arXiv subjects
Publications and source records attributed to representing BES Collaboration.
Over sixty million J/psi events have been collected by the BES Collaboration at the Beijing Electron-Positron Collider (BEPC). J/psi decays provide an excellent place for studying excited nucleons and hyperons -- N*, $Λ^*$, $Σ^*$ and $Ξ^*$ resonances, as well as meson resonances, including possible glueballs and hybrids. Physics objectives, recent results and future prospects of light hadron spectroscopy at BEPC are presented.
BES Collaboration has collected 58 million $J/ψ$ events at the Beijing Electron-Positron Collider (BEPC). $J/ψ$ decays provide an excellent place for studying excited nucleons and hyperons -- $N^*$, $Λ^*$, $Σ^*$ and $Ξ^*$ resonances. Physics motivation, data status, partial wave analyses and future prospects are presented for the baryon resonance program at BES.
$J/Ψ$ particles are abundantly produced at the Beijing Electron Positron Collider (BEPC). The $J/Ψ$ decays provide an excellent place for studying $N^*$ resonances. For $J/Ψ\to\bar NNπ$ and $\bar NNππ$, the $πN$ and $ππN$ systems are limited to be pure isospin 1/2 due to isospin conservation. This is a big advantage in studying $N^*$ resonances from $J/Ψ$ decays, compared with $πN$ and $γN$ experiments which suffer difficulty on the isospin decomposition of 1/2 and 3/2. All other $N^*$ decay channels which are presently under investigation at CEBAF(JLab, USA), ELSA(Bonn,Germany) and GRAAL(Grenoble, France) with real photon or space-like virtual photon can also be studied at BEPC complementally with the time-like virtual photon. The process $J/Ψ\to\bar NN^*$ or $N\bar N^*$ provides a new way to probe the internal structure of the $N^*$ resonances. The recent results and outlook of our new $N^*$ program at BEPC are presented.