Isolated photons without fragmentation contribution

Abstract

I illustrate how to define an isolated-photon cross section which is independent of the parton-to-photon fragmentation contribution, it is infrared safe to all orders in perturbative QCD, and it is exclusive in the kinematical variables of the photon and of the accompanying jets. This isolation prescription is applicable to any kind of polarized or unpolarized hard collisions. It can also be used without any modifications in the case of two or more isolated photons in the final state. I present results for one-photon production in hadronic collisions, and I compare them with existing results obtained in the framework of the conventional cone approach.