dt = 7.9 ± 0.6 pb-1 N(total)= 67±22(stat.) ∫L dt = 19.7 pb-1 N(total)= 145±26(stat.) STAR Preliminary 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

12  Comparison to NLO pQCD
CEM: R. Vogt, Phys. Rep , 2008 CSM: J.P. Lansberg and S. Brodsky, PRD 81, , 2010 Comparison to NLO STAR √s=200 GeV p+p ++→e+e- cross section consistent with pQCD Color Evaporation Model (CEM) 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

13 Manuel Calderón de la Barca Sánchez
 in p+p 7 TeV in CMS Excellent resolution at midrapidity. Separation of 3 states. PRD 83, (2011) 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

14 Manuel Calderón de la Barca Sánchez
 vs √s, World Data STAR Preliminary STAR √s=200 GeV and CMS √s=7 TeV p+p ++→e+e- cross section consistent with pQCD and world data trend 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

15 Manuel Calderón de la Barca Sánchez
 in d+Au 200 GeV STAR Preliminary Signal has ~8σ significance pT reaches ~ 5 GeV/c ∫L dt = 32.6 nb-1 N+DY+bb(total)= 172 ± 20(stat.) Final results on RdAu coming soon. LHC pPb run in January/February. 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

16 Manuel Calderón de la Barca Sánchez
 in Au+Au 200 GeV Raw yield of e+e- with |y|<0.5 = 197 ± 36 ∫L dt ≈ 1400 µb-1 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

17  in Au+Au 200 GeV, Centrality
STAR Preliminary STAR Preliminary STAR Preliminary Peripheral Central 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

18 Bottomonia at 2.76 TeV: 2010 data
pp PbPb PRL 107 (2011) 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

19 Bottomonia: 2011 data pp PbPb
Ratios not corrected for acceptance and efficiency 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

20 Manuel Calderón de la Barca Sánchez
 in Au+Au 200 GeV, RAA Models from M. Strickland and D. Bazow, arXiv: v4 Indications of Suppression of Upsilon(1S+2S+3S) getting stronger with centrality. Reduced pp statistical uncertainties, increased statistics from 2009 data vs 2006 data. 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

21 ϒ(2S)/ϒ(1S) Double Ratio, CMS
Separated ϒ(2S) and ϒ(3S) Measured ϒ(2S) double ratio vs. centrality no strong centrality dependence 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

22 ϒ(1S) Nuclear Modification Factor: RAA
CMS PbPb at 2.76 TeV In 2010: 7.28 µb−1 ϒ(1S) RAA, 3 centrality bins JHEP 1205 (2012) 063 In 2011: 150 µb−1 ϒ(1S) RAA, 7 centrality bins First results on ϒ(2S) RAA Clear suppression of ϒ(2S) ϒ(1S) suppression Consistent with excited state suppression only ~50% feed down CMS Preliminary, arXiv: 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

23 Comparison: RHIC and LHC
STAR measured RAA of ϒ(1S+2S+3S) combined arXiv: min. bias value: CMS: separate RAA for ϒ(1S) and ϒ(2S) can calculate min. bias RAA of ϒ(1S+2S+3S): CMS Preliminary, arXiv: 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

24 ϒ RAA Comparison to models I
Incorporating lattice-based potentials, including real and imaginary parts A: Free energy Disfavored, not shown. B: Internal energy Consistent with data vs. Npart Includes sequential melting and feed-down contributions ~50% feed-down from cb. Dynamical expansion, variations in initial conditions (T0, η/S) Data indicate: 428 < T0 < 442 MeV at RHIC 552 < T0 < 580 MeV at LHC for 3 > 4pη/S > 1 M. Strickland, PRL 107, (2011). 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

25 ϒ RAA Comparison to models II
Strong Binding Weak Binding Weak vs. Strong Binding Narrower spectral functions for “Strong” case Ratios of correlators compared to Lattice: favor “Strong” binding case Kinetic Theory Model Rate Equation: dissociation + regeneration Fireball model: T evolution. T ~ 300 MeV 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

26 ϒ RAA Comparison to models II
Eur. Phys. J. A (2012) 48: 72 Comparison to data for “Strong” binding: Mostly consistent with data Little regeneration: Final result ~ Primordial suppression Large uncertainty in nuclear absorption. Need dAu, pPb. 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

27 ϒ RAA pT and y dependence
Indications that suppression is largest at low pT. and mid rapidity. Need more statistics for firmer conclusions. 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez

28 Manuel Calderón de la Barca Sánchez
The bottom line... STAR and CMS: ϒ suppression vs. Npart. RAA consistent with suppression of feed down from excited states only (~50%) CMS: First measurement of ϒ(2S) suppression RAA(ϒ(3S)) < 0.09 (95% C.L.) ϒ(1S) RAA consistent with suppression of feed down from excited states only (~50%) Need more pp statistics to pin down lower-pT double ratio Pinning down the medium properties. Cold nuclear matter: coming soon! 9/18/12 HIT Seminar, Berkeley Lab Manuel Calderón de la Barca Sánchez


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