1. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 1/25 Future Direction?! Nu Xu (1,2) (1) College of Physical Science & Technology, Central China Normal University, China (2) Nuclear Science Division, Lawrence Berkeley National Laboratory, USA Many Thanks to Organizers!

2. New Direction?!

3. Unintended consequences, some could be rather dramatic! “If you do not know which harbor you want to go there is no favorable wind.” - Feb. 1998

4. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 4/25 2 RHIC 3 RHIC, FAIR Exploring QCD Phase Structure 1 LHC, RHIC Quarkyonic matter? 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 ~ 0.1 - 5 TeV LHC+RHIC Property of sQGP √s NN ~ 0.1 - 5 TeV RHIC + FAiR* CP and Quarkyonic Matter? √s NN ≤ 8 GeV RHIC + FAiR* CP and Quarkyonic Matter? √s NN ≤ 8 GeV

5. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 5/25 sQGP Properties - Precision HF measurements - Dilepton invariant mass ( m ll > 1 GeV/c 2 )

6. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 6/25 STAR Heavy Flavor Tracker STAR Preliminary Unique for studying sQGP properties: D 0 R AA : precision result D 0 v 2: First measurement at RHIC. Finite value of v 2, ≤ v 2 (light hadrons) => Charm quarks are not fully thermalized at RHIC Model Comparison: D C = 2~12, also consistent with Lattice calculations STAR Preliminary

7. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 7/25 STAR HF II (2021-2022) (from Zhenyu Ye) Projected R AA (0-10%) stat. uncertainties for RHIC 200 GeV pp and AuAu running in 2021-22 1)Precise bottom-hadron measurements with HFT + ; 2)Complete heavy flavor physics at RHIC, extract sQGP property; 3)Complementary to ALICE HF and sPHENIX Jet/Upsilon programs. HFT + with Faster MAPS sensors Fast: τ int ≤ 40 μs, improved tracking efficiency Cost effective: ALICE ITS chips and existing HFT infrastructure

8. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 8/25 0 1 2 3 Mass ee (GeV/c 2 ) p T (GeV/c) μ B ~ 0: 200 GeV Au+Au Collisions 1)Precision measurements for dileptons (1 < m ee < 3 GeV/c 2 ) and HF hadrons at the top energy at RHIC 2)‘Read-out’ sQGP temperature and parameters of the medium

9. ?

10. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 10/25 Collectivity

11. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 11/25 Directed Flow v 1 Results STAR: PRL112, 162301(2014) 1)Mid-rapidity net-proton dv 1 /dy published in 2014 by STAR, except the point at 14.5 GeV 2)Minimum at √s NN = 14.5 GeV for net-proton, but net-Kaon data continue decreasing as energy decreases 3)At low energy, or in the region where the net-baryon density is large, repulsive force is expected, v 1 slope is large and positive! M. Isse, A. Onishi et al, PRC72, 064908(05)

12. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 12/25 Criticality

13. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 13/25 Net-proton Higher Moment Question: What will happen at even lower collision energy, higher baryon density, region?

14. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 14/25 CBM@SPS CBM@AGS or CBM@FAIR or HI@JPARC CBM@AGS or CBM@FAIR or HI@JPARC RHIC Fix-Target Experiments FXT

15. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 15/25 Model Simulation Results Z. Feckova, J. Steonheimer, B. Tomasik, M. Bleicher, 1510.05519, PRC92, 064908(15) - Baryon conservations - Deuteron productions suppress the higher order net-proton fluctuations, especially below √s NN ~ 10 GeV But, data is above the unity! - Baryon conservations - Deuteron productions suppress the higher order net-proton fluctuations, especially below √s NN ~ 10 GeV But, data is above the unity! 1)X.F. Luo et al, NP A931, 808(14) 2)P.K. Netrakanti et al. NP A947, 248(2016) 3)P. Garg et al. Phys. Lett. B726, 691(13)

16. Facility for Antiproton & Ion Research SIS100/300 SIS18 CBM p-Linac CBM Beams 10 9 /s Au up to 11 GeV/u 10 9 /s C, Ca,... up to 14 GeV/u 10 11 /s p up to 29 GeV 100 m FAIR phase 1 FAIR phase 2 CBM: FAIR Day-1 Experiment!

17. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 17/25 CBM Experiment at FAIR TOF MVD/STS PSD EMCal RICH/TRD Target FAIR: One of 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 correlations; (iii) Flavor productions (s, c)

18. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 18/25 CBM@SPS 2019 CBM@SPS 6.5 ≤ √s NN ≤ 17.2 GeV E, e, μ ID PID eveID TRK Magnet CBM 1)Study QCD phase structure 2)Maintain heavy ion community with physics results 1)Study QCD phase structure 2)Maintain heavy ion community with physics results

19. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 19/25 CBM@BNL 2020 - 2025 CBM@AGS √s NN ≤ 5.4 GeV E, e, μ ID PID eveID TRK Magnet CBM E, e, μ ID PID eveID TRK Magnet CBM 2025 - … CBM@eRHIC √s NN ≤ 14 GeV 1)Study QCD phase structure 2)Maintain heavy ion community 3)CBM@eRHIC is an add on cost 1)Study QCD phase structure 2)Maintain heavy ion community 3)CBM@eRHIC is an add on cost AGS eRHIC

20. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 20/25 Chirality

21. Study Chiral Effects (Global) Charge pair correlation results are consistent with CME effect in non-central Au+Au collisions STAR: F. Zhao, NPA931, c746(14) PRL. 103, 251601(09) ; 113, 52302(14) 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)

22. Charge Separation wrt Event Plane 1)CVE 2)Global Chiral effect hierarchy: 3) LPV(CME) disappears at low energy:  hadronic interactions become dominant at √s NN ≤ 11.5 GeV STAR: PRL. 103, 251601(09) ; 113, 52302(14) Q.Y. Shou, NPA931, c758(14); F. Zhao, NPA931, c746(14) L.W. Wen, poster at QM2015 D. Kharzeev. PLB633, 260 (06) D. Kharzeev, et al. NPA803, 227(08)

23. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 23/25 ‘Polarization Measurements’

24. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 24/25

25. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 25/25 Summary RHIC e-cooling and iTPC upgrades bring BES-II a new era for studying the QCD phase structure at high net-baryon region (200 < μ B < 420 MeV) with unprecedented precision and coverage. Possible new discovers are: 1) Partial QCD critical point (region) 2)Chiral Properties 3)ϕ-meson v 2 Longer Future: fixed-target experiment at extreme large net-baryon density, 350 < μ B < 750 MeV ( 2 < √s NN < 8 GeV ) FXT program, BES-III, needed for QCD Critical Regiont! RHIC BESII collider mode 200 < μ B < 420 MeV RHIC BESII collider mode 200 < μ B < 420 MeV Fixed-target BES-III 350 < μ B < 750 MeV Fixed-target BES-III 350 < μ B < 750 MeV

26. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 26/25 2014201520162017201820192020202120222023202420252026 Future Plans HF-I, (e,μ) EIC HF-II, p  A BESII HFT/MTD e-Cooling, iTPC HFT+, EM/HCAL STAR physics upgrades - HFT: Charm - Di-lepton sQGP properties - HFT: Charm - Di-lepton sQGP properties - QCD phase structure - Critical Point - QCD phase structure - Critical Point AA: HFT+: B, Λ C Jet, γ-jet pA: CNM, p-spin AA: HFT+: B, Λ C Jet, γ-jet pA: CNM, p-spin Phase structure with dense gluons p+p, isobar p+p, isobar sPHENIX BESIII: at AGS or FAiR STAR SATR STAR STAR STAR

27. - Collectivity - Criticality - Chirality Study the emergent properties of QCD matter in high-energy nuclear collisions!

28. Thank You!

29. Nu Xu STAR Regional Meeting, NISER, BHUBANESWAR, India, February 12 - 13, 2016 29/25 Nu XuStudent Lecture, “Quark Matter 2006”, Shanghai, Nov. 14 - 20, 2006 29/59 STAR Collaboration

30. New Direction?!