Least supersymmetric standard model

Abstract

We propose the minimal (Least) version of the Supersymmetric Standard Model which can solve the hierarchy problem in the same way as the so-called Minimal Supersymmetric Standard Model (MSSM) and presents solutions to some of its problems. Supersymmetry is broken in a secluded sector and mediated to the observable sector by messengers of a gauge group G under which the first two generations transform. The group G spontaneously breaks (almost) supersymmetrically at a scale at most a few orders of magnitude below the scale of gauge messengers M_*\sim 10^{15} GeV. By gauge mediation sfermions of the first two generations acquire supersymmetry breaking masses \hat m \sim 10 TeV. Supersymmetry breaking is also mediated by gravity which generates masses for all sfermions, Higgsinos and gauginos at the TeV scale and can provide appropriate values to the \mu and B_\mu parameters by D-term effective operators. If gravity mediation is Minimal Flavor Violating there is no supersymmetric flavor problem. In the presence of R-parity dark matter can be the lightest neutralino, as in the MSSM, and the LHC model phenomenology is characterized by the fact that only third generation squarks and sleptons are present.