Parton showers as sources of energy-momentum deposition in the quark-gluon plasma and their implication for shockwave formation at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

R. B. Neufeld and I. Vitev

Phys. Rev. C 86, 024905 – Published 8 August 2012

Abstract

We derive the distribution of energy and momentum transmitted from a primary fast parton and its medium-induced bremsstrahlung gluons to a thermalized quark-gluon plasma. Our calculation takes into account the important and thus far neglected effects of quantum interference between the resulting color currents. We use our result to obtain the rate at which energy is absorbed by the medium as a function of time to leading logarithmic accuracy. We find that the quantum color interference persists for time scales relevant to heavy ion phenomenology. We further couple the newly derived source of energy and momentum deposition to linearized hydrodynamics to obtain the bulk medium response to realistic parton propagation and splitting in the quark-gluon plasma. We find that because of the characteristic large angle in-medium gluon emission and the multiple sources of energy deposition in a parton shower, formation of well defined Mach cones by energetic jets in heavy ion reactions is not likely.