相关论文: BES R measurements and $J/\psi$ decays

Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector, the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and…

Using a sample of 58 million $J/\psi$ events recorded in the BESII detector, the decay $J/\psi \to \omega \pi^+ \pi^-$ is studied. There are conspicuous $\omega f_2(1270)$ and $b_1(1235)\pi$ signals. At low $\pi \pi$ mass, a large broad…

Results are reported based on samples of 58 million $\jpsi$ and 14 million $\psip$ decays obtained by the BESII experiment. Improved branching fraction measurements are determined, including branching fractions for $\jpsi\to\ppp$, $\psip\ra…

BES data on $J/\psi \to \gamma (\pi^{+} \pi^{-} \pi^{+} \pi^{-})$ have been analyzed into partial waves. We fit with resonances having $J^{PC}=2^{++}$ at 1275 MeV, $0^{++}$ at 1500 MeV, $2^{++}$ at 1565 MeV, $0^{++}$ at 1740 MeV, $2^{++}$…

We report partial wave analysis results for $J/\psi \to \gamma K^+ K^-$ based on $7.8 \times 10^6$ BESI $J/\psi$ events, and find $0^{++}$ to be dominant in the $f_J(1710)$ mass region. Some very preliminary results are presented from the…

Based on $5.8 \times 10^7 J\psi$ events collected with BESII at the Beijing Electron-Positron Collider (BEPC), the decay branching fractions of $J\psi\to\omega\pi^0$, $\omega\eta$, and $\omega\eta'$ are measured using different $\eta$ and…

We report the preliminary R values for all the 85 energy points scanned in the energy region of 2-5 GeV with the upgraded Beijing Spectrometer (BESII) at Beijing Electron Positron Collider (BEPC). Preliminary results from the J/psi data…

Based on a sample of 7.8 million BESI $J/\psi$ events, the decay of $ J/\psi \to \omega \pi^+ \pi^-$ is studied. A low mass enhancement in the $\pi^+ \pi^-$ invariant mass spectrum recoiling against $\omega$ particle is clearly seen which…

The studies on the multi-quark candidates, light scalar mesons and excited baryon states at BES are presented, based on $5.8 \times 10^7$ $J/\psi$ data collected with BESII detector. The measurements of some $J/\psi$ and $\eta_c$ decays are…

Recently BES at BEPC found evidence for the existence of the $\sigma$ meson in the process of $J/\Psi \to \sigma\omega \to\pi\pi\omega$. In this paper we firstly discuss the relevant coupling $g_{\sigma\pi\pi}$ and show that the linear…

Based on 5.8x10^7 J/psi events detected in BESII, the branching fractions of J/psi--> phi eta and phi eta^prime are measured for different eta and eta^prime decay modes. The results are significantly higher than previous measurements. An…

Decays of the $\psi(2S)$ into Vector plus Pseudoscalar meson final states have been studied with 14 million $\psi(2S)$ events collected with the BESII detector. Branching fractions of $\psi(2S) \rar\phi\eta$, $\phi\etap$, and $\omega\etap$,…

The previous results of J/psi radiative decays from MARKIII, DM2, Crystal Ball and BESI are briefly reviewed in this talk. The main part of this talk focuses on presenting the recent results from BESII 58 million J/psi data, including the…

The decay $J/\psi \to \omega p \bar p$ is studied using a $5.8 \times 10^7$ $J/\psi$ event sample accumulated with the BES II detector at the Beijing electron-positron collider. The decay branching fraction is measured to be $B(J/\psi \to…

Using J/psi -> mu^+ mu^- decays from a sample of approximately 4 million psi(2S) events collected with the BESI detector, the branching fractions of psi(2S) -> eta J/psi, pi^0 pi^0 J/psi, and anything J/psi normalized to that of psi(2S) ->…

The values of $R = \sigma(e^+e^-\to{hadrons})/ \sigma(e^+e^-\to\mu^+\mu^-)$ for 85 center-of-mass energies between 2 and 5 GeV are reported. Preliminary results using partial wave analysis for $J/\psi$ decays to $\gamma \pi^+ \pi^-$,…

We present results of a study of the decay $J/\psi\rightarrow\omega\eta\pi^+\pi^-$ using a sample of $(225.2\pm2.8)\times10^6$ $J/\psi$ events collected by the BESIII detector, and report the observation of a new process of…

Using 58 million J/psi and 14 million psi' decays obtained by the BESII experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous…

The new observation of X(1835)is reported using 58 million $\jpsi$ events collected at BES II detector. We also present the measurements of J/\Psi and eta_c decays, of them some are the first measurements and some improve the precision in…

This report highlights the recent BESIII results related to the measurement of the $R$ value, radiative decays of $J/\psi$ and the polarization of $D^0 \to \omega \phi$ decay. BESIII, a symmetric electron-positron collider experiment, has…