Amplitude analysis for pion photoproduction in the optimal formalism

Data for neutral pion photoproduction between 1.3 and 2.1 GeV and at four different angles are analyzed in terms of the four complex amplitudes, using the optimal formalism. Although the sets of data are incomplete for a complete determination of these amplitudes, with the help of the optimal formalism one can find frames in which the incomplete set of data yield an accurate determination of most of the amplitude parameters. The results show many interesting features which can be considered as clues toward findng the proper dynamics of such a reaction. Among these features we see evidence that it is possible to find a amplitude formalism in which all four complex amplitudes determined from the data have the same phase