Search for Decays of B^{0} Mesons into Pairs of Leptons: B{0} -> e^{+}e^{-}, B^{0} -> μ^{+}μ^{-} and B^{0} -> e^{\pm}μ^{\mp}

Abstract

We search for the decays of the $B^0$ meson into $e^{+}{e}^{-}$, ${\mu }^{+}{\mu }^{-}$ $e^{\pm }{\mu }^{\mp }$ pairs in a sample of $9.7\times 10^6$ $B\bar{B}$ pairs recorded by CLEO detector. No signal is found, and the following upper limits on the corresponding branching fractions are established: $<8.3\times 10^{-7}$, $<6.1\times 10^{-7}$, $<15\times 10^{-7}$ at 90% confidence level. A new lower limit on the Pati-Salam leptoquark mass $M_{LQ}>27$ TeV is established at 90% confidence level.

10 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS