Lowest excited 2+ and 3− states in even- A N=82 and N=126 isotones from relativistic quasiparticle random-phase approximation

A Ansari

doi:10.1103/physrevc.95.054309

Abstract

Lowest excited <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>2</mml:mn><mml:mo>+</mml:mo></mml:msup></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>3</mml:mn><mml:mo>−</mml:mo></mml:msup></mml:math> states in even- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>A</mml:mi><mml:mo> </mml:mo><mml:mrow><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>82</mml:mn></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>126</mml:mn></mml:mrow></mml:math> isotones from relativistic quasiparticle random-phase approximation

Highlights

Since the early 1980s there have been attempts to study the structure of N = 82 isotones
As early as 1971, Maier et al [3] studied the excited levels of the N = 126 isotones with Z = 85–88 (Z > 82) by in-beam γ -ray spectroscopy with heavy ion reactions
For the type of isotones considered here some recent studies [6,7,8] put forward arguments that for Z < 50 shell quenching should occur at N = 82

Summary

INTRODUCTION

Regarding shell quenching for Z < 82 in N = 126 nuclei, again a similar conclusion was drawn by Steer et al [5] studying the isomeric decays in 204Pt emphasizing the need for investigations towards Z 72. To further extend our earlier studies, I have undertaken to study the structure of 2+ and 3− excited states of these isotones in the relativistic quasiparticle random phase approximation (RQRPA) which has been quite successful for the description of tin and lead isotopic chains [11,12]. It may be useful to discuss briefly as to how successful has been the RQRPA predictions regarding the experimental data, say, on B(E2; 0+ → 2+) [in short B(E2) ↑] of the long chain of Sn isotopes before proceeding further to present and discuss the results on N = 82 and N = 126 isotones.

CALCULATIONAL DETAILS

RESULTS AND DISCUSSIONS

CONCLUSION