Transverse electron scattering response function of 3He in the quasi-elastic peak region and beyond with Δ isobar degrees of freedom

摘要

The 3 He transverse electron scattering response function R T ( q , ω ) is calculated in the quasi-elastic peak region and beyond for momentum transfers q = 500 , 600 and 700 MeV/ c . Distinct from our previous work for these kinematics where we included meson exchange currents and relativistic corrections we now additionally include Δ isobar currents (Δ-IC). The Δ-IC contribution increases the quasi-elastic peak height by about 5% and leads to an excellent agreement with experimental data in the whole peak region. In addition it is shown that effects due to the three-nucleon force largely cancel those due to the Δ-IC in the peak region. Finally, we have found that Δ-IC are important for three-body break-up reactions in the so-called dip region. This could explain why in a previous study of such a reaction, where Δ degrees of freedom were not included, no agreement between experimental and theoretical results could be obtained.