Measuring the longest range P-odd pion-nucleon coupling in pion
photoproton production near the threshold
J.-W. Chen
University of Maryland
The longest range P-odd pion-nucleon coupling hp is important for low
energy non-leptonic parity violation. However, after considerable effort
in the past two decades, its value is still poorly constrained largely due
to many-body theoretical complications. It will be shown that the single
nucleon process, polarized gamma p -> p+ n in the threshold region, is
an excellent candidate for measuring h_pi to an uncertainty of 20% if it
has a natural size from dimensional analysis.