08/10/2009 Zebo Tang, Weihai J/  production at high transverse momentum in p+p and A+A collisions Zebo Tang (USTC)

08/10/2009 Zebo Tang, Weihai Outline Introduction –Quark Gluon Plasma (QGP) –J/  as a probe of QGP –J/  production mechanism in p+p collisions High p T J/  reconstruction –Electron identification –High p T J/   e + e - reconstruction Results –J/  spectra in p+p collisions –J/  spectra in Cu+Cu collisions –J/  -hadron correlation in p+p collisions Summary and outlook

08/10/2009 Zebo Tang, Weihai Quark-Hadron phase transition Net Baryon Density

08/10/2009 Zebo Tang, Weihai Relativistic Heavy Ion Collider (RHIC) Animation M. Lisa RHIC BRAHMS PHOBOS PHENIX STAR AGS TANDEMS v =  c = 186,000 miles/sec Au + Au at 200 GeV

08/10/2009 Zebo Tang, Weihai J/  melting in QGP J/  dissociation due to color screening  Signature of the QGP formation

08/10/2009 Zebo Tang, Weihai J/  measurements in Heavy Ion Collisions SPS: Anomalous suppression  Significant evidence of deconfinement in central Pb+Pb PLB 477,28 (2000) NA 50, PLB 477,28 (2000) RHIC: Similar suppression as SPS, why? Balance of dissociation and regeneration? Or sequential suppression?

08/10/2009 Zebo Tang, Weihai Sequential suppression H. Satz, Nucl. Phys. A (783): (2007) J/  suppression at low p T maybe only from excited stats (  ’,  c ) F. Karsch, D. Kharzeev and H. Satz, PLB 637, 75 (2006) 60% from direct J/  : not suppressed 30%  c and 10%  ’: dissociated NA50, EPJ39,335 NA60, QM05

08/10/2009 Zebo Tang, Weihai Survival possibility pTpT Direct J/  suppression J/  H. Liu, K. Rajagopal and U.A. Wiedemann PRL 98, (2007) and hep-ph/ M. Chernicoff, J. A. Garcia, A. Guijosa hep-th/ T. Gunji, QM08 Can we observed direct J/  suppression? Hot wind dissociation  high p T direct J/  suppression Hot wind dissociation AdS/CFT calculation

08/10/2009 Zebo Tang, Weihai Charmonium production mechanism NRQCD Color singlet Color octet Color singlet model (CSM), LO underpredicted CDF data by order of magnitude Color octet model (COM), LO good agreement with CDF cross section disagreement with CDF polarization LO Know your reference! LO CSMLO COM J/  3S13S1 CDF measurement: PRL79,572

08/10/2009 Zebo Tang, Weihai Charmonium production mechanism NRQCD Color singlet Color octet Color singlet model (CSM), LO underpredicted CDF data by order of magnitude Color octet model (COM), LO good agreement with CDF cross section disagreement with CDF polarization CSM*, NLO better agreement NNLO* applicable at p T >5-7 GeV/c COM* improvement of polarization, NLO will come, valid at p T >3 GeV/c Decay feeddown (CDF):  (2s): 7%-15%, slightly increase with p T  c0,1,2 : ~30%, slightly decrease with p T B: Strong p T dependence LO Know your reference!

08/10/2009 Zebo Tang, Weihai Disentangle contributions via Correlations J/  -hadron correlation can also shed light on different source contribution to J/  production CSM vs. COM 1) no near side correlation 2) strong near side correlation PLB 200, 380(1988) and PLB 256,112(1991)

08/10/2009 Zebo Tang, Weihai The STAR Detector MRPC ToF barrel 75% for run 9 RPSD PMD FPD FMSFMS EMC barrel EMC End Cap DAQ1000 Take data FGT Complete Ongoing MTD (BNL LDRD) R&D HFT: R&D TPC TPC+EMC for this analysis

08/10/2009 Zebo Tang, Weihai Electron identification (TPC only) With TPC only: no electron ID at low p T difficult to get a good electron sample at high p T possible to get a electron sample with reasonable purity at intermediate p T x sigma deviation from electron dE/dx curve Note: electron yield is much less than hadrons

08/10/2009 Zebo Tang, Weihai Electron ID (EMC) Online fast trigger: enhance high p T electron enhance recorded luminosity Offline deposited energy: Further suppress high p T hadrons  x  0.05x0.05) ~5X 0

08/10/2009 Zebo Tang, Weihai Electron ID (SMD) electron hadron Shower Maximum Detector: shower size shower position Further suppress hadron contamination

