2015/08/31 by L. Xia, Li-Gang Xia
Physics and Astronomy · #Bar (unit) #Baryon #Branching fraction #High-Energy Particle Collisions Research #Lambda #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Sigma #hep-ex #hep-ph
paper · pdf · doi:10.1016/j.physletb.2016.03.015
published as Physics Letters B 756 (2016) 77-83 · version accepted by Physics Letters B, revised, discussed added, references added
arxiv created 2016/03/03 · openalex publication_date 2016/03/07 · arxiv updated 2016/03/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
To study the decays of ψ(3770) going to baryon anti-baryon pairs (BB¯), all available experiments of measuring the cross sections of e+e−→BB¯ at center-of-mass energy ranging from 3.0 GeV to 3.9 GeV are combined. To relate the baryon octets, a model based on the SU(3) flavor symmetry is used and the SU(3) breaking effects are also considered. Assuming the electric and magnetic form factors are equal (|GE|=|GM|), a global fit including the interference between the QED process and the resonant process is performed. The branching fraction of ψ(3770)→BB¯ is determined to be (2.4±0.8±0.3)×10−5, (1.7±0.6±0.1)×10−5, (4.5±0.9±0.1)×10−5, (4.5±0.9±0.1)×10−5, (2.0±0.7±0.1)×10−5, and (2.0±0.7±0.1)×10−5 for B=p,Λ,Σ+,Σ0,Ξ− and Ξ0, respectively, where the first uncertainty is from the global fit and the second uncertainty is the systematic uncertainty due to the assumption |GE|=|GM|. They are at least one order of magnitude larger than a simple scaling of the branching fraction of J/ψ/ψ(3686)→BB¯.