Yukawa Unification in an SO(10) SUSY GUT: SUSY on the Edge

TL;DR

This paper investigates Yukawa unification within an SO(10) SUSY GUT, revealing that SUSY effects persist at high scalar masses and making several testable predictions about sparticle masses and flavor observables.

Contribution

It provides a comprehensive global fit showing SUSY effects do not decouple at high scalar masses and introduces the concept of 'SUSY on the Edge' for this parameter space.

Findings

SUSY effects remain significant at scalar masses of 15-30 TeV.

Gauginos are the lightest sparticles.

The model predicts a Standard Model-like Higgs and flavor observables close to experimental bounds.

Abstract

In this paper we analyze Yukawa unification in a three family SO(10) SUSY GUT. We perform a global $\chi^2$ analysis and show that SUSY effects do not decouple even though the universal scalar mass parameter at the GUT scale, $m_{16}$, is found to lie between 15 and 30 TeV with the best fit given for $m_{16} \approx 25$ TeV. Note, SUSY effects don't decouple since stops and bottoms have mass of order 5 TeV, due to RG running from $M_{GUT}$. The model has many testable predictions. Gauginos are the lightest sparticles and the light Higgs boson is very much Standard Model-like. The model is consistent with flavor and CP observables with the $BR(\mu \to e\gamma)$ close to the experimental upper bound. With such a large value of $m_{16}$ we clearly cannot be considered "natural" SUSY nor are we "Split" SUSY. We are thus in the region in between or "SUSY on the Edge."