Effectiveness of the TGI-QRPA approach for studying the electric dipole response

Abstract

Despite various RPA-based approaches being widely used, each has its own advantages and disadvantages that can influence the results. In spite of its several drawbacks, using realistic mean-field potential and just small number model-dependent parameter makes TGI-QRPA a very efficient RPA-based approach for investigating dipole responses. This work tests the applicability of the TGI-QRPA approach for investigating dipole excitations through a comparison with the up-to-date, fully self-consistent FAM-QRPA approach and the available experimental data. Take into account the fact FAM-QRPA approach has its own drawbacks, such a comparison will also show how the pros and cons of both models can influence the results. The result obtained here with the TGI-QRPA approach was close to that obtained through the up-to-date FAM-QRPA approach and in some aspects, it better reflected the experimental results in terms of the resonance energy and photo-absorption cross -sections of E1 strength. It can therefore be said that despite not being fully self-consistent, using the realistic mean-field potential (Woods–Saxon), analytically restoring the broken translational and Galilean invariances, and using a only two model parameters make the TGI-QRPA approach an effective tool for investigating dipole excitations, where calculations are performed for the electric dipole responses in deformed 156Gd, 160Gd, 166Er, and 168Er isotopes.