Low-energy enhancement and fluctuations of $\gamma$-ray strength functions in ${}^{56,57}$Fe: test of the Brink-Axel hypothesis

A. C. Larsen, M. Guttormsen, N. Blasi +21

Nuclear level densities and $\gamma$-ray strength functions of ${}^{56,57}$Fe have been extracted from proton-$\gamma$ coincidences. A low-energy enhancement in the $\gamma$-ray strength functions…