Dark Matter at the Pseudoscalar Higgs Resonance in the pMSSM and SUSY GUTs

TL;DR

This paper investigates dark matter detection prospects at the pseudoscalar Higgs resonance in the MSSM and GUT models, highlighting parameter space constraints and the necessity of gaugino mass non-universality.

Contribution

It compares phenomenological MSSM and Yukawa unified GUT models, revealing how different constraints shape the pseudoscalar resonance parameter space and the need for gaugino mass non-universality.

Findings

pMSSM parameter space mostly accessible to upcoming direct detection experiments

Blind spots exist at high $m_A$ for $$ < 0 in pMSSM

Gaugino mass non-universality is required in Yukawa unified models

Abstract

We study dark matter at the MSSM pseudoscalar Higgs resonance (A-funnel), which is one of the few remaining MSSM thermal dark matter candidates in the $100-1000$ GeV range safe from direct detection constraints. To illustrate the various factors at play, this study is performed in two contrasting set-ups: a bottom-up phenomenological MSSM (pMSSM) approach that allows significant freedom, and the top-down, highly constrained Yukawa unified $SO(10)$ GUT model. In the pMSSM, for $\mu > 0$, the entire parameter space lies above the coherent neutrino background and mostly within reach of XENON1T and LZ, while blind spots exist at $m_A\,> \, 800\,$GeV for $\mu < 0$; the strongest constraints come from $A/H \rightarrow \tau \tau$ searches at the LHC. For Yukawa unified models, the confluence of $B_s \rightarrow \mu^+ \mu^-$ constraints, fits to the bottom quark and Higgs masses, and gluino mass bounds from the LHC result in a prediction: realizing the pseudoscalar resonance $requires$ gaugino mass non-universality, with a mass ratio that is determined to within a small range.