# Hard Probe 2016

22-27 September 2016
East Lake International Conference Center
Asia/Chongqing timezone
<a href="http://hp2016.ccnu.edu.cn">http://hp2016.ccnu.edu.cn</a>

### Conference Secretary

25 Sep 2016, 08:50
20m
Shi-Yan Hall (East Lake International Conference Center)

### Shi-Yan Hall

#### East Lake International Conference Center

Donghu Road 142, Wuchang District, Wuhan, Hubei, China

### Speaker

Shu-yi Wei (CCNU)

### Description

Dijet, dihadron, hadron-jet angular correlations have been reckoned as important probes of the transverse momentum broadening effects in relativistic nuclear collisions.
When a pair of high-energy jets created in hard collisions traverse the quark-gluon plasma produced in heavy-ion collisions, they become de-correlated due to the vacuum soft gluon radiation associated with the Sudakov logarithms and the medium-induced transverse momentum broadening.
For the first time, we employ the systematical resummation formalism and establish a baseline calculation to describe the dihadron and hadron-jet angular correlation data in $pp$ and peripheral $AA$ collisions where the medium effect is negligible.
We demonstrate that the medium effects, especially the so-called jet quenching parameter $\hat q$, can be extracted from the angular de-correlations observed in $AA$ collisions.
A global $\chi^2$ analysis of dihadron and hadron-jet angular correlation data renders the best fit $\langle \hat q L\rangle_{\textrm{tot}} \sim 14 \textrm{GeV}^2$ for a quark jet at RHIC top energy, with $L$ the typical traversed medium length.
Further experimental and theoretical efforts along the direction of this work shall significantly advance the quantitative understanding of transverse momentum broadening and help us acquire unprecedented knowledge of jet quenching parameter in relativistic heavy-ion collisions.

Presentation type Oral