Measuring the p-odd pion-nucleon coupling h(1)πNN in π+-photoproton production near threshold

We show that <()over right arrow>p --> pi (+)n in the threshold region is an excellent candidate fur measuring the leading parity-violating pion-nucleon coupling h(pi NN)((1)) to an uncertainty of 20% if it has a natural size from dimensional analysis. The conclusion is based on a large unpolarized cross section, a new low-energy theorem for the photon polarization asymmetry at the threshold A(gamma)\(th) = root2 f(pi)(mu (p) - mu (n))h(pi NN)((1))/g(A)m(N) similar to h(pi NN)((1))/2 and its strong dominance at forward and backward angles in the threshold region.