Double-real radiation in hadronic top quark pair production as a proof of a certain concept

Using the recently introduced STRIPPER approach to double-real radiation, we evaluate the total cross sections for the main partonic channels of the next-to-next-to-leading order contributions to top quark pair production in hadronic collisions: gg→tt-bargg, gg→tt-barqq-bar, qq-bar→tt-bargg, qq-bar→tt-barq'q-bar', q'≠q. The results are given as Laurent expansions in ε, the parameter of dimensional regularization, at a number of m/ECM values spreading the entire variation range, with m the mass of the top quark and ECM the center-of-mass energy. We describe the details of our implementation and demonstrate its main properties: pointwise convergence and efficiency. We also prove the cancellation of leading divergences after inclusion of the double-virtual and real-virtual contributions. On a more technical note, we extended the double-soft current formulae to the case of massive partons.