Eur. Phys. J. A 12, 453-477 (2001)
Transport theory for a scalar quark & gluon model
D.S. Isert and S.P. KlevanskyInstitut für Theoretische Physik, Philosophenweg 19, D-69120 Heidelberg, Germany D.Isert@tphys.uni-heidelberg.de
(Received: 7 November 2001 Communicated by A. Schäfer)
Abstract
A model for scalar quarks and gluons that successfully gives rise to a ln
s
behavior in high-energy
qq scattering and which contains a non-trivial three-gluon vertex is used to study collision theory with the following
aspects: i) A three-body interaction simulating QCD is present and ii)
particle production and annihilation occur naturally. In this
paper, the collision term in the model is examined in detail in the
quasiparticle approximation. The construction of cross-sections in which
self-energy terms are ordered according to a coupling constant expansion is
undertaken. It is shown explicitly which terms of second order are
required to obtain the scattering amplitudes that are two body in
nature. Additional ordering in the number of colors shows that quark loop
diagrams are suppressed and gluon production or scattering processes
dominate. It is also shown that a consistent calculation of the scattering
graphs
at the two-loop level also simultaneously yields terms that renormalize
one-loop level graphs. This can then be extended to arbitrary
processes. We examine the constraint equation briefly, discussing the
appearance of a width. The issue of pinch singularities is also addressed, and
examples of the elimination of such singularities in equilibrium are given
explicitly.
12.40.-y - Other models for strong interactions.
05.20.Dd - Kinetic theory.
12.38.Mh - Quark-gluon plasma.
24.85.+p - Quarks, gluons, and QCD in nuclei and nuclear processes.
© Società Italiana di Fisica, Springer-Verlag 2001
