Effects of 2p-2h configurations on low-energy dipole states in neutron-rich N=80, 82 and 84 isotones

N N Arsenyev,V V Voronov,A P Severyukhin,Nguyen Van Giai

doi:10.1051/epjconf/201610705006

Abstract

Starting from the Skyrme interaction SLy4 we study the effects of phonon-phonon coupling on the low-energy electric dipole response in 130−134 Sn, 132−136 Te and 134−138 Xe. Our calculations are performed within the finite-rank separable approximation, which enables one to perform quasiparticle random phase approximation calculations in very large two-quasiparticle configuration spaces. A dependence of the pygmy dipole resonance strengths on the neutron skin thickness is found. The inclusion of the two-phonon configurations gives a considerable contribution to the low-lying strength.

Highlights

With the advent of advanced radioactive beam facilities and novel experimental techniques, unexplored regions of exotic nuclei and new phenomena became accessible for detailed spectroscopic studies
The electric dipole (E1) response of nuclei at energies around particle separation energy is presently attracting much attention, for unstable neutron-rich nuclei produced as radioactive beams [1]
We report the systematic analysis of the E1 response for 130−134Sn, 132−136Te and 134−138Xe in the self-consistent quasiparticle random phase approximation (QRPA) with some Skyrme interactions, focusing on the emergence and the properties of the pygmy dipole resonance (PDR)

Summary

Introduction

With the advent of advanced radioactive beam facilities and novel experimental techniques, unexplored regions of exotic nuclei and new phenomena became accessible for detailed spectroscopic studies. The electric dipole (E1) response of nuclei at energies around particle separation energy is presently attracting much attention, for unstable neutron-rich nuclei produced as radioactive beams [1]. There are two major reasons in the case of the PDR. One reason is a special structure of the PDR which appears as a new collective motion in neutron-rich nuclei, but this has not been clarified [2]. The other reason is the role of the PDR in nucleosynthesis. We report the systematic analysis of the E1 response for 130−134Sn, 132−136Te and 134−138Xe in the self-consistent QRPA with some Skyrme interactions, focusing on the emergence and the properties of the PDR. Properties of the PDR are investigated in terms of their relation with the neutron skin thickness

Brief outline of the FRSA

Results and discussion

Summary