Effects of the formation time of parton shower on jet quenching in heavy-ion collisions

Mengxue Zhang, Yang He, Shanshan Cao, Li Yi

Published 2022-08-29Version 1

Jet quenching has successfully served as a hard probe to study the properties of the Quark-Gluon Plasma (QGP). As a multi-particle system, jets take time to develop from a highly virtual parton to a group of partons close to mass shells. In this work, we present a systematical study on the effects of this formation time on jet quenching in relativistic nuclear collisions. Jets from initial hard scatterings are simulated with Pythia and their interactions with the QGP are described using a Linear Boltzmann Transport (LBT) model that incorporates both elastic and inelastic scatterings between jet partons and the thermal medium. Three different estimations of the jet formation time are implemented and compared, including instantaneous formation, formation from single splitting and formation from sequential splittings, before which no jet-medium interaction is assumed. We found that deferring the jet-medium interaction with a longer formation time not only affects the overall magnitude of the nuclear modification factor of jets, but also its dependence on the jet transverse momentum.