CHIRAL CORRECTIONS TO THE KROLL-RUDERMAN THEOREM

We calculate the one-loop corrections to the Kroll-Ruderman low-energy theorems for charged pion photoproduction in the framework of heavy b aryon chiral perturbation theory. We predict the threshold S-wave mult ipole E(0+) to be E(0+)(thr)(gamma p --> pi(+)n) = (28.2 +/- 0.6). 10( -3)/M(pi) and E(0+)(thr)(gamma n --> pi(-)p) = (-32.7 +/- 0.6). 10(-3) /M(pi), respectively, for a fixed pion-nucleon coupling constant, g(pi )N = 13.4. A comparison to the existing data is also given.