Low-lying states and degree of chaoticity of40K in IBFFM

Abstract

The results of a 7-~ angular correlation and a low energy 7-ray singles measurement using thermal neutron capture in 39K are presented. The properties of low-lying levels of 4~ are interpreted in a comparison of the experimental data with the InteractingBoson-Fermion-Fermion Model (IBFFM). The level fluctuation properties of the IBFFM spectrum are analysed and a sizeable deviation from chaoticity is found.

Quantum chaos forN=79 nuclei in the IBFM model

“…It is, however, enlightening to apply the statistical analysis to spectra obtained in the calculations where the nuclear model have been used to interprete the reaction and spectroscopy data. Such are the calculations which analyse statistical fluctuations of spectra of some odd-odd nuclei in the IBFFM model [18][19][20].…”

Structure of the Triplet of low-lying states in101Mo

“…They were suspended at an angle of 30 ~ to the axis of the vertical neutron beam within the neutron shielding tube in front of a 1.4 cm 3 HPGe detector. Details of the set-up and the relative detection efficiency have been given elsewhere [20]. Absolute y-ray intensities have been derived by normalization to the intensity of the strong l~ transition of 191.9 keV for which Ir = 18.8(4)/100 decays [4].…”

Classical and Quantal Chaos Described by a Fourth Order Quadrupole Boson Hamiltonian

“…These pioneering papers were followed by many theoretical works aimed at seeking the degree of chaos of nuclear states exhibiting a certain symmetry. Investigations were made within microscopic, 9 ' 20-27 phenomenological, [29][30][31][32] and semimicroscopic formalisms, [33][34][35] respectively. Fluctuation properties of nuclear spectra have been obtained by calculating either of the statistics: NNS, A3 (this is a measure for the deviation from equal spacing 36 and is conventionally called spectral rigidity), E 2 (r) (the variance of the level number in an interval of length r).…”