Study of J\psi decaying into \omega p \bar p

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 $B(J/\psi \to \omega p \bar p)=(9.8\pm 0.3\pm 1.4)\times 10^{-4}$. No significant enhancement near the $p\bar p$ mass threshold is observed, and an upper limit of $B(J/\psi \to \omega X(1860))B(X(1860)\to p\bar p)$$$$< 1.5 \times 10^{-5}$ is determined at the 95% confidence level, where X(1860) designates the near-threshold enhancement seen in the $p\bar p$ mass spectrum in $J/\psi \to \gamma p \bar p$ decays.Comment: 5 pages, 4 figure

Study of the Hadronic Decays of \chi_c States

Hadronic decays of the P-wave spin-triplet charmonium states \chi_cJ (J=0,1,2) are studied using a sample of \psi(2S) decays collected by the BES detector operating at the BEPC storage ring. Branching fractions for the decays \chi_c1 going to K_s^0 K^+ \pi^- + c.c., \chi_c0 going to K_s^0 K_s^0, \chi_c2 going to K_s^0 K_s^0, \chi_c0 going to \phi \phi, \chi_c2 going to \phi \phi and \chi_cJ going to K^+ K^- K^+ K^- are measured for the first time, and those for \chi_cJ going to \pi^+ \pi^- \pi^+ \pi^-, $ \chi_cJ going to \pi^+ \pi^- K^+ K^-, \chi_cJ going to \pi^+ \pi^- p \bar{p} and \chi_cJ going to 3(\pi^+ \pi^-) are measured with improved precision. In addition, we determine the masses of the \chi_c0 and \eta_c to be M_{\chi_{c0}}=3414.1 \pm 0.6(stat) \pm 0.8 (sys) MeV and M_{\eta_c}=2975.8 \pm 3.9(stat) \pm 1.2 (sys) MeV.Comment: 24 pages, 12 figures, 6 tables, use revtex, submitted to Phys. Rev.

Tangential stresses in two-material curved beams

The formulae for tangential stresses in two-material curved beams, with general cross-sectional shapes were derived and analyzed. The resulting solutions were used to calculate the tangential stresses in a cantilevered curved beam subjected to a concentrated force at its free end. The axial force, shearing forces, and bending moments on any cross-section of the observed composite curved beam were assumed to be positive when they act in a particular direction. A simple experimental setup was designed and loaded by weight, to achieve the anticipated loading cases. Six strain gauges were attached to the inner and outer surfaces of the crown of the bushing of the composite curved beams, to record maximum tangential stresses during each test performed

Reconstructing temperature fields from OH distribution and soot volume fraction in turbulent flames using an artificial neural network

Available online 15 November 2023We present a methodology based on artificial neural networks for reconstructing flame temperature fields from planar distributions of hydroxyl (OH) radicals and soot volume fraction in turbulent jet flames. A convolutional neural network was trained using planar images of flame temperature, soot volume fraction and OH simultaneously recorded with laser-based experimental methods. Then, the capacity and accuracy of the neural network on reconstructing flame temperatures were assessed for the flame conditions not only within the training domain but also out of it. The results showed that the supervised neural network can reconstruct instantaneous temperature fields to within ± 60 K for the flame conditions within the training domain, and to within ± 150 K for the flame conditions outside of the training domain. Probability density functions (PDF) of reconstructed temperature and the joint PDFs with OH signals and soot volume fractions also show good statistical agreement with experiments. This work has application in extending measurement techniques into regimes that are presently difficult to achieve, such as by obtaining the training data for temperature with established low-speed imaging methods and using the neural network method to predict temperature from high-speed imaging of the other two scalars.Xiangyu Nie, Wei Zhang, Xue Dong, Paul R. Medwell, Graham J. Nathan, Zhiwei Su