Top partners and scalar dark matter: A nonminimal reappraisal

A large set of models beyond the Standard Model of particle physics suggest that the top quark plays a special role in fundamental interactions. At the same time some of these models predict that a particle responsible for dark matter is present in the physical spectrum of the theory, and in particular cases dark matter may be specially linked to the top sector. Such a new physics configuration occurs, for instance, in composite frameworks that additionally feature vectorlike quarks as mediators of the interactions of the dark matter with the Standard Model. We investigate the interplay of top-philic dark matter and the presence of several vectorlike top partners. Such a nonminimal setup with several vectorlike fermions is typical of composite scenarios, and we make use of an effective model to study to which extent such nonminimality modifies the collider and cosmological phenomenology of the minimal model, the latter only including one vectorlike mediator of the dark matter interactions with the Standard Model.