1. Nu Xu1/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Study the QCD Phase Structure in High-Energy Nuclear Collisions Nu Xu (1,2) Outline: 1) Introduction 2) Selected results from RHIC BES-I 3) Selected day-I observables for CBM (1) College of Physical Science & Technology, Central China Normal University, China (2) Nuclear Science Division, Lawrence Berkeley National Laboratory, USA

2. Nu Xu2/23 Seminar, USTC, Modern Physics Department, October 16, 2014 2 RHIC 3 RHIC, FAIR Exploring QCD Phase Structure 1 LHC, RHIC Quarkyonic matter? 39 11.5 8 For region μ B > 500 MeV, √s NN ≤ 5 GeV, fixed- target experiments are much more efficient CBM LHC+RHIC Property of sQGP √s NN ~ 0.05 - 5 TeV LHC+RHIC Property of sQGP √s NN ~ 0.05 - 5 TeV RHIC BES-II QCD CP and phase structure √s NN ≤ 20 GeV RHIC BES-II QCD CP and phase structure √s NN ≤ 20 GeV RHIC + FAiR CP and Quarkyonic Matter? √s NN ≤ 8 GeV RHIC + FAiR CP and Quarkyonic Matter? √s NN ≤ 8 GeV RHIC

3. Nu Xu3/23 Seminar, USTC, Modern Physics Department, October 16, 2014 QCD Thermodynamics SB Ideal Gas CBM RHICLHC Zoltan Fodor, Lattice 2007 1)At μ B = 0: cross over transition, 150 < T c < 200 MeV 2)The SB ideal gas limit: T/T c ~ 10 7 3)T ini (LHC) ~ 2-3*T ini (RHIC) 4)Thermodynamic evolutions are similar for RHIC and LHC

4. Nu Xu4/23 Seminar, USTC, Modern Physics Department, October 16, 2014 LHC, RHIC, FAIR （ I ） 2000 - 2012: RHIC, LHC 1)sQGP: strongly coupled QGP, η/S =>0, ideal fluid. 2)At μ B ＝ 0 smooth cross over. （ I ） 2000 - 2012: RHIC, LHC 1)sQGP: strongly coupled QGP, η/S =>0, ideal fluid. 2)At μ B ＝ 0 smooth cross over. （ II ） 2010 - 2014: RHIC BESI (20≤ μ B ≤420 MeV, 200 ≥ √s NN ≥ 7.7 GeV) 1)√s NN ≤15 GeV, μ B ≥300 MeV: Hadronic interactions become dominant. 2)Collectivity and fluctuation results hint phase transition. However, more data are needed to confirm. RHIC BESII and FAIR CBM. （ II ） 2010 - 2014: RHIC BESI (20≤ μ B ≤420 MeV, 200 ≥ √s NN ≥ 7.7 GeV) 1)√s NN ≤15 GeV, μ B ≥300 MeV: Hadronic interactions become dominant. 2)Collectivity and fluctuation results hint phase transition. However, more data are needed to confirm. RHIC BESII and FAIR CBM. （ III ） 2018 and beyond: Collider: RHIC/LHC (√s NN > 200 GeV, μ B ≤ 20 MeV) Collider: RHIC BESII (7.7<√s NN < 20 GeV, 420 ≥μ B ≥300 MeV) Fixed-target: FAIR CBM (√s NN ≤12 GeV, μ B ≥ 300 MeV) 1)High luminosity, new detectors 2)Physics focus ： sQGP, Cp, Pb and Qm （ III ） 2018 and beyond: Collider: RHIC/LHC (√s NN > 200 GeV, μ B ≤ 20 MeV) Collider: RHIC BESII (7.7<√s NN < 20 GeV, 420 ≥μ B ≥300 MeV) Fixed-target: FAIR CBM (√s NN ≤12 GeV, μ B ≥ 300 MeV) 1)High luminosity, new detectors 2)Physics focus ： sQGP, Cp, Pb and Qm

5. Nu Xu5/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Bulk Properties at Freeze-out Chemical Freeze-out: (GCE) - RHIC (20 ≤ μ B ≤ 420 MeV): small temperature variation - CBM (400 ≤ μ B ≤ 750 MeV): temperature changes dramatically! STAR Preliminary CBM

6. Nu Xu6/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Collectivity v 2 Measurements 1)Number of constituent quark (NCQ) scaling in v 2 => partonic collectivity => deconfinement in high-energy nuclear collisions 2)At √s NN < 11.5 GeV, the universal v 2 NCQ scaling is broken, consistent with hadronic interactions becoming dominant. STAR: Phys. Rev. Lett. 110 (2013) 142301

