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

We reanalyze the contributions to neutrinoless double beta (beta beta(0v)) decay from supersymmetry with explicit breaking of R-parity. Although we ke ep both bilinear and trilinear terms, our emphasis is put on bilinear R-par ity breaking terms, because these mimic more closely the models where the b reaking of R-parity is spontaneous. Comparing the relevant Feynman diagrams we conclude that the usual mass mechanism of double beta decay is the domi nant one. From the non-observation of beta beta(0v) decay we set limits on the bilinear R-parity breaking parameters of typically a (few) 100 keV. Des pite such stringent bounds, we stress that the magnitude of R-parity violat ing phenomena that can be expected at accelerator experiments can be very l arge, since they involve mainly the third generation, while beta beta(0v) d ecay constrains only the first generation couplings. (C) 1999 Elsevier Scie nce B.V. All rights reserved.