Ft. Baker et al., SEPARATION OF DELTA-S=0 AND DELTA-S=1 IN THE RESPONSE OF C-12 TO 318 MEV PROTONS, Physical review. C. Nuclear physics, 48(3), 1993, pp. 1106-1115
Angular distributions of the double-differential cross section d2sigma
/dOMEGA dE (sigma) and the spin-flip probability S(nn) have been measu
red for inclusive inelastic proton scattering from C-12 at E(p) = 318
MeV. Data have been obtained over an excitation energy range 9 MeV les
s-than-or-equal-to E(x) less-than-or-equal-to 42 MeV for laboratory sc
attering angles of 3-degrees, 5-degrees, 7-degrees, 9-degrees, 12-degr
ees, 15-degrees, and 18-degrees. Multipole decompositions of angular d
istributions 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 gi
ant-dipole resonance) strength peaks near E(x) = 22 MeV; although ther
e is apparently much more strength relative to the energy-weighted sum
rule (EWSR) than expected, this appears to be an artifact of instrume
ntal background at small angles. Approximately 55% of the EWSR for DEL
TAL = 2, DELTAS = 0 was observed spread uniformly across the spectrum
with no evidence for a giant-quadrupole resonance. Angular distributio
ns for sigma(SF) were analyzed using the predictions from random-phase
approximation calculations for the nuclear structure and distorted-wa
ve impulse approximation calculations for the scattering. These predic
tions are found to provide a good description of the sigma(SF) data ab
ove E(x) = 25 MeV; values of S(nn) are predicted somewhat too low in t
his region.