Eur. Phys. J. C 18, 765-777
DOI: 10.1007/s100520100554

Damping of very soft moving quarks in high-temperature QCD

A. Abada¹, K. Bouakaz¹ and N. Daira-Aifa<sup>2

1</sup>  Département de Physique, Ecole Normale Supérieure, BP 92 Vieux Kouba, 16050 Alger, Algeria
²  Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene, BP 32 El-Alia, Bab Ezzouar 16111 Alger, Algeria

abada@wissal.dz

(Received: 1 September 2000 / Published online: 5 February 2001 -© Springer-Verlag 2001)

Abstract
We determine the analytic expression of the damping rates for very soft moving quarks in an expansion to second order in powers of their momentum in the context of QCD at high temperature. The calculation is performed using the hard-thermal-loop-summed perturbation scheme. We describe the range of validity of the expansion and make a comparison with other calculations, particularly those using a magnetic mass as a shield from infrared sensitivity. We discuss the possible occurrence of infrared divergences in our results and argue that they are due to magnetic sensitivity.

© Società Italiana di Fisica, Springer-Verlag 2001