Handbook of vectorlike quarks: Mixing and single production

Abstract

We obtain constraints on the mixing of vectorlike quarks coupling predominantly to the third generation. We consider all (seven) relevant types of vectorlike quarks, individually. The constraints are derived from oblique corrections and Z→bb¯ measurements at the Large Electron-Positron (LEP) Collider and the Stanford Linear Collider. We investigate the implications of these constraints on LHC phenomenology, concerning the decays of the heavy quarks and their single production. We also explore indirect effects of heavy quark mixing in top and bottom couplings. A remarkable effect is the possibility of explaining the anomalous forward-backward asymmetry in Z→bb¯ at the LEP with a hypercharge −5/6 doublet. We also study the impact of the new quarks on single Higgs production at the LHC and Higgs decay.