Understand
We study light, thermal neutralino dark matter in the sub-GeV to 65 GeV mass range in the Minimal Supersymmetric extension of the Standard Model (MSSM).
- We consider realizations of the limit of alignment without decoupling in the Higgs sector where the heavier CP-even Higgs impersonates the observed Higgs state at 125 GeV, while the lighter CP-even Higgs is the mediator of dark matter annihilation.
- We single out three distinct and novel possibilities for light dark matter: (i) a neutralino with mass around half the light Higgs mass, in the sub-GeV to 30 GeV mass range; (ii) a neutralino with a mass around half the pseudoscalar Higgs boson mass, in our examples around 60 to 65 GeV; (iii) a very light neutralino with mass around the light Higgs mass, pair-annihilating to Higgs pairs.
- We discuss the implications of all these possibilities for indirect and direct dark matter detection experiments, and we demonstrate that all scenarios will be tested by next generation direct detection experiments.