G. Aad, B. Abbott, J. Abdallah, O. Abdinov, R. Aben, K. Augsten, D. Caforio, P. Gallus, J. Guenther, J. Jakůbek et al.: Search for type-III seesaw heavy leptons in pp collisions at root s=8 TeV with the ATLAS detector. Physical Review D 92(3), 032001 (2015). doi:10.1103/PhysRevD.92.032001