Photon fragmentation in the antenna subtraction formalism

A bstract The theoretical description of photon production at particle colliders combines direct radiation and fragmentation processes, which can not be separated from each other for definitions isolation used in experimental measurements. these processes must account collinear parton-photon configurations, retaining the dependence on momentum fraction, includes parton-to-photon functions. We extend antenna subtraction method to include up next-to-next-to-leading order (NNLO) QCD. Collinear is handled using newly introduced functions associated phase space mappings. derive integrated forms describe their interplay with mass factorisation construction principles terms NNLO identified photons are outlined, thereby enabling application different colliders.