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, $pp \to tH^\pm +X$. 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%.