Dependence of energy loss of hard jets on the initial thermodynamic state of deconfined matter

Abstract

The dependence of the radiative energy loss of hard partons $(E>10 \mathrm{GeV})$ on the initial thermodynamic parameters is studied for deconfined matter to be expected at the Relativistic Heavy-Ion Collider (RHIC). We demonstrate that the specific QCD radiation pattern with a nonlinear dependence of the energy loss on the propagated distance leads to a strong increase of the energy loss with increasing initial entropy of deconfined matter supposing its lifetime is less than the average time to pass through the medium. This is in contrast to a parametrization with constant energy loss per unit length of propagation. For a sufficiently high initial temperature a two-regime behavior of the energy loss as a function of the initial parton momentum occurs. The angular structure of the energy loss of hard jets with respect to the initial temperature is also discussed for RHIC conditions.