D. L. Shen
A5039489134- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Computational Physics and Python Applications
- Superconducting Materials and Applications
- Nuclear physics research studies
- Particle Accelerators and Free-Electron Lasers
- Radioactive Decay and Measurement Techniques
- Magnetic confinement fusion research
- Black Holes and Theoretical Physics
- Cosmology and Gravitation Theories
- Adaptive Control of Nonlinear Systems
- Textile materials and evaluations
- Quantum chaos and dynamical systems
- Nuclear Physics and Applications
- Smart Grid Security and Resilience
- Urologic and reproductive health conditions
- Nuclear reactor physics and engineering
- Advanced NMR Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Gamma-ray bursts and supernovae
Fudan University
2024
Guangxi Normal University
2005-2024
Huzhou University
2024
Ball State University
2024
Central China Normal University
2024
Argonne National Laboratory
2024
Frankfurt Institute for Advanced Studies
2024
Creighton University
2024
Shandong University
2024
Liaoning University of Technology
2024
Using the upgraded Beijing Spectrometer, we have measured total cross section for e+e− annihilation into hadronic final states at center-of-mass energies of 2.6, 3.2, 3.4, 3.55, 4.6, and 5.0 GeV. Values R, σ(e+e−→hadrons)/σ(e+e−→μ+μ−), are determined.Received 28 July 1999DOI:https://doi.org/10.1103/PhysRevLett.84.594©2000 American Physical Society
The BES experiment at the Beijing electron-positron collider has observed ξ(2230) signal in π+π−, K+K−, K0SK0S, and p¯p final states with 4.6σ, 4.1σ, 4.0σ, 3.8σ statistical significances, respectively. new observations of two nonstrange decay modes ξ→π+π− are important evidence for glueball interpretation ξ(2230).Received 30 October 1995DOI:https://doi.org/10.1103/PhysRevLett.76.3502©1996 American Physical Society
The decay channel J/psi --> gamma(pi)(+)pi(-)eta is analyzed using a sample of 5.8 x 10(7) events collected with the BESII detector. A resonance, Chi(1835), observed in pi(+)pi(-)eta invariant-mass spectrum statistical significance 7.7 sigma. fit Breit-Wigner function yields mass M = 1833.7 +/- 6.1(stat) 2.7(syst) MeV/c(2), width Tau 67.7 20.3(stat) 7.7(syst) and product branching fraction B(J/psi gammaChi) . B(Chi pi(+)pi(-)eta) [2.2 0.4(stat) 0.4(syst)] 10(-4). Chi(1835) are not compatible...
Based on 58 million BESII J/psi events, the bar{K}^*(892)^0K^+pi^- channel in K^+K^-pi^+pi^- is studied. A clear low mass enhancement invariant spectrum of K^+pi^- observed. The does not come from background other decay channels, nor phase space. Two independent partial wave analyses have been performed. Both favor that kappa, an isospinor scalar resonant state. average and width kappa two are 878 +- 23^{+64}_{-55} MeV/c^2 499 52^{+55}_{-87} MeV/c^2, respectively, corresponding to a pole at...
Using the BES-II detector at BEPC Collider, we measured lowest order cross sections and R values (R=σe+e−→hadrons0/σe+e−→μ+μ−0) for inclusive hadronic event production center-of-mass energies of 3.650, 3.6648 3.773 GeV. The results lead to R¯uds=2.218±0.019±0.089 which is average these 3.650 GeV GeV, R=3.746±0.037±0.187 s=3.773GeV. We determined section ψ(3770) be σψ(3770)B=(9.323±0.253±0.801)nb branching fractions decays BF(ψ(3770)→D0D¯0)=(49.5±1.3±3.8)%, BF(ψ(3770)→D+D−)=(35.7±1.1±3.4)%...
We measure the branching fractions for $\ensuremath{\psi}(3770)\ensuremath{\rightarrow}{D}^{0}{\overline{D}}^{0}$, ${D}^{+}{D}^{\ensuremath{-}}$, $D\overline{D}$, and non-$D\overline{D}$ to be $(46.7\ifmmode\pm\else\textpm\fi{}4.7\ifmmode\pm\else\textpm\fi{}2.3)%$, $(36.9\ifmmode\pm\else\textpm\fi{}3.7\ifmmode\pm\else\textpm\fi{}2.8)%$, $(83.6\ifmmode\pm\else\textpm\fi{}7.3\ifmmode\pm\else\textpm\fi{}4.2)%$, $(16.4\ifmmode\pm\else\textpm\fi{}7.3\ifmmode\pm\else\textpm\fi{}4.2)%$,...
