O(α_s) Corrections to b bar b to W^(pm)H^(mp) at the CERN Large Hadron Collider

The $O(\alpha_{s})$ corrections to the cross section for $b \bar b \to W^{\pm}H^{\mp}$ at the LHC are calculated in the minimal supersymmetric standard model (MSSM) in the $\bar{MS}$ and OS (on-mass-shell) renormalization schemes. The results in two schemes are in good agreement. In the $\bar{MS}$ scheme, the QCD corrections are negative and within $ -14% \sim -20%$ for charged Higgs mass up to 1 TeV and $\tan\beta >15$. For $\tan\beta =2$, the magnitude of the QCD corrections can be greater than 30%.