Charged Higgs production at the LHC and CP asymmetries

We study CP violation in associated production of a charged Higgs boson and a top quark at the LHC, $pp\to t{H}^{\pm }+X$. The asymmetry between the total cross sections for $H^{+}$ and $H^{-}$ production at next-to-leading order in the MSSM is calculated analytically and a detailed numerical analysis is performed. Furthermore, subsequent decays of $H^{\pm }$ to $tb$ and ${\tau }^{\pm }{\nu }_{\tau }$ are considered. In the case with $H^{\pm }\to tb$ decay the asymmetry can go up to $\sim$~12%.