An enhancement near threshold is observed in the omega(phi) invariant mass spectrum from doubly Okubo-Zweig-Iizuka-suppressed decays of J/psi-->gamma(omega)phi, based on a sample 5.8 x 10(7) J/psi events collected with BESII detector. A partial wave analysis shows that this favors JP=0+, and its width are M=1812(+19)(-26)(stat)+/-18(syst) MeV/c2 Gamma=105+/-20(stat)+/-28(syst) MeV/c2. The product branching fraction determined to be...
The decays of $J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\phi}{f}_{0}(980)[\ensuremath{\eta}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma},\ensuremath{\phi}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}},{f}_{0}(980)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}]$ are analyzed using a sample $5.8\ifmmode\times\else\texttimes\fi{}{10}^{7}$ $J/\ensuremath{\psi}$ events collected with the BESII detector at...
The mass of the τ lepton has been measured at Beijing Electron-Positron Collider using Spectrometer. A search near threshold for e+e−→τ+τ− was performed. Candidate events were identified by requiring that one decay via τ→eνν¯, and other τ→μνν¯. value, obtained from a fit to energy dependence τ+τ− cross section, is mτ=1776.9+0.4−0.5±0.2 MeV.Received 7 August 1992DOI:https://doi.org/10.1103/PhysRevLett.69.3021©1992 American Physical Society
The absolute branching fractions for the decays $D^0 \to K^-e ^+\nu_e$ and \pi^-e^+\nu_e$ are determined using $7584\pm 198 \pm 341$ singly tagged $\bar D^0$ sample from data collected around 3.773 GeV with BES-II detector at BEPC. In system recoiling against meson, $104.0\pm 10.9$ events $9.0 3.6$ observed. Those yield to be $BF(D^0 K^-e^+\nu_e)=(3.82 0.40\pm 0.27)%$ \pi^-e^+\nu_e)=(0.33 0.13\pm 0.03)%$. vector form factors $|f^K_+(0)| = 0.78 0.04 0.03$ $|f^{\pi}_+(0)| 0.73 0.14 0.06$....
A partial wave analysis of ${\ensuremath{\chi}}_{c0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{K}^{+}{K}^{\ensuremath{-}}$ in $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c0}$ decay is presented using a sample $14\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\psi}(2S)$ events accumulated by the BES II detector. The data are fitted to sum relativistic covariant tensor amplitudes for intermediate...
We report measurements of the continuum R(uds) near center-of-mass energy 3.70 GeV, R[uds(c)+psi(3770)](s) and R(had)(s) values in e(+)e(-) annihilation at 68 points region between 3.650 3.872 GeV with BES-II detector BEPC Collider. obtain for light hadron (containing u, d, s quarks) production DD threshold to be R(uds)=2.141+/-0.025+/-0.085.
Using 14M $\psi(2S)$ events accumulated by BESII at the BEPC, a Covariant Helicity Amplitude Analysis is performed for $\psi(2S)\to\pi^+\pi^-J/\psi, J/\psi\to \mu^+\mu^-$. The $\pi^+\pi^-$ mass spectrum, distinctly different from phase space, suggests $\sigma$ production in this process. Two theoretical schemes are used global fit to data. results consistent with existence of $\sigma$. pole position determined be $(552^{+84}_{-106})-i(232^{+81}_{-72})$ MeV/$c^2$.
Using psi(2S) --> pi(+)pi(-) J/psi events in a sample of 14.0 x 10(6) decays collected with the BES-II detector, search for decay to invisible final states is performed. No signal found, and an upper limit at 90% confidence level determined be 1.2 10(-2) ratio B(J/psi invisible)/B(J/psi-->mu(+)mu(-)). This first states.
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 Beijing electron-positron collider. branching fraction measured to be $B(J/\psi p)=(9.8\pm 0.3\pm 1.4)\times 10^{-4}$. No significant enhancement near $p\bar mass threshold observed, and an upper limit of X(1860))B(X(1860)\to p\bar p)$$ $$< 1.5 10^{-5}$ determined 95% confidence level, where X(1860) designates near-threshold seen in spectrum \gamma decays.
By analyzing the data collected at center-of-mass energy ${E}_{\mathrm{cm}}=3.773\text{ }\text{ }\mathrm{GeV}$ and below $D\overline{D}$ meson pair production threshold with BES-II detector BEPC Collider, we directly measured observed non-$D\overline{D}$ cross section of $\ensuremath{\psi}(3770)$ decay to be...