Exotic vectorlike quark phenomenology in the minimal linear <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>σ</mml:mi></mml:math> model
J. A. Aguilar–Saavedra, J. Alonso-González, Luca Merlo, José Miguel No
Abstract
Extensions of the Standard Model that include vectorlike quarks commonly also include additional particles that may mediate new production or decay modes. Using the minimal linear $\ensuremath{\sigma}$ model as an example, which reduces to the minimal $SO(5)/SO(4)$ composite Higgs model in a specific limit, we consider the phenomenology of vectorlike quarks when a scalar singlet $\ensuremath{\sigma}$ is present. This new particle may be produced in the decays $T\ensuremath{\rightarrow}t\ensuremath{\sigma}$, $B\ensuremath{\rightarrow}b\ensuremath{\sigma}$, where $T$ and $B$ are vectorlike quarks of charges $2/3$ and $\ensuremath{-}1/3$, respectively, with the subsequent decay $\ensuremath{\sigma}\ensuremath{\rightarrow}{W}^{+}{W}^{\ensuremath{-}}$, $ZZ$, $hh$. By scanning over the allowed parameter space we find that these decays may be dominant. In addition, we find that the presence of several new particles allows for single $T$ production cross sections larger than those expected in minimal models. We discuss the observability of these new signatures in existing searches.