%0 Journal Article %T Search for New Phenomena in t(t)overbar Events with Large Missing Transverse Momentum in Proton-Proton Collisions at root s=7 TeV with the ATLAS Detector %A ATLAS Collaboration (Aad, G. et al %A Amoros, G. %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 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 Ros, E. %A Salt, J. %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 Physical Review Letters %D 2012 %V 108 %N 4 %I Amer Physical Soc %@ 0031-9007 %G English %F ATLASCollaborationAad_etal2012 %O WOS:000299828100003 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=897), last updated on Thu, 01 Mar 2012 11:32:36 +0000 %X A search for new phenomena in t (t) over bar events with large missing transverse momentum in proton-proton collisions at a center-of-mass energy of 7 TeV is presented. The measurement is based on 1: 04 fb(-1) of data collected with the ATLAS detector at the LHC. Contributions to this final state may arise from a number of standard model extensions. The results are interpreted in terms of a model where new top-quark partners are pair produced and each decay to an on-shell top (or antitop) quark and a long-lived undetected neutral particle. The data are found to be consistent with standard model expectations. A limit at 95% confidence level is set excluding a cross section times branching ratio of 1.1 pb for a top-partner mass of 420 GeVand a neutral particle mass less than 10 GeV. In a model of exotic fourth generation quarks, toppartner masses are excluded up to 420 GeV and neutral particle masses up to 140 GeV. %R 10.1103/PhysRevLett.108.041805 %U http://arxiv.org/abs/1109.4725 %U https://doi.org/10.1103/PhysRevLett.108.041805 %P 041805-18pp