Threshold production from the neutron in
D. L. Hornidge
Department of Physics, University of Saskatchewan
Institut für Kernphysik, J.J.-Becherweg 45, D-55099 Mainz, Germany
A significant body of experimental results now exists for the proton photo-pion
amplitudes near threshold and are in good agreement with ChPT predictions. Due
to the experimental intricacies involved, there is a clear lack of data in the
threshold region for the neutron. Preliminary attempts to determine the neutron
amplitudes using the coherent production from the deuteron were hampered by the
difficulties in separating out nuclear effects. For these reasons, a measurement
of photoproduction in the threshold region from the neutron via the
n)p reaction channel has been performed using the Mainz Microtron
(MAMI). Photons in the energy range
MeV were tagged
using the Glasgow tagger, the TAPS spectrometer was employed to detect the
neutral-pion decay photons, and a segmented liquid-scintillator detector covering
the angular range
was used to detect recoil neutrons under quasi-free kinematical conditions.
Preliminary results will be presented.
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