(YSF) Searches for ttbar resonances with the CMS detector at 13 TeV

We present the most recent results on searches for new massive resonances decaying to a top-antitop quark pair with the CMS detector at the LHC. Searches are performed by measuring the invariant mass distribution of the $t\bar{t}$ system, both in semileptonic and fully-hadronic final states, using the data collected by the CMS experiment in pp collisions at $\sqrt{s}=\text{13 TeV}$ in 2015, the first year of the LHC Run-2. In order to maximize the analysis sensitivity for BSM resonances with a mass above the TeV scale, dedicated techniques are used to identify the decay of highly-boosted top quarks these methods include the identification of poorly isolated prompt leptons overlapping with a b-jet and the use of a top-tagging algorithm to reconstruct fully-merged jets with substructure properties. No significant excess is observed in the data compared to the expected SM background and exclusion limits are set on the cross section of a $t\bar{t}$ resonance in different BSM scenarios.