2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/177783We describe a calculation of the fully differential cross section for Higgs boson production in the gluon fusion channel through next-to-next-to-leading order (NNLO) in perturbative QCD. The decay of the Higgs boson into two photons is included. Technical aspects of the computation are discussed in detail. The implementation of the calculation into a numerical code, called FEHiP, is described. The NNLO K-factors for completely realistic photon acceptances and isolation cuts, including those employed by the ATLAS and CMS collaborations, are computed. We study various distributions of the photons from Higgs decay through NNLO.48 pgs, uses axodraw.sty; typos, numerical bugs in Figs. 7,9 fixedHigh Energy Physics - PhenomenologyHigh Energy Physics - Experimenttext