The nuclear response in the 54Fe(p vector, p' vector) reaction at 290 Mev

Cross sections, analysing powers and spin-flip probabilities have been measured for inclusive inelastic scattering of 290 MeV protons from 54Fe at laboratory angles between 3.1 degrees and 20 degrees. The momentum transfers vary from small values (q ∼ 0.2 fm-1) where individual giant resonances of low multipolarity are observed, to larger values (q ∼ 1.4 fm-1) where quasielastic scattering dominates. For the observed range of momentum and energy transfers (ω ≤ 96 MeV at 20 degrees, ≤ 45 MeV at smaller angles) the spin-flip probabilities Snn and spin-flip strengths σSnn appear to be insensitive to assumptions about the reaction mechanism and are qualitatively described by a nonrelativistic model of quasielastic scattering which approximates the nuclear response by that of a semi-infinite slab with RPA correlations. Strongly enhanced Snn values are observed for ω > 25 MeV and q ≅ 100 MeV/c in agreement with similar observations for several other nuclei. The slab model gives a reasonable account of cross sections and angular distributions for the 54Fe(n,p)54Mn reaction at 298 MeV. The inclusion of damping of the response by 2 particle-2 hole excitations and of contributions from two-step processes improves the agreement with the (n,p) data. Using the experimental cross sections for (p,p') and (n,p) reactions and the measured spin-flip strengths in (p,p'), we have separated the nuclear response into spin (ΔS = 0, ΔS = 1), isospin (Tf = 1,2) and angular momentum (L 0,1,2...) components. The distribution and strengths of the Gamow Teller, the isovector giant dipole, and the (isoscalar) giant quadrupole resonances have been determined from this analysis and are compared to results from complementary reactions. Relative to quasiparticle RPA calculations the Gamow Teller quenching factors deduced from the σSnn data are slightly smaller than those from (p,n) and (n,p) reactions. (Author) (64 refs., 5 tabs., 20 figs.)