Amelioration of Little Hierarchy Problem in SU(4)_c x SU(2)_L x SU(2)_R

TL;DR

This paper shows that supersymmetric models based on the G_{422} gauge symmetry can reduce the little hierarchy problem by relaxing universal gaugino mass assumptions, leading to less fine-tuning in electroweak symmetry breaking.

Contribution

It introduces a modified supersymmetric model with G_{422} symmetry that alleviates the little hierarchy problem by allowing non-universal gaugino masses, improving fine-tuning.

Findings

Achieves 10% fine tuning with specific Higgs and sparticle spectra.

Demonstrates significant reduction in fine-tuning compared to CMSSM.

Provides examples of mass spectra consistent with reduced hierarchy problem.

Abstract

The little hierarchy problem encountered in the constrained minimal supersymmetric model (CMSSM) can be ameliorated in supersymmetric models based on the gauge symmetry G_{422} \equiv SU(4)_c x SU(2)_L x SU(2)_R. The standard assumption in CMSSM (and in SU(5) and SO(10)) of universal gaugino masses can be relaxed in G_{422}, and this leads to a significant improvement in the degree of fine tuning required to implement radiative electroweak breaking in the presence of a characteristic supersymmetry breaking scale of around a TeV. Examples of Higgs and sparticle mass spectra realized with 10% fine tuning are presented.