Multiplicity distributions inside parton cascades developing in a medium

Abstract

The jet‐quenching explanation of the suppressed high‐pT hadron yields at RHIC implies that the multiplicity distributions of particles inside a jet and jet‐like particle correlations differ strongly in heavy‐ion collisions at RHIC or at the LHC from those observed at e+e− or hadron colliders. We present a framework for describing the medium‐induced modification, which has a direct interpretation in terms of a probabilistic medium‐modified parton cascade, and which treats leading and subleading partons on an equal footing. We show that our approach implies a characteristic distortion of the single inclusive distribution of soft partons inside the jet. We determine, as a function of the jet energy, to what extent the soft fragments within a jet can be measured above some momentum cut.