Giant dipole resonance in Sm isotopes within TDHF method

TL;DR

This study uses the TDHF method with Skyrme forces to analyze the giant dipole resonance in Sm isotopes, comparing results with experimental data and exploring shape transitions and deformation effects.

Contribution

It applies the TDHF approach with four Skyrme forces to systematically study IVGDR in Sm isotopes, including predictions and shape analysis, extending previous work on Nd isotopes.

Findings

Overall agreement with experimental dipole strength data.

Predictions for neutron-deficient and neutron-rich Sm isotopes.

Confirmed correlation between quadrupole deformation and GDR splitting.

Abstract

In this work, we have studied the isovector giant dipole resonance (IVGDR) in even-even Sm isotopes within time-dependent Hartree-Fock (TDHF) with four Skyrme forces SLy6, SVbas, SLy5 and UNEDF1. The approach we have followed is somewhat similar to the one we did in our previous work in the region of Neodymium (Nd, Z=60) [\href{https://iopscience.iop.org/article/10.1088/1402-4896/ab73d8}{Physica Scripta (2020)}]. We have calculated the dipole strength of $ ^{128-164}\text{Sm}$, and compared with the available experimental data. An overall agreement between them is obtained. The dipole strength in neutron-deficient $ ^{128-142}\text{Sm}$ and in neutron-rich $^{156-164}\text{Sm}$ isotopes are predicted. Shape phase transition as well as shape coexistence in Sm isotopes are also investigated in the light of IVGDR. In addition, the correlation between the quadrupole deformation parameter $\beta_{2}$ and the splitting $\Delta E/ \bar{E}_{m}$ of the giant dipole resonance (GDR) spectra is studied. The results confirm that $\Delta E/ \bar{E}_{m}$ is proportional to quadrupole deformation $\beta_{2}$