期刊
SCIENCE BULLETIN
卷 65, 期 23, 页码 1983-1993出版社
ELSEVIER
DOI: 10.1016/j.scib.2020.08.032
关键词
QCD; Exotics; Tetraquark; Spectroscopy; Quarkonium; Particle and resonance production
资金
- CERN
- CAPES (Brazil)
- CNPq (Brazil)
- FAPERJ (Brazil)
- FINEP (Brazil)
- MOST (China)
- NSFC (China)
- CNRS/IN2P3 (France)
- BMBF (Germany)
- DFG (Germany)
- MPG (Germany)
- INFN (Italy)
- NWO (Netherlands)
- MNiSW (Poland)
- NCN (Poland)
- MEN/IFA (Romania)
- MSHE (Russia)
- MinECo (Spain)
- SNSF (Switzerland)
- SER (Switzerland)
- NASU (Ukraine)
- STFC (United Kingdom)
- DOE NP (USA)
- NSF (USA)
- AvH Foundation (Germany)
- EPLANET (European Union)
- Marie Sklodowska-Curie Actions (European Union)
- ERC (European Union)
- A*MIDEX (France)
- ANR (France)
- Labex P2IO (France)
- Labex OCEVU (France)
- Region Auvergne-Rhone-Alpes (France)
- Key Research Program of Frontier Sciences of CAS (China)
- CAS PIFI (China)
- Thousand Talents Program (China)
- RFBR (Russia)
- RSF (Russia)
- Yandex LLC (Russia)
- GVA (Spain)
- XuntaGal (Spain)
- GENCAT (Spain)
- Royal Society (United Kingdom)
- Leverhulme Trust (United Kingdom)
- STFC [ST/S000801/1, LHCb, ST/S000909/1, ST/S000739/1, ST/S000879/1] Funding Source: UKRI
Using proton-proton collision data at centre-of-mass energies of root s = 7, 8 and 13 TeV recorded by the LHCb experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 9 fb(-1), the invariant mass spectrum of J/psi pairs is studied. A narrow structure around 6.9 GeV/c(2) matching the line-shape of a resonance and a broad structure just above twice the J/psi mass are observed. The deviation of the data from nonresonant J/psi-pair production is above five standard deviations in the mass region between 6.2 and 7.4 GeV/c(2), covering predicted masses of states composed of four charm quarks. The mass and natural width of the narrow X(6900) structure are measured assuming a Breit-Wigner lineshape. (C) 2020 Science China Press. Published by Elsevier B.V. and Science China Press.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据