The light neutralino dark matter in the generalized minimal supergravity (GmSUGRA)

We investigate the Higgs/Z poles solutions for the Higgsino mass parameter, $\mu >0$ and $\mu <0$ scenarios. In the framework of Generalized Minimal Supergravity (GmSUGRA), we consider the constraints from Higgs measurements, B-physics observables, LEP limits, and the Planck 2018 relic density bounds, together with the results from direct detection dark matter experiments, including PandaX-4T, XENON-1T, PICO-60, and LUX-ZEPLIN (LZ). Our study indicates that the latest experimental constraints from the LHC and LZ Collaborations exclude the light Higgsinos in the Z and H pole regions for the $\mu >0$ case. Interestingly, for the $\mu <0$ case, a very light Higgsinos can still be consistent with the current constraints from the electroweakino searches and LZ experiment in the $Z$ and $H$ poles. Consequently, the $\mu <0$ case appears more promising and thus requires the dedicated efforts to make definitive conclusions about their current status from the experimental Collaborations. In this framework, our findings indicate a deviation of up to $2\sigma$ from the central value of $a_{\mu }\equiv {(g-2)}_{\mu }/2$, resonating with the experimental results reported by CMD and BDM.