A study of Jet Quenching near the QCD Phase Transition

We study the dependence of jet quenching in quark gluon plasma on the local density of the plasma. Liao and Shuryak* have previously suggested that quenching reaches a maximum for entropy densities around the QCD phase transition. This ``shell-like'' quenching scenario seems to be favored by the large azimuthal asymmetry v$_{2 }$for large momentum hadrons measured at the Relativistic Heavy Ion Collider (RHIC). Our calculations confirm the results by Liao and Shuryak qualitatively, and describe RHIC data on the nuclear suppression factor R$_{AA}$ and v$_{2}$ simultaneously quite well. We then extrapolate to nuclear collisions at the Large Hadron Collider (LHC) using the same density dependence that fits RHIC data. We show that ``shell-like'' quenching gives unique predictions for R$_{AA}$ and v$_{2}$ at LHC. Data from LHC will hence help us to distinguish between different scenarios for the density dependence of jet quenching. *Phys. Rev. Lett. 102,202302(2009)