English

Recent BES charmonium results

High Energy Physics - Experiment 2011-09-13 v1

Abstract

Using 58 million J/ψJ/\psi decays, we have investigated the ppˉp \bar{p} invariant mass spectrum in the radiative decay J/ψγppˉJ/\psi \to \gamma p \bar{p} and observe a prominent structure with mass near 2mp2m_p. Fitting with an S-wave Breit-Wigner, we obtain a peak mass of M=185910+3(stat)25+5(sys)MeV/c2M= 1859^{+3}_{-10}(\rm stat)^{+5}_{-25}(sys) MeV/c^2. J/ψγηcJ/\psi \to \gamma \eta_c decays from the same sample are used to determine the mass, width, and hadronic branching ratios of the ηc\eta_c. From a sample of 14 million ψ(2S)\psi(2S) events, the first observation of χcJ\chi_{cJ} (J=0,1,2) decays to ΛΛˉ\Lambda\bar{\Lambda} is made, and branching ratios are determined, which are larger than expected from the Color Octet Model. Branching ratios of Ks0KL0K_s^0K_L^0 in both ψ(2S)\psi(2S) and J/ψJ/\psi decays are measured, and a more than four sigma deviation from the pQCD predicted "12% rule" is observed. In ψ(3770)\psi(3770) decays, evidence for the non-DDˉD\bar{D} decay to π+πJ/ψ\pi^+\pi^-J/\psi is observed.

Keywords

Cite

@article{arxiv.hep-ex/0310036,
  title  = {Recent BES charmonium results},
  author = {Jiangchuan Chen and Frederick A. Harris},
  journal= {arXiv preprint arXiv:hep-ex/0310036},
  year   = {2011}
}

Comments

Submitted to the proceedings of EPS2003. 5 pages, 10 figures

R2 v1 2026-07-22T13:02:56.072Z