Orateur
Description
We investigate and compare two simple models of dark matter (DM): a vector and a scalar DM. In the former case an extra gauged group factor $U(1)$ is introduced, and the DM is the corresponding massive gauge boson $A_X^\mu$. The $U(1)$ symmetry is spontaneously broken by a vacuum of an extra scalar complex field $S$. Dark charge conjugation $A_X^\mu\to -A_X^\mu$ with $S \to S^*$ is responsible for stabilization of DM. In the latter case the gauge group remains standard, but an extra scalar complex field $S$ is also introduced. The DM is an imaginary part of $S$ and the stabilizing symmetry is also the dark charge conjugation $S \to S^*$. In this case, in order to avoid spontaneous breaking, the $U(1)$ symmetry is broken explicitly, but softly, in the scalar potential. The possibility to disentangle the two models has been investigated.
