Direct Photon Measurements at PHENIX

TL;DR

This paper reports on direct photon measurements at PHENIX in proton-proton and gold-gold collisions at 200 GeV, showing consistency with theoretical models and no suppression in heavy-ion collisions.

Contribution

First measurement of direct photons at PHENIX in p+p and Au+Au collisions at 200 GeV, with results consistent with multiple theoretical models.

Findings

p+p data agrees with pQCD predictions

Nuclear modification factor in Au+Au is approximately unity

Data aligns with models including initial and final state effects

Abstract

PHENIX has measured direct photons in p+p and Au+Au collisions at sqrt{s_{NN}}=200 GeV. The p+p measurement is in good agreement with pQCD expectations. The nuclear modification factor in Au+Au is found to be consistent with unity for all centralities, and is compared to theoretical models. The data are found in agreement with models that take into account initial state modifications, as well as with those that account also for final state modifications.