@article{c25e138e49b8414bb526f2f2918ef844,
title = "Observation of Two Excited Bc+ States and Measurement of the Bc+ (2S) Mass in pp Collisions at s =13 TeV",
abstract = "Signals consistent with the Bc+(2S) and Bc∗+(2S) states are observed in proton-proton collisions at s=13 TeV, in an event sample corresponding to an integrated luminosity of 143 fb-1, collected by the CMS experiment during the 2015-2018 LHC running periods. These excited bc states are observed in the Bc+π+π- invariant mass spectrum, with the ground state Bc+ reconstructed through its decay to J/ψπ+. The two states are reconstructed as two well-resolved peaks, separated in mass by 29.1±1.5(stat)±0.7(syst) MeV. The observation of two peaks, rather than one, is established with a significance exceeding five standard deviations. The mass of the Bc+(2S) meson is measured to be 6871.0±1.2(stat)±0.8(syst)±0.8(Bc+) MeV, where the last term corresponds to the uncertainty in the world-average Bc+ mass.",
author = "{CMS Collaboration} and Sirunyan, {A. M.} and A. Tumasyan and W. Adam and F. Ambrogi and T. Bergauer and J. Brandstetter and M. Dragicevic and J. Er{\"o} and {Escalante Del Valle}, A. and M. Flechl and R. Fr{\"u}hwirth and M. Jeitler and N. Krammer and I. Kr{\"a}tschmer and D. Liko and T. Madlener and I. Mikulec and N. Rad and J. Schieck and R. Sch{\"o}fbeck and M. Spanring and D. Spitzbart and W. Waltenberger and J. Wittmann and Wulz, {C. E.} and M. Zarucki and V. Drugakov and V. Mossolov and {Suarez Gonzalez}, J. and Darwish, {M. R.} and {De Wolf}, {E. A.} and {Di Croce}, D. and X. Janssen and J. Lauwers and A. Lelek and M. Pieters and {Van Haevermaet}, H. and {Van Mechelen}, P. and {Van Remortel}, N. and F. Blekman and Bols, {E. S.} and Chhibra, {S. S.} and J. D'Hondt and {De Clercq}, J. and G. Flouris and D. Lontkovskyi and S. Lowette and I. Marchesini and S. Moortgat and {Carrera Jarrin}, E.",
note = "Publisher Copyright: {\textcopyright} 2019 CERN for the CMS Collaboration. Published by the American Physical Society under the terms of the »https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.",
year = "2019",
month = apr,
day = "2",
doi = "10.1103/PhysRevLett.122.132001",
language = "Ingl{\'e}s",
volume = "122",
journal = "Physical Review Letters",
issn = "0031-9007",
number = "13",
}