Relativistic Transport Theory for Systems Containing Bound States
  Using a Lagrangian which contains quarks as elementary degrees of freedom and mesons as bound states, a transport formalism is developed, which allows for a dynamical transition from a quark plasma to a state, where quarks are bound into hadrons. Simultaneous transport equations for both particle species are derived in a systematic and consistent fashion. For the mesons a formalism is used which introduces off-shell corrections to the off-diagonal Green functions. It is shown that these off-shell corrections lead to the appearance of elastic quark scattering processes in the collision integral. The interference of the processes $q\bar q\to\pi$ and $q\bar q\to\pi\to q\bar q$ leads to a modification of the $s$-channel amplitude of quark-antiquark scattering. 
P. Rehberg