Description of the Structural Properties of Low-Lying States in ¹⁰² Ru with IBM2

Abstract

We describe the properties of low-lying states of 102 Ru within the framework of the proton-neutron interacting model IBM2. The theoretical predictions of the ground state, quasi-𝛾 and quasi-𝛽 bands, and the ratios of the 𝐵(𝐸2) transition strengths are reproduced very well. The structural properties of 102 Ru are identified in the parameters space of the interacting boson model (IBM2). The characteristic feature of the energy spectrum structure exhibits that 102 Ru is very close to the critical point of 𝑈𝜋𝜈 (5)-𝑂𝜋𝜈 (6) transition and towards 𝑈𝜋𝜈 (5) symmetry. The key sensitive quantities of the 𝐵(𝐸2) branching ratio clearly indicate that 102 Ru is a primary 𝑂𝜋𝜈 (6) symmetry, while with a somewhat 𝑈𝜋𝜈 (5) symmetry. It is possible that the shape coexistence persists in 102 Ru, whereas the evident fingerprint of the shape coexistence has not been observed.

Description of the Shape Coexistence in 98 Mo with IBM2

“…The parameters are determined so as to reproduce as closely as possible the excitation energies of both the yrast and non-yrast bands, in the same procedure described in Refs. [3,10,28]. By a leastsquares fit to the energies of the experimental data, the best fit IBM2 parameters are 𝜀 𝑑𝜋 = 0.980 MeV, 𝜀 𝑑𝜈 = 0.190 MeV, 𝜅 = −0.066 MeV, 𝜒 𝜋 = −0.600, 𝜒 𝜈 = 0.600, 𝜔 𝜋𝜈 = −0.135, 𝜔 𝜈 = 0.100, 𝜆 1 = 0.500 MeV, 𝜆 2 = 0.510 MeV, and 𝜆 3 = 1.300 MeV for 98 Mo.…”