Determination of the γp→π0p multipole amplitudes from experimental data in the vicinity of the first resonance

The complex s- and p-wave amplitudes for the γp→π0p process in the photon-energy range 300--420 MeV are estimated on the basis of the data from the S-group experiments without resorting to data from double-polarization experiments. The presence of the previously predicted discrete (double) ambiguity of the solutions is confirmed. A continuous ambiguity due to the indefinite common phase of the amplitudes is observed. Means for eliminating these ambiguities are presented and the resulting amplitudes are compared with theoretical predictions