2003/09/30 by Paul Romatschke, Michael Strickland · 6 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Pulsars and Gravitational Waves Research #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.69.065005
published as Phys.Rev.D69:065005,2004 · 19 pages, 18 figures. v2 - Correction to normalization of numerical results; some figures modified as a result; discussion of role of unstable modes added along with two new figures
arxiv created 2003/10/06 · openalex publication_date 2004/03/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We compute the leading-order collisional energy loss of a heavy fermion propagating in a QED plasma with an electron distribution function which is anisotropic in momentum space. We show that in the presence of such anisotropies there can be a significant directional dependence of the heavy fermion energy loss with the effect being large for highly relativistic velocities. We also repeat the analysis of the isotropic case more carefully and show that the final result depends on the intermediate scale used to separate hard and soft contributions to the energy loss. We then show that the canonical isotropic result is obtained in the weak-coupling limit. For intermediate coupling we use the residual scale dependence as a measure of our theoretical uncertainty. We also discuss complications which could arise due to the presence of unstable soft photonic modes and demonstrate that the calculation of the energy loss is safe.