Fourier Harmonics of High-pT Particles Probing the Fluctuating Intitial Condition Geometries in Heavy-Ion Collisions

Abstract

Second Fourier harmonics of jet quenching have been thoroughly explored in the literature and shown to be sensitive to the underlying jet path-length dependence of energy loss and the differences between the mean eccentricity predicted by Glauber and CGC/KLN models of initial conditions. We compute the jet path-length dependence of energy-loss for higher azimuthal harmonics of jet-fragments in a generalized model of energy-loss for RHIC energies and find, however, that even the high-$p_T$ second moment is most sensitive to the poorly known early-time evolution during the first fm/c. Moreover, we demonstrate that higher-jet harmonics are remarkably insensitive to the initial conditions, while the different $v_n(N_{part})$ vs. $v_n^{I_{AA}}(N_{part})$ correlations between the moments of monojet and dijet nuclear modifications factors remain a most sensitive probe to differentiate between Glauber and CGC/KLN initial state sQGP geometries.Comment: 6 pages, 7 figures, updated figures, version accepted for publication in Phys. Rev.