1. Nu Xu1/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 High-Energy Nuclear Collisions and QCD Phase Structure What is the phase structure of QCD matter? - Motivations and recent results - Observables and schedule Bedanga Mohanty and Nu Xu

2. Nu Xu2/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 Phase Diagram: Water Phase diagram: A map shows that, at given degrees of freedom, how matter organize itself under external conditions. The QCD Phase diagram: structure of matter with quark- and gluon-degrees (color degrees) of freedom.

3. Nu Xu3/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 QCD Phase Diagram (2009) 1983 US Long Range Plan - by Gordon Baym nucl-th: 0907.4489, NPA830,709(09) L. McLerran nucl-th 0911.4806: A. Andronic, D. Blaschke, P. Braun-Munzinger, J. Cleymans, K. Fukushima, L.D. McLerran, H. Oeschler, R.D. Pisarski, K. Redlich, C. Sasaki, H. Satz, and J. Stache Systematic experimental measurements (E beam, A) : extract numbers that may be related to the QCD phase diagram!

4. nuclei hadron gas CSC quark-gluon plasma TETE Baryon Chemical Potential Critical Point? Temperature Early Universe 1 2 3 2 T E RHIC, FAIR 1 T ini, T C LHC, RHIC 3 Phase boundary RHIC, FAIR, NICA The QCD Phase Diagram and High-Energy Nuclear Collisions TCTC

5. Nu Xu5/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 BNL PAC, 21 - 22, 2010 HFT 2013 TPC FGT 2011 STAR Detectors Fast and Full azimuthal particle identification EMC+EEMC+FMS (-1 ≤  ≤ 4) TOF DAQ1000 MTD 2013

6. Nu Xu6/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 TOF Performance √s NN = 39 GeV Au + Au Collisions TPC TPC+ToF Beam EnergyTiming ResolutionRemarks 200 (GeV)85 (ps) At 39 GeV, using a new calibration scheme without information of start time from VPD, 87 ps of timing resolution has been achieved. 62.4 (GeV)90 (ps) 39 (GeV)85 (ps) 11.5 & 7.7 (GeV)~ 80 (ps)

7. Nu Xu7/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 PID: 7.7, 39, 200 GeV (π ±, K ±, p) Au+Au at 7.7 GeV Au+Au at 39 GeV Au+Au at 200 GeV

8. Nu Xu8/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 Low p T (≤ 2 GeV/c): hydrodynamic mass ordering High p T (> 2 GeV/c): number of quarks ordering s-quark hadron: smaller interaction strength in hadronic medium light- and s-quark hadrons: similar v 2 pattern => Partonic Collectivity at RHIC ! (I) Partonic Collectivity at RHIC STAR: preliminary PHENIX: nucl-ex/0604011 QM09: arXiv 0907.2265

9. Nu Xu9/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 Observable: n q Scaling of v 2 - m  ~ m p ~ 1 GeV - ss   not K + K -   -   h <<  p ,  In the hadronic case: (i)No number of quark scaling (ii)Very small value of  v 2 !  

10. Nu Xu10/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 High Order Correlations Event by event: 1.net-proton Kurtosis K p (E)* 2. two proton correlation functions C 2 (E) 3. ratio of the d/p 4. ratio of K/p * Gavai and Gupta, 03, 05; Gupta 0909.4630 M. Cheng et al. 08 Gupta, Karsch, Stephanov, INT, 08

11. Nu Xu11/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 Observable: High Moments STAR: 1004.4959, PRL in print 1)High moments are more sensitive to critical point related fluctuation. 2)The 4 th moment, Kurtosis, is directly related to the corresponding thermodynamic quantity: susceptibility for conserved quantum numbers such as Baryon number, charge, strangeness…

12. Nu Xu12/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 Observable: LPV The separation between the same-charge and opposite- charge correlations. - Strong external EM field - De-confinement and Chiral symmetry restoration L or B STAR; PRL 103, 251601(09); PRC 81, 54908(10). Parity even observable Beam Energy Dependence & U+U

