Neutrino mass induced radiatively by supersymmetric leptoquarks

We show how nonzero Majorana neutrino masses can be radiatively generated by extending the MSSM with leptoquark chiral multiplets without violating R-parity. It is found that, with these particles, the R-parity conservation does not imply lepton number conservation. Neutrino masses generated at a one-loop level are closely related to the down quark mass matrix. The ratio of neutrino mass-squared splittings Δm2ν2–ν1/Δm2ν3–ν2 obtained is naturally close to Δm2s−d/Δm2b−s∼10−3 which is in the right region required to explain both the atmospheric neutrino data and the MSW solutions for the solar neutrino data.