2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/189250We calculate the one-loop squared contributions to the next-to-next-to-leading order ${\cal O}(α^2α_s^2)$ radiative QCD corrections for the production of heavy quark pairs in the collisions of unpolarized on--shell photons. In particular, we present analytical results for the squared matrix elements that correspond to the product of the one--loop amplitudes. All results of the perturbative calculation are given in the dimensional regularization scheme. These results represent the Abelian part of the corresponding gluon--induced next-to-next-to-leading order cross section for heavy quark pair hadroproduction.11 pages, Revtex, slight change in title and abstract, one paragraph and reference added, matches published versionHigh Energy Physics - Phenomenologytext