Nuclear Structure and Mixed-Symmetry States in N=60 Isotones Within the Interacting Boson Model

The nuclear structure and mixed-symmetry states of N=60 isotones ( 100 Zr, 102 Mo, 104 Ru, 106 Pd, and 108 Cd) were successfully investigated using the proton-neutron interacting boson model (IBM-2). In this study, energy levels, electromagnetic transition probabilities B(E2) and B(M1), and mixing ratios were calculated. The calculated results show acceptable agreement with the experimental data, based on the parameters used, despite some discrepancies between the calculated quantities. The calculated energy ratios indicate a gradual structural evolution from a γ-soft toward a more vibrational character along the (N=60) isotonic chain, within the adopted IBM-2 configuration. Furthermore, the model was able to describe (2 + ) mixed-symmetry state and 1 + , 2 + and 3 + mixedsymmetry states, particularly the (1 + ) state, in Molybdenum, Ruthenium, and Palladium isotones. The results also helped determine how Majorana coefficients, particularly ξ 2 , influence collective behavior, proton-neutron interactions, and mixed-symmetry states, specifically the scissor mode, within the studied nuclei. These results provide further insight into proton-neutron symmetry and collective excitations in transitional medium-mass nuclei.