Asymmetry of angular distribution in the π0 meson photoproduction on light nuclei

The asymmetry of angular distributions (AD) of cross sections for the following reactions: γ+3H(3He)→π0+3H(3He), γ+4He→π0+4He, γ+3H(3He)→π0+f and γ+4He→π0+f, where f means an arbitrary nuclear state, has been calculated in the framework of the impulse approximation. The calculations were performed for the energy range from 180 to 700 MeV, using the γ+N→π+N multipole analysis. The AD asymmetries for the γ+3H→π0+3H and γ+d→π0+d reactions are found to have the same sign; mean asymmetries are of the order of 90%. The sign, magnitude and angular dependence of asymmetries in the γ+3He→π0+3He and γ+3H→π0+3H reactions are found to be close to each other. In the γ+4He→π0+4He reaction the asymmetry is found to be equal to unity, irrespective of energy and angle. It is emphasized that experiments with light nuclei may serve as an additional source of information when performing the multipole analysis of the pion photoproduction on nucleons