Polarization of High-Transverse-Momentum Single Photons as a Test of Quantum Chromodynamics

Abstract
It is shown that high-transverse-momentum photons originating from the process quark+gluon→quark+photon exhibit a substantial linear polarization in perturbative quantum chromodynamics. The angular dependence of the polarization is quite sensitive to the non-Abelian structure of the interaction, and can be used to check the equality of the quark-gluon and three-gluon couplings.