Evolution Effects on Parton Energy Loss with Detailed Balance

Luan cheng, Enke Wang

Published 2008-09-12, updated 2010-04-30Version 3

The initial conditions in the chemical non-equilibrated medium and Bjorken expanding medium at RHIC are determined. With a set of rate equations describing the chemical equilibration of quarks and gluons based on perturbative QCD, we investigate the consequence for parton evolution at RHIC. With considering parton evolution, it is shown that the Debye screening mass and the inverse mean free-path of gluons reduce with increasing proper time in the QGP medium. The parton evolution affects the parton energy loss with detailed balance, both parton energy loss from stimulated emission in the chemical non-equilibrated expanding medium and in Bjorken expanding medium are linear dependent on the propagating distance rather than square dependent in the static medium. The energy absorption can not be neglected at intermediate jet energies and small propagating distance of the energetic parton in contrast with that it is important only at intermediate jet energy in the static medium. This will increase the energy and propagating distance dependence of the parton energy loss and will affect the shape of suppression of moderately high P_T hadron spectra.