# Hard Probes 2018: International Conference on Hard & Electromagnetic Probes of High-Energy Nuclear Collisions

30 September 2018 to 5 October 2018
Aix-Les-Bains, Savoie, France
Europe/Zurich timezone
PROCEEDINGS OPEN UNTIL DECEMBER 15th 2018

## Hard probe radiative energy loss beyond soft-gluon approximation

2 Oct 2018, 16:25
20m
Aix-Les-Bains, Savoie, France

#### Aix-Les-Bains, Savoie, France

Aix-Les-Bains, Congress Center Student Lectures Day: September 30 at CERN
2a) Jets and high-pT hadrons (TALK)

### Speaker

Bojana Blagojevic (Institute of Physics Belgrade)

### Description

One of the widely used kinematic assumptions in calculating hard probe radiative energy loss within QGP, is the soft-gluon approximation, which considers that energy loss of the parent parton via gluon's bremsstrahlung is small compared to its initial energy. However, diverse theoretical formalisams obtained a notable energy loss of high $p_{\perp}$ particles, implicitly suggesting inadequacy of this approximation.

To address this issue, we relaxed the soft-gluon approximation within DGLV formalism [1]. The obtained analytic expressions are quite more involved compared to the soft-gluon case. The effects of this relaxation on numerical predictions for the first order in opacity fractional radiative energy loss and number of radiated gluons are small, although of opposite signs. Moreover, a joint effect for these two variables results in an insignificant suppression alternation. Consequently, the results presented here provide confidence that, regardless of the concerns mentioned above, surprisingly, the soft-gluon approximation can reliably be applied within DGLV formalism. Finally, we discuss generalizing the relaxation in the dynamical medium as well, which ensures broader relevance of the conclusions obtained here.

[1] B. Blagojevic, M. Djordjevic and M. Djordjevic, arXiv:nucl-th/1804.07593 (2018).

### Primary author

Bojana Blagojevic (Institute of Physics Belgrade)

### Co-authors

Magdalena Djordjevic (Institute of Physics Belgrade) Marko Djordjevic