A local Monte Carlo implementation of the non-abelian Landau-Pomerantschuk-Migdal effect

Abstract

The non-abelian Landau-Pomeranschuk-Migdal (LPM) effect arises from the quantum interference between spatially separated, inelastic radiation processes in matter. A consistent probabilistic implementation of this LPM effect is a prerequisite for extending the use of Monte Carlo (MC) event generators to the simulation of jet-like multi-particle final states in nuclear collisions. Here, we propose a local MC algorithm, which is based solely on relating the LPM effect to the probabilistic concept of formation time for virtual quanta. We demonstrate that this implementation of formation time physics alone accounts probabilistically for all analytically known features of the non-abelian LPM-effect, including the characteristic L^2-dependence of average parton energy loss and the characteristic $\sqrt{\omega}$-modification of the gluon energy distribution. Additional kinematic constraints are found to modify these L^2- and $\omega$-dependencies characteristically in accordance with analytical estimates.