Reactions initiated by 5-parton subpocesses: One loop corrections

Abstract

Using the helicity method and recently determined virtual amplitudes, finite one loop higher order corrections (HOC) to processes dominated by 5-parton subprocesses are determined. From the Bremsstrahlung contributions (6-parton subprocesses), those due to soft and collinear partons are taken into account : thus the totality of virtual, soft and collinear HOC (≡ total contribution of distributions) is included. We consider pp¯→γ+γ+X (tevatron) and pp → γ + γ + X (LHC) dominated by qq¯−γγg and gq−γ;q. The resulting K-factors well exceed unity.