Systematics of low-lying energy level ratios in near closed shell nuclei

Abstract

To correlate the single particle and collective behaviour of the nuclei, some of the isotopic chains in the vicinity of doubly magic Sn and Pb-cores have been studied with the most recent data available. Energy ratios E (6₁⁺)/E(4₁⁺) and E(4₁⁺)/E(2₁⁺) have been calculated to predict the nature of the studied isotopes. The energy space has been divided into four regimes, classifying the single particle, collective, and two forbidden regions. Signature of coexisting structures (collective and non-collective) arising out of intruder configurations in the yrast excitation has also been interpreted. Recently observed neutron rich ¹³⁰Sn to ¹³⁸Sn, and ²¹⁰Pb to ²¹⁶Pb isotopes have also been included in the present study.