TeV Higgsino Dark Matter from LZ Nuclear Recoil to Fermi-LAT Gamma Rays

Abstract: The Higgsino dark matter of the minimal supersymmetric standard model is one of the most minimal and canonical WIMP candidates. We demonstrate that this classic candidate can account for both the high-energy nuclear-recoil excess reported by the LZ experiment and the mild preference in the 14 years of FermiLAT Galactic-center data, with the relic abundance fixing the Higgsino dark matter mass near 1.1 TeV and the recoil spectrum selecting a mass splitting of a few hundred keV. Together with the 10-year IceCube solar-neutrino constraint, the Higgsino interpretation further pins down a viable region of parameter space. It predicts a Galactic-center gamma-ray line and endpoint signal near the present H.E.S.S. sensitivity and within CTAO's projected reach, making this classic candidate testable in the near future.