First evidence of direct CP violation in charmless two-body decays of Bs mesons

Using a data sample corresponding to an integrated luminosity of 0.35 $mathrm{fb}^{-1}$ collected by LHCb in 2011, we report the first evidence of CP violation in the decays of $B^0_s$ mesons to $K^pm pi^mp$ pairs, $A_{CP}(B^0_s rightarrow K pi)=0.27 pm 0.08,mathrm{(stat)} pm 0.02,mathrm{(syst)}$, with a significance of 3.3$sigma$. Furthermore, we report the first observation of CP violation in $B^0$ decays at a hadron collider, $A_{CP}(B^0 rightarrow Kpi)=-0.088 pm 0.011,mathrm{(stat)} pm 0.008,mathrm{(syst)}$, with a significance exceeding 6$sigma$.