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.
Original language | English |
---|---|
Article number | 221801 |
Journal | Physical Review Letters |
Volume | 119 |
Issue number | 22 |
DOIs | |
Publication status | Published - 28 Nov 2017 |
Funding
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 Skłodowska-Curie Actions and ERC (European Union), ANR, Labex P2IO, ENIGMASS, and OCEVU, and Région Auvergne-Rhône-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). 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).
Funders | Funder number |
---|---|
Not added | 1681016, 1796908, ST/H006737/1 |
EPLANET | |
Herchel Smith Fund | |
MinES | |
OCEVU | |
XuntaGal | |
Yandex LLC | |
National Science Foundation | |
California Department of Fish and Game | |
Alexander von Humboldt-Stiftung | |
H2020 Marie Skłodowska-Curie Actions | |
CERN | |
Science and Technology Facilities Council | ST/J004332/1, ST/L001152/1, ST/N000250/1, 1641747, ST/M003140/1, ST/K003410/1, LHCb, ST/N000331/1, GRIDPP, LHCb Upgrades |
Leverhulme Trust | |
Royal Society | |
English-Speaking Union | |
European Commission | |
European Research Council | |
Deutsche Forschungsgemeinschaft | |
Agence Nationale de la Recherche | |
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | 166208 |
National Natural Science Foundation of China | |
Russian Foundation for Basic Research | |
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior | |
Bundesministerium für Bildung und Forschung | |
Ministry of Science and Technology of the People's Republic of China | |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | |
Generalitat Valenciana | |
Conselho Nacional de Desenvolvimento Científico e Tecnológico | |
Instituto Nazionale di Fisica Nucleare | |
Max-Planck-Gesellschaft | |
Narodowe Centrum Nauki | |
Narodowym Centrum Nauki | |
Ministerstwo Nauki i Szkolnictwa Wyższego | |
Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro | |
Ministry of Science and Technology, Taiwan | |
National Academy of Sciences of Ukraine | |
Centre National de la Recherche Scientifique | |
Financiadora de Estudos e Projetos | |
Bundesministerium für Bildung und Frauen | |
Région Auvergne-Rhône-Alpes | |
Institut national de physique nucléaire et de physique des particules | |
Federal Agency for Scientific Organizations | |
Sociedad Española de Reumatología |