Associated production of a W boson and massive bottom quarks at next-to-next-to-leading order in QCD

We present the first calculation for the hadroproduction of a W boson in association with a massive bottom (b) quark-antiquark pair at next-to-next-to-leading order (NNLO) in QCD perturbation theory. We exploit the hierarchy between the b-quark mass and the characteristic energy scale of the process to obtain a reliable analytic expression for the two-loop virtual amplitude with three massive legs, starting from the corresponding result available for massless b quarks. The use of massive b quarks avoids the ambiguities associated with the correct flavor assignment in massless calculations, paving the way to a more realistic comparison with experimental data. We present phenomenological results considering proton-proton ffifficollisions at center-of-mass energy p s 1/4 13.6 TeV for inclusive Wbb over bar production and within a fiducial region relevant for the associated production of a W boson and a Higgs boson decaying into a bb over bar pair, for which Wbb over bar production represents one of the most relevant backgrounds. We find that the NNLO corrections are substantial and that their inclusion is mandatory to obtain reliable predictions.