Accurate predictions for charged Higgs production: Closing the mH±∼mt window

We present predictions for the total cross section for the production of a charged Higgs boson in the intermediate-mass range (mH±∼mt) at the LHC, focusing on a type-II two-Higgs-doublet model. Results are obtained at next-to-leading order (NLO) accuracy in QCD perturbation theory, by studying the full process pp→H±W∓bb¯ in the complex-(top)-mass scheme with massive bottom quarks. Compared to lowest-order predictions, NLO corrections have a sizeable impact: they increase the cross section by roughly 50% and reduce uncertainties due to scale variations by more than a factor of two. Our computation reliably interpolates between the low- and high-mass regime. Our results provide the first NLO prediction for charged Higgs production in the intermediate-mass range and therefore allow to have NLO accurate predictions in the full mH± range. The extension of our results to different realisations of the two-Higgs-doublet model or to the supersymmetric case is also discussed.