Search for $t \bar{t}$ Resonances at CMS

We present a search for new massive particles decaying to a pair of top quarks with the CMS de- tector at the LHC. Proton-proton collision data recorded at a center-of-mass energy of 13 TeV is used. The search is performed by measuring the invariant mass distribution of the top-quark pair and testing for deviations from the expected Standard Model background. Final states with 0 or 1 leptons are considered, and the selection is optimized accordingly. In the high mass ranges acces- sible by the LHC at these energies, the top quarks are produced with high transverse momenta: the products of hadronically decaying top quarks emerge as a single jet, whereas the products of the semileptonic decay mode are characterized by the overlap of the lepton and the b jet. Specific reconstruction algorithms and selections are employed to address the identification of boosted top quark signatures. The results are presented in terms of upper limits on the model cross sec- tion. Models of Randall-Sundrum Kaluza-Klein gluon production as well as narrow, wide, and extra-wide Z ′ boson models are considered.