7. Nu Xu7/23 Seminar, USTC, Modern Physics Department, October 16, 2014 BES v 2 and Model Comparison (a)Hydro + Transport: consistent with baryon data. [ J. Steinheimer, V. Koch, and M. Bleicher PRC86, 44902(13).] (b) NJL model: Hadron splitting consistent. Sensitive to vector-coupling, CME, net-baryon density dependent. [J. Xu, et al., arXiv:1308.1753/PRL112.012301]

8. Chiral Effects 1)The opposite baryon number (Λ- pbar or Λbar-p) correlations (OB) are similar 2)The same baryon number (Λ-p or Λbar-pbar) correlations (SB) are lower than that of the OB, as expected from the CVE. D. Kharzeev, D.T. Son, PRL106, 062301(11) D. Kharzeev. PLB633, 260 (06) D. Kharzeev, et al. NPA803, 227(08) Hot/dense QCD Medium Parity odd domains form Hot/dense QCD Medium Parity odd domains form External Magnetic Field Chiral magnetic effect (CME) (electric charge) Chiral magnetic effect (CME) (electric charge) Initial Angular Momentum  Fluid Vorticity Chiral vortical effect (CVE) (baryon charge) Chiral vortical effect (CVE) (baryon charge) Chiral Vortical Effect Λ-proton correlation measurement:

9. Charge Separation wrt Event Plane SS - OS LPV(CME) disappears: with neutral hadrons: LPV(CME) disappears at low energy:  hadronic interactions become dominant at √s NN ≤ 11.5 GeV STAR: PRL. 103, 251601(09) D. Kharzeev. PLB633, 260 (06) D. Kharzeev, et al. NPA803, 227(08) STAR: PRL, arXiv: 1404.1433

10. Nu Xu10/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Higher Moments 1) Higher moments of conserved quantum numbers: Q, S, B, in high-energy nuclear collisions 2)Sensitive to critical point (ξ correlation length): 3)Direct comparison with calculations at any order: 4)Extract susceptibilities and freeze-out temperature. An independent/important test of thermal equilibrium in heavy ion collisions. References: - STAR: PRL105, 22303(10); ibid, 032302(14) - M. Stephanov: PRL102, 032301(09) // R.V. Gavai and S. Gupta, PLB696, 459(11) // F. Karsch et al, PLB695, 136(11) // S.Ejiri et al, PLB633, 275(06) - A. Bazavov et al., PRL109, 192302(12) // S. Borsanyi et al., PRL111, 062005(13) // V. Skokov et al., PRC88, 034901(13) μ B = 0

11. Nu Xu11/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Net-proton results: 1)All data show deviations below Poisson for κσ 2 at all energies. Larger deviation at √s NN ~20GeV 1)UrQMD model shows monotonic behavior in the moment products STAR: PRL112, 32302(14)/arXiv: 1309.5681 Net-charge results: 1)No non-monotonic behavior 2)More affected by the resonance decays STAR: arXiv: 1402.1558 P. Garg et al, PLB726, 691(13) BESII is needed: Higher statistics needed for collisions at √s NN < 20 GeV Comparing to LGT calculations T f = 146 ± 6 MeV,√s NN > 39 GeV Higher Moments Results BESII

12. Nu Xu12/23 Seminar, USTC, Modern Physics Department, October 16, 2014 2 RHIC 3 RHIC, FAIR Exploring QCD Phase Structure 1 LHC, RHIC Quarkyonic matter? 39 11.5 8 For region μ B > 500 MeV, √s NN ≤ 5 GeV, fixed- target experiments are much more efficient CBM LHC+RHIC Property of sQGP √s NN ~ 0.05 - 5 TeV LHC+RHIC Property of sQGP √s NN ~ 0.05 - 5 TeV RHIC BES-II QCD CP and phase structure √s NN ≤ 20 GeV RHIC BES-II QCD CP and phase structure √s NN ≤ 20 GeV RHIC + FAiR CP and Quarkyonic Matter? √s NN ≤ 8 GeV RHIC + FAiR CP and Quarkyonic Matter? √s NN ≤ 8 GeV RHIC

13. Nu Xu13/23 Seminar, USTC, Modern Physics Department, October 16, 2014 20152016201720182019202020212022202320242025202620272028 STAR: Near Future Plans HF-I, (e,μ) eSTAR HF-II* p  A, sPHENIX HFT’ (mid-y) Forward upgrade-i HF-II* p  A, sPHENIX HFT’ (mid-y) Forward upgrade-i BESII * 1)Mid-rapidity upgrade: Λ C and bottom production at RHIC, complimentary with LHC HF-jets program 2)Forward upgrade-i: p  A, DY measurements & AA physics. ‘Training’ for the future eA physics program at eRHIC era