08/10/2009 Zebo Tang, Weihai High p T J/   e + e - reconstruction technique PYTHIA decay p+p run6 Trigger efficiency Tracking efficiency acceptance High p T electron High p T J/   high p T electron (TPC+EMC) lower p T electron (TPC only)

08/10/2009 Zebo Tang, Weihai High p T J/  in p+p at 200 GeV J/  p T EMC+TPC electrons:  1, p T >2.5 GeV/c TPC only electrons:  1, p T >1.2 GeV/c EMC+TPC electrons:  1, p T >4.0 GeV/c TPC only electrons:  1, p T >1.2 GeV/c No background at p T >5 GeV/c Reach higher p T (~14 GeV/c) p+p 2005 p+p 2006 STAR Preliminary EMC (High Tower) trigger: 5 < p T < 14 GeV/c

08/10/2009 Zebo Tang, Weihai J/  spectra in p+p and Cu+Cu at 200 GeV Significantly extend p T range of previous measurements in p+p at RHIC to 14 GeV/c Agreement of charm measurements between STAR and PHENIX ~3 orders

08/10/2009 Zebo Tang, Weihai Compare to pQCD and NRQCD Model comparisons: Color singlet model: direct NNLO still miss the high p T part. P. Artoisenet et al., Phys. Rev. Lett. 101, (2008), and J.P. Lansberg private communication. LO CS+CO : better agreement with the measurements, leave little room for higher charmonium states and B feeddown contribution. G. C. Nayak, M. X. Liu, and F. Cooper, Phys. Rev. D68, (2003), and private communication. CS and LO CS+CO have different power parameters  different diagram contribution? power parameter: n=8 for NNLO CS n=6 for LO CS+CO STAR Preliminary

08/10/2009 Zebo Tang, Weihai x T scaling in p+p collisions n is related to the number of point-like constituents taking an active role in the interaction n=8: diquark scattering n=4: QED-like scattering p T >2 GeV/c STAR Preliminary p T >5 GeV/c  and proton at p T >2 GeV/c: n=6.6±0.1 ( PLB 637, 161(2006)) J/  at high p T : n=5.6±0.2 (close to CS+CO prediction) Soft processes affect low p T J/  production

08/10/2009 Zebo Tang, Weihai Nuclear modification factor R AA Consistent with no suppression at high p T : R AA (p T >5 GeV/c) = 1.4± 0.4±0.2 All RHIC measurements: R AA = 1.1 ± 0.3 ± 0.2 Indicates R AA increase from low p T to high p T STAR Preliminary

08/10/2009 Zebo Tang, Weihai Nuclear modification factor R AA Consistent with no suppression at high p T : R AA (p T >5 GeV/c) = 1.4± 0.4±0.2 All RHIC measurements: R AA (p T >5 GeV/c) = 1.1 ± 0.3 ± 0.2 Indicates R AA increase from low p T to high p T Contrast to AdS/CFT+ Hydro prediction H. Liu, K. Rajagopal and U.A. Wiedemann PRL 98, (2007), T. Gunji, JPG 35, (2008) How does production mechanism (CS vs. CO) affect energy loss? Good jobs: transport+hydro: from initial produced instead of regenerated Y.Liu, Zhen Qu, N. Xu and P. Zhuang, arXiv: ; N. Xu, QM2009 two-component model: leakage and B feeddown is important R. Rapp, X. Zhao, arXiv: STAR Preliminary

08/10/2009 Zebo Tang, Weihai Disentangle contributions via Correlations J/  -hadron correlation can also shed light on different source contribution to J/  production CSM vs. COM 1) no near side correlation 2) strong near side correlation PLB 200, 380(1988) and PLB 256,112(1991)

08/10/2009 Zebo Tang, Weihai J/  -hadron correlation (S+B)/B: 54/  Heavy quark fragmentation Near side correlation Good S/B ratio makes this measurement possible

08/10/2009 Zebo Tang, Weihai J/  hadron correlation in p+p PRL 95,152301(2005) h-h correlation No significant near side J/  -hadron azimuthal angle correlation Constrain B meson’s contribution to J/  yield

08/10/2009 Zebo Tang, Weihai Constrain bottom yields Correlations shows low B contribution (13  5) % Can used to further constrain B yields STAR Preliminary

08/10/2009 Zebo Tang, Weihai Constrain bottom yields pQCD predicts significant B  J/  Correlations shows low B contribution Can used to further constrain B yields Constrain B  e M. Cacciari, P. Nason and R. Vogt RL 95(2005),122001; CLEO collaboration PRL 89(2002), STAR Preliminary

