Regular Article - Theoretical Physics
Is natural higgsino-only dark matter excluded?
Department of Physics and Astronomy, University of Oklahoma, Norman, OK, 73019, USA
2 Department of Physics, University of Wisconsin, Madison, WI, 53706, USA
3 Department of Physics and Astronomy, University of Hawaii, Honolulu, HI, 96822, USA
4 Centre for High Energy Physics, Indian Institute of Science, Bangalore, 560012, India
* e-mail: email@example.com
Accepted: 6 October 2018
Published online: 17 October 2018
The requirement of electroweak naturalness in supersymmetric (SUSY) models of particle physics necessitates light higgsinos not too far from the weak scale characterized by . On the other hand, LHC Higgs mass measurements and sparticle mass limits point to a SUSY breaking scale in the multi-TeV regime. Under such conditions, the lightest SUSY particle is expected to be a mainly higgsino-like neutralino with non-negligible gaugino components (required by naturalness). The computed thermal WIMP abundance in natural SUSY models is then found to be typically a factor 5–20 below its measured value. To gain concordance with observations, either an additional DM particle (the axion is a well-motivated possibility) must be present or additional non-thermal mechanisms must augment the neutralino abundance. We compare present direct and indirect WIMP detection limits to three natural SUSY models based on gravity-, anomaly- and mirage-mediation. We show that the case of natural higgsino-only dark matter where non-thermal production mechanisms augment its relic density, is essentially excluded by a combination of direct detection constraints from PandaX-II, LUX and Xenon-1t experiments, and by bounds from Fermi-LAT/MAGIC observations of gamma rays from dwarf spheroidal galaxies.
© The Author(s), 2018