Speaker
Description
A spontaneously broken hidden U(1)h gauge symmetry can explain both the dark matter stability and the observed relic abundance. In this framework, the light gauge boson can mediate the strong dark matter self-interaction, which addresses astrophysical observations that are hard to explain in collisionless cold dark matter. Motivated by flavoured grand unified theories, we introduce right-handed neutrinos and a flavoured B-L gauge symmetry for the third family U(1){B-L}. The unwanted relic of the U(1)h gauge boson decays into neutrinos via the kinetic mixing with the U(1){(B - L)_3}$ gauge boson. This model can also explain the lepton flavour universality violation in semi-leptonic B meson decays that is recently found in the LHCb experiment. We found that the dark sector is naturally obtained when there is a strong SU(5) gauge interaction, U(1) gauge interaction, and fermions with appropriate representations at a UV scale. This implies that the whole sector can be unified by a [SU(5)*U(1)]^4 gauge theory. The first three sets of gauge groups are spontaneously broken to the SM gauge groups while the last one becomes strong at an intermediate scale and gives a self-interacting dark matter at a low energy scale.
