Collision integral in a model for scalar quarks and gluons

A model of scalar quarks and scalar gluons is used to derive transport equations for quarks and gluons. In particular, the collision integral is studied. The self-energy diagrams are organized according to the number of loops. A generalized Boltzmann equation is obtained, which involves at the level up to two loops all possible two -> two parton scattering processes and corrections to the process q bar q -> g.