Meson and isobar degrees of freedom in A((e)over-right-arrow),e′(p)over-right-arrow) reactions at 0.2≤Q2≤0.8 (GeV/c)2 -: art. no. 034604

The effect of meson and isobar degrees of freedom in A((e) over right arrow,e '(p) over right arrow) and A(e,e'n) is studied for four-momentum transfers Q(2) in the range between 0.2 and 0.8 (GeV/c)(2). The calculations are performed in a nonrelativistic framework with explicit (N, Delta, pi) degrees of freedom. For the whole range of momentum transfers under investigation the effect of the meson-exchange and isobar degrees of freedom is significant. At low missing momenta and quasielastic conditions, a tendency to reduce the (e,a'p) and (e,e',nt) differential cross sections is noticed. The greatest sensitivity is found in the interference structure functions W-LT and W-TT The recoil polarization observables, on the other hand, are moderately affected by the meson-exchange and Delta-isobar currents. [S0556-2813(99)05508-9].