1 / 46

J/ y production at high transverse momentum in p+p and A+A collisions

J/ y production at high transverse momentum in p+p and A+A collisions. Zebo Tang (USTC). Outline. Introduction Quark Gluon Plasma (QGP) J/ y as a probe of QGP J/ y production mechanism in p+p collisions High p T J/ y reconstruction Electron identification

yetta
Download Presentation

J/ y production at high transverse momentum in p+p and A+A collisions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. J/y production at high transverse momentum in p+p and A+A collisions Zebo Tang (USTC) Zebo Tang, Weihai 2009

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

  3. Net Baryon Density Quark-Hadron phase transition Zebo Tang, Weihai 2009

  4. PHOBOS BRAHMS RHIC PHENIX STAR AGS TANDEMS Relativistic Heavy Ion Collider (RHIC) v = 0.99995c = 186,000 miles/sec Au + Au at 200 GeV Animation M. Lisa Zebo Tang, Weihai 2009

  5. J/y melting in QGP J/y dissociation due to color screening  Signature of the QGP formation Zebo Tang, Weihai 2009

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

  7. Sequential suppression H. Satz, Nucl. Phys. A (783):249-260(2007) J/ suppression at low pT 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 Zebo Tang, Weihai 2009

  8. J/y Survival possibility pT Direct J/y suppression Hot wind dissociation AdS/CFT calculation H. Liu, K. Rajagopal and U.A. Wiedemann PRL 98, 182301(2007) and hep-ph/0607062 M. Chernicoff, J. A. Garcia, A. Guijosa hep-th/0607089 Can we observed direct J/ suppression? Hot wind dissociation  high pT direct J/ suppression T. Gunji, QM08 Zebo Tang, Weihai 2009

  9. Color octet Color singlet NRQCD J/y 3S1 J/y Charmonium production mechanism • 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 CDF measurement: PRL79,572 Know your reference! LO CSM LO COM Zebo Tang, Weihai 2009

  10. Color octet Color singlet NRQCD Charmonium production mechanism • 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 pT>5-7 GeV/c • COM* improvement of polarization, NLO will come, valid at pT>3 GeV/c LO Decay feeddown (CDF): y(2s): 7%-15%, slightly increase with pT cc0,1,2: ~30%, slightly decrease with pT B: Strong pT dependence Know your reference! Zebo Tang, Weihai 2009

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

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

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

  14. (DhxDf=0.05x0.05) ~5X0 Electron ID (EMC) • Online fast trigger: • enhance high pT electron • enhance recorded luminosity Offline deposited energy: Further suppress high pT hadrons Zebo Tang, Weihai 2009

  15. electron hadron Electron ID (SMD) • Shower Maximum Detector: • shower size • shower position • Further suppress hadron contamination Zebo Tang, Weihai 2009

  16. PYTHIA decay High pT J/e+e- reconstruction technique High pT electron p+p run6 Trigger efficiency Tracking efficiency acceptance High pT J/y  high pT electron (TPC+EMC) lower pT electron (TPC only) Zebo Tang, Weihai 2009

  17. STAR Preliminary High pT J/y in p+p at 200 GeV EMC (High Tower) trigger: 5 < pT < 14 GeV/c p+p 2005 J/y pT EMC+TPC electrons: |h|<1, pT>2.5 GeV/c TPC only electrons: |h|<1, pT>1.2 GeV/c No background at pT>5 GeV/c J/y pT p+p 2006 EMC+TPC electrons: |h|<1, pT>4.0 GeV/c TPC only electrons: |h|<1, pT>1.2 GeV/c Reach higher pT (~14 GeV/c) Zebo Tang, Weihai 2009

  18. J/y spectra in p+p and Cu+Cu at 200 GeV • Significantly extend pT range of previous measurements in p+p at RHIC to 14 GeV/c • Agreement of charm measurements between STAR and PHENIX ~3 orders Zebo Tang, Weihai 2009

  19. Compare to pQCD and NRQCD Model comparisons: Color singlet model:direct NNLO still miss the high pT part. P. Artoisenet et al., Phys. Rev. Lett. 101, 152001 (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, 034003 (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 Zebo Tang, Weihai 2009

  20. xT 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 pT>2 GeV/c pT>5 GeV/c STAR Preliminary  and proton at pT>2 GeV/c: n=6.6±0.1 (PLB 637, 161(2006)) J/ at high pT: n=5.6±0.2 (close to CS+CO prediction) Soft processes affect low pT J/ production Zebo Tang, Weihai 2009

  21. Nuclear modification factor RAA STAR Preliminary • Consistent with no suppression at high pT: RAA(pT>5 GeV/c) = 1.4± 0.4±0.2 • All RHIC measurements:RAA = 1.1 ± 0.3 ± 0.2 • Indicates RAA increase from low pT to high pT Zebo Tang, Weihai 2009

  22. Nuclear modification factor RAA • Consistent with no suppression at high pT: RAA(pT>5 GeV/c) = 1.4± 0.4±0.2 • All RHIC measurements: • RAA(pT>5 GeV/c) = 1.1 ± 0.3 ± 0.2 • Indicates RAA increase from low pT to high pT STAR Preliminary • Contrast to AdS/CFT+ Hydro prediction • H. Liu, K. Rajagopal and U.A. WiedemannPRL 98, 182301(2007),T. Gunji, JPG 35, 104137(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:0901.2757; N. Xu, QM2009 • two-component model: leakage and B feeddown is important • R. Rapp, X. Zhao, arXiv:0806.1239 Zebo Tang, Weihai 2009

