SEPARATION OF DELTA-S=0 AND DELTA-S=1 IN THE RESPONSE OF C-12 TO 318 MEV PROTONS

Citation
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
Citations number
24
Categorie Soggetti
Physics, Nuclear
ISSN journal
05562813
Volume
48
Issue
3
Year of publication
1993
Pages
1106 - 1115
Database
ISI
SICI code
0556-2813(1993)48:3<1106:SODADI>2.0.ZU;2-Z
Abstract
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.