Несохранение барионов и лептонов в суперсимметричных моделях

Abstract

The possible baryon- and lepton-nonconserving effective interactions among ordinary particles are analysed in the frame ofSU 3×SU2×U1supersymmetric models. Operators of lower dimensionalities than in ordinary GUTs are generally allowed in the supersymmetric schemes of Dimopoulos and Georgi type, in which a discrete symmetry is imposed to guaranteeB andL conservation in renormalizable terms. Operators of the same dimensionalities as in GUTs are obtained, instead, in the schemes of the type considered by Weinberg and by Sakai and Yanagida, where eitherR-invariance or an extraU 1 gauge factor is assumed. However, the different terms lead in most cases, with the exception of the ΔB=ΔL proton decay, to unobservable rates for physical processes, unless Higgs supermultiplets are introduced at an intermediate mass scale.