Phenomenological analysis of ΔI = 4 bifurcation and identical superdeformed bands

For the first time, a systematic study of identical superdeformed (SD) bands in [Formula: see text] mass region is made, where [Formula: see text] bifurcation is present. Four pairs of identical SD bands viz. [Formula: see text] and [Formula: see text] of [Formula: see text] mass region and [Formula: see text] and [Formula: see text] of [Formula: see text] mass region have been systematically studied. The present systematic study provides the universal description of the identical SD bands in various mass regions. We presented the empirical evidence of a similar structure of identical SD bands in various mass regions. For this purpose, we have used various rotational energy formulae. The free parameters are extracted from four identical SD bands. The [Formula: see text] bifurcation in identical SD bands is calculated from shape fluctuation formulae. For the first time, this shape fluctuation model is employed to calculate the [Formula: see text] bifurcation, making it an alternate powerful tool to study SD bands of various mass regions.

Examination of phenomenological formulae in superdeformed bands of A ∼ 190,150 mass regions

The rotational energy formulae viz. VMI model, ab-formula, Harris [Formula: see text] expansion, Exponential model with pairing attenuation and Nuclear softness formula are employed to the superdeformed bands of [Formula: see text] and [Formula: see text] mass regions in order to test the validity of various rotational energy formulae in describing the general nature of superdeformed bands. These formulae are used to deduce the band-head spins of the nine superdeformed bands in [Formula: see text] mass region and two superdeformed bands of [Formula: see text] mass region. The band-head spins of these superdeformed bands have been established experimentally and hence they prove to be excellent candidates to examine the adequacy of rotational energy formulae in superdeformed bands. The least-squares fitting of [Formula: see text]-transition energies is performed to calculate the model parameters such as the band-head moment of inertia, the effective pairing gap parameter and the softness parameter, and a careful analysis of these parameters is made. For the first time, we have performed a systematic study of the rotational energy formulae to establish which formula gives the best estimate of spin in [Formula: see text] mass regions.

Tests of Collective Models Based on the Systematics of Experimental Data

The systematics of energy ratios of successive levels of collective bands in medium and heavy mass even-even nuclei are studied. Applications to ground state, β, γ, octupole, intruder and superdeformed bands, as well as to superbands in cases of backbending are made. Implications for the U(5), SU(3) and 0(6) limits of the Interacting Boson Model are discussed.