Large evolution of the bilinear Higgs coupling parameter in SUSY models and reduction of phase sensitivity(Summer Institute 2007)

Abstract

The phase parameters in low-energy supersymmetry(SUSY) models are highly constrained by the electric dipole moments(EDM) of the fermions. Further imposing radiative electroweak symmetry breaking(REWSB) condition results in a large degree of fine tuning of the phase parameters at the unification scale. In supergravity models, one finds highly fine tuned values for the phases of the bilinear Higgs coupling parameter B at the unification scale(GUT) scale which in turn also constrain the phase of universal trilinear coupling A_0. We analysed how a GUT inspired definite non-universal gaugino mass(NUGM) model can reduce such fine-tuning keeping superparticle masses within the naturalness domain.