Search for the lepton number violating decays $B^{+}\to \ddot{I}{€}^{-}\hat{I}{¼}^{+}\hat{I}{¼}^{+}$ and $B^{+}\to K^{-}\hat{I}{¼}^{+}\hat{I}{¼}^{+}$

Abstract

A search is performed for the lepton number violating decay $B^{+}\to h^{-}\hat{I}{¼}^{+}\hat{I}{¼}^{+}$, where $h^{-}$ represents a $K^{-}$ or a $\ddot{I}{€}^{-}$, using data from the LHCb detector corresponding to an integrated luminosity of $36p{b}^{-1}$. The decay is forbidden in the Standard Model but allowed in models with a Majorana neutrino. No signal is observed in either channel and limits of $B(B^{+}\to K^{-}\hat{I}{¼}^{+}\hat{I}{¼}^{+})<5.4\times 10^{-8}$ and $B(B^{+}\to \ddot{I}{€}^{-}\hat{I}{¼}^{+}\hat{I}{¼}^{+})<5.8\times 10^{-8}$ are set at the 95% confidence level. These improve the previous best limits by factors of 40 and 30, respectively.