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Zhangbu Xu （许长补） University of Science & Technology of China Brookhaven National Laboratory

Heavy-Flavor at RHIC. Zhangbu Xu （许长补） University of Science & Technology of China Brookhaven National Laboratory. Introduction Open Heavy Quarks J/ y results Tools to probe Temperature, viscosity of QCD matter under extreme conditions 实验上研究极端条件下 QCD 强场的温度及其流体力学的基本参数.

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Zhangbu Xu （许长补） University of Science & Technology of China Brookhaven National Laboratory

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  1. Heavy-Flavor at RHIC Zhangbu Xu （许长补）University of Science & Technology of China Brookhaven National Laboratory • Introduction • Open Heavy Quarks • J/y results • Tools to probe Temperature, viscosity of QCD matter under extreme conditions实验上研究极端条件下QCD强场的温度及其流体力学的基本参数 Zhangbu Xu

  2. Fundamentals of QCD relevant to our field T.D. Lee, 1995 • Quark Confinement • Symmetry Breaking Gluons carry color-charge Asymptotic Freedom Zhangbu Xu

  3. SU(3) Color Factors QCD : For SU(3) : Nc = 3 CA = 3, CF = 4/3 CA/CF=9/4 CF ~ strength of a gluon coupling to a quark CA ~ strength of the gluon self coupling TF ~ strength of gluon splitting into a quark pair Zhangbu Xu

  4. path length L Eg hard parton ~ 9/4 Eq 2 D E <q> ^ L  a C s Energy Loss and QCD One mechanism of energy loss : Medium induced gluon radiation  C Experimentally observable (of Eloss) related to basic ingredient of QCD - Gauge Group through Color Factors Or extracting an effective Color Factor S. Wicks et al, nucl-th/0512076 M. Gyulassy et al., PRL 85 (2000) 5535 R. Baier et al., NPB 483 (1997) 291 Zhangbu Xu

  5. Consequence of CA/CF=9/4 in A+A WHDG, arXiv:nucl-th/0512076 Other models: S. Wicks, I. Vitev, QM08 Zhangbu Xu

  6. Energy loss STAR Preliminary PRL97,98 STAR Preliminary • Heavy quark suppression ~= light flavor • Bottom suppression ~=charm suppression Zhangbu Xu

  7. Fragmentation Functions • Will these ingredients be sufficient for p+p collisions? • How will p+p collisions provide additional information for our understanding of QCD and for model developments • What will be modified in A+A collisions • FF • Running of aS • Effective Color Charge factor Zhangbu Xu

  8. pT>5 GeV/c 4<pT<5 GeV/c Jet Chemistry in p+p Zhangbu Xu

  9. ALEPH : ZPC 76 (1997) 1 OPAL :EJPC 20 (2001) 601 SU(3) is the gauge group for QCD S = 0.119 Extract effective Color Factors Zhangbu Xu, QM08, Jaipur, India

  10. Heavy Quark Energy loss and thermalization Deadcone effect of Energy loss Brownian motion in thermal system G. Moore, D. Teaney PRC 71 (2005) 064904; H. Van Hees, R. Rapp PRC 71 (2005) 034907 Y.L. Dokshitzer, D. Kharzeev, PLB519(2001)199 WHDG, arXiv:nucl-th/0512076 Heavy object in sQGP with AdS/CFT H. Liu, K. Rajagopal and U.A. Wiedemann PRL 97, 182301(2006) J. Casalderrey-Solana, D. Teaney PRD 74(2006) 085012 Upper bound on escaping parton p D.E. Kharzeev, arXiv:0806.0358,0809.3000 Zhangbu Xu

  11. Brownian motion and thermalization Brownian motion: arXiv:0805.0364 Hadronic excited states increase interaction cross-sections Zhangbu Xu

  12. Can Energy Loss and Thermalization explain data? PHENIX:PRL98(2007)172301 New Precise vertex detector upgrades In STAR (HFT) and PHENIX (VTX) precision charm hadron spectra and v2 with improved kinematics. Zhangbu Xu

