Top partners and scalar dark matter -- a non-minimal reappraisal

TL;DR

This paper explores how adding multiple vector-like top partners in models with top-philic dark matter affects collider signals and cosmological behavior, extending beyond minimal models with a single mediator.

Contribution

It provides a detailed analysis of non-minimal composite models with several vector-like fermions, highlighting their impact on dark matter phenomenology and collider signatures.

Findings

Multiple top partners significantly alter collider phenomenology.

Non-minimal models show different cosmological implications.

Effective model approach clarifies the role of additional fermions.

Abstract

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 vector-like 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 vector-like top partners. Such a non-minimal setup with several vector-like fermions is typical of composite scenarios, and we make use of an effective model to study to which extent such non-minimality modifies the collider and cosmological phenomenology of the minimal model, the latter only including one vector-like mediator of the dark matter interactions with the Standard Model.