Recent Results on $\psi (3770)$ Physics at BES

Abstract

There are about 33, 6.5 and 1.0 pb${}^{-1}$ of $e^{+}{e}^{-}$ annihilation data have been taken around the center-of-mass energies of $\sqrt{s}=$ 3.773 GeV, at $\sqrt{s}=$ 3.650 GeV and at $\sqrt{s}=$ 3.6648 GeV, respectively, with the BES-II detector at the BEPC collider. By analyzing these data sets, we have measured the branching fraction for $\psi (3770)\to$ non-$D\bar{D}$ by several different methods; and have observed an anomalous line shape of ${\sigma }^{e^{+}{e}^{-}\to \mathrm{hadrons}}$ in energy region from 3.65 to 3.87 GeV; and have measured the line shapes of the $D^{+}{D}^{-}$, $D^0{\bar{D}}^0$ and $D\bar{D}$ production and together with the ratios of the production rates of $D^{+}{D}^{-}$ and $D^0{\bar{D}}^0$ in $e^{+}{e}^{-}$ annihilation around the $\psi (3770)$ resonance.

4 pages, 0 figures, to appear in the proceedings of 44th Rencontres de Moriond on QCD and High Energy interactions, La Thuile, Aosta Valley, Italy, 14-21 March 2009