Two-component Dark Matter in the vectorlike hypercolor extension of the Standard Model

Abstract

We consider a minimal vectorlike extension of the Standard Model that naturally contains two types of stable neutral particles. They can be interpreted as the Dark Matter candidates. Here, the SM is supplemented by a new fermion (H-quark) sector that is in confilnement providing by the SU(2)HC gauge group. H-quarks interact with the SM particles via standard electroweak bosons. In analogy with the conventional QCD, H-quarks can form bound states, H-hadrons, that emerge in the σ− model framework. Along with the stable neutral H-pion, there is one more pseudo-goldstone (diquark) state, B0, which is stable and also can be a component of the DM. Mass splittings both for components of the H-pion triplet and for neutral H-pion and B0 have been calculated, it is shown that this splittings can be small. The relic abundance for this composition of the DM is analyzed as well as the DM particles scattering off nucleons. A feature of this scenario is that Dark Matter turns out to consist of particles which are close in mass but have different origin and interact differently with ordinary matter. So, the model predicts two-component structure of the DM together with some specifilc manifestations of it.