LAUSR

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 σ 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 σ is present. This new particle may be produced in the decays T→tσ, B→bσ, where T and B are vectorlike quarks of charges 2/3 and -1/3, respectively, with the subsequent decay σ→W+W-, 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.