# Quark Matter 2014 - XXIV International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

19-24 May 2014
Europe/Zurich timezone

## Is the LHC Fireball Less Opaque Than the RHIC Fireball, and Why?

20 May 2014, 16:30
2h

Board: E-42
Poster Jets

### Speaker

Dr Xilin Zhang (Institute of Nuclear and Particle Physics and Department of Physics and Astronomy, Ohio University, Athens, OH, USA)

### Description

High energy jets, penetrating the hot QCD matter created in heavy ion collisions, provide unique probe of the medium property. Recently there has been a lot of interests in extracting the possibly nontrivial temperature dependence of the jet-medium coupling. Particularly sensitive to such T-dependence are two sets of observables: the anisotropy of jet energy loss via the azimuthal angle dependence of suppression $R_{aa}(\phi)$ (or equivalently the various harmonic coefficients $v_n$ at high $p_t$), as well as the evolution of the overall suppression with beam energy, $R_{aa}(\sqrt{s})$. We report our systematic study of these observables using event-by-event simulations, and compare with available data from RHIC and LHC. The results strongly suggest a nontrivial temperature dependence of the jet-medium coupling and in particular its enhancement near the parton/hadron phase boundary. Recently emerging evidences for such a possibility from various other jet modelings, as well as efforts to understand such peculiar medium property from microscopic theories will also be discussed. Finally we also briefly discuss potentially final state jet attenuation effect in (possibly created) hot medium in the "mini-bang" (pPb and dAu collisions) and demonstrate that jet quenching anisotropy could provide a clean probe to tell whether there is substantial final state interaction in those collisions.  References: Zhang & Liao, arXiv:1311.5463; PRC89(2014)014907; PRC87(2013)044910; PLB713(2012)35.

### Primary authors

Prof. Jinfeng Liao (Physics Department and Center for Exploration of Energy and Matter, Indiana University, Bloomington, IN, USA; RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, NY, USA) Dr Xilin Zhang (Institute of Nuclear and Particle Physics and Department of Physics and Astronomy, Ohio University, Athens, OH, USA)

### Presentation Materials

There are no materials yet.