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

  24. (S+B)/B: 54/14 5.4s J/y-hadron correlation Near side correlation Heavy quark fragmentation Good S/B ratio makes this measurement possible Zebo Tang, Weihai 2009

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

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

  27. Constrain bottom yields STAR Preliminary STAR Preliminary • 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),282001 Zebo Tang, Weihai 2009

  28. Yields in near/away side STAR Preliminary • 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 Zebo Tang, Weihai 2009

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

  30. Summary • J/y 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 pT J/yfollows xT scaling with n=5.6, consistent with COM slope • Low pT J/y deviates from xT scaling suggests soft process can affect low pT J/y production. • J/y spectra in 200 GeV Cu+Cu collisions • First observation of no suppression for hadron at high pT at STAR • Indication of RAA increasing from low pT to high pT • J/y-hadron azimuthal correlation in p+p • First quarknonium-hadron correlation measurement at RHIC • No significant near side correlation • BJ/y contribution = 135% • Can be used to constrain B production, and help to separate be from ce Zebo Tang, Weihai 2009

  31. Extra slides Zebo Tang, Weihai 2009

  32. TPC+TOF What I am going to try (low pT) 500 GeV p+p, 2009, preliminary calibration • Low pT J/yee: • Total cross section • <pT2> Zebo Tang, Weihai 2009

  33. What I am going to try (other charmonia) TOF: p/K upto 1.6 GeV/c, p/(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 Zebo Tang, Weihai 2009

  34. Future dramatic improvement of J / at low pT EMC+TOF+HFT (large acceptance): J/ production Different states predicted to melt at different T in color medium Charmonia (J/), bottonia () dE/dx after TOF cut pT (e)>1.5 GeV/c Quarkonium dissociation temperatures – Digal, Karsch, Satz PHENIX Acceptance: |h|<0.35, f=2*p/2 STAR TOF-Upgrade Acceptance: |h|<0.9, f=2*p J/y yields from 1 billion minbias Au+Au events: 43.8x10-9/0.040x109*292*0.5*1.8*0.5=144,0000.3% v2 error sJ/y spp N Nbine y RAA Zebo Tang, Weihai 2009

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

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

  37. Jpsi-h correlation from PYTHIA Zebo Tang, Weihai 2009

  38. High pT J/y in heavy ion collisions (Cont.) 2-component approach: dissociation + recombination RAA decreases slightly or flat with pTX. Zhao and R. Rapp, hep-ph/07122407 RAA increase slightly with pT including formation time and B decay X. Zhao, WWND2008 Color singlet model: RAA increase with pT (formed out of medium) F. Karsch and R. Petronzio, PLB 193(1987), 105 ; J.P. Blaizot and J.Y. Ollitrault, PLB 199(1987),499 Zebo Tang, Weihai 2009

  39. Datasets Triggered data High-pT J/y p+p data sample: • 1. J/ψ triggered events in year 2006 • Integrated luminosity: 377 (nb)-1 • 2. 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 p+p data sample: • 1. EMC triggered events in year 2005 ET>3.5 GeV Integrated luminosity: 3 (pb)-1 • 2. EMC triggered events in year 2006 ET>5.4 GeV Integrated luminosity: 11 (pb)-1 Cu+Cu data sample: • 1. EMC triggered events in year 2005 ET>3.75 GeV Integrated luminosity: 0.9 (nb)-1 pp-equivalent: 3 (pb)-1 Zebo Tang, Weihai 2009

  40. Heavy Quark Potential Cornell-potential: F. Karsch, E. Laermann, A. Peikert, Nucl. Phys. B605, 579(2001) • 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) Zebo Tang, Weihai 2009 Nu Xu, Lecture at USTC, Oct. 2006

  41. NA60, QM08 J/y 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 pT is similar to at SPS at similar Npart: 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, 054905 (2001); Yan, Zhang and Xu, Phys.Rev.Lett.97, 232301 (2006); PHENIX: Phys.Rev.Lett.98, 232301,2007. • At SPS, suppression decreases versus pT: 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/07122407; X. Zhu, P. Zhuang, PRC67, 067901(2003) Zebo Tang, Weihai 2009

  42. STAR:PRL98(2007) 192301 High pT J/y in heavy ion collisions How the formation time effect, jet energy loss and hot wind dissociation affect the high pT J/psi in the medium: 2-component approach: dissociation + recombination RAA increases slightly with pT including formation time and B decay X. Zhao, WWND2008; X.Zhao and R. Rapp, hep-ph/07122407 Formation time effect:RAA increases with pT (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: RAA decreases versus pT Zebo Tang, Weihai 2009

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

  44. J/y-h correlation from PYTHIA Zebo Tang, Weihai 2009

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

  46. Plasma thermometer ? Sequential suppression H. Satz, Nucl. Phys. A (783):249-260(2007) J/ suppression at low pT 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 Zebo Tang, Weihai 2009

More Related