Discrete Gauge Symmetries in Axionic Extensions of the SSM

Abstract

We examine discrete gauge symmetries in axionic extensions of the SSM which provide a solution of the $\mu$-problem. Automatic-PQ symmetry and proton stability are shown to be guaranteed by certain discrete symmetries. Focusing on the L-violating discrete symmetries we discuss two sources of neutrino masses and their relevance for the solar neutrino problem.Comment: 13 pages, TUM-TH-150/92, MPI-Ph/92-7