Production of γZg and associated processes via gluon fusion at hadron colliders

We present results for the process gg -> gamma Zg within the standard model at hadron colliders. Due to a large gluon flux at the LHC and the proposed HE-LHC, this process can have significant cross section at these machines. Several thousand such events have already been produced at the LHC according to the standard model predictions. This process can also be a background to new physics signals. We discuss some of the important features of this process related to the structure of its amplitude. We also compute the total cross section at the hadron colliders and give some important kinematic distributions. A comparison of our results is made with the corresponding NLO calculation using the MCFM program. We briefly discuss the production of gamma gamma g and gamma gamma Z via gluon fusion. The amplitudes of these processes are closely related to the gg -> gamma Zg amplitude.