Elastic scattering ofF17,O17, andF19on a heavy target in a microscopic continuum discretized coupled-channels method

Abstract

Background: In the traditional continuum discretized coupled-channels (CDCC) method, the clusters of the projectile are structureless. Exotic nuclei exhibit unusual properties and often show significant couplings to the continuum. Therefore, reaction models that consider a more accurate structure of the projectile are often preferable. A microscopic description of the projectile, based on an effective nucleon-nucleon (NN) interaction, in a microscopic CDCC (MCDCC) model [Descouvemont and Hussein, Phys. Rev. Lett. 111, 082701 (2013)] has been successfully applied to $^{7}\mathrm{Li}+^{208}\mathrm{Pb}$ scattering.Purpose: The MCDCC method is applied to low-energy elastic scattering of $^{17}\mathrm{F},^{17}\mathrm{O}$, and $^{19}\mathrm{F}$ on $^{58}\mathrm{Ni}$ and $^{208}\mathrm{Pb}$ targets. The goal of the calculations is twofold: to test the adequacy and the accuracy of the MCDCC model for heavier projectiles and to study the contribution of various channels to the elastic scattering cross sections.Methods: The elastic scattering cross sections are calculated by using the MCDCC method. The nucleon-target optical potential is folded with the projectile densities resulting from an effective NN interaction, which includes central nuclear, spin-orbit, and Coulomb terms. Discretization of the continuum is achieved via the pseudostate method. Coupled equations are solved by using the $R$-matrix method on a Lagrange mesh.Results: For the test case of $^{17}\mathrm{F}$ at 10 MeV/nucleon, the cross sections are weakly sensitive to the choice of the effective NN interaction. Three different energy-dependent optical nucleon-target potentials provide a similar reasonable agreement with data. Just below the Coulomb barrier, the MCDCC significantly underestimates the cross sections at larger angles. The coupling to the continuum is not significant in most of the assessed cases.Conclusions: The MCDCC is very satisfactory in the sense that it includes the microscopic properties of the projectile in a reaction model. Well above the Coulomb barrier, the cross sections are in a good agreement with the data. The reasons for the discrepancy between the data and the calculated cross sections at the lower energies, which is also observed in a traditional CDCC, are unclear.