Measuring tensor analyzing power component T 20 of the coherent photoproduction of a neutral pion on a tensor-polarized deuteron in the VEPP-3 storage ring

Abstract

An experiment to measure tensor analyzing power component T 20 of the coherent photoproduction reaction of a neutral pion on a tensor-polarized deuterium target \(\left( {\gamma \vec d \to d\pi ^0 } \right)\) is described. Measurements are made in two kinematic ranges: photon energy E γ = 200–500 MeV and neutral pion escape angle \(\Theta _{\pi ^0 }^{cm} = 100^ \circ - 140^ \circ\), E γ = 300–600 MeV, and \(\Theta _{\pi ^0 }^{cm} = 40^ \circ - 70^ \circ\). A hyperfine internal gas polarized target is used in the experiment. Detectors of neutral pions and deuterons register these particles when they coincide. The degree of target polarization and experimental luminosity are measured via the registration of elastic electron scattering on a deuteron at a low momentum of transfer. The preliminary experimental results are compared to certain theoretical predictions.