A model-independent technique was used to determine the $\gamma$-ray strength function ($\gamma \mathrm{SF}$) of ${}^{56}\mathrm{Fe}$ down to $\gamma$-ray energies less than 1 MeV for the first time with GRETINA using the $(p,p^{\prime })$ reaction at 16 MeV. No difference was observed in the energy dependence of the $\gamma \mathrm{SF}$ built on $2^{+}$ and $4^{+}$ final states, supporting the Brink hypothesis. In addition, angular distribution and polarization measurements were performed. The angular distributions are consistent with dipole radiation. The polarization results show a small bias towards magnetic character in the region of the enhancement.

• Received 13 November 2017

DOI:https://doi.org/10.1103/PhysRevC.97.024327