1. 1Erice 2012, Roy A. Lacey, Stony Brook University

2. p Conjectured Phase Diagram 2 Quantitative study of the QCD phase diagram is central to our field Erice 2012, Roy A. Lacey, Stony Brook University Interest  Location of the critical End point  Location of phase coexistence lines  Properties of each phase All are fundamental to the phase diagram of any substance Spectacular achievement: Validation of the crossover transition leading to the QGP Full characterization of the QGP is a central theme at RHIC and the LHC

3. Characterization of the QGP produced in RHIC and LHC collisions requires: I. Development of experimental constraints to map the topological, thermodynamic and transport coefficients II. Development of quantitative model descriptions of these properties QGP Characterization? Erice 2012, Roy A. Lacey, Stony Brook University 3 Experimental Access: Temp/time-averaged constraints as a function of √s NN (with similar expansion dynamics) (I) Expect space-time averages to evolve with √s NN (II)

4. 4 RHIC (0.2 TeV)  LHC (2.76 TeV)  Power law dependence (n ~ 0.2)  increase ~ 3.3  Multiplicity density increase ~ 2.3  increase ~ 30% The energy density lever arm Lacey et. al, Phys.Rev.Lett.98:092301,2007 Essential questions:  How do the transport coefficients evolve with T?  Any indication for a change in coupling close to T o ? Erice 2012, Roy A. Lacey, Stony Brook University Energy scan Take home message: The scaling properties of flow and Jet quenching measurements give crucial new insights

5. The Flow Probe 5 Idealized Geometry Crucial parameters Actual collision profiles are not smooth, due to fluctuations! Initial Geometry characterized by many shape harmonics (ε n )  drive v n Initial eccentricity (and its attendant fluctuations) ε n drive momentum anisotropy v n with specific scaling properties Acoustic viscous modulation of v n Staig & Shuryak arXiv:1008.3139 Isotropic p Anisotropic p Erice 2012, Roy A. Lacey, Stony Brook University Yield(  ) =2 v 2 cos[2(   ]

6. KE T & scaling validated for v n  Partonic flow 6 v n PID scaling Flow is partonic @ RHIC Erice 2012, Roy A. Lacey, Stony Brook University

7. 7  Flow increases from RHIC to LHC Sensitivity to EOS increase in  Proton flow blueshifted [hydro prediction] Role of radial flow Role of hadronic re- scattering? Flow increases from RHIC to LHC

8. 8 Flow is partonic @ the LHC Scaling for partonic flow validated after accounting for proton blueshift Larger partonic flow at the LHC Erice 2012, Roy A. Lacey, Stony Brook University

9. Hydrodynamic flow is acoustic Characteristic n 2 viscous damping for harmonics  Crucial constraint for η/s Associate k with harmonic n 9 Erice 2012, Roy A. Lacey, Stony Brook University Note: the hydrodynamic response to the initial geometry [alone] is included ε n drive momentum anisotropy v n with modulation Modulation  Acoustic

10. Constraint for η/s & δf Deformation 10 Characteristic p T dependence of β  reflects the influence of δf and η/s Erice 2012, Roy A. Lacey, Stony Brook University

11. ATLAS-CONF-2011-074 11 High precision double differential Measurements are pervasive Do they scale? Erice 2012, Roy A. Lacey, Stony Brook University v n (ψ n ) Measurements - ATLAS

12. Acoustic Constraint Characteristic viscous damping of the harmonics validated  Important constraint Wave number 12 LHCRHIC Erice 2012, Roy A. Lacey, Stony Brook University arXiv:1105.3782 at RHIC; small increase for LHC

13. 13 Erice 2012, Roy A. Lacey, Stony Brook University Acoustic Scaling β is essentially independent of centrality for a broad centrality range

14. 14 β scales as 1/√p T  Important constraint Erice 2012, Roy A. Lacey, Stony Brook University Constraint for η/s & δf ~ 1/4π at RHIC; small increase for LHC

15. Scaling properties of Jet Quenching Erice 2012, Roy A. Lacey, Stony Brook University15

16. 16 Erice 2012, Roy A. Lacey, Stony Brook University Jet suppression Probe Suppression (∆L) – pp yield unnecessary Jet suppression drives R AA & azimuthal anisotropy with specific scaling properties Suppression (L), Phys.Lett.B519:199-206,2001 For Radiative Energy loss: Modified jet More suppression Less suppression Fixed Geometry Path length (related to collision centrality)

17. 17 Geometric Quantities for scaling A B  Geometric fluctuations included  Geometric quantities constrained by multiplicity density. Phys. Rev. C 81, 061901(R) (2010) arXiv:1203.3605 σ x & σ y  RMS widths of density distribution Erice 2012, Roy A. Lacey, Stony Brook University

18. R AA Measurements - CMS Specific p T and centrality dependencies – Do they scale? 18 Eur. Phys. J. C (2012) 72:1945 arXiv:1202.2554 Centrality dependence p T dependence Erice 2012, Roy A. Lacey, Stony Brook University

