Stony Brook University vn in relation to initial-state geometry and medium properties Roy A. Lacey Chemistry Dept., Stony Brook University Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

A central Issue in RHIC & LHC collisions? How to fully characterize of the QGP produced in RHIC & LHC collisions? Characterization requires Development of experimental constraints for thermodynamic and transport coefficients Development of quantitative model descriptions of these properties T, cs, Essential question: Do azimuthal anisotropy (vn) measurements provide constraints to nail down initial-state geometry & the transport properties of the QGP? Focus  The role of scaling in answering this question! Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

A scenario for Azimuthal Anisotropy 4< pT <10 GeV/c Transition Region pT < 4 GeV/c Flow pT > 10 GeV/c Jet quenching Path length (∆L) driven Pressure driven (acoustic ) Both are linked by Geometry & interactions in the sQGP This scenario implies very specific scaling properties which must be validated experimentally Scaling validation  Flow and Jet Quenching provide straightforward probes of the QGP Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

The Flow Probe Idealized Geometry Control parameters Initial Geometry characterized by many harmonics Actual collision profiles are not smooth, due to fluctuations! Acoustic viscous damping Initial eccentricity (and its attendant fluctuations) εn drive momentum anisotropy vn with specific scaling properties Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Jet quenching Probe Color charge scattering centers Radiative: Control parameters Range of Color Force Obtain via RAA measurements Suppression for ∆L Density of Scattering centers Scattering Power Of Medium Gyulassy, Wang, Müller, … Jet quenching drives RAA & azimuthal anisotropy with specific scaling properties Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Geometric Quantities for scaling Phys. Rev. C 81, 061901(R) (2010) A B arXiv:1203.3605 σx & σy  RMS widths of density distribution Geometric fluctuations included Geometric quantities constrained by multiplicity density. Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Scaling properties of Jet Quenching Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012 7

Specific pT and centrality dependencies – Do they scale? RAA Measurements - LHC Eur. Phys. J. C (2012) 72:1945  arXiv:1202.2554 Centrality dependence pT dependence Specific pT and centrality dependencies – Do they scale? Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012 8

Scaling of Jet Quenching arXiv:1202.5537 RAA scales with L, slopes (SL) encodes info on Compatible with the dominance of radiative energy loss Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012 9

Scaling of Jet Quenching arXiv:1202.5537 RAA scales as 1/√pT , slopes (SpT) encodes info on L and 1/√pT scaling  single universal curve Compatible with the dominance of radiative energy loss Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012 10

Specific pT and centrality dependencies – Do they scale? High-pT v2 measurements arXiv:1204.1850 Centrality dependence pT dependence Specific pT and centrality dependencies – Do they scale? Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012 11

Scaling of high-pT v2 arXiv:1203.3605 v2 follows the pT dependence observed for jet quenching Note the expected inversion of the 1/√pT dependence Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012 12

Combined ∆L and 1/√pT scaling  single universal curve for v2 Scaling of high-pT v2 arXiv:1203.3605 Combined ∆L and 1/√pT scaling  single universal curve for v2 Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012 13

Jet suppression from high-pT v2 arXiv:1203.3605 Jet suppression obtained directly from v2 Rv2 scales as 1/√pT , slopes encodes info on Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012 14

Scaling of Jet Quenching Phys.Rev.C80:051901,2009 arXiv:1202.5537 arXiv:1203.3605 obtained from high-pT v2 and RAA [same αs]  similar - medium produced in LHC collisions less opaque! Conclusion similar to those of Liao, Betz, Horowitz, Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012 15

Scaling patterns of low-pT azimuthal anisotropy Essential argument: Flow is dominantly partonic Flow is pressure driven (acoustic) viscous damping follows dispersion relation for sound propagation  These lead to characteristic scaling patterns which must be experimentally validated Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012 16

Is hydrodynamic flow acoustic? εn drive momentum anisotropy vn with modulation Not analogous CBM Modulation  Acoustic Deformation Note: the hydrodynamic response to the initial geometry [alone] is included Characteristic n2 viscous damping for harmonics  Crucial constraint for η/s Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Constraint for η/s & δf Deformation Characteristic pT dependence of β expected,  reflects the influence of δf Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

AMPT – Simulations with fluctuating initial conditions Is flow partonic? AMPT – Simulations with fluctuating initial conditions Deformation Characteristic scaling patterns are to be expected for the ratios of vn Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Is flow partonic? AMPT – Simulations with (w) and without (wo) fluctuating initial conditions Deformation Characteristic scaling patterns are to be expected for identified particle species vn Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

High precision double differential Measurements are pervasive vn(ψn) Measurements Phys.Rev.Lett. 107 (2011) 252301  (arXiv:1105.3928) v4(ψ4) ~ 2v4(ψ2) High precision double differential Measurements are pervasive Do they scale? Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

High precision double differential Measurements are pervasive vn(ψn) Measurements ATLAS-CONF-2011-074 High precision double differential Measurements are pervasive Do they scale? Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Flow is acoustic Characteristic viscous damping RHIC LHC Deformation Characteristic viscous damping of the harmonics validated  Crucial constraint for η/s Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Acoustic Scaling β is essentially independent of centrality for a broad centrality range Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Acoustic Scaling β scales as 1/√pT Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Similar scaling observed at the LHC Flow is partonic Scaling for partonic flow validated for vn Constraints for εn Similar scaling observed at the LHC Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Scaling for partonic flow validated for vn Flow is partonic v3 PID scaling Flow is partonic Flow is partonic STAR PHENIX KET & scaling validated for v3  Partonic flow Scaling for partonic flow validated for vn Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Decoupling the Interplay between εn and η/s http://arxiv.org/abs/1105.3928 v3 breaks the ambiguity between MC-KLN vs. MC-Glauber initial conditions and η/s, because of the n2 dependence of viscous corrections Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Much work remains to be done η/s estimates – QM2009 Good Convergence Conjectured Lower bound 4πη/s ~ 1 Temperature dependence Not fully mapped yet Much work remains to be done Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

Flow is acoustic η/s Summary Remarkable scaling have been observed for both Flow and Jet Quenching They lend profound mechanistic insights, as well as New constraints for estimates of transport and thermodynamic coefficients! What do we learn? RAA and high-pT azimuthal anisotropy stem from the same energy loss mechanism Energy loss is dominantly radiative RAA and anisotropy measurements give consistent estimates for ˆq The QGP created in RHIC collisions is less opaque than that produced at the LHC 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 viscous horizon sound horizon Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012

End Roy A. Lacey, Stony Brook University; Ridge Workshop, INT, Seattle, May 7-11, 2012