Solving the $R_{AA}\otimes v_2$ puzzle

Abstract

For the past ten years $R_{AA}(p_T)$, the nuclear modification factor that encodes the suppression of high $p_T$ particles due to energy loss within the medium was fairly well described by many theoretical models. However, the same models systematically under-predicted the high $p_T$ elliptic flow, $v_2$, which is experimentally measured as the correlation between soft and hard hadrons. All previous calculations neglected the effect of event-by-event fluctuations of an expanding viscous hydrodynamical background as well as the soft-hard flow harmonic correlations in the experimentally measured $v_2$. In this talk I show how event-by-event viscous hydrodynamics (computed using the v-USPhydro code) coupled to an energy loss model (BBMG) is able to simultaneously describe soft physics observables as well as the high-$p_T$ $R_{AA}$ and $v_2$. Suggestions for future more differential calculations at the LHC run2 are made to explore soft-hard flow correlations.

7 pages, 5 figures, proceedings for the Winter Workshop on Nuclear Dynamics 2016

References in corpus (15)

• Effects of initial flow velocity fluctuation in event-by-event (3+1)D hydrodynamics
• Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
• Toward a solution to the $R_{AA}$ and $v_2$ puzzle for heavy quarks
• Effects of fluctuations on the initial eccentricity from the Color Glass Condensate in heavy ion collisions
• Effect of flow fluctuations and nonflow on elliptic flow methods
• Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV
• On the necessity to include event-by-event fluctuations in experimental evaluation of elliptical flow
• Small Shear Viscosity of a Quark-Gluon Plasma Implies Strong Jet Quenching
• Evidence of sub-nucleonic degrees of freedom in J/$\psi$ photoproduction in ultraperipheral collisions at the CERN Large Hadron Collider
• Bulk viscosity-driven suppression of shear viscosity effects on the flow harmonics at RHIC
• Linear and cubic response to the initial eccentricity in heavy-ion collisions
• Viscous Effects on the Mapping of the Initial to Final State in Heavy Ion Collisions
• Measurement of flow harmonics with multi-particle cumulants in Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV with the ATLAS detector
• Hydrodynamic predictions for 5.02 TeV Pb-Pb collisions
• Constraints on the Path-Length Dependence of Jet Quenching in Nuclear Collisions at RHIC and LHC