Associated production of a <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>W</mml:mi></mml:math> boson and massive bottom quarks at next-to-next-to-leading order in QCD
Luca Buonocore, Simone Devoto, Stefan Kallweit, Javier Mazzitelli, Luca Rottoli, Chiara Savoini
Abstract
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 collisions at center-of-mass energy $\sqrt{s}=13.6\text{ }\text{ }\mathrm{TeV}$ for inclusive $Wb\overline{b}$ production and within a fiducial region relevant for the associated production of a $W$ boson and a Higgs boson decaying into a $b\overline{b}$ pair, for which $Wb\overline{b}$ 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.