# Quark Matter 2018

May 13 – 19, 2018
Venice, Italy
Europe/Zurich timezone
The organisers warmly thank all participants for such a lively QM2018! See you in China in 2019!

## Medium response to jet energy loss and redistribution of lost energy via the AMPT model

May 15, 2018, 5:00 PM
2h 40m
First floor and third floor (Palazzo del Casinò)

### First floor and third floor

#### Palazzo del Casinò

Poster Correlations and fluctuations

### Speaker

Mr Ao Luo (Central China Normal University)

### Description

Jet-medium interaction has two important aspects: jet energy loss and the medium response to the lost energy/momentum. The study of jet energy loss has been very successful in the explanation of the suppression of high $p_T$ hadron and jet productions as well as the nuclear modification of dihadron, dijet, photo-jet and hadron-jet correlations. The search for the signal of the medium response to jet transport has been a long-standing topic: how does the lost energy from the jets evolve with the dynamical medium and where does it show up in the final state particle distributions and correlations?

We study the medium response and redistribution of the lost energy from hard jets via the AMPT model. In particular, we study asymmetric dijet events in PbPb collisions at 2.76 TeV. We first investigate in detail the contribution from the final charged hadrons carrying different transverse momenta and emitted from different angular directions, the projected transverse momentum $\langle p_{T}^{||} \rangle$ [1]. It is found that $\langle p_{T}^{||} \rangle$ in the leading jet direction is mainly contributed by hard hadrons in both peripheral and central PbPb collisions, while the opposite direction in central collisions is dominated by soft hadrons. Our study of the in-cone and out-of-cone contributions to $\langle p_{T}^{||} \rangle$ shows that these soft hadrons are mostly emitted at large angles away from the dijet axis. These results indicate that in the AMPT model, a large amount of the lost energy from hard jets occurred in the partonic stage is transported by elastic collisions to soft partons at large angles; this is qualitatively consistent with the CMS measurements. To further investigate the signals of the medium response effect and the redistribution of the lost energy at large angles, we also study the jet shape functions with a wide range of $r$ for asymmetric dijet events.

[1] Z. Gao, A. Luo, G. L. Ma, G.Y. Qin, H.Z. Zhang, arXiv:1612.02548 [hep-ph].

Centralised submission by Collaboration Presenter name already specified Theory

### Primary authors

Mr Zhan Gao (Central China normal university) Mr Ao Luo (Central China Normal University) Prof. Guang-You Qin (Central China Normal University) Prof. Hanzhong Zhang (IOPP, CCNU)

### Co-author

Prof. Guo-Liang Ma (Shanghai INstitute of Applied Physics (SINAP), CAS)