Investigation of low-lying magnetic dipole excitations in the Eu-153 nucleus

The properties of low-lying magnetic dipole (M 1.) excitations in Eu-153 were studied within a rotational invariant quasipurtlcle phonon model that takes into account the symmetry-restoring as well us spin-spin residual forces. The calculations show that there are purely collective M 1 excitations lying at 2-4 MeV fragmented over orbital 1 (+) states of the Sm-152 core nucleus. The results were compared to the experimentally known M I excitations at 2-3 MeV. A reasonably good agreement in the total transition strength, the centroid energy, and the resonance width was obtained.