Calculating QCD corrections to single top production in hadronic interactions Original Research Article

We give a detailed exposé on the calculation of O(αs) corrections to the cross section for the semiweak production of single top quarks in hadronic interactions. After introducing the different sub-processes and defining their kinematics, we briefly recall the computation of the O(α2) qb → q′t and O(αsα2) qg → q′tb Born amplitudes squared. Next, the calculation of virtual and bremsstrahlung corrections is presented. We adopt a massive quark and massive gluon regularisation scheme. We explicitly demonstrate cancellations among various radiative corrections and we describe the procedure of absorbing remaining singularities in the parton density distribution functions. Finally, numerical results are given. We find a cross-section enhancement of roughly 30% (for mt ≈ 174 GeV/c2) with respect to the Born contribution. We observe good agreement between the exact calculation and the approach where the mass singularity is subtracted from the sum of the O(α2) and O(αsα2) tree-level expressions.