F. Petrovich

Search for isobaric analogues of M1 states and giant spinflip resonances in the 208Pb(p, n) reaction

Abstract The 208 Pb(p, n) 208 Bi reaction has been studied at E p =120 and 160 MeV . The GT resonance is found to be concentrated in disagreement with a recent theoretical suggestion that it is highly fragmented in heavy nuclei, but in good agreement with an earlier calculation. A giant Δl = 1, ΔS = 1 resonance is also observed.

Single nucleon knockout exchange contribution to nucleus-nucleus potentials

Abstract A method for calculating the single nucleon knockout exchange contributions to nucleus-nucleus scattering potentials is described. Calculations show they are comparable to the direct contribution and can be included in the double folding model by means of a simple approximation.

Density dependent interactions and the consistency of folding estimates of nucleon-nucleus and nucleus-nucleus potentials

Abstract It is shown that density dependence in the interaction does effect the consistency of the results obtained in folding calculations of nucleon-nucleus and nucleus-nucleus potentials. A modified density dependent version of the new G matrix interaction of Bertsch et al. gives reasonable results for both.

Inelastic excitation of normal parity levels in 208Pb by 135 MeV protons

Abstract New cross section data for the inelastic excitation of normal parity levels in 208Pb with spins ranging from J=2 to J =2 are reported. The data are examined in terms of the collective model including deformed spin-orbit coupling. The experimental differential cross sections exhibit a striking transition from central dominated shapes to spin-orbit dominated shapes at J=8.

Effect of the spin-orbit potential on the single particle levels in the superheavy region☆

Abstract A new potential fit to single particle levels in doubly closed shell nuclei from 16 O to 208 Pb is presented and the effect of a negative spin-orbit symmetry term on the single particle levels in the superheavy region is discussed.

Microscopic description of normal parity excitations in the 208Pb(p, p′) reaction at 135 MeV and the shape of the nucleon-nucleon interaction

Abstract A microscopic study of new 135 MeV inelastic proton scattering data for the excitation of normal parity levels in 208 Pb with spins covering the range J =2 to 10 is reported. The short range repulsion in the central nucleon-nucleon interaction results in small central contributions to the cross sections for the transitions with J =8 and 10.

Quadrupole effects in the elastic scattering of 10B, 11B, and 12C by 27Al

Abstract Differences in the elastic differential cross section for 10,11 B + 27 Al at 50 MeV and 12 C + 27 Al at 55 MeV at back angles are attributed to expected quadrupole terms in the elastic scattering potentials. The theoretical results presented are based on a microscopic model.

Neutron transition density for the lowest 2+ state of 18O

Abstract Scattering of 135 MeV protons is used to fit an expansion in radial basis functions of the neutron transition density for the lowest 2 + state of 18 O. The narrow error envelope shows good radial sensitivity. The results are consistent with electromagnetic decay data for the mirror transition in 18 Ne.

Analyzing powers for the proton excitation of high-spin states in 28Si: A new look at the effective interaction☆

Abstract Analyzing powers have been measured for the 5−, T = 0, 6−, T = 0 and 6−, T = 1 high-spin states in 28Si using the inelastic scattering of polarized protons at 135 MeV. These data contain new information on the spin-independent central and the tensor components of the effective nucleon-nucleon interaction at high momentum transfer. The new measurements are in reasonable agreement with distorted-wave impulse approximation calculations.

Differences in the structure of isoscalar and isovector “stretched” excitations in 24Mg and 28Si☆

Abstract A comparison of theoretical distorted wave impulse approximation results with the experimental data for the excitation of “stretched” 6− T = 0 and 6− T = 1 levels in 24Mg and 28Si by 135 MeV protons suggests significant differences in the structure of the isoscalar and isovector levels. This is consistent with the results of a recent study of the (π, π′) reaction on 28Si.