English

Towards softer scales in hot QCD

High Energy Physics - Phenomenology 2009-10-31 v2

Abstract

An effective theory for the soft field modes in hot QCD has been obtained recently by integrating out the field modes of momenta of order T and g T. The mean hard particle distribution obeys a transport equation with a collision term. The scale that comes out for the soft field is g^2 T ln 1/g . N-gluon soft amplitudes are shown to be a sum of tree diagrams and to obey tree-like Ward identities. These effective amplitudes are used to compute the one-soft loop contribution to the gluon self-energy when the loop momentum is of order g^2 T ln 1/g. It allows to identify a new collision term which, when included into the transport equation, takes into account collisions with gluon exchange of order g^2 T ln 1/g. The infrared behaviour of the collision term exhibits a significant change.

Keywords

Cite

@article{arxiv.hep-ph/0004046,
  title  = {Towards softer scales in hot QCD},
  author = {F. Guerin},
  journal= {arXiv preprint arXiv:hep-ph/0004046},
  year   = {2009}
}

Comments

52 pages, 3 figures, RevteX The proof is now complete with a new perspective. A new appendix contains eigenvalues' expressions

R2 v1 2026-07-22T13:26:19.534Z