Evaluation of the polarization observables IS and IC in the reaction gamma p --> pi0 eta p
Abstract
We evaluate the polarization observables IS and IC for the reaction gamma p --> pi0 eta p, using a chiral unitary framework developed earlier. The IS and IC observables have been recently measured for the first time by the CBELSA/TAPS collaboration. The theoretical predictions of IS and IC, given for altogether 18 angle dependent functions, are in good agreement with the measurements. Also, the asymmetry dSigma/dcos(theta) evaluated here agrees with the data. We show the importance of the Delta(1700)D33 resonance and its S-wave decay into eta Delta(1232). The result can be considered as a further confirmation of the dynamical nature of this resonance. At the highest energies, deviations of the predictions from the data start to become noticeable, which leaves room for additional processes and resonances such as a Delta(1940)D33. We also point out how to further improve the calculation.