Modeling coherence effects of gluon emission for heavy flavor studies
Heavy quarks with large transverse momenta lose energy mainly through radiative processes. However, a Monte-Carlo implementation of gluon emission in an event-by-event fluctuating medium background is a non-trivial task. This is because the Landau-Pomeranchuk-Migdal (LPM) effect of the medium-induced bremsstrahlung introduces coherence over long distances that may be comparable to the typical expansion time scale or even the size of the QGP fireball. We have developed a new partonic transport model to implement the LPM effect approximately. The simulated in-medium bremsstrahlung spectra quantitatively agree with leading order theory calculations in a static medium and also display expected reduction in an expanding medium. Integrating the transport model into a multistage heavy-flavor dynamical model for heavy-ion collisions, we extract the heavy-quark transport coefficient by comparing to open heavy-flavor measurements at the LHC.