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PHENIX Measurements of Higher-order Flow Harmonics in Au+Au Collisions at GeV: Implications for Initial-eccentricity Models and the Specific Viscosity of the Quark Gluon Plasma: Roy A. Lacey (for the PHENIX Collaboration) Chemistry Dept., Stony Brook University. p.

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Big Bang

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  1. PHENIX Measurements of Higher-order Flow Harmonics in Au+Au Collisions at GeV: Implications for Initial-eccentricity Models and the Specific Viscosity of the Quark Gluon Plasma: Roy A. Lacey (for the PHENIX Collaboration) Chemistry Dept., Stony Brook University Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  2. p Quantitative study of the phases of QCD is a central goal of our field Big Bang “The major discoveries in the first five years at RHIC must be followed by a broad, quantitative study of the fundamental properties of the quark gluon plasma …” The Frontiers of Nuclear Science A Long Range Plan - 2007 Characterization requires T, cs, The extraction of transport coefficients is central to the heavy ion programs at RHIC and the LHC Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  3. η/s estimates – QM2009 Remarkable Convergence Conjectured Lower bound 4πη/s ~ 1 - 2 (still 100% uncertainty) Major remaining uncertainty stems from Incomplete knowledge of the Initial eccentricity εn – η/s interplay New constraints required for the initial eccentricity model and η/s • Do higher-order flow harmonics provide such constraints? • Implications for decomposition of two-particle correlation functions Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  4. The Flow probe Azimuthal Distribution Primary Parameters Odd harmonics = 0 Odd harmonics ≠ 0 Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  5. Schematic Detector Layout PHENIX Measurements PHENIX Central Arms (CA) |η’| < 0.35 (particle detection) Two complimentary analysis methods employed: RXN RXN BBC/MPC Correlate hadrons in central Arms with event plane (RXN, etc) BBC/MPC ∆η’ = 5-7 (I) ψn RXN (|h|=1.0~2.8) MPC (|h|=3.1~3.7) BBC (|h|=3.1~3.9) • ∆φ correlation function for EPN - EPS Sub-event participant plane = ΦN,S (II) Correlations between sub-event planes (EPN - EPS ) also studied! • ∆φ correlation function for EP - CA Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  6. Results: Event plane Correlations • Clear 12correlation • well known • Weak 24 correlation • well known • Weak 13 correlation • Not unexpected • No vis. 23 correlation • Fluctuations important Sub-event correlations give crucial insights on the expected correlations and the role of fluctuations Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  7. Results: vn(ψn) http://arxiv.org/abs/1105.3928 v4(ψ4) ~ 2v4(ψ2) Robust PHENIX measurements performed at 200 GeV (Crosschecked with correlation method) Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  8. Results: vn(∆φ) Robust measurements performed at 200 GeV (Crosschecked with event-plane method) Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  9. What do we learn from these new vn measurements? Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  10. New constraints for εn and η/s http://arxiv.org/abs/1105.3928 v3 breaks the ambiguity between CGC vs. Glauber initial conditions and η/s Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  11. Baryons Mesons Phys. Rev. Lett. 98, 162301 (2007) v3 PID scaling Flow is partonic Flow is pressure driven Flow is partonic KET & scaling validated for v3  Partonic flow v4 scaling Reminder v2 scaling Consistent partonic flow picture for vn Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  12. See Xiaoyang Gong’s talk Energy Scan Session – Friday 17:50 – 18:10 on Friday Results: vn(∆φ) v2,3,4 saturates for the range √sNN 39 - 200 GeV Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  13. Results: Decomposition of two-particle ∆φ Correlation Functions Two particle ∆φ correlations for 0.3 < |∆η| < 0.7 show the effects of jet contributions to the correlation function Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  14. Results: Decomposition of two-particle ∆φ Correlation Functions Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  15. Acoustic scaling http://arxiv.org/abs/1105.3782 Acoustic Scaling Deformation Approx. Viscous effects ~ cancel Higher-order harmonics should scale as a power of v2 Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  16. Acoustic scaling Cancellation of viscous effects allow constraint for eccentricity Staig & Shuryak arXiv:1008.3139 The viscous horizon (rv) is the length-scale which characterizes the highest harmonic that survives viscous damping • New constraints from acoustic scaling • Glauber eccentricity • 4πη/s = 1.4 • rv ~ 1.9 fm • Similar estimates for LHC Estimate 4πη/s from slope (Independent estimate) Viscous Horizon (rv) Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  17. summary Higher-order flow harmonics extracted by PHENIX! • Provide new constraints for εn and η/s • Further confirm that flow is partonic • v2,3,4 saturates for √sNN 39 - 200 GeV • Allow a more robust decomposition of • Of two-particle ∆φ correlation functions • Show that Flow is acoustic • new constraints for: • η/s • initial geometry • viscous horizon Precision extractions underway! Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  18. End Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  19. Acoustic scaling Acoustic Scaling Deformation Data Higher-order harmonics should scale as a power of v2 Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  20. Acoustic scaling Acoustic Scaling Deformation Higher-order harmonics should scale as a power of v2 Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  21. Acoustic scaling Scaling observed for vn independent of pT Similar scaling For all centrality Viscous effects cancel Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  22. Acoustic scaling http://arxiv.org/abs/1105.3782 independent of pT Similar scaling For all centrality Viscous effects cancel Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  23. New constraints for εn and η/s http://arxiv.org/abs/1105.3928 • Good agreement between data and theory for • Glauber with fluctuating initial conditions • 4πη/s ~ 1 Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  24. Flow Measurements Phys.Rev.Lett.105:062301,2010 High precision double differential measurements are pervasive! Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  25. RXN RXN Precision Data BBC/MPC BBC/MPC Good agreement between measurements Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  26. Precision Data Excellent agreement between experiments for √s = 39 -200 GeV! Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  27. Precision Data Preliminary, STAR, PHENIX and E895 data Excellent agreement between experiments for the excitation function!  Crucial for η/s extraction and the critical point search Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  28. Estimates for η/s G. Denicol et al v2 pT Relaxation time limits η/s to small values Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  29. Constraints for η/s Hydrodynamic Model Comparison Song et al. arXiv:1011.2783 Model uncertainty dominated by ε Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  30. Flow scales across centrality PHENIX Preliminary PHENIX Preliminary PHENIX Preliminary PHENIX Preliminary PHENIX Preliminary PHENIX Preliminary KET & nqscaling validated for v2 as a function of centrality Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

  31. Scaling constrains η/s Demir et al η/s from hadronic phase is very large 10-12x(1/4π) No room for such values! Partonic flow dominates! Hadronic contribution cannot be large Roy A. Lacey, Stony Brook University; QM11, Annecy, France 2011

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