Nuclear level densities and γ-ray strength functions in 44,45Sc

The scandium isotopes 44,45 Sc were studied with the 45 Sc( 3 He, αγ) 44 Sc and 45 Sc( 3 He, 3 He'γ) 45 Sc reactions, respectively. The nuclear level densities and γ-ray strength functions have been extracted using the Oslo method. The experimental level densities are compared to calculated level densities obtained from a microscopic model based on BCS quasiparticles within the Nilsson level scheme. This model also gives information about the parity distribution and the number of broken Cooper pairs as a function of excitation energy. The experimental γ-ray strength functions are compared to theoretical models of the E1, Ml, and E2 strength and to data from (γ,n) and (y,p) experiments. The strength functions show an enhancement at low y energies that cannot be explained by the present standard models.