Pion scattering from a bound nucleon at medium energies

Impulse-approximation correction in pion-nucleus optical potential

“…Above 100MeV the general structure of differential cross sections is not changed and the effect of IA correction is restricted to a small increase in the depths of diffraction minima. The results that have been discussed above are consistant with earlier IA correction calculations [5,7]. This, in a way, justifies the use of local density approximation in incorporating IA corrections.…”

“…The optical potential can now be obtained by substituting (7) z(E) depends on nuclear density and hence it is an implicit function of R. From the structure of (7,8) one can conclude that in the nuclear surface, where nuclear density is small, z(E) is very close to the free N scattering matrix. In the nuclear interior, however, z(E) may differ significantly from t(co).…”

“…There exist a number of calculations which include these corrections [5,7]. The approach used in the present calculation is, however, different from those adopted in the earlier calculations in the sense that we have used the local density approximation (LDA) [8] to express the optical potential in terms of the nuclear density and the effective pionnucleon (TrN) scattering matrix in the nuclear medium.…”