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arXiv · 1611.09619

Random matrix analysis of the monopole strength distribution in $^{208}$Pb

A. P. Severyukhin·S. Aberg·N. N. Arsenyev·R. G. Nazmitdinov·K. N. Pichugin
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Abstract

We study statistical properties of the $0^+$ spectrum of $^{208}$Pb in the energy region $E_x\leq20$ MeV. We use the Skyrme interaction SLy4 as our model Hamiltonian to create a single-particle spectrum and to analyze excited states. The finite-rank separable approximation for the particle-hole interaction enables us to perform the calculations in large configuration spaces. We show that while the position of the monopole resonance centroid is determined by one phonon excitations of $0^+$, the phonon-phonon coupling is crucial for the description of a strength distribution of the $0^+$ spectrum. In fact, this coupling has an impact on the spectral rigidity $Δ_3(L)$ which is shifted towards the random matrix limit of the Gaussian orthogonal ensembles.

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A. P. Severyukhin, S. Aberg, N. N. Arsenyev, R. G. Nazmitdinov, K. N. Pichugin. 2016-11-29. Random matrix analysis of the monopole strength distribution in $^{208}$Pb. https://doi.org/10.1134/s1063778816060223

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