08/10/2009 Zebo Tang, Weihai Yields in near/away side Associated hadron spectra with leading J/  : Away side: Consistent with leading charged hadron correlation measurement (h-h)  away-side from gluon or light quark fragmentation Near side: Consistent with no associated hadron production B  J/  not a dominant contributor to inclusive J/  constrain J/  production mechanism STAR Preliminary

08/10/2009 Zebo Tang, Weihai High-p T J/  in run8 d+Au dAu EMC data sampled luminosity: 31 nb -1 p+p equivalent: 13 pb -1 J/  spectra  (2S)  c J/  -hadron correlation Isolated J/  J/  in Jet Reduced material budget by a factor of ~10 Efficiency under going 420 signals 13  New 500 GeV p+p data is coming! Also 200 GeV p+p with higher lum. 200 GeV Au+Au and Energy scan.

08/10/2009 Zebo Tang, Weihai Summary  J/  spectra in 200 GeV p+p collisions at STAR Significantly extend previous measurement from 5 GeV/c to ~14 GeV/c, provide powerful tool to constrain model calculations High p T J/  follows x T scaling with n=5.6, consistent with COM slope Low p T J/  deviates from x T scaling suggests soft process can affect low p T J/  production.  J/  spectra in 200 GeV Cu+Cu collisions First observation of no suppression for hadron at high p T at STAR Indication of R AA increasing from low p T to high p T  J  hadron azimuthal correlation in p+p First quarknonium-hadron correlation measurement at RHIC No significant near side correlation B  J/  contribution = 13  5% Can be used to constrain B production, and help to separate b  e from c  e

08/10/2009 Zebo Tang, Weihai Extra slides

08/10/2009 Zebo Tang, Weihai What I am going to try (low p T ) 500 GeV p+p, 2009, preliminary calibration TPC+TOF Low p T J/   ee: Total cross section

08/10/2009 Zebo Tang, Weihai What I am going to try (other charmonia) TOF:  /K upto 1.6 GeV/c, p/( ,K) upto 3 GeV/c With extended PID from TOF and high luminosity of RHICII: The reconstruction of the other charmonium states through their hadronic channels are possible and worth to try

08/10/2009 Zebo Tang, Weihai Future dramatic improvement of J /  at low p T EMC+TOF+HFT (large acceptance): J/  production Different states predicted to melt at different T in color medium Charmonia (J/  ), bottonia (  ) Quarkonium dissociation temperatures – Digal, Karsch, Satz pT (e)>1.5 GeV/c PHENIX Acceptance: ||<0.35,=2*/2 STAR TOF-Upgrade Acceptance: ||<0.9,=2* J /  yields from 1 billion minbias Au+Au events: 43.8x10 -9 /0.040x10 9 *292*0.5*1.8*0.5= 144,000  0.3% v 2 error  J/  pp N N bin  y R AA dE/dx after TOF cut

08/10/2009 Zebo Tang, Weihai Detector upgrades: HFT and MTD Heavy Flavor Tracker: Muon Telescope Detector: n   >0 STAR Preliminary Prototype in run VII   e + e - rejection Topologically reconstruct J/  from B decay Rejection power: ~16 Muon identification simulation

08/10/2009 Zebo Tang, Weihai MRPC ToF barrel Ready for run 10 RPSD PMD FPD FMSFMS EMC barrel EMC End Cap DAQ1000 Ready for run 9 FGT Complete Ongoing MTD (BNL LDRD) R&D HFT TPC The STAR Detector Run8: without any inner tracker

08/10/2009 Zebo Tang, Weihai Jpsi-h correlation from PYTHIA

08/10/2009 Zebo Tang, Weihai High p T J/  in heavy ion collisions (Cont.) 2-component approach: dissociation + recombination R AA decreases slightly or flat with p T X. Zhao and R. Rapp, hep-ph/ R AA increase slightly with p T including formation time and B decay X. Zhao, WWND2008 Color singlet model: R AA increase with p T (formed out of medium) F. Karsch and R. Petronzio, PLB 193(1987), 105 ; J.P. Blaizot and J.Y. Ollitrault, PLB 199(1987),499

