Exploring the structure of Xe isotopes in A ~ 130 region: Single particle and collective excitations

R Banik,A Goswami,S Rajbanshi,G Mukherjee,H Pai,R Raut,S S Ghugre,S Das Gupta,S Bhattacharyya,Subhashish Bhattacharya ,Rahbar Ali ,Deepak Pandit ,Shabir Dar ,Debashis Mondal ,Sangeeta Das ,Pulak Ray ,Sujit Kumar Pal ,S Biswas,S Mukhopadhyay,S Chatterjee,S Nandi,Sudip Samanta

doi:10.1051/epjconf/202023204001

Abstract

High and medium spin structures of 130,131Xe have been studied using α-induced fusion-evaporation reaction and the Indian National Gamma Array (INGA) coupled with a digital data acquisition system. Various new band structures and near yrast levels of 131Xe have been established. The multipolarities of the observed transitions have been assigned on the basis of the DCO ratios and the polarization asymmetry measurements. Band structures based on 1-quasi-particle (qp), 3-qp configurations have been observed. A new Magnetic Rotational (MR) band based on 5-qp configuration has also been established in 131Xe. The MR band has been interpreted in terms of shears mechanism with principal axis cranking (SPAC) calculations. Shell Model calculations are carried out to describe the non yrast states of 131Xe above the 11/2− isomer. New excited states have also been identified in 130Xe, produced in the same reaction.

Highlights

The transitional nuclei in the A ∼ 130 region are of current interest to explore the variety of nuclear structures arising from interplay between the single particle and the collective degrees of freedom
The role of the unique parity h11/2 orbital is important in inducing deformation to the system and having deformed band structures based on both one quasi-particle and multi qp configurations
Availability of high- j h11/2 orbital for both proton particles and neutron holes makes 131Xe a suitable candidate to exhibit Magnetic Rotation (MR) at high spin. Such MR band is reported in 123Xe [5] and described using the tilted axis configuration with πh11/2 ⊗ νh11/2

Summary

Introduction

The transitional nuclei in the A ∼ 130 region are of current interest to explore the variety of nuclear structures arising from interplay between the single particle and the collective degrees of freedom. Availability of high- j h11/2 orbital for both proton particles and neutron holes makes 131Xe a suitable candidate to exhibit Magnetic Rotation (MR) at high spin. Such MR band is reported in 123Xe [5] and described using the tilted axis configuration with πh11/2 ⊗ νh11/2. The possible phase transition for the even-A Xe isotopes can be described using E(5) symmetry, where the nucleus undergoes from spherical vibrator to γ-soft rotor. To know the detail low lying structures, it is worth to re-investigate the non-yrast and yrast states of 130Xe

Experiment and Data Analysis

Results

Discussion

SPAC Calculation

Summary