Lepton-Number Violating Decays of Heavy Mesons

TL;DR

This paper explores lepton-number violating decays of heavy mesons into vector or pseudoscalar mesons, calculating their branching ratios and proposing experimental searches, especially at LHCb, to detect potential Majorana neutrino signatures.

Contribution

It extends previous studies by analyzing rare heavy meson decays into vector mesons, providing theoretical predictions for their branching fractions and suggesting experimental search strategies.

Findings

Calculated branching fractions for heavy meson decays involving lepton-number violation.

Proposed experimental searches at LHCb and other facilities.

Highlighted potential for observing Majorana neutrino effects.

Abstract

The experimental observation of lepton-number violating processes would unambiguously indicate the Majorana nature of neutrinos. Various $\Delta L$ = 2 processes for pseudoscalar meson $M_1$ decays to another pseudoscalar meson $M_2$ and two charged leptons $\ell_1$, $\ell_2$ ($M_1^+\to \ell_1^+\ell_2^+M_2^-$) have been studied extensively. Extending the existing literature on the studies of these kinds of processes, we consider the rare decays of heavy mesons to a vector meson or a pseudoscalar meson. These processes have not been searched for experimentally, while they may have sizable decay rates. We calculate their branching fractions and propose to search for these decay modes in the current and forthcoming experiments, in particular at the LHCb.