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

TL;DR

This paper investigates how the timing of jet formation influences jet quenching phenomena in heavy-ion collisions, revealing that formation time significantly impacts jet suppression and its momentum dependence.

Contribution

It introduces a systematic comparison of different jet formation time models within a transport framework, highlighting their effects on jet quenching observables.

Findings

Longer formation times reduce jet suppression effects.

Formation time alters the jet transverse momentum dependence.

Different formation scenarios produce distinguishable jet quenching patterns.

Abstract

Jet quenching has successfully served as a hard probe to study the properties of 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 study, we present a systematical study on the effects of this formation time on jet quenching in relativistic nuclear collisions. Jets from initial hard scatterings were simulated with Pythia, and their interactions with QGP were 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 were implemented and compared, including instantaneous formation, formation from single splitting, and formation from sequential splittings, before which no jet-medium interaction was 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.