PT Journal AU ATLAS Collaboration (Aad, Gea Cabrera Urban, S Castillo Gimenez, V Costa, MJ Fassi, F Ferrer, A Fiorini, L Fuster, J Garcia, C Garcia Navarro, JE Gonzalez de la Hoz, S Hernandez Jimenez, Y Higon-Rodriguez, E Irles Quiles, A Kaci, M Lacasta, C Lacuesta, VR March, L Marti-Garcia, S Miñano, M Mitsou, VA Moles-Valls, R Moreno Llacer, M Oliver Garcia, E Pedraza Lopez, S Perez Garcia-Estañ, MT Romero Adam, E Ros, E Salt, J Sanchez Martinez, V Solans, CA Soldevila, U Sanchez, J Torro Pastor, E Valero, A Valladolid Gallego, E Valls Ferrer, JA Villaplana Perez, M Vos, M TI Search for resonances decaying into top-quark pairs using fully hadronic decays in pp collisions with ATLAS at root s=7 TeV SO Journal of High Energy Physics JI J. High Energy Phys. PY 2013 BP 116 EP 50pp VL 01 IS 1 DI 10.1007/JHEP01(2013)116 LA English DE Hadron-Hadron Scattering AB A search for resonances produced in 7 TeV proton-proton collisions and decaying into top-quark pairs is described. In this Letter events where the top-quark decay produces two massive jets with large transverse momenta recorded with the ATLAS detector at the Large Hadron Collider are considered. Two techniques that rely on jet substructure are used to separate top-quark jets from those arising from light quarks and gluons. In addition, each massive jet is required to have evidence of an associated bottom-quark decay. The data are consistent with the Standard Model, and limits can be set on the production cross section times branching fraction of a Z' boson and a Kaluza-Klein gluon resonance. These limits exclude, at the 95% credibility level, Z' bosons with masses 0.70-1.00 TeV as well as 1.28-1.32 TeV and Kaluza-Klein gluons with masses 0.70-1.62 TeV. ER