Measurement of the helicity dependence for single π0 photoproduction on the deuteron

Abstract

The subject of this thesis is the measurement of the helicity dependence of single π0 photoproduction with deuteron target in the energy region from pion threshold up to 1500 MeV. This work is part of a systematic measurement of the excited states of the nucleon performed by the A2@MAMI collaboration. Because the electromagnetic excitations are isospin dependent, it is fundamental to study the excited states both of the proton and of the neutron. The experimental data were collected using the circularly photon beam and the large acceptance Crystal Ball/TAPS detector available in the taggerhall at MAMI, in combination with the Mainz-Dubna frozen spin target, that provides a highly longitudinal polarized deuteron target. The new results of the single π 0 inclusive polarized photoproduction cross section on the deuteron and of the E observable for single π 0 photoproduction on quasi-free protons and quasi free-neutrons provide addition information and input for the theoretical models, particularly important especially for the neutron channel.