Resonant Majorana neutrino effects in $\Delta$L=2 four-body hyperon decays

Abstract

We computed the $\Sigma^{-}\to n\pi^+e^-\ell^-$ ($\ell=e,\mu$), $\Xi^-\to \Lambda\pi^+e^-e^-$, and $\Lambda\to p\pi^+e^-e^-$ lepton number violating (LNV) hyperon decays mediated by a resonant Majorana neutrino. The expected hyperon production rate of experiments like BES-III of around $10^6-10^8$ may allow searching for these rare hyperon decays at enough sensitivities. We illustrate the limits on the new heavy mixing parameters derived from these hyperon channels and compare them with other LNV meson decays in similar mass regions of the resonant neutrino state.