The χb(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider at √s=7TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4fb-1, these states are reconstructed through their radiative decays to Υ(1S,2S) with Υ→μ+μ-. In addition to the mass peaks corresponding to the decay modes χ b(1P,2P)→Υ(1S)γ, a new structure centered at a mass of 10.530±0.005(stat)±0.009(syst)GeV is also observed, in both the Υ(1S)γ and Υ(2S)γ decay modes. This structure is interpreted as the χb(3P) system. © 2012 CERN.
Aad, G., Abbott, B., Abdallah, J., Abdelalim, A. A., Abdesselam, A., Abdinov, O., … Zwalinski, L. (2012). Observation of a new χb state in radiative transitions to Y(1S) and Y(2S) at ATLAS. Physical Review Letters, 108(15). https://doi.org/10.1103/PhysRevLett.108.152001