Giant Resonances in the High-Energy Inelastic Scattering Continuum

Abstract

The details of the structure previously observed in the high-energy proton-scattering continuum are inspected for collective multipole contributions. Evidence is shown that in the $E*\approx 10-25$-MeV excitation region of the ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ continuum, at least dipole, quadrupole, and octupole excitations contribute to the structure of the cross section [$\sigma (\theta ,E*)$]. While the dipole and quadrupole strengths exhaust most of their corresponding sum rules, the octupole component does not. The possible nature of the less structured component at this continuum region is discussed.