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Poisson and Porter-Thomas Fluctuations in off-Yrast Rotational Transitions

M. Matsuo·T. Døssing·B. Herskind·S. Frauendorf
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Abstract

Fluctuations associated with stretched E2 transitions from high spin levels in nuclei around $^{168}$Yb are investigated by a cranked shell model extended to include residual two-body interactions. It is found that the gamma-ray energies behave like random variables and the energy spectra show the Poisson fluctuation, in the cranked mean field model without the residual interaction. With two-body residual interaction included, discrete transition pattern with unmixed rotational bands is still valid up to around 600 keV above yrast, in good agreement with experiments. At higher excitation energy, a gradual onset of rotational damping emerges. At 1.8 MeV above yrast, complete damping is observed with GOE type fluctuations for both energy levels and transition strengths(Porter-Thomas fluctuations).

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M. Matsuo, T. Døssing, B. Herskind, S. Frauendorf. 1992-12-14. Poisson and Porter-Thomas Fluctuations in off-Yrast Rotational Transitions. https://doi.org/10.1016/0375-9474(93)90509-v

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