Examination of the Low-Energy Enhancement of the gamma-ray Strength Function of 56Fe

A model-independent technique was used to determine the γ -ray strength function ( γ SF ) of 56 Fe down to γ -ray energies less than 1 MeV for the first time with GRETINA using the (p,p′ ) reaction at 16 MeV. No difference was observed in the energy dependence of the γ 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