Scaling patterns for the suppression of charged hadron yields in Pb+Pb collisions at Root_s = 2.76 TeV: Constraints on transport coefficients

Abstract

Suppression measurements for charged hadrons are used to investigate the path length (L) and transverse momentum (p_T) dependent jet quenching patterns of the hot and dense QCD medium produced in Pb+Pb collisions at Root_s =2.76 TeV at the LHC. The observed scaling patterns, which are similar to those observed for Au+Au collisions at Root_s = 0.20 TeV at RHIC, show the trends predicted for jet-medium interactions dominated by radiative energy loss. They also allow a simple estimate of the transport coefficient $\hat{q}$, which suggests that the medium produced in LHC collisions is somewhat less opaque than that produced at RHIC, if the same parton-medium coupling strength is assumed. The higher temperature produced in LHC collisions could reduce the parton-medium coupling strength to give identical values for $\hat{q}$ in LHC and RHIC collisions.