$\Delta$L=2 hyperon decays induced by Majorana neutrinos and doubly-charged scalars

Abstract

Searches for $\Delta L=2$ decays are crucial to disentangle the Dirac vs Majorana nature of neutrinos. While neutrinoless nuclear double beta decays are the most promising tool to look for di-electron signals of $\Delta L=2$, searches of di-lepton channels with other flavors are far less limited by statistics. We revisit the calculation of $\Delta L=2$ decays of hyperons $B_i^{-}\to B_f^{+}{\ell }^{-}{\ell }^{\prime -}$. We compute the rates of these decays by including the hyperon form factors, which yields finite results in the one-loop model mechanism involving Majorana neutrinos (long-range contributions). In addition, we study the short-range contributions to these kinds of processes in two appealing scenarios. First, we consider the effects of heavy Majorana neutrinos in low-scale seesaw models that involve a minimal parametrization with only two heavy Majorana states. Second, we study an alternative model where $\Delta L=2$ decays are induced by a scalar boson coupled to di-leptons to provide additional predictions.

13 pages and 3 figures; clarification and discussion added, typos corrected, version accepted for publication in PRD

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Cited by in corpus (4)

• Resonant Majorana neutrino effects in $\Delta$L=2 four-body hyperon decays
• Dirac-Majorana neutrinos distinction in four-body decays
• Search for the lepton number violating process ${\Xi }^{-}\to {\Sigma }^{+}{e}^{-}{e}^{-}+c.c.$
• Exploring hadronic de-excitation via Lepton Flavor Violation