Pentaquark Search and Other Multiquark Candidates at BES

Abstract

Results are presented on $\psi (2S)$ and $J/\psi$ hadronic decays to $K_S^{0}p{K}^{-}\bar{n}$ and $K_S^0\bar{p}{K}^{+}n$ final states from data samples of 14 million $\psi (2S)$ and 58 million $J/\psi$ events accumulated at the BES II detector. No $\Theta (1540)$ signal, the pentaquark candidate, is observed, and the upper limits are set. We also present a narrow enhancement near $2m_p$ in the invariant mass spectrum of $p\bar{p}$ pairs from $J/\psi \to \gamma p\bar{p}$ decays, an enhancement near the $m_p+M_{\Lambda }$ mass threshold and an enhancement near the $m_K+m_{\Lambda }$ mass threshold from $J/\psi \to p{K}^{-}\bar{\Lambda }+c.c.$ decays, based on 58 million $J/\psi$ events.

ICHEP04 proceedings, 4 pages, 6 figures