Extracting $\hat{q}$ in event-by-event hydrodynamics and the centrality/energy puzzle

Abstract

In our analysis, we combine event-by-event hydrodynamics, within the EKRT formulation, with jet quenching -ASW Quenching Weights- to obtain high-$p_T$ $R_{\mathrm{AA}}$ for charged particles at RHIC and LHC energies for different centralities. By defining a $K$-factor that quantifies the departure of $\hat{q}$ from an ideal estimate, $K=\hat{q}/(2{ϵ}^{3/4})$, we fit the single-inclusive experimental data for charged particles. This $K$-factor is larger at RHIC than at the LHC but, surprisingly, it is almost independent of the centrality of the collision.

Comments: 4 pages, 2 figures, proceedings for Quark Matter 2017