Neutron Resonances: Widths Distribution versus the Porter-Thomas Law
V.V. Sokolov
Budker Institute of Nuclear Physics of SB RAS, Novosibirsk, Russia
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The neutron resonance scattering off heavy nuclei is a paradigmatic example of the chaotic processes that are well described within the framework of the standard Random Matrix Theory (RMT). In zero approximation of non-overlapping resonances, the resonance width distribution is given by the standard Porter-Thomas law (PTD) dw/dx = e-x/2/√(2πx), where x=Γ/⟨Γ⟩ is the resonance width measured in the units of its mean value. We analyze the influence of the resonance overlapping and show that the experimentally observed deviations from of the PTD arise due to the influence of a moderate number of neighboring resonances located inside a restricted energy interval within which the mean level spacing D remains constant.

DOI: 10.12693/APhysPolA.132.1704
PACS numbers: 05.45.Gg, 24.60.Lz, 05.45.Mt