A Realization of Effective SUSY with Strong Unification

Abstract

A natural model of realizing the effective supersymmetry is presented. Two sets of the Standard Model-like gauge group $G_1\times G_2$ are introduced, where $G_i=SU(3)_i\times SU(2)_i\times U(1)_i$, which break diagonally to the Standard Model gauge group at the energy scale $M \sim 10^7$ GeV. Gauge couplings in $G_1$ are assumed much larger than that in $G_2$. Gauge mediated supersymmetry breaking is adopted. The first two generations (third one) are charged only under $G_1$ ($G_2$). The effective supersymmetry spectrum is obtained. How to reproduce realistic Yukawa couplings is studied. Fine-tuning for an 126 GeV Higgs is much reduced by the large $A$ term due to direct Higgs-messenger interaction. Finally, $G_2$ is found to be a non-trivial realization of the strong unification scenario in which case we can predict $α_s(M_Z)$ without real unification

11 pages,references added,version to appear in PRD