Abstract
There exist full leading-order-in- numerical calculations of the rates for massless quarks and gluons to split and join in the background of a quark-gluon plasma through hard, nearly collinear bremsstrahlung and inverse bremsstrahlung. In the limit of partons with very high energy , where the physics is dominated by the Landau-Pomeranchuk-Migdal effect, there are also analytic leading-log calculations of these rates, where the logarithm is . We extend those analytic calculations to next-to-leading-log order. We find agreement with the full result to within roughly 20% for , where is the energy of the least energetic parton in the splitting/joining process. We also discuss how to account for the running of the coupling constant in the case that is very large. Our results are also applicable to isotropic nonequilibrium plasmas if the plasma does not change significantly over the formation time associated with particle splitting.
- Received 21 April 2008
DOI:https://doi.org/10.1103/PhysRevD.78.065008
©2008 American Physical Society