Search for the rare decays $B_s^0\to e^{+}{e}^{-}$ and $B^0\to e^{+}{e}^{-}$

Abstract

A search for the decays $B_s^0\to e^{+}{e}^{-}$ and $B^0\to e^{+}{e}^{-}$ is performed using data collected with the LHCb experiment in proton-proton collisions at center-of-mass energies of $7$, $8$ and $13\text{TeV}$, corresponding to integrated luminosities of $1$, $2$ and $2{\text{fb}}^{-1}$, respectively. No signal is observed. Assuming no contribution from $B^0\to e^{+}{e}^{-}$ decays, an upper limit of $\mathcal{B}(B_s^0\to e^{+}{e}^{-})<9.4(11.2)\times 10^{-9}$ is obtained at $90(95)\%$ confidence level. If no $B_s^0\to e^{+}{e}^{-}$ contribution is assumed, a limit of $\mathcal{B}(B^0\to e^{+}{e}^{-})<2.5(3.0)\times 10^{-9}$ is determined at $90(95)\%$ confidence level. These upper limits are more than one order of magnitude lower than the previous values.

All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2020-001.html