Measurement of the tensor analyzing power T20 for the reaction γd → pnπ0

Abstract

This paper presents new results for the [Formula: see text]-component of the tensor analyzing power of the reaction [Formula: see text] in the photon energy range of [Formula: see text]. The experimental statistics accumulated in 2013 at the VEPP-3 accelerator-storage complex is used. The reaction events are identified by the coincidence registration of the proton and two [Formula: see text]-quanta from the decay of the neutral pion. To determine the [Formula: see text]-component, the asymmetry of the yields with respect to the change of sign of the tensor polarization of the deuterium target is measured. The experimental results are compared with the theoretical calculations in which the MAID 2007 model is used as the elementary pion–nucleon photoproduction amplitude and contributions from the pion–nucleon and nucleon–nucleon rescattering are taken into account.