Neutrinoless double-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>β</mml:mi></mml:math>decay in left-right-symmetric models

Abstract

We calculate neutrinoless double-$\ensuremath{\beta}$ decay due to doubly charged Higgs bosons, which occur naturally in left-right-symmetric models. We find that the comparison with known half-lives yields values of phenomenological parameters which are compatible with earlier analyses of neutral-current data. In particular, we obtain a right-handed gauge-boson mass lower bound of the order of 240 GeV. Using this result and expressions for neutrino masses derived in a parity-nonconserving left-right-symmetric model, we obtain ${m}_{{\ensuremath{\nu}}_{e}}\ensuremath{\le}1.5$ eV, ${m}_{{\ensuremath{\nu}}_{\ensuremath{\mu}}}\ensuremath{\le}0.05$ MeV, and ${m}_{{\ensuremath{\nu}}_{\ensuremath{\tau}}}\ensuremath{\le}18$ MeV.