%0 Journal Article %T A search for t (t)over-bar resonances with the ATLAS detector in 2.05 fb(-1) of proton-proton collisions at root s=7 TeV %A ATLAS Collaboration (Aad, G. et al %A Cabrera Urban, S. %A Castillo Gimenez, V. %A Costa, M. J. %A Ferrer, A. %A Fiorini, L. %A Fuster, J. %A Garcia, C. %A Garcia Navarro, J. E. %A Gonzalez de la Hoz, S. %A Hernandez Jimenez, Y. %A Higon-Rodriguez, E. %A Irles Quiles, A. %A Kaci, M. %A Lacasta, C. %A Lacuesta, V. R. %A Marti-Garcia, S. %A Miñano, M. %A Mitsou, V. A. %A Moles-Valls, R. %A Moreno Llacer, M. %A Oliver Garcia, E. %A Perez Garcia-Estañ, M. T. %A Romero Adam, E. %A Ros, E. %A Salt, J. %A Sanchez Martinez, V. %A Solans, C. A. %A Soldevila, U. %A Sanchez, J. %A Torro Pastor, E. %A Valladolid Gallego, E. %A Valls Ferrer, J. A. %A Villaplana Perez, M. %A Vos, M. %A Wildauer, A. %J European Physical Journal C %D 2012 %V 72 %N 7 %I Springer %@ 1434-6044 %G English %F ATLASCollaborationAad_etal2012 %O WOS:000307269400029 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=1132), last updated on Tue, 25 Sep 2012 11:13:40 +0000 %X A search for top quark pair resonances in final states containing at least one electron or muon has been performed with the ATLAS experiment at the CERN Large Hadron Collider. The search uses a data sample corresponding to an integrated luminosity of 2.05 fb(-1), which was recorded in 2011 at a proton-proton centre-of-mass energy of 7 TeV. No evidence for a resonance is found and limits are set on the production cross-section times branching ratio to t (t) over bar for narrow and wide resonances. For narrow Z' bosons, the observed 95 % Bayesian credibility level limits range from 9.3 pb to 0.95 pb for masses in the range of m(Z') = 500 GeV to m(Z') = 1300 GeV. The corresponding excluded mass region for a leptophobic topcolour Z' boson (Kaluza-Klein gluon excitation in the Randall-Sundrum model) is m(Z') < 880 GeV (m(gKK) < 1130 GeV). %R 10.1140/epjc/s10052-012-2083-1 %U http://arxiv.org/abs/1205.5371 %U https://doi.org/10.1140/epjc/s10052-012-2083-1 %P 2083-23pp