# 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!

## PHENIX measurement of low momentum direct photon radiation from p$+$p and p$+$A collisions

May 14, 2018, 4:50 PM
20m
Sala Casinò, 1st Floor (Palazzo del Casinò)

### Sala Casinò, 1st Floor

#### Palazzo del Casinò

Parallel Talk Electromagnetic and weak probes

### Description

In recent years data from small collision systems at LHC and RHIC have revealed
evidence for collective behavior of the produced hadrons. Collective behavior in
small systems clearly points towards a strongly coupled system being formed in
these collisions. If so, the matter formed must also radiate thermal or low
momentum direct photons. PHENIX is ideally positioned to search for any indications for thermal photon emission from small systems.

The versatility of RHIC allowed PHENIX to collect large data sets with a high
multiplicity trigger for p+p, p+A, d+Au and $^{3}$He$+$Au collisions at 200 GeV. These data sets are being analyzed with the methods already developed for the
measurement of low momentum direct photons from Au+Au collisions. Photons are measured through their conversions to electron-positron pairs in the material of the PHENIX vertex detector, and the fraction of direct photons is determined
after tagging photons from neutral pion decays. In this talk we will present
results from p+p and p+Au collisions.

Collaboration PHENIX Presenter name already specified Experiment

### Primary author

Gabor David (Brookhaven National Laboratory)