Circular Future of Yukawa Unification in Supersymmetric Pati-Salam Model: Stop on Neutralino

TL;DR

This paper investigates the implications of non-holomorphic terms in SUSY Pati-Salam models on Yukawa unification, dark matter, and collider phenomenology, highlighting potential signals at future high-energy colliders.

Contribution

It introduces the role of non-holomorphic contributions from D-brane perturbations in enabling Yukawa unification with heavy gluinos and light third-family squarks, and assesses collider prospects.

Findings

Heavy gluinos (2.2-10 TeV) compatible with Yukawa unification.

Third-family squarks can be as light as 1.5 TeV, nearly degenerate with neutralino.

Future colliders can detect stop-neutralino signals with high significance.

Abstract

We explore the low scale implications of SUSY models based on the gauge symmetry SU(4)_CxSU(2)_LxSU(2)_R. We include the non-holomorphic terms arises from the perturbations on D-branes, which also break SUSY. These terms significantly change the implications of Yukawa unification, since they are directly included in the threshold contributions to Yukawa couplings. With these contributions, YU can be compatible with low fine-tuning and yet heavy Higgsino-like LSP, but these solutions receive strong negative impact from the dark matter observations. Besides, in contrast to the earlier results, the NH contributions accommodate heavy gluino masses from about 2.2 to 10 TeV compatible with Yukawa unification. These gluinos can be probed up to about 2.5 in the collider experiments of high luminosity, and to about 6 TeV in future experiments of 100 TeV center of mass energy. In contrast to the gluino mass scales, the NH contributions can drive the squarks of the third family to the light masses. We observe that the Yukawa unification solutions can be compatible with the sbottom mass of about 1.5 TeV, and they are more likely to be tested soon. The stop can also be as light as about 1.5 TeV, and it can be nearly degenerate with the LSP neutralino. Even though these solutions are beyond the sensitivity of the current collider analyses, they can be subjected to be tested in future experiments such as those of Future Circular Collider proposal. We project the current analyses for stop-neutralino degenerate solutions to the Future Circular Collider experiments, and realize that the signal processes with semi-leptonic final states can yield about 5 sigma significance with appropriate cuts on the kinematic variables. Such a large significance can be realized when L ~ 97 fb^-1. We also present a slight improvement by performing BDT analyses, which can yield a similar significance with L ~ 54 fb-1.