Колебательно-вращательный спектр высокого разрешения в районе полос 3ν-=SUB=-4-=/SUB=-, ν-=SUB=-2-=/SUB=-+2ν-=SUB=-4-=/SUB=- и 2ν-=SUB=-2-=/SUB=-+ν-=SUB=-4-=/SUB=- молекулы -=SUP=-72-=/SUP=-GeH-=SUB=-4-=/SUB=-

The high-resolution spectrum of the 72GeH4 molecule was recorded on a Bruker IFS 125HR Fourier spectrometer with an optical resolution of 0.003 cm-1. The line positions were analyzed for ten interacting vibrational-rotational bands 3ν4 (1F2, F1, 2F2), v2+ 2ν4 (1E, F1, F2, 2E) and 2ν2+v4 (1F2, F1, 2F2) in the range 2350-2750 cm-1. As a result of the analysis, 1726 experimental lines were identified with the maximum value of the quantum number Jmax = 17; then used in the fitting procedure with parameters of the effective Hamiltonian. The resulting set of 35 spectroscopic parameters describes the vibrational-rotational structure of the spectrum with drms = 7.5 · 10-4 cm-1.

Proton-neutron symplectic model description of $^{20}$Ne

A microscopic description of the low-lying positive-parity rotational bands in $^{20}$Ne is given within the framework of the symplectic-based proton-neutron shell-model approach provided by the proton-neutron symplectic model (PNSM). For this purpose a model Hamiltonian is used which includes an algebraic interaction, lying in the enveloping algebra of the $Sp(12,R)$ dynamical group of the PNSM, that introduces both horizontal and vertical mixings of different $SU(3)$ irreducible representations within the $Sp(12,R)$ irreducible collective space of $^{20}$Ne. A good overall description is obtained for the excitation energies of the ground and first two excited $\beta$ bands, as well as for the ground state intraband $B(E2)$ quadrupole collectivity and the known interband $B(E2)$ transition probabilities between the low-lying collective states without the use of an effective charge.

Partial dynamical symmetry versus quasi dynamical symmetry examination within a quantum chaos analyses of spectral data for even–even nuclei

Statistical analyses of the spectral distributions of rotational bands in 51 deformed prolate even–even nuclei in the 152 ≤ A ≤ 250 mass region $$R_{{4_{1}^{ + } /2_{1}^{ + } }} \ge 3.00$$ R 4 1 + / 2 1 + ≥ 3.00 are examined in terms of nearest neighbor spacing distributions. Specifically, the focus is on data for 0+, 2+, and 4+ energy levels of the ground, gamma, and beta bands. The chaotic behavior of the gamma band, especially the position of the $$2_{\gamma }^{ + }$$ 2 γ + band-head compared to other levels and bands, is clear. The levels are analyzed within the framework of two models, namely, a SU(3)-partial dynamical symmetry Hamiltonian and a SU(3) two-coupled quasi-dynamical symmetry Hamiltonian, with results that are further analyzed using random matrix theory. The partial and quasi dynamics both yield outcomes that are in reasonable agreement with the known experimental results. However, due to the degeneracy of the beta and gamma bands within the simplest SU(3) picture, the theory cannot be used to describe the fluctuation properties of excited bands. By changing relative weights of the different terms in the partial and quasi dynamical Hamiltonians, results are obtained that show more GOE-like statistics in the partial dynamical formalism as the strength of the pairing term is increased. Also, in the quasi-dynamical symmetry limit, more correlations are found because of the stronger couplings.

Parity partner bands in 163Lu: A novel approach for describing the negative parity states from a triaxial super-deformed band

The wobbling spectrum of [Formula: see text]Lu is described through a novel approach, starting from a triaxial rotor model within a semi-classical picture, and obtaining a new set of equations for all four rotational bands that have wobbling character. Redefining the band structure in the present model is done by adopting the concepts of Signature Partner Bands and Parity Partner Bands. Indeed, describing a wobbling spectrum in an even–odd nucleus through signature and parity quantum numbers is an inedited interpretation of the triaxial super-deformed bands.