Discovery potential for split supersymmetry with thermal dark matter

Supersymmetric extensions of the Standard Model with scalar superpartners above 10 TeV are well motivated since the Higgs boson mass can be explained by quantum corrections while maintaining gauge coupling unification. If supersymmetry breaking is transmitted to gauginos via anomaly mediation, the gaugino masses are loop suppressed compared to scalar masses, and the lightest supersymmetric particle is the Higgsino or wino, which can be the dark matter. In this setup, we identify the regions of parameter space that reproduce the observed Higgs boson mass and the thermal abundance of dark matter. We analyze the effects of complex phases in the gaugino mass parameters on the electron electric dipole moment (EDM) and the dark matter scattering cross section. We find that, for scalar masses up to 10 PeV and any size of the complex phases, the model with Higgsino dark matter is within reach of planned experiments-Advanced ACME via electron EDM and LUX-ZEPLIN via dark matter direct detection-with complementary discovery potentials, and the model with wino dark matter is within reach of future electron EDM experiments.

Automated summary

In this study, the parameter space of the Higgsino and wino dark matter models in supersymmetric models was identified, and the effects of complex phases on the electron EDM and dark matter scattering cross section were analyzed. The study found that the Higgsino dark matter model can be discovered through existing experiments, while the wino dark matter model can be discovered through future experiments.