The JINR Publishing Department issued a preprint entitled “Harris model and IBM for Pu, Cm, Fm, No” E4-2025-14. The authors are employees of the Flerov Laboratory of Nuclear Reactions at JINR, Admiral Makarov State University of Maritime and Inland Shipping, and Ioffe Physical-Technical Institute of RAS (Saint Petersburg).

For heavy even nuclei of plutonium, curium, fermium and nobelium, the description of the energies of yrast bands in the Harris phenomenological model of the variable moment of inertia and in the interacting boson model (IBM), including IBM phenomenology, is considered. For two nuclei, ²⁴⁴Pu и ²⁴⁸Cm, the results of calculations in the extended IBM version are also presented. Comparison of these results made it possible to identify different characteristics of the behavior of the moment of inertia as a function of the square of the rotational frequency and obtain corresponding interpretations of their features. In particular, a version is proposed that explains the weakening of the growth of the moment of inertia for spins of states greater than 24⁺ in a number of nuclei.

The investigation has been performed at the Flerov Laboratory of Nuclear Reactions at JINR.

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