19. L scaling of Jet Quenching - LHC R AA scales with L, slopes (S L ) encodes info on α s and q Compatible with the dominance of radiative energy loss 19 arXiv:1202.5537 ˆ, Phys.Lett.B519:199-206,2001 Erice 2012, Roy A. Lacey, Stony Brook University

20. 20 Phys.Rev.C80:051901,2009 Erice 2012, Roy A. Lacey, Stony Brook University L scaling of Jet Quenching - RHIC R AA scales with L, slopes (S L ) encodes info on α s and q Compatible with the dominance of radiative energy loss ˆ

21. R AA scales as 1/√p T ; slopes (S pT ) encode info on α s and q L and 1/√p T scaling  single universal curve Compatible with the dominance of radiative energy loss 21 arXiv:1202.5537 p T scaling of Jet Quenching ˆ, Phys.Lett.B519:199-206,2001 Erice 2012, Roy A. Lacey, Stony Brook University

22. High-pT v 2 measurements - CMS Specific p T and centrality dependencies – Do they scale? 22 arXiv:1204.1850 p T dependence Centrality dependence Erice 2012, Roy A. Lacey, Stony Brook University

23. Specific p T and centrality dependencies – Do they scale? 23 Erice 2012, Roy A. Lacey, Stony Brook University High-pT v 2 measurements - PHENIX p T dependence Centrality dependence

24. 24 High-pT v 2 scaling - LHC v 2 follows the p T dependence observed for jet quenching Note the expected inversion of the 1/√p T dependence arXiv:1203.3605 Erice 2012, Roy A. Lacey, Stony Brook University

25. 25 ∆L Scaling of high-pT v 2 – LHC & RHIC Combined ∆L and 1/√p T scaling  single universal curve for v 2 arXiv:1203.3605 Erice 2012, Roy A. Lacey, Stony Brook University

26. 26 Erice 2012, Roy A. Lacey, Stony Brook University ∆L Scaling of high-pT v 2 - RHIC Combined ∆L and 1/√p T scaling  single universal curve for v 2  Constraint for ε n

27. 27 Jet v 2 scaling - LHC v 2 for reconstructed Jets follows the p T dependence for jet quenching Similar magnitude and trend for Jet and hadron v 2 after scaling Erice 2012, Roy A. Lacey, Stony Brook University (z ~.62) ATLAS

28. 28 Jet suppression from high-pT v 2 Jet suppression obtained directly from pT dependence of v 2 arXiv:1203.3605 R v2 scales as 1/√p T, slopes encodes info on α s and q ˆ Erice 2012, Roy A. Lacey, Stony Brook University

29. 29 Erice 2012, Roy A. Lacey, Stony Brook University Jet suppression from high-pT v 2 - RHIC Jet suppression obtained directly from pT dependence of v 2 R 2 scales as 1/√p T, slopes encodes info on α s and ˆqˆq

30. Consistent obtained 30 Erice 2012, Roy A. Lacey, Stony Brook University q LHC ˆ Heavy quark suppression

31. 31 Extracted stopping power Phys.Rev.C80:051901,2009  obtained from high-pT v 2 and R AA [same α s ]  similar  - medium produced in LHC collisions less opaque! arXiv:1202.5537arXiv:1203.3605 Conclusion similar to those of Liao, Betz, Horowitz,  Stronger coupling near T c ? q RHIC > q LHC ˆ q LHC ˆ Erice 2012, Roy A. Lacey, Stony Brook University

32. Remarkable scaling have been observed for both Flow and Jet Quenching They lend profound mechanistic insights, as well as New constraints for estimates of the transport and thermodynamic coefficients! 32  R AA and high-pT azimuthal anisotropy stem from the same energy loss mechanism  Energy loss is dominantly radiative  R AA and anisotropy measurements give consistent estimates for  R AA and anisotropy measurements give consistent estimates for  R AA for D’s give consistent estimates for  R AA for D’s give consistent estimates for  The QGP created in LHC collisions is less opaque than that produced at RHIC  Flow is acoustic Flow is pressure driven Obeys the dispersion relation for sound propagation  Flow is partonic exhibits scaling  Constraints for: initial geometry η/s similar at LHC and RHIC ~ 1/4π What do we learn? Summary Erice 2012, Roy A. Lacey, Stony Brook University

33. End 33 Erice 2012, Roy A. Lacey, Stony Brook University

34. 34 Flow @ RHIC and the LHC Erice 2012, Roy A. Lacey, Stony Brook University  Multiplicity-weighted PIDed flow results reproduce inclusive charged hadron flow results at RHIC and LHC respectively  Charge hadron flow similar @ RHIC & LHC

35. 35 Erice 2012, Roy A. Lacey, Stony Brook University For partonic flow, quark number scaling expected  single curve for identified particle species v n Is flow partonic? Note species dependence for all v n