# Quark Matter 2018

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

## Prompt photon production in $p$+Pb collisions with the ATLAS detector

15 May 2018, 17:00
2h 40m
First floor and third floor (Palazzo del Casinò)

### First floor and third floor

#### Palazzo del Casinò

Poster Electromagnetic and weak probes

### Speaker

Kurt Keys Hill (University of Colorado Boulder (US))

### Description

Electroweak bosons produced in heavy ion collisions are excellent tools to probe a variety of initial state effects on hard processes involving nuclei. They are expected to be unmodified by final state hot nuclear matter effects while being sensitive to the initial state nuclear modification of the partonic momentum structure and the energy loss of the incoming partons participating in a hard scattering. Thus, these probes are important for serving as a standard candle against which to compare the production of strongly interacting particles, such as hadron and jet production, which are sensitive to both the initial and final state. This poster presents a new measurement of prompt photon production in the recently collected high-statistics 8.16 TeV $p$+Pb collision data. Photon yields are reported over a broad kinematic range, $25 < p_\mathrm{T}^{\gamma} < 500$ GeV and $\left|\eta^\mathrm{lab}\right|<2.37$, and the production rates are compared to an extrapolated $pp$ reference based on existing $\sqrt{s}=8$ TeV $pp$ collision data. The measured spectra and nuclear modification factors are compared to theoretical calculations of initial state energy loss as well as the expectations from nuclear parton distribution functions.

Collaboration ATLAS Experiment Presenter name already specified

### Primary authors

Barbara Krystyna Wosiek (Institute of Nuclear Physics Polish Academy of Sciences (PL)) Kurt Keys Hill (University of Colorado Boulder (US))