POINCARE COVARIANT PARTICLE DYNAMICS .2. FRAGMENTATION FOR ULTRARELATIVISTIC REACTIONS

We present a Poincare covariant model for ultrarelativistic particle r eactions without any field degrees of freedom. A relativistic two-part icle interaction is made possible by an enlargement of phase space and a distinction between physical and canonical particle coordinates. A Hamiltonian formalism with a mass-like quasipotential defines the dyna mics of the system. Then interaction at a distance causes a change of effective particle masses instead of energy. Particle production is in corporated by a phenomenological decay procedure for the constituents (partons) in a manner analogous to a string fragmentation mechanism. T his pure particle picture for Poincare covariant collision dynamics (P CD model) is compared to other microscopic models and tested by simula tions of e+e- jet events. Before application to more complex scenarios like ultrarelativistic heavy ion collisions, hard gluonic effects sho uld be included. In the PCD model, this can be done by introduction of massive gluons as particles.