Volume 281 - The 26th International Nuclear Physics Conference (INPC2016) - Nuclear Structure B - Thursday 15
Is The Generalized Brink-Axel Hypothesis Valid?
M. Guttormsen,* A.C. Larsen, A. Görgen, T. Renstrøm, S. Siem, T. Tornyi, G.M. Tveten
*corresponding author
Full text: pdf
Pre-published on: 2017 May 04
Published on: 2017 May 09
Abstract
Experimental results of the $^{237}$Np($d, p \gamma)^{238}$Np reaction are presented, which verifies the generalized Brink-Axel (gBA) hypothesis for $\gamma$ transitions between states in the quasi-continuum. The gBA hypothesis holds not only for specific collective resonances, but for the full dipole strength below the neutron separation energy. We discuss the validity of the gBA hypothesis also for lighter systems like $^{92}$Zr where the concept of a unique $\gamma$-ray strength function ($\gamma$SF) is problematic due to large Porter-Thomas fluctuations. Methods for studying the $\gamma$SF and the fluctuations as function of excitation energy are presented.
DOI: https://doi.org/10.22323/1.281.0062
Open Access