Is the light neutralino thermal dark matter in the pMSSM ruled out?

TL;DR

This paper investigates whether light neutralino thermal dark matter in the pMSSM is still viable given recent collider and direct detection constraints, finding that some parameter regions are ruled out while others remain uncertain.

Contribution

It provides a comprehensive analysis of the pMSSM parameter space considering recent experimental results, highlighting which regions are excluded or still possible.

Findings

Z-funnel region ruled out for positive μ by LHC and LZ data

h-funnel region severely restricted for positive μ, but still testable

Light higgsinos in both funnels may survive for negative μ, requiring further experimental efforts

Abstract

We explore the parameter space of the phenomenological Minimal Supersymmetric Standard Model (pMSSM) with a light neutralino thermal dark matter ($m_{\tilde{\chi}_1^0} \leq m_h/2$) that is consistent with current collider and astrophysical constraints. We consider both positive and negative values of the higgsino mass parameter ($\mu$). Our investigation shows that the recent experimental results from the LHC as well as from direct detection searches for dark matter by the LUX-ZEPLIN (LZ) collaboration rule out the $Z$-funnel region for the $\mu>0$ scenario. The same results severely restrict the $h$-funnel region for positive $\mu$, however, the allowed points can be probed easily with few more days of data from the LZ experiment. In the $\mu<0$ scenario, we find that very light higgsinos in both the $Z$ and $h$ funnels might survive the present constraints from the electroweakino searches at the LHC, and dedicated efforts from experimental collaborations are necessary to make conclusive statements about their present status.