Separation Of Delta-S=0 And Delta-S=1 In The Response Of C-12 To 318 Mev Protons

Angular distributions of the double-differential cross section d2sigma/dOMEGA dE (sigma) and the spin-flip probability S(nn) have been measured for inclusive inelastic proton scattering from C-12 at E(p) = 318 MeV. Data have been obtained over an excitation energy range 9 MeV less-than-or-equal-to E(x) less-than-or-equal-to 42 MeV for laboratory scattering angles of 3-degrees, 5-degrees, 7-degrees, 9-degrees, 12-degrees, 15-degrees, and 18-degrees. Multipole decompositions of angular distributions of both the spin-flip cross section sigma(SF) = sigmaS(nn) and the estimated cross section for DELTAS = 0 transitions have been performed. The distribution of deduced DELTAL = 1, DELTAS = 0 (the giant-dipole resonance) strength peaks near E(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 DELTAL = 2, DELTAS = 0 was observed spread uniformly across the spectrum with no evidence for a giant-quadrupole resonance. Angular distributions for sigma(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 sigma(SF) data above E(x) = 25 MeV; values of S(nn) are predicted somewhat too low in this region.