Search for the lepton number violating decay ?- ? pe- e- and the rare inclusive decay ?- ? ?+ X

Abstract

Using a data sample of (1310.6 +/- 7.0) x 10(6) J/psi events taken with the BESIII detector at the center-of-mass energy of 3.097 GeV, we search for the first time for the lepton number violating decay Sigma(-) -> pe(-) e(-) and the rare inclusive decay Sigma(-) -> Sigma(+) X, where X denotes any possible particle combination. The Sigma(-) candidates are tagged in J/psi -> (Sigma) over bar (1385)(+)Sigma(-) decays. No signal candidates are found, and the upper limits on the branching fractions at the 90% confidence level are determined to be B(Sigma(-) -> pe(-) e(-)) < 6.7 x 10(-5) and B(Sigma(-) -> Sigma(+) X) < 1.2 x 10(-4).