Simultaneous Microscopic Description of Nuclear Level Density and Radiative Strength Function.

The nuclear level density (NLD) and radiative strength function (RSF) are simultaneously described within a microscopic approach, which takes into account the thermal effects of the exact pairing as well as the giant resonances within the phonon-damping model. The good agreement between the results of calculations and experimental data extracted by the Oslo group for ^{170,171,172}Yb isotopes shows the importance of exact thermal pairing in the description of NLD at low and intermediate excitation energies. It also invalidates the assumption based on the Brink-Axel hypothesis in the description of the RSF.