Investigation of high-spin states of 176−180Hf nuclei by the extended interacting boson model

In this paper, the high-spin states of 176−180Hf isotopic chain are studied in the framework of the extended sdg-interacting boson model. To this aim, the $$6^{ + } ,8^{ + } ,10^{ + } ,12^{ + } ,14^{ + } ,16^{ + }$$ energy levels of considered nuclei are labeled based on the $$SU(3)$$ dynamical limit and then, both two (sd) and three (sdg)-levels versions of the model are used to determine the energy values. The Born’s first approximation is used to extend the different elements of two-body interactions in the sdg model. The parameters of the extended model are determined via the Jacobi iteration method to make a satisfactory description of energy spectra. The results show the significant advantages of the three-level interacting boson model in comparison with the two-level ones in the description of energy levels with high spins, and the spectrum obtained by this model is in good agreement with the experimental counterparts. Also, the theoretical predictions suggest more accuracy for 12+, 14+ &16+ levels in comparison with 6+, 8+ & 10+ levels and make different effects of one and two-body terms of sdg model for ground and excited rotational bands.