Global and consistent analysis of the heavy-ion elastic scattering and fusion processes

Abstract

We have developed a model for the nuclear interaction which is based on the effects of the Pauli nonlocality. In earlier works, we have successfully used this interaction to describe the elastic scattering for several systems in a very wide energy range. In the present work, we have checked the validity of the same interaction in the description of about 2500 fusion cross section data for 165 different systems. By introducing only one energyand system-independent effective parameter, the nonlocal model describes the global behavior of the fusion process with good precision.The heavy-ion fusion process has been extensively studied over the last decades [1]. It is well known that fusion cross sections for heavy-ion systems have shown large enhancements at sub-barrier energies in comparison with theoretical predictions from the barrier penetration model [2]. These enhancements can be described by introducing effective barrier parameters, which have been studied in a global way for a large number of systems [2][3][4]. On the other hand, the enhancements have been explained for several particular systems by considering the internal structure of the participating nuclei through couped-channel calculations (e.g., Refs. [5,6]). A few models have also been presented to describe the elastic scattering process and the energy and system dependences of the corresponding optical potential [7]. However, the consistency between the models for the fusion and elastic scattering processes has only been verified in certain particular cases (e.g., Ref.[8]). We have developed a model for the nuclear interaction which has been successful in describing the elastic scattering for several systems in a wide energy range [9][10][11][12][13][14][15]. The model is based on the effects of the Pauli nonlocality and is totally parameter free. In this work, we use this interaction in the description of about 2500 fusion cross section data for 165 different systems from sub-barrier to high energies.Within the nonlocal model, the bare interaction V N is connected with the folding potential V F through [54]where c is the speed of light and v is the local relative velocity between the two nuclei,The folding potential ͓Eq. ͑3͔͒ can be obtained in two different ways ͓54͔: ͑i͒ using the nucleon distributions of the nuclei and an appropriate form for the nucleon-nucleon interaction, and ͑ii͒ using the matter distributions of the nuclei with a zero-range approach for v͑r ជ͒. We distinguish the matter density from the nucleon one by taking into account the finite size of the nucleon. Both alternatives are equivalent in describing the heavy-ion nuclear potential ͓54͔, and we have adopted the zero-range approach to describe the fusion process:With the aim of providing a global description of the nuclear interaction, we proposed ͓54͔ an extensive systematization of nuclear densities, based on experimental charge distributions and theoretical densities calculated through the DiracHartree-Bogoliubov model. In that work, we adopted the two-parameter Fermi ͑2pF͒...

Fusion of neutron-rich oxygen nuclei

“…polarization effects). The influence of the static contribution can be estimated by using a onedimensional barrier penetration model such as the Sao-EPJ Web of Conferences 163, 00013 (2017) DOI: 10.1051/epjconf/201716300013 FUSION17 Paulo model [3]. For the density distributions presented in Fig.…”

Nuclear Reaction Dynamics Research at the Australian National University

“…In principle this is achieved by adding the multitude of individual nucleon-nucleon interactions into an overall attractive nuclear and repulsive Coulomb potential felt by the two nuclei as a whole. The double folding model is one approach to determine the nucleusnucleus potential [1][2][3], the Time-Dependent HartreeFock (TDHF) approach is another [4,5]. In practice a simple Woods-Saxon parameterization is often used, with the a e-mail: david.hinde@anu.edu.au b Permanent address: Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, India potential diffuseness at the barrier radius being a key parameter, along with the barrier energy itself, arising from the sum of Coulomb and nuclear potentials.…”

Above-barrier fusion enhancement of proton-halo systems

“…This prescription, based on the well-known analytic expression σ W (E) derived for the cross section by Wong [13], had been used as early as 1996 by Prasad, et al [35] to compare a few systems with widely differing reactants, and was first applied to a systematic study of many systems by Gasques, et al [36] in 2004. More recently, it has been extensively studied by Canto, et al [7,8], mainly in the context of reactions with weakly bound projectiles.…”