Search for the lepton number violating decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi mathvariant="normal">Σ</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:mi>p</mml:mi><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> and the rare inclusive decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi …

Using a data sample of (1310.6±7.0)×106 J/ψ events taken with the BESIII detector at center-of-mass energy 3.097 GeV, we search for first time lepton number violating decay Σ−→pe−e− and rare inclusive Σ−→Σ+X, where X denotes any possible particle combination. The Σ− candidates are tagged in J/ψ→Σ¯(1385)+Σ− decays. No signal found, upper limits on branching fractions 90% confidence level determined to be B(Σ−→pe−e−)<6.7×10−5 B(Σ−→Σ+X)<1.2×10−4.Received 8 December 2020Accepted 2 February 2021DOI:https://doi.org/10.1103/PhysRevD.103.052011Published by American Physical Society under terms Creative Commons Attribution 4.0 International license. Further distribution this work must maintain attribution author(s) published article’s title, journal citation, DOI. Funded SCOAP3.Published SocietyPhysics Subject Headings (PhySH)Research AreasBranching fractionRare decaysPhysical SystemsHyperonsPropertiesBaryon & symmetriesParticles Fields