Measurement of the p (. gamma. ,. pi. sup 0 ) cross section at threshold

Differential and absolute cross sections for the reaction {ital p}({gamma},{pi}{sup 0}) have been measured with energy-defined photons in the threshold region ({ital E}{sub {gamma}}=131.4--157.2 MeV). The {ital E}{sub 0+} amplitude has been extracted out of the data. The values found are in disagreement with predictions of low-energy theorems.