Searches with top quarks

Heavy new physics particles including vector-like quarks, excited quarks, and heavy vector bosons can decay to top quarks alongside other standard model particles. Searches at the CERN LHC in final states with top quarks set strong constraints on the existence of such particles, and measurements of top quark associated production and branching fractions constrain models with flavor-changing neutral currents. No evidence for new physics is seen in these searches, although discovery potential exists for several models.