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Experimental 7 Li + 27 Al elastic scattering angular distributions in the 6–89 MeV laboratory energy range have been re-analysed using different phenomenological and microscopic potentials to investigate the cluster nature of the weakly-bound 7 Li projectile and the associated break-up effect on the elastic scattering data. The consistency of the results obtained within the various implemented potentials was also analysed. A new microscopic dynamical polarisation potential was applied to simulate the significant coupling effect to the break-up channel, which is responsible for the observed reduction in the strength of the implemented real potentials. A reasonable agreement between the considered experimental results and the present theoretical calculations was obtained. The study confirms the absence of the usual threshold anomaly present in nuclear systems involving tightly-bound projectiles. [ABSTRACT FROM AUTHOR]

The α-cluster model has been employed to generate the α-cluster and nucleon (matter) density distributions for light even–even (N = Z ≤ 20) nuclei. This approach is applied to 12C, 16O, 20Ne, 24Mg, 28Si, 32S, 36Ar, and 40Ca nuclei. The three-parameter Fermi (3 pF) form has been proposed for the α-cluster density distributions inside these nuclei. Accordingly, the corresponding matter density distributions have been deduced. The extracted density parameters revealed clear mass dependences. The obtained densities are tested through constructing the α+nucleus optical potential in the framework of the single and double folding models. The single and double folding procedures are carried out based upon the α–α and JLM nucleon–nucleon (nn) effective interactions, respectively. For the sake of comparison, the CDM3Y6 effective nn interaction is also considered in the double folding calculations. The extracted potentials have been introduced in the analysis of α-particle elastic scattering from 12C, 16O, 20Ne, 24Mg, and 28Si targets. Forty-seven sets of data through a wide range of energy (31–240 MeV) have been investigated using the derived potentials. Successful predictions of the observed angular distributions of elastic scattering differential cross sections are obtained. The extracted reaction cross sections are also investigated. [ABSTRACT FROM AUTHOR]

The vector analyzing power and differential cross-section for the elastic scattering of 8He nucleus from polarized protons at 71 MeV/nucleon have been analyzed in the framework of the optical model potentials. Microscopic single folding (SF) optical potentials (OP) have been constructed based upon two different effective nucleon-nucleon (NN) interactions, namely Jeukenne-Lejeune-Mahaux (JLM) and BDM3Y1 effective interactions. The effect of 8He nuclear structure has been tested through two different choices of the nuclear density distribution. It is concluded that the nucleus 8He may be considered as a thick skin exotic nucleus. In order to investigate the vector analyzing power data, besides the Thomas phenomenological representation, three different forms of the spin-orbit (SO) part of the OP have been considered. These forms are based directly or indirectly upon the density distribution of 8He nucleus. It is found that SO potentials of larger root mean square radii are able to successfully describe the vector analyzing power data more than those of shorter radii. [ABSTRACT FROM AUTHOR]

The elastic scattering of 6,7Li+28Si reactions has been analyzed in the framework of the double folding optical model. Semi-microscopic folded potentials are generated based on the alpha (α)-cluster structure of the colliding nuclei. Successful reproduction of the observed angular distributions of the elastic scattering differential cross section and reaction cross sections has been obtained at different energies using the derived potentials. A microscopic folding approach based on the effective DDM3Y nucleon-nucleon interaction and the nuclear matter densities of the interacting nuclei is also considered. [ABSTRACT FROM AUTHOR]

Angular distributions of 160 + 160 elastic scattering at energies that range from 124 to 1120 MeV have been analyzed in the framework of the double folding (DF) optical model. Based upon the ɑ-cluster structure of the 160 nucleus, two different versions of the real DF optical potential have been generated by using three effective ɑ-ɑ, ɑ-nucleon (N) and nucleon-nucleon (AW) interactions. A microscopic optical potential built upon the M3Y effective NN interaction and the matter density distribution of the 160 nucleus has also been extracted. The obtained real potentials, in conjunction with phenomenological squared Woods-Saxon imaginary parts, have successfully reproduced seven sets of elastic-scattering data. No renormalization of the real folded ɑ-cluster potentials is required to fit the data. The energy dependence of the extracted real and imaginary volume integrals and total reaction cross section has also been investigated. [ABSTRACT FROM AUTHOR]

Angular distributions of the differential cross section of 16O+12C elastic and inelastic scattering in the energy range Elab=181-1503 MeV were fitted with the full cluster folded approach (DFC1) using the coupled-channels (CC) method by taking into account the effect of the low-lying states, 0+ and 2+ (Eex=4.44 MeV) for the target nucleus. The cluster transition density is generated macroscopically by deforming the cluster ground state modified Gaussian density distribution of the target nucleus. The coupled-channels calculations with the fitted parameters for the elastic scattering provide a successful description of the inelastic experimental measurements. The obtained results are compared with the finding of the phenomenological Woods-Saxon potential. It was found that the characteristic features of the nuclear rainbow phenomena can be reproduced successfully by our CC calculations with both potentials but fail to reproduce the new Airy minimum of the nuclear rainbow structure. The deduced intrinsic quadrupole moment values, Q20, derived from the analyses are compared with results of previous studies. The deformation lengths, d20, obtained by CC calculations are in agreement with those obtained from the electromagnetic measurement values and those reported in previous studies. [ABSTRACT FROM AUTHOR]