A search for high-mass resonances decaying to t+t- in pp collisions at sv=8s=8 TeV with the ATLAS detector

A search for high-mass resonances decaying into _+_final states using proton–proton collisions at p s = 8 TeV produced by the Large Hadron Collider is presented. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 19.5–20.3 fb1. No statistically significant excess above the Standard Model expectation is observed; 95% credibility upper limits are set on the cross section times branching fraction of Z0 resonances decaying into [ ] pairs as a function of the resonance mass. As a result, Z0 bosons of the Sequential Standard Model with masses less than 2.02 TeV are excluded at 95% credibility. The impact of the fermionic couplings on the Z0 acceptance is investigated and limits are also placed on a Z0 model that exhibits enhanced couplings to third-generation fermions.