14. Nu Xu14/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Heavy Flavor Energy Loss: Puzzle 1)Both pQCD and AdS/CFT predict ΔE(b) < ΔE(c)! 2)Heavy flavor jet trigger needed (At LO, HF-jets conserved) 3) Without B info, the HF program at RHIC is incomplete! W. Horowitz and M. Gyulassy, arXiv:0710.0703 pQCD AdS/CFT pQCD AdS/CFT

15. Nu Xu15/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Efficiency: fast vs. slow HFT HFT: ~ 200 μs HFT’ ~ 30 μs Xin Dong

16. Nu Xu16/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Faster Pixels From Leo: “30 μs integration time pixel size of 22x66μm 2 (7μm single point resolution) size of ~ 2 x 3 cm heat dissipation that can be handled by air cooling” - 6-7 times fast than current HFT pixel.

17. Nu Xu17/23 Seminar, USTC, Modern Physics Department, October 16, 2014 B  D 0 p T Distribution Pythia event: 1)5B MB 200GeV Au+Au events 2)B-decay D 0 spectrum up to p T ~ 10 GeV/c, corresponding to B-meson p T ~ 17 GeV/c 3)20 weeks run in 2020-2023 Guannan Xie

18. Nu Xu18/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Bottom Decay Kinematics J/ψDe Xin

19. Nu Xu19/23 Seminar, USTC, Modern Physics Department, October 16, 2014 HFT’ Summary 1) A faster HFT for studying sQGP properties with heavy quarks including bottom. -Collect ~10B events -B  (D, J/ψ) spectra and correlation functions 2) Cost effective. Technologies/team are in hand (… IPHC, CCNU, LBL, UIC). 3) STAR needs it for its AA, pA and pp physics program. Complimentary to LHC HF and sPHENIX jet programs during 2020-2024.

20. Nu Xu20/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Baryon Density Peaks at ~ √s NN = 8 GeV Collision Energy √s NN (GeV) NICA (4 - 11) BESII (8 - 20) CBM (2 - 5 - 8) ???? 2019 2018/19 High Baryon Density CP 1304.2969

21. Nu Xu21/23 Seminar, USTC, Modern Physics Department, October 16, 2014 The CBM Experiment TOF STS ZDC EMCal RICH/TRD Target FAIR: the highest intensity accelerator complex in the 21 st century Precision measurements at high baryon density region for: (i) dileptons (e, μ); (ii) high order baryon correlations; (iii) flavor productions (s, c)

22. Nu Xu22/23 Seminar, USTC, Modern Physics Department, October 16, 2014 2 RHIC 3 RHIC, FAIR Exploring QCD Phase Structure 1 LHC, RHIC Quarkyonic matter? 39 11.5 8 RHIC For region μ B > 500 MeV, √s NN ≤ 5 GeV, fixed- target experiments are much more efficient CBM LHC+RHIC Property of sQGP √s NN ~ 0.05 - 5 TeV LHC+RHIC Property of sQGP √s NN ~ 0.05 - 5 TeV RHIC BESII QCD CP and phase structure √s NN ≤ 20 GeV RHIC BESII QCD CP and phase structure √s NN ≤ 20 GeV RHIC + FAiR CP and Quarkyonic Matter? √s NN ≤ 8 GeV RHIC + FAiR CP and Quarkyonic Matter? √s NN ≤ 8 GeV

23. Nu Xu23/23 Seminar, USTC, Modern Physics Department, October 16, 2014  HFT’: Complete the heavy flavor physics programs at RHIC and LHC  Properties of sQGP  CBM: Complete the beam energy scan program at RHIC  QCD Phase Boundary and Critical Point The Future HI Programs at RHIC

24. Nu Xu24/23 Seminar, USTC, Modern Physics Department, October 16, 2014 Energy Dependence of Di-electrons Bulk-penetrating probe: 1)M ee ≤ 1GeV/c 2 : In-medium broadened ρ, model results* are consistent with exp. data. At 200GeV, the enhancement is in the order of 1.77±0.11 ±0.24±0.33 within 0.3<M ee <0.7GeV/c 2 ) (* driven by the baryon density in the medium) 2)1≤M ee ≤ 3GeV/c 2 : Thermal radiation: exp(-M ee /T)? HFT: Charm contributions. 3)High statistics data are needed, BESII! - STAR: (200GeV data) sub. to PRL. 1312.7397 - R. Rapp: PoS CPOD13, 008(2013) - O. Linnyk et al, PRC85, 024910(12) 200GeV 62.4GeV 39GeV 27GeV 19.6GeV STAR Preliminary