Extended optical model analyses of 11^{11}Be+197^{197}Au with dynamic polarization potentials

We discuss angular distributions of elastic, inelastic, and breakup cross sections for $^{11}$Be + $^{197}$Au system, which were measured at energies below and around Coulomb barrier. To this end, we employ Coulomb dipole excitation (CDE) and long-range nuclear (LRN) potential to take into account long range effects by halo nuclear system and break up effects by weakly-bound structure. We then analyze recent experimental data including 3-channes i.e. elastic, inelastic, and breakup cross sections, at $E_{\textrm{c.m.}}$=29.6 MeV and $E_{\text{c.m.}}$=37.1 MeV. From the extracted parameter sets using $\chi^{2}$ analysis, we successfully reproduce the experimental angular distributions of the elastic, inelastic, and breakup cross sections for $^{11}$Be+$^{197}$Au system simultaneously. Also we discuss the necessity of LRN potential around Coulomb barrier from analyzed experimental data

Suppression of the elastic scattering cross section for 17Ne + 208Pb system

We investigated the elastic scattering, inelastic scattering, breakup reaction, and total fusion reactions of 17Ne + 208Pb system using the optical model (OM) and a coupled channel (CC) approaches. The aim of this study is to elucidate the suppress of the elastic cross-section that is invisible in proton-rich nuclei such as 8B and 17F projectiles but appears in neutron-rich nuclei such as 11Li and 11Be projectiles. The results revealed that this suppression was caused mainly by the nuclear interaction between the projectile and target nucleus rather than the strong Coulomb interaction observed in neutron-rich nuclei and the contributions of Coulomb excitation interaction due to two low-lying E2 resonance states are relatively small. From the simultaneous chi-square analysis of the 17Ne + 208Pb system, we can infer a strong suppression effect in the elastic scattering cross-section due to the nuclear interaction between the projectile and target nucleus, rather than the Coulomb interaction as observed in neutron-rich nuclei. Also, the contribution of the direct reaction, comprising the inelastic scattering and breakup reaction cross-sections, accounted for almost half of the total reaction. Finally, we perform the CC calculation using the parameters obtained from our OM calculation but our CC calculations could not explain the 15O production cross section.Comment: 20 pages, 7 figure

Folding potential with modern nuclear density functionals and application to 16O+208Pb reaction

Double folding potential is constructed using the M3Y interaction and the matter densities of the projectile and target nuclei obtained from four microscopic energy density functional (EDF) models. The elastic scattering cross sections for the 16O+208Pb system are calculated using the optical model with the double folding potentials of the four EDF models. We focus on the correlation between the matter densities and the behavior the double folding potential and the elastic scattering cross sections. First, the matter and charge densities are examined by comparing the results of the four EDF models. There is a slight difference in the density in the internal region, but it is negligible in the outer region. Next, we calculate the double folding potential with the matter densities obtained from the four EDF models. Differences between the models are negligible in the outer region, but the potential depth in the internal region shows model dependence, which can be understood from the behavior of matter densities in the internal region. Another point is that the double folding potential is shown to be weakly dependent on the incident energy. Finally, the elastic scattering cross sections have no significant model dependence except for the slight difference in the backward angle.Comment: 17 pages, 13 figure

Reinvestigating the Gamow Factor of Reactions on Light Nuclei

We present a modified Gamow factor by reinvestigating the conventional assumptions used in its derivation. The conventional Gamow factor, factorized from the total cross section, effectively describes the penetration probabilities (PPs) in low-energy nuclear reactions under the assumption of particle energies significantly lower than the Coulomb barrier. However, we find that the assumption is invalid for light nuclei, resulting in PPs that depend on the nuclear potential depth for such nuclei. By adopting a potential depth fitted to experimental fusion cross sections, we demonstrate that PPs for light nuclei (D+D, D+T, D+ ^3 He, p+D, p+ ^6 Li, and p+ ^7 Li) become higher than those predicted by the conventional form near the Coulomb barrier. This reduces the Gamow peak energy by a factor of 5.3 maximally compared to the conventional form. Furthermore, we show that the enhancement factor due to the Debye screening effects in the solar core can be reduced by approximately 5%–10% due to the modified PP. Our findings hold implications for evaluating the available energy region in low-energy reaction experiments based on the Gamow peak energy region and for understanding electron screening effects in typical astrophysical environments

Extended optical model analyses of

We discuss angular distributions of elastic, inelastic, and break-up cross-sections for the $$^{11}\hbox {Be} + ^{197}\hbox {Au}$$ system, measured at energies below and around the Coulomb barrier. To this end, we employ Coulomb dipole excitations and a long-range nuclear (LRN) potential in order to account for long-range effects of the halo nuclear system and break-up effects of the weakly bound structure. We then analyze recent experimental data, comprising three channels, viz., elastic, inelastic, and break-up cross-sections, at $$E_{\text {c.m.}}=29.6\hbox { MeV}$$ and $$E_{\text {c.m.}}=37.1\hbox { MeV}$$. From the parameter sets extracted using a $$\chi ^{2}$$ analysis, we successfully reproduce the experimental angular distributions of the elastic, inelastic, and break-up cross-sections for the $$^{11}\hbox {Be+}^{197}\hbox {Au}$$ system simultaneously. Finally, we discuss the necessity of the LRN potential around the Coulomb barrier from a detailed analysis of the experimental data