Folding model study of the isobaric analog excitation: isovector density dependence, Lane potential and nuclear symmetry energy

TL;DR

This study employs a folding model analysis with a calibrated isovector density-dependent interaction to analyze charge exchange reactions and estimate nuclear symmetry energy, providing insights into isobaric analog excitations and isovector nuclear properties.

Contribution

It introduces a carefully calibrated complex isovector density dependence of the CDM3Y6 interaction, enhancing the accuracy of folding model predictions for charge exchange reactions and nuclear symmetry energy estimation.

Findings

Accurate modeling of extit{pn} reactions on various targets at 35 and 45 MeV.

Successful calibration of the isovector density dependence against microscopic calculations.

Realistic estimation of nuclear symmetry energy using the developed interaction.

Abstract

A consistent folding model analysis of the ($\Delta S=0, \Delta T=1$) charge exchange \pn reaction measured with $^{48}$Ca, $^{90}$Zr, $^{120}$Sn and $^{208}$Pb targets at the proton energies of 35 and 45 MeV is done within a two-channel coupling formalism. The nuclear ground state densities given by the Hartree-Fock-Bogoljubov formalism and the density dependent CDM3Y6 interaction were used as inputs for the folding calculation of the nucleon optical potential and \pn form factor. To have an accurate isospin dependence of the interaction, a complex isovector density dependence of the CDM3Y6 interaction has been carefully calibrated against the microscopic Brueckner-Hatree-Fock calculation by Jeukenne, Lejeune and Mahaux before being used as folding input. Since the isovector coupling was used to explicitly link the isovector part of the nucleon optical potential to the cross section of \pn reaction exciting the 0$^+$ isobaric analog states in $^{48}$Sc, $^{90}$Nb, $^{120}$Sb and $^{208}$Bi, the newly parameterized isovector density dependence could be well tested in the folding model analysis of the \pn reaction. The isospin- and density dependent CDM3Y6 interaction was further used in the Hartree-Fock calculation of asymmetric nuclear matter, and a realistic estimation of the nuclear symmetry energy has been made.