Description of nuclei in the A$\sim$100 mass region with the interacting boson model

TL;DR

This paper models nuclei in the A~100 mass region using the interacting boson model-1, successfully describing energy spectra and transition properties, and predicting unknown isotopes' features.

Contribution

It provides a global parametrization of the IBM-1 Hamiltonian for nuclei in this mass region, enabling accurate descriptions and predictions of nuclear properties.

Findings

Describes about 300 energy levels with 120 keV RMS deviation.

Highlights the significance of the N=56 subshell closure.

Predicts properties of neutron-rich isotopes.

Abstract

Even--even nuclei in the $A\sim100$ mass region are investigated within the framework of the interacting boson model-1 ({IBM-1}). The study includes energy spectra and electric quadrupole transition properties of zirconium, molybdenum, ruthenium and palladium isotopes with neutron number $N\geq52$. A global parametrization of the {IBM-1} Hamiltonian is found leading to a description of about 300 collective levels in 30 nuclei with a root-mean-square deviation from the observed level energies of 120 keV. The importance of the $d_{5/2}$ subshell closure at neutron number N=56 is pointed out. The geometric character of the nuclei can be visualized by plotting the potential energy surface $V(\beta,\gamma)$ obtained from the {IBM-1} Hamiltonian in the classical limit. The parametrization established on the basis of known elements is used to predict properties of the unknown, neutron-rich isotopes $^{106}$Zr, $^{112}$Mo, $^{116}$Ru and $^{122}$Pd.