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

TL;DR

This paper explores a focus point behavior in gaugino mediation models that can significantly reduce fine-tuning, suggesting high-energy physics influences the naturalness of SUSY models.

Contribution

It demonstrates a focus point-like behavior in gaugino mediation that reduces fine-tuning and proposes a natural origin for the required mass ratio in a product group unification model.

Findings

Fine-tuning can be reduced to about 2% with specific gaugino mass ratios.

A natural origin for the mass ratio is proposed in a product group unification model.

Fine-tuning depends crucially on high-energy physics assumptions.

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.