摘要: The gamma-ray excess observed by the Fermi-LAT in the Galactic Center can
be interpreted by the dark matter annihilation to b
¯b via a light pseudoscalar in the
NMSSM. It is interesting to note that the corresponding singlet scalar is useful to
achieve a strongly first order phase transition required by the electroweak baryogenesis.
In this paper, we investigate the possibility that the NMSSM model can
simultaneously accommodate these two issues. The phase transition strength can
be characterized by the vacua energy gap at zero temperature and be sufficiently
enhanced by the tree-level effect in the NMSSM. We find that the annihilation of
Singlino/Higgsino DM particles occurring close to the light pseudoscalar resonance
is favored by the galactic center excess and the observed DM relic density, and a
resulting small κ/λ and a negative Aκ can also lead to a successful strongly first
order electroweak phase transition