Electron scattering in the dip region

Abstract

Two-body exchange currents in the noninteracting relativistic Fermi gas model are taken into account with special emphasis put on the role of the delta-isobar to reproduce the transverse response function in the dip region. Due to a resonance behaviour relativistic two-body isobar currents are found to be important for a comparison with the experimental data. Real-pion production is studied within the same framework and the importance and physical implications of the energy dependence of the delta-isobar decay width are stressed. The contents of these lectures have been/will be published in M.J. Dekker, P.J. Brussaard, and J.A. Tjon: Phys. Rev. C49 (1994) 2650–2670 and Phys. Rev. C (1995).