13. Nu Xu13/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 Student Lecture, “Quark Matter 2006”, Shanghai, Nov. 14 - 20, 2006 Slope Parameter Systematics

14. Nu Xu14/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 Observable: Direct Radiation (M ≥ 1) Expanding partonic matter at RHIC and LHC! Di-leptons allow us to measure the direct radiation from the matter with partonic degrees of freedom, no hadronization! - Low mass region: , ,   e - e + m inv  e - e + medium effect Chiral symmetry - Intermediate region: J/   e - e + m inv  e - e + Direct radiation hadronic partonic Direct radiation:

15. Nu Xu15/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 Maximum Baryon Density 1)The maximum baryon density at freeze-out: √s NN ~ 8 GeV 2)Both K+/π and Λ/π ratios reach maximum at this energy

16. Physics Experimental Measurements DetectorsRemarks A. Critical Point (i)Net-p σ, S, κ, fluctuations (ii),,, (iii)Light nuclei cluster multiplicity distributions TPC, FTPC, TOF B. Phase Boundary (i)Heavy flavor collectivity including J/ψ v 2 (ii)Di-lepton spectra and v 2 vs. mass and p T (iii)The n q -v 2 scaling (iv)Net-p & net-K: σ, S, κ (v)LPV TPC, FTPC, TOF, HFT C. Exotics (i)Light nuclei, strangelets (ii)Di-lepton spin alignment at high mass region, including J/ψ, γ and DY TPC, TOF, EMCalHLT

17. Runs√s NN (GeV)DetectorsRemarks Run10 7.7, 11.5, 39, 62.4, 200 TPC, FTPC, TOF, BBC, PMD Run11 6.1(?), 18, 27, 200 TPC, FTPC, TOF, BBC, PMD Run14-15 (DM11) Finer steps in beam energy (?) TPC, TOF, BBC - FTPC removed - Energy region depends on the outcomes of Run 10- 11

18. Nu Xu18/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 Year#Milestone 2013HP8Measure flavor-identified q and qbar contributions to the spin of the proton via the longitudinal-spin asymmetry of W production. 2013HP12 (update of HP1) Utilize polarized proton collisions at center of mass energies of 200 and 500 GeV, in combination with global QCD analyses, to determine if gluons have appreciable polarization over any range of momentum fraction between 1 and 30% of the momentum of a polarized proton. 2015HP13 (new) Test unique QCD predictions for relations between single-transverse spin phenomena in p-p scattering and those observed in deep-inelastic lepton scattering 2014DM9 (new) Perform calculations including viscous hydrodynamics to quantify, or place an upper limit on, the viscosity of the nearly perfect fluid discovered at RHIC. 2014DM10 (new) Measure jet and photon production and their correlations in A≈200 ion+ion collisions at energies from medium RHIC energies to the highest achievable energies at LHC. 2015DM11 (new) Measure bulk properties, particle spectra, correlations and fluctuations in Au+Au collisions at √s NN between 5 and 60 GeV to search for evidence of a critical point in the QCD matter phase diagram. 2016DM12 (new) Measure production rates, high p T spectra, and correlations in heavy-ion collisions at √s NN = 200 GeV for identified hadrons with heavy flavor valence quarks to constrain the mechanism for parton energy loss in the quark-gluon plasma. 2018DM13 (new) Measure real and virtual thermal photon production in p+p, d+Au and Au+Au collisions at energies up to √s NN = 200 GeV. DOE New RHIC Performance Milestones spin Heavy ion

19. Nu Xu19/18STAR Decadal Plan Meeting at UIC, September 10 th, 2010 STAR Physics Focus Polarized p+p program - Study proton intrinsic properties Forward program - Study low-x properties, initial condition, search for CGC - Study elastic and inelastic processes in pp2pp 1) At 200 GeV top energy - Study medium properties, EoS - pQCD in hot and dense medium 2) RHIC beam energy scan (BES) - Search for the QCD critical point - Chiral symmetry restoration