Neutrinoless double beta decay, neutrino mass and bilinear R-parity breaking supersymmetry

TL;DR

This paper investigates how neutrinoless double beta decay constrains R-parity violating supersymmetry, showing that even with perfect parameter alignment, loop corrections imply a non-zero effective Majorana neutrino mass.

Contribution

It provides new bounds on R-parity breaking parameters from double beta decay data and demonstrates the non-zero neutrino mass induced by loop effects in supersymmetric models.

Findings

Current experimental limits set upper bounds on R-parity breaking parameters.

Loop corrections induce a non-zero effective Majorana neutrino mass.

Even perfect alignment among parameters does not eliminate neutrino mass contributions.

Abstract

Neutrinoless double beta ($\znbb$) decay violates lepton number; its absence stringently constrains the parameters of theories beyond the standard model in which the neutrino has a Majorana mass. R-parity violating weak-scale supersymmetry is a prominent example of such models. Double beta decay in supersymmetry with explicit bilinear R-parity breaking is discussed and current limits on the $\znbb$ decay half life of $^{76}$Ge are used to extract upper bounds on the R-parity breaking parameters of the first generation. Moreover, it is shown that the effective Majorana neutrino mass, measured in $\znbb$ decay, is non-zero once the 1-loop corrections are taken into account even for the case of perfect alignment ($\Lambda_i:=(< {\tilde \nu}_i > \mu - v_1 \epsilon_i) \equiv 0$) among the R-parity violating parameters.