Angular distributions of the double-differential cross section ${\mathit{d}}^2$σ/dΩ dE (σ) and the spin-flip probability ${\mathit{S}}_{\mathit{n}\mathit{n}}$ have been measured for inclusive inelastic proton scattering from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ at ${\mathit{E}}_{\mathit{p}}$=318 MeV. Data have been obtained over an excitation energy range 9 MeV ≤${\mathit{E}}_{\mathit{x}}$≤42 MeV for laboratory scattering angles of 3°, 5°, 7°, 9°, 12°, 15°, and 18°. Multipole decompositions of angular distributions of both the spin-flip cross section ${\mathrm{\sigma }}_{\mathrm{SF}}$=σ${\mathit{S}}_{\mathit{n}\mathit{n}}$ and the estimated cross section for ΔS=0 transitions have been performed. The distribution of deduced ΔL=1, ΔS=0 (the giant-dipole resonance) strength peaks near ${\mathit{E}}_{\mathit{x}}$=22 MeV; although there is apparently much more strength relative to the energy-weighted sum rule (EWSR) than expected, this appears to be an artifact of instrumental background at small angles. Approximately 55% of the EWSR for ΔL=2, ΔS=0 was observed spread uniformly across the spectrum with no evidence for a giant-quadrupole resonance. Angular distributions for ${\mathrm{\sigma }}_{\mathrm{SF}}$ were analyzed using the predictions from random-phase approximation calculations for the nuclear structure and distorted-wave impulse approximation calculations for the scattering. These predictions are found to provide a good description of the ${\mathrm{\sigma }}_{\mathrm{SF}}$ data above ${\mathit{E}}_{\mathit{x}}$=25 MeV; values of ${\mathit{S}}_{\mathit{n}\mathit{n}}$ are predicted somewhat too low in this region.

• Received 21 April 1993

DOI:https://doi.org/10.1103/PhysRevC.48.1106