Lepton number violation by heavy Majorana neutrino in $B$ decays

TL;DR

This paper explores lepton number violation in B meson decays caused by heavy Majorana neutrinos, analyzing potential signals and experimental sensitivities at future colliders like Belle II and FCC-ee.

Contribution

It provides a detailed analysis of LNV in B decays mediated by GeV-scale Majorana neutrinos and estimates experimental sensitivities for future collider searches.

Findings

Derived sensitivity limits on the mixing angle $ heta_6$ for future experiments.

Analyzed the decay channel $B^+ o 5^+ N o 5^+ 5^+ C6^-$.

Estimated the potential to observe LNV signals at Belle II and FCC-ee.

Abstract

Heavy Majorana neutrinos are predicted in addition to ordinary active neutrinos in the models with the seesaw mechanism. We investigate the lepton number violation (LNV) in $B$ decays induced by such a heavy neutrino $N$ with GeV-scale mass. Especially, we consider the decay channel $B^+ \to \mu^+ \, N \to \mu^+ \mu^+ \pi^-$ and derive the sensitivity limits on the mixing angle $\Theta_\mu$ by the future search experiments at Belle II and in $e^+ e^-$ collisions at the Future Circular Collider (FCC-ee).