Charge Exchange Spin-Dipole Excitations of 90Zr and 208Pb and Neutron Matter Equation of State

TL;DR

This paper investigates charge exchange spin-dipole excitations in zirconium-90 and lead-208 using Skyrme Hartree-Fock and RPA, linking the results to neutron skin thickness and neutron matter EOS to enhance understanding of nuclear structure.

Contribution

It introduces a combined theoretical and experimental analysis of SD excitations to constrain neutron skin thickness and neutron matter EOS parameters.

Findings

Calculated SD strength distributions agree with experimental data.

Neutron skin thickness of 90Zr is constrained by SD sum rule analysis.

Neutron matter pressure and symmetry energy are discussed in relation to SD results.

Abstract

Charge exchange spin-dipole (SD) excitations of $^{90}$Zr and $^{208}$Pb are studied by using a Skyrme Hartree-Fock(HF) + Random Phase approximation (RPA). The calculated spin-dipole strength distributions are compared with experimental data obtained by $^{90}$Zr (p,n) $^{90}$Nb and $^{90}$Zr (n,p) $^{90}$ Nb reactions. The model-independent SD sum rule values of various Skyrme interactions are studied in comparison with the experimental values in order to determine the neutron skin thickness of $^{90}$Zr. The pressure of the neutron matter equation of state (EOS) and the nuclear matter symmetry energy are discussed in terms of the neutron skin thickness and peak energies of SD strength distributions.