Unification of gauge couplings and the tau-neutrino mass in supergravity without R parity Original Research Article

Minimal R-parity violating supergravity predicts a value for αs(MZ) smaller than in the case with conserved R-parity, and therefore closer to the experimental world average. We show that the R-parity violating effect on the αs prediction comes from the larger two-loop b-quark Yukawa contribution to the renormalization group evolution of the gauge couplings which characterizes R-parity violating supergravity. The effect is related to the tau neutrino mass and is sensitive to the initial conditions on the soft supersymmetry breaking parameters at the unification scale. We show how a few percent effect on αs(MZ) may occur even with ντ masses as small as indicated by the simplest neutrino oscillation interpretation of the atmospheric neutrino data from Super-Kamiokande.