Bounding resonant Majorana neutrinos from four-body B and D decays

TL;DR

This paper derives new constraints on Majorana neutrino properties by analyzing four-body B and D meson decays, showing potential for future experimental improvements to enhance these bounds.

Contribution

It introduces a novel method to constrain Majorana neutrinos using four-body meson decays and compares the effectiveness of B and D decay channels.

Findings

B^- decay constraints are competitive with existing limits.

D^0 decay improvements could yield similar constraints.

Resonant production assumptions are key to the analysis.

Abstract

Searches of lepton-number violation in different processes are very useful to constrain the parameter space of Majorana neutrinos. Here we use available upper bounds on the branching fractions of B^- -> D^0pi^+mu^-mu^- and D^0 -> (pi^-pi^-/K^-pi^-) mu^-mu^- decays to derive constraints on the mass and mixings of Majorana neutrinos by assuming they are produced resonantly in these four-body decays. While the excluded region obtained from B^- decays are competitive with existing limits from three-body D^- and B^- decays, it is shown that experimental improvements on D^0 decays offer a good potential to provide similar results.