Focus Point in Gaugino Mediation ~ Reconsideration of the Fine-tuning Problem ~

Abstract: We reconsider the fine-tuning problem in SUSY models, motivated by the recent observation of the relatively heavy Higgs boson and non-observation of the SUSY particles at the LHC. Based on this thought, we demonstrate a focus point-like behavior in a gaugino mediation model, and show that the fine-tuning is indeed reduced to about 2 percent level if the ratio of the gluino mass to wino mass is about 0.4 at the GUT scale. We show that such a mass ratio may arise naturally in a product group unification model without the doublet-triplet splitting problem. This fact suggests that the fine-tuning problem crucially depends on the physics at the high energy scale.