Higgsino Dark Matter Confronts 14 Years of Fermi γ-Ray Data

Christopher Dessert; Joshua W Foster; Yujin Park; Benjamin R Safdi; Weishuang Linda Xu

doi:10.1103/PhysRevLett.130.201001

Higgsino Dark Matter Confronts 14 Years of Fermi γ-Ray Data

Phys Rev Lett. 2023 May 19;130(20):201001. doi: 10.1103/PhysRevLett.130.201001.

Authors

Christopher Dessert^{1

2

3}, Joshua W Foster⁴, Yujin Park^{1

2}, Benjamin R Safdi^{1

2}, Weishuang Linda Xu^{1

2}

Affiliations

¹ Berkeley Center for Theoretical Physics, University of California, Berkeley, California 94720, USA.
² Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
³ Leinweber Center for Theoretical Physics, Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 USA.
⁴ Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

PMID: 37267565
DOI: 10.1103/PhysRevLett.130.201001

Abstract

Thermal Higgsino dark matter (DM), with mass around 1 TeV, is a well-motivated, minimal DM scenario that arises in supersymmetric extensions of the standard model. Higgsinos may naturally be the lightest superpartners in split-supersymmetry models that decouple the scalar superpartners while keeping Higgsinos and gauginos close to the TeV scale. Higgsino DM may annihilate today to give continuum γ-ray emission at energies less than a TeV in addition to a linelike signature at energies equal to the mass. Previous searches for Higgsino DM, for example with the H.E.S.S. γ-ray telescope, have not reached the necessary sensitivity to probe the Higgsino annihilation cross section. In this work we make use of 14 years of data from the Fermi Large Area Telescope at energies above ∼10 GeV to search for the continuum emission near the Galactic Center from Higgsino annihilation. We interpret our results using DM profiles from Milky Way analog galaxies in the FIRE-2 hydrodynamic cosmological simulations. We set the strongest constraints to date on Higgsino-like DM. Our results show a mild, ∼2σ preference for Higgsino DM with a mass near the thermal Higgsino mass and, depending on the DM density profile, the expected cross section.