, 2012:94,
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Date: 16 Nov 2012

Search for a heavy top-quark partner in final states with two leptons with the ATLAS detector at the LHC

Abstract

The results of a search for direct pair production of heavy top-quark partners in 4.7 fb−1 of integrated luminosity from pp collisions at \( \sqrt{s}=7 \) TeV collected by the ATLAS detector at the LHC are reported. Heavy top-quark partners decaying into a top quark and a neutral non-interacting particle are searched for in events with two leptons in the final state. No excess above the Standard Model expectation is observed. Limits are placed on the mass of a supersymmetric scalar top and of a spin-1/2 top-quark partner. A spin-1/2 top-quark partner with a mass between 300 GeV and 480 GeV, decaying to a top quark and a neutral non-interacting particle lighter than 100 GeV, is excluded at 95% confidence level.

Deceased (V. V. Ammosov,E. Arik, A. Bogouch, H. M. Braun, C. Caso, L. Chikovani, R. Dobinson, Y. Doi, B. A. Dolgoshein, G. M. Kolachev, M. J. Losty, K. W. McFarlane, S. V. Mouraviev, S. W. O’Neale, F. Pastore, C. Ruwiedel, G. Sauvage, A. N. Sisakyan, P. Stavina, J. A. Strong, I. Stumer, M. Virchaux, V. V. Zmouchko)