%0 Journal Article %T A search for t(t)over-bar resonances in lepton plus jets events with highly boosted top quarks collected in pp collisions at root s=7 TeV with the ATLAS detector %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 Valero, A. %A Valladolid Gallego, E. %A Valls Ferrer, J. A. %A Villaplana Perez, M. %A Vos, M. %A Wildauer, A. %J Journal of High Energy Physics %D 2012 %V 09 %N 9 %I Springer %@ 1126-6708 %G English %F ATLASCollaborationAad_etal2012 %O WOS:000310341300030 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=1260), last updated on Fri, 28 Dec 2012 00:29:50 +0000 %X A search for resonant production of high-mass top-quark pairs is performed on 2.05 fb(-1) of proton-proton collisions at root s = 7 TeV collected in 2011 with the ATLAS experiment at the Large Hadron Collider. This analysis of the lepton+jets final state is specifically designed for the particular topology that arises from the decay of highly boosted top quarks. The observed t (t) over bar invariant mass spectrum is found to be compatible with the Standard Model prediction and 95% credibility level upper limits are derived on the t (t) over bar production rate through new massive states. An upper limit of 0.7 pb is set on the production cross section times branching fraction of a narrow 1 TeV resonance. A Kaluza-Klein gluon with a mass smaller than 1.5 TeV is excluded. %K Hadron-Hadron Scattering %R 10.1007/JHEP09(2012)041 %U http://arxiv.org/abs/arXiv:1207.2409 %U https://doi.org/10.1007/JHEP09(2012)041 %P 041-45pp