Grand unification scale<i>CP</i>violating phases and the electric dipole moment

Abstract

The question of CP violating phases in supersymmetry and electric dipole moments (EDMs) is considered within the framework of supergravity grand unification (GUT) models with a light (\ensuremath{\lesssim}1 TeV) mass spectrum. In the minimal model, the nearness of the t-quark Landau pole automatically suppresses the t-quark cubic soft breaking phase at the electroweak scale. However, current EDM data require the quadratic soft breaking phase to be small at the electroweak scale unless $\mathrm{tan}\ensuremath{\beta}$ is small $(\mathrm{tan}\ensuremath{\beta}\ensuremath{\lesssim}3),$ and the EDM data combined with the requirement of electroweak symmetry breaking require this phase to be both large and highly fine-tuned at the GUT scale unless $\mathrm{tan}\ensuremath{\beta}$ is small. Nonminimal models are also examined and generally show the same behavior.