@article{50e6b34af45c43b9976c80042b3a9a10,
title = "χc1 and χc2 Resonance Parameters with the Decays χc1,c2 →j /ψμ+μ-",
abstract = "The decays χc1→J/ψμ+μ- and χc2→J/ψμ+μ- are observed and used to study the resonance parameters of the χc1 and χc2 mesons. The masses of these states are measured to be m(χc1)=3510.71±0.04(stat)±0.09(syst) MeV and m(χc2)=3556.10±0.06(stat)±0.11(syst) MeV, where the knowledge of the momentum scale for charged particles dominates the systematic uncertainty. The momentum-scale uncertainties largely cancel in the mass difference m(χc2)-m(χc1)=45.39±0.07(stat)±0.03(syst) MeV. The natural width of the χc2 meson is measured to be Γ(χc2)=2.10±0.20(stat)±0.02(syst) MeV. These results are in good agreement with and have comparable precision to the current world averages.",
author = "{(LHCb Collaboration)} and R. Aaij and B. Adeva and M. Adinolfi and Z. Ajaltouni and S. Akar and J. Albrecht and F. Alessio and M. Alexander and {Alfonso Albero}, A. and S. Ali and G. Alkhazov and {Alvarez Cartelle}, P. and Alves, {A. A.} and S. Amato and S. Amerio and Y. Amhis and L. An and L. Anderlini and G. Andreassi and M. Andreotti and Andrews, {J. E.} and Appleby, {R. B.} and F. Archilli and P. D'Argent and {Arnau Romeu}, J. and A. Artamonov and M. Artuso and E. Aslanides and M. Atzeni and G. Auriemma and M. Baalouch and I. Babuschkin and S. Bachmann and Back, {J. J.} and A. Badalov and C. Baesso and S. Baker and V. Balagura and W. Baldini and A. Baranov and Barlow, {R. J.} and C. Barschel and S. Barsuk and W. Barter and F. Baryshnikov and V. Batozskaya and V. Battista and A. Bay and {Calvo Gomez}, M. and X. Vilasis-Cardona",
note = "Funding Information: We thank Jielei Zhang for useful discussions concerning Dalitz decays. We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ, and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG, and MPG (Germany); INFN (Italy); NWO (Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MinES and FASO (Russia); MinECo (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); NSF (USA). We acknowledge the computing resources that are provided by CERN, IN2P3 (France), KIT and DESY (Germany), INFN (Italy), SURF (Netherlands), PIC (Spain), GridPP (United Kingdom), RRCKI and Yandex LLC (Russia), CSCS (Switzerland), IFIN-HH (Romania), CBPF (Brazil), PL-GRID (Poland) and OSC (USA). We are indebted to the communities behind the multiple open-source software packages on which we depend. Individual groups or members have received support from AvH Foundation (Germany), EPLANET, Marie Sk{\l}odowska-Curie Actions and ERC (European Union), ANR, Labex P2IO, ENIGMASS, and OCEVU, and R{\'e}gion Auvergne-Rh{\^o}ne-Alpes (France), RFBR and Yandex LLC (Russia), GVA, XuntaGal, and GENCAT (Spain), Herchel Smith Fund, the Royal Society, the English-Speaking Union, and the Leverhulme Trust (United Kingdom). Funding Information: We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ, and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG, and MPG (Germany); INFN (Italy); NWO (Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MinES and FASO (Russia); MinECo (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); NSF (USA). We acknowledge the computing resources that are provided by CERN, IN2P3 (France), KIT and DESY (Germany), INFN (Italy), SURF (Netherlands), PIC (Spain), GridPP (United Kingdom), RRCKI and Yandex LLC (Russia), CSCS (Switzerland), IFIN-HH (Romania), CBPF (Brazil), PL-GRID (Poland) and OSC (USA). We are indebted to the communities behind the multiple open-source software packages on which we depend. Individual groups or members have received support from AvH Foundation (Germany), EPLANET, Marie Sklodowska-Curie Actions and ERC (European Union), ANR, Labex P2IO, ENIGMASS, and OCEVU, and Region Auvergne-Rhne-Alpes (France), RFBR and Yandex LLC (Russia), GVA, XuntaGal, and GENCAT (Spain), Herchel Smith Fund, the Royal Society, the English-Speaking Union, and the Leverhulme Trust (United Kingdom). Publisher Copyright: {\textcopyright} 2017 CERN, for the LHCb Collaboration.",
year = "2017",
month = nov,
day = "28",
doi = "10.1103/PhysRevLett.119.221801",
language = "English",
volume = "119",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "22",
}