  Many models beyond the standard model predict the existence of vector-like
quarks or other types of heavy resonances. Using proton-proton collision data
at center-of-mass energies of 8 and 13 TeV, the ATLAS and CMS Collaborations
have performed a multitude of searches for pair and singly produced vector-like
quarks decaying to W, Z, or Higgs bosons. Heavy gauge and (pseudo)scalar
resonances decaying to top quarks have been searched for as well. No evidence
for any of these hypothetical particles has been found yet, and stringent
exclusion limits are derived on their masses, cross sections and couplings in
various models.

High Energy Physics - Experiment