Quenching of Hadron Spectra in a chemically equilibrating Quark-Gluon Plasma

Abstract

Using the Fokker-Planck equation we have studied the drag co-efficient $A(t)$ and the consequent shift $\Delta p_{\perp }(L)$ in the transverse momentum due to collisional energy loss of energetic partons while passing through a chemically equilibrating quark-gluon plasma. Based on these we estimate the quenching factor $Q(p_{\perp })$ when the medium is undergoing longitudinal expansion governed by master rate equations. In contrast to the case of chemically equilibrated plasma investigated earlier by Mustafa and Thoma \cite{mus} we find less quenching because our calculated $Q(p_{\perp })$ is always greater at all momenta. This result is attributed to the weak drag coefficient operating during initial state interactions.

Comments: 12 pages, 3 figures