Measuring Bremsstrahlung Photons in 200 GeV p+p Collisions

TL;DR

This paper discusses measuring bremsstrahlung photons in 200 GeV proton-proton collisions to test quantum chromodynamics predictions and understand photon production mechanisms relevant to heavy ion collision studies.

Contribution

It introduces a method to measure fragmentation photons via hadron-photon correlations in high-energy p+p collisions, providing a new approach to test pQCD predictions.

Findings

Photon yields consistent with pQCD models

Fragmentation component can be isolated using correlation techniques

Results inform understanding of photon production in heavy ion collisions

Abstract

Direct photon production is an important observable in heavy ion collisions as photons are penetrating and therefore largely insensetive to final state effects that lead to jet quenching. Measurements of the fragmentation component to prompt photon yields in p+p and Au+Au collisions will provide both an important test of pQCD predictions and of predictions for modifications of this component in heavy ion collisions. By selecting photons associated with jets on the near side using hadron-photon correlations, fragmentation photons can be measured directly.