Search for a pygmy resonance in resonant n-γ spectra of 197Au

Resonant γ-ray spectra in ¹⁹⁷Au have been measured over a neutron energy range of 0.025 eV to 800 eV with a Ge(Li) detector at the 60 MeV electron linac at Saclay. No evidence has been found for the much discussed pygmy resonance in ¹⁹⁷Au from a comparison of thermal and averaged γ-ray spectra. The earlier observed bump in the thermal neutron capture spectra arises mainly from Porter-Thomas fluctuations of transitions in the lowest resonance, at 4.9 eV.