Refine
Year of publication
Document Type
- Article (138)
- Preprint (71)
- Conference Proceeding (2)
- Working Paper (1)
Language
- English (212)
Has Fulltext
- yes (212)
Is part of the Bibliography
- no (212)
Keywords
- BESIII (9)
- Branching fraction (8)
- e +-e − Experiments (5)
- Hadronic decays (4)
- Lepton colliders (4)
- Branching fractions (3)
- Charmed mesons (3)
- Electroweak interaction (3)
- Particle and Resonance Production (3)
- Bhabha (2)
Institute
- Physik (196)
- Medizin (5)
- Frankfurt Institute for Advanced Studies (FIAS) (4)
- Informatik (4)
- Biochemie, Chemie und Pharmazie (2)
- Biowissenschaften (2)
- ELEMENTS (2)
- Geowissenschaften (2)
- Mathematik (2)
- Buchmann Institut für Molekulare Lebenswissenschaften (BMLS) (1)
- Center for Financial Studies (CFS) (1)
- House of Finance (HoF) (1)
- Institut für Ökologie, Evolution und Diversität (1)
- Sustainable Architecture for Finance in Europe (SAFE) (1)
- Wirtschaftswissenschaften (1)
Using about 23 fb−1 of data collected with the BESIII detector operating at the BEPCII storage ring, a precise measurement of the 𝑒+𝑒−→𝜋+𝜋−𝐽/𝜓 Born cross section is performed at center-of-mass energies from 3.7730 to 4.7008 GeV. Two structures, identified as the 𝑌(4220) and the 𝑌(4320) states, are observed in the energy-dependent cross section with a significance larger than 10𝜎. The masses and widths of the two structures are determined to be (𝑀,Γ)=(4221.4±1.5±2.0 MeV/𝑐2,41.8±2.9±2.7 MeV) and (𝑀,Γ)=(4298±12±26 MeV/𝑐2,127±17±10 MeV), respectively. A small enhancement around 4.5 GeV with a significance about 3𝜎, compatible with the 𝜓(4415), might also indicate the presence of an additional resonance in the spectrum. The inclusion of this additional contribution in the fit to the cross section affects the resonance parameters of the 𝑌(4320) state.
The absolute branching fraction of the decay Λc(2625)+→Λ+cπ+π− is measured for the first time to be (50.7±5.0stat.±4.9syst.)% with 368.48 pb−1 of e+e− collision data collected by the BESIII detector at the center-of-mass energies of s√=4.918 and 4.950 GeV. This result is lower than the naive prediction of 67\%, obtained from isospin symmetry, by more than 2σ, thereby indicating that the novel mechanism referred to as the \textit{threshold effect}, proposed for the strong decays of Λc(2595)+, also applies to Λc(2625)+. This measurement is necessary to obtain the coupling constants for the transitions between s-wave and p-wave charmed baryons in heavy hadron chiral perturbation theory. In addition, we search for the decay Λc(2595)+→Λ+cπ+π−. No significant signal is observed, and the upper limit on its branching fraction is determined to be 80.8\% at the 90\% confidence level.