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 Mi̱ano, M Mitsou, VA Moles-Valls, R Moreno Llacer, M Oliver Garcia, E Pedraza Lopez, S Perez Garcia-Esta̱, MT Romero Adam, E Ros, E Salt, J Sanchez Martinez, V Soldevila, U Sanchez, J Torro Pastor, E Valero, A Valladolid Gallego, E Valls Ferrer, JA Villaplana Perez, M Vos, M TI Measurement of the mass difference between top and anti-top quarks in pp collisions at root s=7 TeV using the ATLAS detector SO Physics Letters B JI Phys. Lett. B PY 2014 BP 363 EP 379 VL 728 DI 10.1016/j.physletb.2013.12.010 LA English AB A measurement of the mass difference between top and anti-top quarks is presented. In a 4.7 fb(-1) data sample of proton-proton collisions at root s = 7 TeV recorded with the ATLAS detector at the LHC, events consistent with t (t) over bar production and decay into a single charged lepton final state are reconstructed. For each event, the mass difference between the top and anti-top quark candidate is calculated. A two b-tag requirement is used in order to reduce the background contribution. A maximum likelihood fit to these per-event mass differences yields Delta m = m(t) Рm((t) over bar) = 0.67 +/- 0.61 (stat) +/- 0.41 (syst) GeV, consistent with CPT invariance. ER