2007/12/17 by F. A. Harris, Frederick A. Harris, Harris, Frederick A.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.48550/arxiv.0712.2851
Invited talk at the 11th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon, Sept. 10 - 14, 2007, Julich, Germany, 10 pages
arxiv created 2007/12/17 · openalex publication_date 2007/12/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using 58 million J/ψ and 14 million ψ(2S) events collected by the BESII detector at the BEPC, branching fractions or upper limits for the decays J/ψ and ψ(2S) → ΛΛ π0 and ΛΛ η are measured, and the decays of J/ψ and ψ(2S) to n K0S Λ+c.c. are observed and measured for the first time. Finally, R measurement data taken with the BESII detector at center-of-mass energies between 3.7 and 5.0 GeV are fitted to determine resonance parameters of the high mass charmonium states, ψ(3770), ψ(4040), ψ(4160), and ψ(4415). The Beijing Electron Collider is being upgraded to a two-ring collider (BEPCII) with a design luminosity of 1 × 1033cm-2 s-1 at 3.89 GeV and will operate between 2 and 4.2 GeV in the center of mass. With this luminosity, the new BESIII detector will beable to collect, for example, 10 billion J/ψ events in one year of running. BEPCII and BESIII are currently nearing completion, and commissioning of both is expected to begin in mid-2008.