Revisiting the two singlet dark matter model

We reinvestigate the two real singlet extension of the Standard Model with a Z<inf>2</inf> × Z<inf>2</inf>^' symmetry. In this model, the destructive interference between the two t-channel scalar mediators to some extent alleviates the otherwise very stringent constraint from the Xenon1T experiment while the Breit-Wigner enhancement of dark matter annihilation cross section not only proves useful in satisfying the relic abundance criterion but also ensures the scope for explaining the observed gamma-ray excess in the galactic centre.