New Minimal Extension of MSSM

Abstract

We construct a new minimal extension of the Minimal Supersymmetric Standard Model (MSSM) by promoting the µ-parameter to a singlet superfield. The resulting renormalizable superpotential is enforced by a Z5 R-symmetry which is imposed on the non-renormalizable operators as well. The proposed model provides a natural solution to the µ-problem and is free from phenomenological and cosmological problems. August 1999The Minimal Supersymmetric extension of the Standard Model (MSSM) [1], defined by promoting each standard field to a superfield, doubling the higgs fields and imposing R-parity conservation, seems to be preferred by the low energy data which support unification of the gauge couplings in the supersymmetric case. The most viable scenario for the breaking of supersymmetry at some low scale ms, no larger than ∼ 1 TeV, is the one based on spontaneously broken supergravity. The breaking of supergravity takes place in some hidden sector and is communicated to the visible sector through gravitational interactions. The resulting theory with broken supersymmetry contains, independently of the details of the underlying high energy theory, a number of soft supersymmetry (susy) breaking terms proportional to