Chaos and regularity of radionuclides with maximum likelihood estimation method

Majarshin, A. Jalili; Sabri, H.; Mobarakeh, S. K. Mousavi; Pan, Feng; Luo, Yanlin; Draayer, J. P.

doi:10.1088/1402-4896/abb634

Cited by 4 publications

(2 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To characterize spectral behavior, we use the standard measure of the probability density P (s) of adjacent levels; that is, we use the nearest-neighbor spacing distribution (NNSD, which is the probability of two nearest-neighbor energy levels the same spin and parity of having a spacing s, see [67]) as captured by P (s) from the unfolded spectrum. Or stated more simply and succinctly, P (s) is a smoothed approximation to the NNSD that is defined as the energy difference (s i = Ẽi+1 − Ẽi ) for two adjacent levels of the same spin and parity.…”

Section: B Spectral Statistics Of Dipole Resonancesmentioning

confidence: 99%

Properties of giant dipole resonances within an extended pairing model with a focus on spectral statistics

et al. 2021

Self Cite

View full text Add to dashboard Cite

In this paper, we report on a study of the spectral features associated with dipole resonances in medium mass nuclei (E ≤ 12 MeV), as revealed in the framework of the spd -interacting boson model. The effect of pairing correlations on the theory follows from solutions obtained through an application of the Bethe Ansatz Equation. In general, calculated spectra around the critical point of the vibrational to γ-soft transitions appears to approach that of a Gaussian Orthogonal Ensemble, while near the rotational and vibrational limits of the theory the spectra show more regular behavior. Specifically, the results reveal that the statistical features of the spectra are sensitive to the vector boson pairing strength, cp, in the transition region; that is, when cp is zero, or when the system approaches one of its dynamical symmetries limits the spectrum display regular features, while for stronger cp values, or when near to the critical phase transition region, the spectral feature show more chaotic behavior. Overall, our results indicate that the statistical features are governed by the interplay between dipole resonant energies, pairing correlations, and interactions between and among the single and vector bosons modes of the theory. As part of this work we also found out that chaoticity occurs when results were fit to a Berry-Robnik distribution. Throughout our analyses, we used experimentally known information about both positive and negative parity states. Our findings suggest that dipole resonances appear to be best-described by Poisson statistics for A ≈ 32-138 nuclei.

show abstract

Section: B Spectral Statistics Of Dipole Resonancesmentioning

confidence: 99%

Properties of giant dipole resonances within an extended pairing model with a focus on spectral statistics

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…, for the chaotic system, and as well an unfolding procedure to calculate the spectral statistics [18][19][20]. In Cd isotopes, the lengths of J π sequences are short, and therefore a much better measure is to use the ratio of consecutive spacings of adjacent energy levels, and recognize that there will be uncertainties associated with the unfolding.…”

Section: Theoretical Modelmentioning

confidence: 99%

Random Matrix Theory in Cd isotopes

Majarshin¹,

Luo²,

Pan³

et al. 2021

J. Phys. G: Nucl. Part. Phys.

Self Cite

View full text Add to dashboard Cite

Random matrix theory (RMT) is used to provide a measure of the chaoticity (q) of calculated results for the spectra for various Cd isotopes. The goal is to gain a better understanding of the internal dynamics in play; namely, whether it tracks with regular or irregular (chaotic) behavior as determined through an RMT analyses of calculated spectra. The basis-state configurations used to determine the spectra includes all positive, negative, natural (J π = 1 − , 2 + , . . .), and unnatural parity configurations (J π = 0 − , 1 + , 2 − , . . .), unless suppressed for comparative purposes. The results show that when intruder-state configurations are in play, regular behavior emerges, but when not in play, chaotic behavior seems to dominate the dynamics.

show abstract