Differential cross section and vector analysing power of the p pol p → {pp} s π0 reaction at 353–700 MeV

Abstract

The reaction ppolp → {pp}sπ0 was studied with the ANKE spectrometer at COSY-Julich using a polarized beam with energies 353, 500, 550 and 700 MeV. The proton pairs {pp}s were detected at low excitation energy Epp < 3 MeV, where S-wave dominates. The angular dependences of vector analysing power Ay and differential cross section dσ/dΩ of the reaction have been obtained for the most of the angular range at 353 MeV and forward angles at the higher beam energies. The partial wave amplitude analysis, done with the 353 MeV results, is important for Chiral Perturbation Theory tests at this energy. The data at higher energies detalize the energy dependence of dσ/dΩ(0°) obtained earlier. It allows to learn about the dynamics of the Δ(1232) resonance excitation in two-nucleon systems.