Gauged B−xiL origin of R parity and its implications

Gauged B−L is a popular candidate for the origin of the conservation of R parity, i.e. R=(−)3B+L+2j, in supersymmetry, but it fails to forbid the effective dimension-five terms arising from the superfield combinations QQQL, ucucdcec, and ucdcdcNc, which allow the proton to decay. Changing it to B−xiL, where xe+xμ+xτ=3 (with xi≠1) for the three families, would forbid these terms while still serving as a gauge origin of R parity. We show how this is achieved in two minimal models with realistic neutrino mass matrices, and discuss their phenomenological implications.