On the Photoproduction Reactions $γd\toπNN$

Abstract

A review of our works providing a theoretical description of incoherent pion photoproduction on the deuteron is presented. The existing γd → πNN data are analysed, especially those obtained more recently by the CLAS Collaboration at JLab, the A2 Collaboration at MAMI at Mainz, and the PION@MAX-lab Collaboration at Lund. A procedure, which accounts for the final-state interactions (FSI), is applied to extract γn → πN differential cross sections from the deuteron data. The role of FSI is discussed. We also comment on the results of other works in connection with some discrepancies seen in comparing the model with experiment. The electromagnetic properties of baryon N * resonances, improved using the extracted γn → πN differential cross sections are presented. A model description of the cross section data from charged-pion photoproduction reactions γd → π ± N N near threshold is also given. The γd → π − pp data are used to extract the E 0+ multipole and total cross section of the reaction γn → π − p near threshold.