G. Aad, B. Abbott, J. Abdallah, A.A. Abdelalim, A. Abdesselam, Z. Hubáček, M. Vlasák, K. Augsten, T. Horažďovský, J. Jakůbek et al.: Observation of a New X-b State in Radiative Transitions to Y(1S) and Y(2S) at ATLAS. Physical Review Letters 108(15), 152001 (2012). doi:10.1103/PhysRevLett.108.152001