Direct photon production in $p\mathbf{+}p$ collisions at $\sqrt{s}\mathbf{=}200\text{ }\text{ }\mathrm{GeV}$ at midrapidity

Direct photon production in $p + p$ collisions at $\sqrt{s} = 200 GeV$ at midrapidity

A. Adare et al. (PHENIX Collaboration)

Phys. Rev. D 86, 072008 – Published 23 October 2012

Abstract

The differential cross section for the production of direct photons in $p + p$ collisions at $\sqrt{s} = 200 GeV$ at midrapidity was measured in the PHENIX detector at the Relativistic Heavy Ion Collider. Inclusive direct photons were measured in the transverse momentum range from $5.5 - 25 GeV / c$ , extending the range beyond previous measurements. Event structure was studied with an isolation criterion. Next-to-leading-order perturbative-quantum-chromodynamics calculations give a good description of the spectrum. When the cross section is expressed versus $x_{T}$ , the PHENIX data are seen to be in agreement with measurements from other experiments at different center-of-mass energies.