Compressed Stop-Neutralino Spectra from Yukawa Unified Non-Holomorphic Pati-Salam Model: Prospects for the FCC

Abstract

We explore the weak-scale phenomenology of SUSY models with the $SU(4)_{C}\times SU(2)_{L}\times SU(2)_{R}$ gauge symmetry. We include non-holomorphic soft supersymmetry breaking terms arising from perturbations on D-branes. These terms significantly alter the implications of Yukawa unification, as they directly interfere in the threshold corrections to the Yukawa couplings. With these corrections, Yukawa unification can be compatible with low fine-tuning alongside a heavy Higgsino-like lightest supersymmetric particle; however, these solutions are strongly constrained by dark matter observations. Furthermore, in contrast to previous studies, the non-holomorphic contributions accommodate heavy gluino masses in this class of models from approximately 2.2 to 10 TeV while preserving Yukawa unification. These gluinos can be probed up to about 2.5 TeV in high-luminosity collider searches, and up to about 6 TeV at future 100 TeV center-of-mass energy colliders. With the non-holomorphic threshold corrections to Yukawa couplings, Yukawa unification can be accommodated with relatively light third-generation squarks. We find that the supersymmetric spectra can accommodate sbottom masses around 1.5 TeV, making them highly accessible to upcoming experimental searches. The stop can also be as light as about 1.5~TeV, resulting in a compressed stop-neutralino spectrum. Although these solutions lie beyond the sensitivity of current collider searches, they can be potentially probed at future facilities, such as the proposed Future Circular Collider. Our results do not include systematic uncertainties, which can heavily impact the experimental analysis. In this context, our findings serve to highlight potential directions and prospects for new physics searches at future collider experiments. Our results assume that overall systematic uncertainties in background modeling do not exceed $0.1\%$.