A nuclear structure effect in $A<\mathrm{}70\mathrm{}$ nuclei for elastic proton scattering, $25<E<\mathrm{}50\mathrm{}$ MeV, is identified with a strong channel coupling to known giant multipole resonances. Numerical studies reveal it as an effective $l$-dependent absorptive and repulsive optical model contribution. For an understanding in terms of microscopic optical potentials the connection between Brueckner-Hartree-Fock and nuclear structure approaches is discussed.

[NUCLEAR REACTIONS Proton elastic scattering on ${}_{}{}^{16,18}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$, and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, $E_p=21-48\mathrm{}$ MeV. Comparisons with optical model and coupled channel calculations. Deduced coupling strengths.]

• Received 18 July 1980

DOI:https://doi.org/10.1103/PhysRevC.24.369