Jet shape modification in a transport calculation

TL;DR

This paper introduces a unified transport model to accurately predict jet shape modifications in heavy ion collisions, accounting for both elastic and inelastic energy loss mechanisms and medium evolution.

Contribution

It develops a comprehensive framework combining jet and medium evolution, enabling realistic predictions of jet shape modifications at large radii in Pb-Pb collisions.

Findings

Model agrees with experimental jet suppression data

Reproduces jet shape functions up to large radii

Highlights the roles of collisional and radiative energy loss

Abstract

A precise quantification of the medium-modification of the high transverse momenta jets in relativistic heavy ion collisions rely on consistent modelling of elastic and inelastic energy loss suffered by the jet and the concurrent underlying medium evolution. We have developed a unified framework for jet and bulk medium evolution within a multiphase transport approach where the jets and medium share energy and momentum via multiple elastic scatterings and medium-induced gluon radiation during the parton transport. The formulation enables realistic predictions of jet based observables extended to a large radius of the jet cone in central Pb-Pb collisions at 5.02 TeV. The model provides reasonable quantitative agreement with the experimental data from inclusive jet suppression and the full jet shape function up to large radial distances induced by both the collisional and radiative jet energy loss and migration of the lost $p_T$ in the medium. We find that gradual degradation of jet energy through gluon emissions alters the energy-momentum evolution in the jet, essential to describe the entire range of jet shape ratio relative to proton-proton collisions. Pure collisional energy loss injects appreciable $p_T$ broadening and migration of the medium partons, resulting in an enhanced population at large angular distances in the jet-shape ratio.