Non-Universal Gaugino Masses and Natural Supersymmetry

TL;DR

This paper shows that natural supersymmetry can be achieved with non-universal gaugino masses in an SU(4)_c imes SU(2)_L imes SU(2)_R framework, resulting in low fine-tuning and specific superpartner mass ranges.

Contribution

It introduces a model with non-universal gaugino masses that achieves low fine-tuning in supersymmetry, addressing the little hierarchy problem.

Findings

Both electroweak and high-scale fine-tuning parameters can be below 100.

The Higgs mass can be in the 123-127 GeV range.

Superpartner masses are constrained within specific ranges.

Abstract

We demonstrate that natural supersymmetry is readily realized in the framework of SU(4)_c \times SU(2)_L \times SU(2)_R with non-universal gaugino masses. Focusing on ameliorating the little hierarchy problem, we explore the parameter space of this model which yields small fine-tuning measuring parameters (natural supersymmetry) at the electroweak scale (\Delta_{EW}) as well as at high scale (\Delta_{HS}). It is possible to have both \Delta_{EW} and \Delta_{HS} less than 100 in these models, (2 % or better fine-tuning), while keeping the light CP-even (Standard Model-like) Higgs mass in the 123 GeV-127 GeV range. The light stop quark mass lies in the range 700 GeV <m_{\tilde{t}_{1}}< 1500 GeV, and the range for the light stau lepton mass is 900 GeV <m_{\tilde{\tau}_{1}}< 1300 GeV. The first two family squarks are in the mass range 3000 GeV <m_{\tilde{t}_{1}}< 4500 GeV, and for the gluino we find 2500 GeV <m_{\tilde{g}_{1}}< 3500 GeV. We do not find any solution with natural supersymmetry which yields significant enhancement for Higgs production and decay in the diphoton channel.