  13. Fundamentals of QCD relevant to our field T.D. Lee, 1995 • Quark Confinement • Symmetry Breaking Gluons carry color-charge Asymptotic Freedom Zhangbu Xu

  14. H. Satz, Nucl. Phys. A (783):249-260(2007) J/y Quarkonium in heavy ion collisions Hot wind dissociation J/y suppression at low pT could be from suppressed excited states (y’, cc) F. Karsch, D. Kharzeev and H. Satz, PLB 637, 75 (2006) High pT direct J/y suppression  related to hot wind dissociation? 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 2-component approach Predicted decrease RAA X. Zhao and R. Rapp, hep-ph/07122407 Color singlet model predicted an increase RAA(formed outside of medium) K. Farsch and R. Petronzio, PLB 193(1987), 105 J.P. Blaizot and J.Y. Ollitrault, PLB 199(1987),499 T. Gunji, QM08 Zhangbu Xu

  15. Recombination of open charm to J/ G.D. Moore and D. Teaney, Phys. Rev. C 71, 064904(2005); H. van Hees, V. Greco and R. Rapp, Phys. Rev.C 73, 034913 (2006); X. Zhu et al., Phys. Lett. B 647,366 (2007); N. Xu and Z. Xu, Nucl. Phys. A 715, 587c(2003); Z.W. Lin and D. Molnar, Phys. Rev. C 68, 044901(2003); V. Greco, C.M. Ko and R. Rapp, Phys. Lett. B595, 202 (2004); S. Batsouli et al., Phys. Lett. B 557, 26(2003).P. Braun-Munzinger and J. Stachel, Phys. Lett. B 490,196 (2000); A. Andronic et al., Phys. Lett. B 571, 36(2003); L. Grandchamp and R. Rapp, Phys. Lett. B 523,60 (2001); M. I. Gorenstein et al., Phys. Lett. B 524,265 (2002); R.L. Thews, M. Schroedter and J. Rafelski,Phys. Rev. C 63, 054905 (2001); M.I. Gorenstein et al.,J. Phys. G 28, 2151 (2002)… QGP c c c+cJ/ c c c c c c Zhangbu Xu

  16. H. Satz, Nucl. Phys. A (783):249-260(2007) 60% direct J/psi color screening and quarkoniumsupression J/ suppression at low pT maybefrom excited stats (’, c)F. Karsch, D. Kharzeev and H. Satz, PLB 637, 75 (2006);B. Alessandro et al. (NA50), Eur. Phys. J. C 39 (2005) 335; R. Arnaldi et al. (NA60), Quark Matter 2005; PHENIX: Phys.Rev.Lett.98, 232301,2007. 60% from direct J/: not suppressed 30% c and 10% ’: dissociated Nu Xu QM09

  17. Production Mechanism from J/spectra in p+p 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

  18. 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 = 1.1 ± 0.3 ± 0.2 • Indicates RAA increase from low pT to high pT STAR Preliminary • Contrast toAdS/CFT+ Hydro prediction • Jet quenching: strong open charm suppression. A. Adil and I. Vitev, Phys. Lett. B649, 139 (2007), and I. Vitev private communication; S. Wicks et al., Nucl. Phys. A784, 426 (2007), and W. A. Horowitz private communication. • Formed out of medium?Karsh, Liu, Zhuang, RappAffect by heavy quark/gluon energy loss • Decay from other particles?

  19. (S+B)/B: 54/14 5.4s J/y-hadron correlation Near side correlationBottom decay or fragmentation Heavy quark fragmentation Good S/B ratio makes this measurement possible

  20. J/y-hadron correlation in p+p • No significant near side J/y-hadron azimuthal angle correlation • Constrain B meson’s contribution to J/y yield • Hints of CSM? h-h correlation PRL 95,152301(2005)

  21. J/ Observations p+p collisions A+A collisions Low-pT suppressioncold nuclear effect +feeddown (excited states)+ Coalescence High-pTRCuCu ~=1Formation timeAdS/CFT (hot wind)Color SingletCu system size too small • Low-pT deviates from xT scaling soft process dominant • J/-h correlation: near-side weak away-side same as light quarks diagram: q+gJ/+jet • d+Au: large cold nuclear effect at low pT Zebo Tang’s afternoon talk Zhangbu Xu

