# Parton energy loss effect on Z+jet production in high-energy nuclear collisions

## TL;DR

This paper investigates how parton energy loss affects Z+jet production in high-energy nuclear collisions, using advanced simulations to match experimental data and reveal the impact of quark-gluon plasma on jet properties.

## Contribution

It introduces a comprehensive simulation framework combining Sherpa and Linear Boltzmann Transport Model to accurately describe medium modifications of Z+jet correlations in heavy-ion collisions.

## Key findings

- Excellent agreement with experimental observables in both pp and Pb+Pb collisions.
- Energy loss effects explain shifts in momentum asymmetry and jet suppression.
- Jet shape analysis shows significant energy carried away from the jet axis in Pb+Pb collisions.

## Abstract

We give a report of medium modification of Z+jet correlations in Pb+Pb collisions at the Large Hadron Collider using Sherpa to generate initial Z+jet at next-leading-order matrix element matched parton shower, and the Linear Boltzmann Transport Model for jet propagation in the expanding quark-gluon-plasma. Our numerical calculations show excellent agreement with all available observables of Z+jet simultaneously in both proton + proton and Pb+Pb collisions. Our results can well explain the shift of momentum asymmetry $x_{jZ}=p_T^{jet}/p_T^Z$ as well as its mean values, the suppression of the jet yields per Z trigger $R_{jZ}$ and the modification of azimuthal angle correlation $\Delta \phi_{jZ}$. We also demonstrate that it is the energy loss effect on multi-jets from high-order corrections that leads to the suppression of the Z+jet correlation at small azimuthal angle difference $\Delta \phi_{jZ}$ and at small $x_{jZ}$. The jet shape reflecting transverse momentum distribution inside the jet is also calculated, which indicates that large fraction of jet energy is carried away from the jet axis in Pb+Pb collisions.