The quark and gluon damping rates in high-temperature QCD /

The dominant term in the damping rate for quarks and transverse gluons at high momentum (p $ gg$ gT) is calculated within the framework of perturbative QCD at finite temperature. It is shown that the damping rate, $ gamma$, takes the form $ gamma$ = cg$ sp2$T log(1/g) with c = N/4$ pi$ for transverse gluons and c = (N$ sp2$-1)/(8$ pi$N) for quarks where N is the number of colours, g is the coupling constant, and T is the temperature. The sign and the gauge invariance of $ gamma$ are easily verifiable due to the simplicity of the argument. This result agrees with the more complicated (unpublished) calculations of Pisarski et al. but disagrees with those of Lebedev and Smilga