Test of lepton flavour universality with $B^{+}\to K^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-}{\ell }^{+}{\ell }^{-}$ decays

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb +1132

The first test of lepton flavor universality between muons and electrons using $B^{+}\to K^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-}{\ell }^{+}{\ell }^{-}$ ($\ell =e,\hat{I}¼$) decays is presented. The measurement is performed wit…