08/10/2009 Zebo Tang, Weihai Datasets p+p data sample:  1. EMC triggered events in year 2005 E T >3.5 GeV Integrated luminosity: 3 (pb) -1  2. EMC triggered events in year 2006 E T >5.4 GeV Integrated luminosity: 11 (pb) -1 Cu+Cu data sample:  1. EMC triggered events in year 2005 E T >3.75 GeV Integrated luminosity: 0.9 (nb) -1 pp-equivalent: 3 (pb) -1 High-p T J/  p+p data sample: 1. J/ψ triggered events in year 2006 Integrated luminosity: 377 (nb) Υ triggered events in year 2006 Integrated luminosity: 9(pb) -1 Au+Au data sample: 1. Υ triggered events in year 2007 Integrated luminosity: 300(μb) -1 pp-equivalent: 12(pb) -1 Triggered data

Lectures on Physics of High-Energy Nuclear Collisions 08/10/2009Zebo Tang, Weihai Heavy Quark Potential Cornell-potential:  At zero temperature, V(r,0)  r,  Confinement !  At high temperature, the confinement potential ‘melted’  De-confinement !  J/  suppression ! T.Matsui and H.Satz, Phys. Lett. B178, 416(1986) F. Karsch, E. Laermann, A. Peikert, Nucl. Phys. B605, 579(2001) Nu Xu, Lecture at USTC, Oct. 2006

08/10/2009 Zebo Tang, Weihai J/  measurements in Heavy Ion Collisions Due to color screening, J/  was thought be dissociated in the medium. T. Masui and H. Satz, Phys. Lett. B178, 416 (1986). At RHIC, the suppression at low p T is similar to at SPS at similar N part : recombination due to large charm cross section. P. Braun-Munzinger and J. Stachel, Phys. Lett. B490,196 (2000); L. Grandchamp and R. Rapp, Phys. Lett. B523, 60 (2001); M. I. Gorenstein et al., Phys. Lett. B524, 265 (2002); R. L. Thews, M. Schroedter, and J. Rafelski, Phys. Rev. C63, (2001); Yan, Zhang and Xu, Phys.Rev.Lett.97, (2006); PHENIX: Phys.Rev.Lett.98, ,2007. At SPS, suppression decreases versus p T : Cronin effect, Nuclear absorption and formation time effect. M. C. Abreu et al., Phys. Lett. B499, 85 (2001); X. Zhao, WWND2008; X. Zhao and R. Rapp, hep-ph/ ; X. Zhu, P. Zhuang, PRC67, (2003) NA60, QM08

08/10/2009 Zebo Tang, Weihai High p T J/  in heavy ion collisions How the formation time effect, jet energy loss and hot wind dissociation affect the high p T J/psi in the medium: 2-component approach: dissociation + recombination R AA increases slightly with p T including formation time and B decay X. Zhao, WWND2008; X.Zhao and R. Rapp, hep-ph/ Formation time effect: R AA increases with p T (formed out of medium) K. Farsch and R. Petronzio, PLB 193(1987), 105 ; J.P. Blaizot and J.Y. Ollitrault, PLB 199(1987),499 Jet energy loss: open charm strongly suppressed observed in the medium AdS/CFT + Hydro: R AA decreases versus p T STAR: PRL98(2007)

08/10/2009 Zebo Tang, Weihai Compare to SPS Similar trend also observed at SPS, might from different physics origin RHIC: Cu+Cu,, consistent with no suppression at p T > 5 GeV/c SPS: In+In,, consistent with no suppression at p T > 1.8 GeV/c NA60, QM08 NA50, 158 AGeV PLB499,85 and NPA774,59 R CP

08/10/2009 Zebo Tang, Weihai J/  -h correlation from PYTHIA

08/10/2009 Zebo Tang, Weihai Summary J/  in p+p and Cu+Cu collisions: p T spectra in p+p: extended to ~14 GeV/c follows x T scaling with n=5.6 at p T >5 GeV/c, deviates from scaling at low p T J/  -hadron azimuthal correlation in p+p: no significant near side correlation constrain the contribution from B  J/  +X away-side spectra consistent with h-h correlation  gluon or light quark fragmentation J/  R AA indication of R AA increasing at high p T production mechanisms: described by NRQCD soft processes affect low p T production constrain decay contribution constrain B production and B  e constrain production mechanism: CSM or COM medium properties

08/10/2009 Zebo Tang, Weihai Sequential suppression H. Satz, Nucl. Phys. A (783): (2007) J/  suppression at low p T maybe only from excited stats (  ’,  c ) F. Karsch, D. Kharzeev and H. Satz, PLB 637, 75 (2006) 60% from direct J/  : not suppressed 30%  c and 10%  ’: dissociated NA50, EPJ39,335 NA60, QM05 ? Plasma thermometer