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

TL;DR

This paper investigates rare hyperon decays mediated by a resonant Majorana neutrino, proposing that experiments like BES-III could detect these processes and set limits on new physics parameters.

Contribution

It provides the first detailed calculations of specific LNV hyperon decays mediated by a resonant Majorana neutrino and compares their sensitivity to existing meson decay constraints.

Findings

Hyperon decay rates could be within experimental reach at BES-III.

Derived new limits on heavy neutrino mixing parameters from hyperon decay channels.

Compared hyperon decay sensitivities with those from meson decay experiments.

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.