First measurement of the $CP$-violating phase ${\varphi }_s^{d\overline{d}}$ in $B_s^0\to (K^{+}{\pi }^{-})(K^{-}{\pi }^{+})$ decays

LHCb collaboration, R. Aaij, B. Adeva +793

A flavour-tagged decay-time-dependent amplitude analysis of $B_s^0\to (K^{+}{\pi }^{-})(K^{-}{\pi }^{+})$ decays is presented in the $K^{\pm }{\pi }^{\mp }$ mass range from 750 to 1600 MeV$/c^2$. The analys…