Scalar Dark Matter Models with Significant Internal Bremsstrahlung

Understand

There has been interest recently on particle physics models that may give rise to sharp gamma ray spectral features from dark matter annihilation.

• Because dark matter is supposed to be electrically neutral, it is challenging to build weakly interacting massive particle models that may accommodate both a large cross section into gamma rays at, say, the Galactic center, and the right dark matter abundance.
• In this work, we consider the gamma ray signatures of a class of scalar dark matter models that interact with Standard Model dominantly through heavy vector-like fermions (the vector-like portal).
• We focus on a real scalar singlet S annihilating into lepton-antilepton pairs.