MEASUREMENT OF THE SPECTRUM OF BACKWARD PHOTONS FROM RADIATIVE PION-PROTON SCATTERING AT 260 AND 295 MeV

Publisher Summary This chapter describes the measurement of the spectrum of backward photons from radiative pion–proton scattering at 260 and 295 MeV. Photon emission is dominated by external bremsstrahlung, where a photon is emitted either before or after the strong interaction. A study of radiative scattering between strongly interacting particles or nuclei is of interest for energetic photons or in a situation where the expansion in photon energy (E γ ) breaks down at low energies. In such cases, the electromagnetic interaction can be considered to be a probe of the associated strong interaction, providing information that cannot be obtained by non-radiative reactions alone, and the off-mass shell effects, electromagnetic structure of the intermediate states, and form factors of the electromagnetic vertices can be observed. The simplest radiative scattering system that can be studied is where the target is a nucleon and the projectile is either a nucleon or a pion.