PT Journal AU ATLAS Collaboration (Aad, Gea Amoros, G Cabrera Urban, S Castillo Gimenez, V Costa, MJ 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 Marti-Garcia, S Miñano, M Mitsou, VA Moles-Valls, R Moreno Llacer, M Oliver Garcia, E Perez Garcia-Estañ, MT Romero Adam, E Ros, E Salt, J Sanchez Martinez, V Solans, CA Soldevila, U Sanchez, J Torro Pastor, E Valladolid Gallego, E Valls Ferrer, JA Villaplana Perez, M Vos, M Wildauer, A TI Search for charged Higgs bosons decaying via H-+/- -> tau nu in t(t)over-bar events using pp collision data at root s=7 TeV with the ATLAS detector SO Journal of High Energy Physics JI J. High Energy Phys. PY 2012 BP 039 EP 50pp VL 06 IS 6 DI 10.1007/JHEP06(2012)039 LA English DE Hadron-Hadron Scattering AB The results of a search for charged Higgs bosons are presented. The analysis is based on 4.6 fb(-1) of proton-proton collision data at root s = 7TeV collected by the ATLAS experiment at the Large Hadron Collider, using top quark pair events with a tau lepton in the final state. The data are consistent with the expected background from Standard Model processes. Assuming that the branching ratio of the charged Higgs boson to a tau lepton and a neutrino is 100%, this leads to upper limits on the branching ratio of top quark decays to a b quark and a charged Higgs boson between 5% and 1% for charged Higgs boson masses ranging from 90GeV to 160GeV, respectively. In the context of the m(h)(max) scenario of the MSSM, tan beta above 12-26, as well as between 1 and 2-6, can be excluded for charged Higgs boson masses between 90GeV and 150GeV. ER