Scattering of α-particles and 3He on 16O nuclei and its excitation mechanism at energies near 50MeV

Abstract

Elastic and inelastic scattering of [Formula: see text]-particles at 48.1[Formula: see text]MeV and 3He at 60[Formula: see text]MeV on [Formula: see text]O nuclei has been measured with excitation of states at 6.05 (0[Formula: see text])–6.13 (3[Formula: see text])[Formula: see text]MeV, 6.92 (2[Formula: see text])–7.12 (1[Formula: see text])[Formula: see text]MeV and 8.87 (2[Formula: see text])[Formula: see text]MeV. The center-of-mass beam momenta are the same for these two strongly absorbed particles. Analysis of angular distributions was performed in the frameworks of the optical model, the coupled channels method and the Distorted Wave Born Approximation (DWBA). A good description of experimental data was obtained over the full angular range without taking into account the spin-orbit interaction and the cluster transfer mechanism with real potentials that have volume integrals of about 400[Formula: see text]MeV fm3. Collective and microscopic models were used in the analysis of the inelastic scattering. The values of the octupole deformation lengths were extracted. It is shown that nuclear rainbow effects appear not only in the elastic, but also in the inelastic scattering with excitation of the 3[Formula: see text] state of [Formula: see text]O.

Construction of density-dependent α-nucleon interaction to describe α-nucleus scattering

“…[10,23,24,28]. We apply the point-nucleon density of 16 O, 40 Ca, 58 Ni, 90 Zr and 208 Pb obtained from the mean-field model (HF+BCS). The detail of the derivation is given in Refs.…”

“…Here, the nucleusnucleus system means heavy-ion scattering. Figure 1 shows the renormalization factors of 4 He, 16 O, 40 Ca, 58 Ni, 90 Zr and 208 Pb. The density distributions are taken from Refs.…”

“…3, first, the results of the p + 4 He elastic scattering are presented. Then, we show the results of the present folding model calculation for the α-nucleus elastic scattering for 16 O, 40 Ca, 58 Ni, 90 Zr and 208 Pb. The total reaction cross sections are also calculated and compared with experimental data.…”

Scattering processes of helium nuclides on nuclei 28Si

“…However, these actions did not lead to a theoretically substantiated description of scattering in a wide range of targets and energies. At the same time, calculations of the differential cross sections for scattering of alpha particles by 1p-shell nuclei, carried out taking into account the link between the channels and the contribution of the cluster transfer mechanism, made it possible to describe the behavior of the angular distributions in the full angular range [11,12].…”

“…Only in [15] did the measurements include inelastic scattering, which made it possible to derive the values of the quadrupole deformation parameters from the analysis of experimental data. Note that the correct reproduction of the angular distributions of scattering of α-particles and 3 Hе ions by 1p-and sdshell nuclei with deformation parameters consistent with their theoretical values was achieved in [12,18], where the calculations were performed using the coupled channel method.…”