  22. +- A novel and compact muon telescope detector for QCDLab • A large area of muon telescope detector • (MTD) at mid-rapidity, allows forthe • detection of • di-muon pairs from QGP thermal • radiation,quarkonia, light vector mesons, • possible correlations of quarksand gluons • as resonances in QGP, and Drell-Yan • production • single muonsfrom theirsemi- • leptonic decays of heavy flavor • hadrons • advantages over electrons: no  • conversion, much less Dalitz decay • contribution, less affected by • radiative losses in the detector • materials BNL LDRD 07—007 project

  23. J/ Efficiency MTD: Large acceptance, effective Trigger Zhangbu Xu

  24. dE/dx after TOF cut What can we do next? TOF/STAR/RHIC TOF/MTD (Made in China)  Lepton Identification (Created by Chinese)  Quarkonia (J/Psi, Upsilon)  Elliptic flow and RAA  QGP temperature, screening length, AdS/CFT 实验上研究极端条件下QCD强场的温度及其流体力学的基本参数 CSR

  25. xT scaling in p+p collisions n is related to the number of point-like constituents taking anactive role in the interaction n=8: diquark scattering n=4: QED-like scattering pT>2 GeV/c STAR Preliminary xT scaling:  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 (the power parameter close to CS+CO prediction) 3. Soft processes affect low pT J/ production

  26. Cosmic Ray Results: Long-Strip Multi-gap Resistive Plate Chamber Technology Long MRPC Technology with double-end readout HV: 6.3 KV gas mixture: 95% Freon + 5% isobutane time resolution: ~60 ps spatial resolution: ~1cm efficiency: >95% 950 mm 25 mm 256 mm Y. Sun et al., nucl-ex/0805.2459

  27. Compared to Simulation pT (GeV/c) z (cm) muons muons pions from data: pT>2 GeV/c, (z) of muon: ~10 cm from simulation: pT=2.5 GeV/c, (z) of muon: ~9 cm Data and simulation show consistent results

  28. A prototype muon telescope (MTD) at STARin d+Au collisions physics results in next few months!!! • MTD hits: matched with real high pT tracks • z distribution has two components: narrow (muon) and broad (hadron) ones • Sample luminosity: 4.19 pb-1 • In the process of decomposing the contributions using velocity, dE/dx, tracking topology, EMC • Physics (open heavy-flavor): • Single muon spectrum • e+m mass spectrum first ever to directly measure irreducible charm dilepton background Lijuan Ruan

  29. A complete MTD at STAR MTD EMC barrel MRPC ToF barrel Ready for run 10 EMC End Cap RPSD FMS • To install another tray with TOF electronics in run9 • Collaborators for a proposal of full scale detector: 56.6% in azimuth, |eta|<0.88; current tray design: 360 modules, 2160 read-out strips, 4320 channels. (TOF: 23 K readout channels). FPD TPC PMD Complete Ongoing DAQ1000 Ready for run 9 HFT FGT R&D

  30. Golden Age for physics of QCD matter in Heavy-Ion “The World, long divided, must unite; long united, must divide. Thus it has ever been.“ ("天下大势，分久必和，和久必分“)--三国演义 LHC RHIC, FAIR QGP c c ALICE STAR, PHENIX c+cJ/ c c c ALICE ATLAS, CMS c c c wQGP sQGP, gQGP 265—420AD 206BC – 220AD

  31. RHIC-II science by-passing RHIC-II project Opportunity for up-grade or 1st EIC stage LHC HI starts EIC = Electron-Ion Collider; eRHIC = BNL realization by adding e beam to RHIC Luminosity upgrade: CSR FAIR RHICx2 Further luminosity upgrades (pp, low-E) Steve Vigdor (AGS/RHIC Users Meeting) RHIC, RHIC-II, LHC-HI and EIC science share a common theme…

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