Observation of the

• Main Authors: CMS Collaboration (Author), Abercrombie, Daniel Robert (Contributor), Allen, Brandon Leigh (Contributor), Azzolini, Virginia (Contributor), Baty, Austin Alan (Contributor), Bauer, Gerry P (Contributor), Bi, Ran (Contributor), Brandt, Stephanie Akemi (Contributor), Busza, Wit (Contributor), Cali, Ivan Amos (Contributor), D'Alfonso, Mariarosaria (Contributor), Demiragli, Zeynep (Contributor), Gomez-Ceballos, Guillelmo (Contributor), Goncharov, Maxim (Contributor), Harris, Philip Coleman (Contributor), Hsu, Dylan George (Contributor), Hu, Miao (Contributor), Iiyama, Yutaro (Contributor), Innocenti, Gian Michele (Contributor), Klute, Markus (Contributor), Kovalskyi, Dmytro (Contributor), Lee, Yen-Jie (Contributor), Luckey Jr, P David (Contributor), Maier, Benedikt (Contributor), Marini, Andrea Carlo (Contributor), McGinn, Christopher Francis (Contributor), Mironov, Camelia Maria (Contributor), Narayanan, Siddharth Madhavan (Contributor), Niu, Xinmei (Contributor), Paus, Christoph M. E. (Contributor), Roland, Christof E (Contributor), Roland, Gunther M (Contributor), Stephans, George S. F. (Contributor), Sumorok, Konstanty C (Contributor), Tatar, Kaya (Contributor), Velicanu, Dragos Alexandru (Contributor), Wang, Jing (Contributor), Wang, Ta-Wei (Contributor), Wyslouch, Boleslaw (Contributor), Shi, Zhaozhong (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Nuclear Science and Engineering (Contributor), Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2019-03-01T17:16:46Z.
• Subjects: Article
• Online Access: Get fulltext

 The χb1(3P) and χb2(3P) states are observed through their Υ(3S)γ decays, using an event sample of proton-proton collisions collected by the CMS experiment at the CERN LHC. The data were collected at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 80.0  fb⁻¹. The Υ(3S) mesons are identified through their dimuon decay channel, while the low-energy photons are detected after converting to e⁺e⁻ pairs in the silicon tracker, leading to a χb(3P) mass resolution of 2.2 MeV. This is the first time that the J = 1 and 2 states are well resolved and their masses individually measured: 10513.42±0.41(stat)±0.18(syst)  MeV and 10524.02±0.57(stat)±0.18(syst)  MeV; they are determined with respect to the world-average value of the Υ(3S) mass, which has an uncertainty of 0.5 MeV. The mass splitting is measured to be 10.60±0.64(stat)±0.17(syst)  MeV.