Collective enhancements in the level densities of Dy and Mo isotopes

Nuclear level densities in Mo-94,Mo-96,Mo-98 and Dy-160,Dy-162,Dy-164 isotopes are calculated using the single-particle spectrum obtained with the Woods-Saxon potential. The level-density parameters, spin cut-off factors, and moments of inertia are studied. Using the available experimental data at low excitation energies, the collective enhancements of the level densities are calculated and compared with those of the phenomenological model. In Mo isotopes, these semiempirical calculations agree better with the experiments in comparison to the phenomenological model assuming a spherical shape.