Configuration Mixing in Pt Nuclei within Interacting Boson Model-2

Malek A H Muhi,Saad N Abood

doi:10.4236/jamp.2020.83039

Malek A H Muhi, Saad N Abood

Open Access

https://doi.org/10.4236/jamp.2020.83039

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Abstract

This article provides to descript a consistent of the even-even 182-200Pt isotopes. This has been achieved using the interacting boson model-2 (IBM-2) and including configuration mixing (IBM-2 CM). Our attention is paid to describe the nuclei shape and to their connecting with shaping coexistence phenomenon. Ten isotopes are studied, ranging from the middle of the neutron shell to very near the doubly closed shell at 208Pb. The same Hamiltonian is used for all the nuclei studied, with parameters which are constant or smoothly varying. In this study, we showed the transition between more axially symmetric deformed features of light Pt isotopes to γ-unstable and vibrational isotopes (near spherical shape) for 198-200Pt isotopes.

Highlights

Some nuclei near closed shells appear to have both the vibrational structure expected for a near-spherical shape, and rotational structure, which is typical of deformed nuclei [1]
The vibrational spectra can be calculated by diagonalizing the interacting boson model-2 (IBM-2) Hamiltonian, (Equation (2)), in the space of two proton and Nν neutron s and d bosons
This corresponds to two proton boson particles and two proton boson hole in the IBM-2 space

Summary

Introduction

Some nuclei near closed shells appear to have both the vibrational structure expected for a near-spherical shape, and rotational structure, which is typical of deformed nuclei [1]. Excitations across the closed shells, but they consider them as extra bosons, i.e., pairs of nucleons This extension is called IBM-2 configuration mixing. Garc’ıa-Ramos et al, [5], studied shape evolution and shape coexistence in Pt isotopes: Comparing interacting boson model configuration mixing and Gogny mean-field energy surfaces. The evolution of the total energy surface and the nuclear shape in the isotopic chain 172–194Pt are studied in the framework of the interacting boson model, including configuration mixing. The Majorana interaction is represented the term Mπν , that accounts for the symmetry energy and shits the states with mixed proton-neutron symmetry state with respect to the fully symmetric ones which affects only the relative location.

Electromagnetic Transitions and Quadrupole Moments in IBM-2

Choice of Parameters

Energy Spectra

Concluding Remarks