Eur. Phys. J. C (2009) 61: 775-778
https://doi.org/10.1140/epjc/s10052-008-0824-y

Regular Article - Theoretical Physics

Implementation of a medium-modified parton shower algorithm

¹ Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706, Santiago de Compostela, Spain
² Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, 00044, Frascati (Rome), Italy

^* e-mail: nestor@fpaxp1.usc.es

Received: 25 September 2008
Published online: 5 December 2008

Abstract

We present a Monte Carlo implementation of medium-induced gluon radiation in the final-state branching process. Medium effects are introduced through an additive term in the splitting functions. We have implemented such modification within PYTHIA. We show the medium effects on the hump-backed plateau, and the transverse-momentum and angular distributions with respect to the parent parton. As expected, with increasing medium densities there is an increase (decrease) of partons with small (large) momentum fraction, and angular broadening is observed. The effects on the transverse-momentum distributions are more involved, with an enhancement of low- and intermediate-p _T partons and a decrease at large p _T, which is related to energy conservation, and to the lack of momentum exchange with the medium in our approach.