Neutrinoless double beta decay in supersymmetry with bilinear R-parity breaking

Abstract

We reanalyze the contributions to neutrinoless double beta ( ββ 0 ν ) decay from supersymmetry with explicit breaking of R-parity. Although we keep both bilinear and trilinear terms, our emphasis is put on bilinear R-parity breaking terms, because these mimic more closely the models where the breaking of R-parity is spontaneous. Comparing the relevant Feynman diagrams we conclude that the usual mass mechanism of double beta decay is the dominant one. From the non-observation of ββ 0 ν decay we set limits on the bilinear R-parity breaking parameters of typically a (few) 100 keV. Despite such stringent bounds, we stress that the magnitude of R-parity violating phenomena that can be expected at accelerator experiments can be very large, since they involve mainly the third generation, while ββ 0 ν decay constrains only the first generation couplings.