Search for the decays $B_s^0\to \ddot{I}{„}^{+}\ddot{I}{„}^{-}$ and $B^0\to \ddot{I}{„}^{+}\ddot{I}{„}^{-}$

Abstract

A search for the rare decays $B_s^0\to \ddot{I}{„}^{+}\ddot{I}{„}^{-}$ and $B^0\to \ddot{I}{„}^{+}\ddot{I}{„}^{-}$ is performed using proton--proton collision data collected with the LHCb detector. The data sample corresponds to an integrated luminosity of 3fb${}^{-1}$ collected in 2011 and 2012. The $\ddot{I}„$ leptons are reconstructed through the decay $\ddot{I}{„}^{-}\to \ddot{I}{€}^{-}\ddot{I}{€}^{+}\ddot{I}{€}^{-}\hat{I}{½}_{\ddot{I}}„$. Assuming no contribution from $B^0\to \ddot{I}{„}^{+}\ddot{I}{„}^{-}$ decays, an upper limit is set on the branching fraction $\mathcal{B}(B_s^0\to \ddot{I}{„}^{+}\ddot{I}{„}^{-})<6.8\times 10^{-3}$ at 95% confidence level. If instead no contribution from $B_s^0\to \ddot{I}{„}^{+}\ddot{I}{„}^{-}$ decays is assumed, the limit is $\mathcal{B}(B^0\to \ddot{I}{„}^{+}\ddot{I}{„}^{-})<2.1\times 10^{-3}$ at 95% confidence level. These results correspond to the first direct limit on $\mathcal{B}(B_s^0\to \ddot{I}{„}^{+}\ddot{I}{„}^{-})$ and the world's best limit on $\mathcal{B}(B^0\to \ddot{I}{„}^{+}\ddot{I}{„}^{-})$.

21 pages, 10 figures. All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2017-003.html