0000000000285502
AUTHOR
G. Nöldeke
Break-up and Coherent Photoproduction ofηMesons on the Deuteron
We present new break-up and coherent data for $\ensuremath{\eta}$ meson photoproduction on the deuteron, using a deuterium target and tagged bremsstrahlung photons up to 1 GeV. The differential cross sections for the coherent process were measured from threshold to 800 MeV. They are much smaller than those previously reported. The break-up channel provides a direct measurement of the neutron to proton differential cross section ratios. At the ${S}_{11}(1535)$ resonance peak, ${\ensuremath{\sigma}}_{n}/{\ensuremath{\sigma}}_{p}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.68\ifmmode\pm\else\textpm\fi{}0.06$ leading to an isoscalar to isovector amplitude ratio of ${A}_{s}{/A}_{\ensurem…
Die elektronenstreu-apparatur am mainzer 300 MeV-elektronen-linearbeschleuniger
Abstract In this paper, we attempt to give a general survey and a comprehensive description of the most significant features of the facilities for electron scattering experiments at the Mainz 300 MeV Linear Accelerator, along with a list of literature, where more detailed information on certain subjects can be found. The accelerator provides energies between 80 and 300 MeV. Scattering angles are available up to 160° resulting in a momentum transfer region up to 3.0 fm −1 . The overall experimental resolution is 0.1%. Cross sections down to 10 −34 cm 2 /sr can be measured. The main features of the apparatus are: an achromatic magnet system with 90° deflection, a double focusing spectrometer,…
An experimental study of the antineutron-light nucleus annihilation at 1.4 GeV/c
The heavy liquid bubble chamber, Gargamelle, has been used to investigate the gross features of the annihilation of antineutrons in light nuclei (mainly Carbon). Results are presented on the distributions of multiplicity, momentum and emission angle for charged pions and protons together with a simple model to describe them.
Measurement ofj/?-decays into channels containing charged and neutral antinucleons
Using the nonmagnetic BONANZA detector for the detection of antineutrons and antiprotons, we measured branching ratios of theJ/ψ into baryonic final states. Our measurements give the new results:\(BR\left( {{J \mathord{\left/ {\vphantom {J {\psi \to \overline {\Sigma ^ - } }}} \right. \kern-\nulldelimiterspace} {\psi \to \overline {\Sigma ^ - } }}\Sigma ^ - } \right) = \left( {0.24 \pm 0.26} \right)\% ;BR\left( {{J \mathord{\left/ {\vphantom {J {\psi \to }}} \right. \kern-\nulldelimiterspace} {\psi \to }}\bar nn\pi ^ + \pi ^ - } \right) = \left( {0.38 \pm 0.36} \right)\% \) and an independent test for the data of the magnetic detectors.