Investigation of low-lying magnetic dipole excitations in the $^{153}$Eu nucleus

Abstract

The properties of low-lying magnetic dipole ($M$1) excitations in $^{153}$Eu were studied within a rotational invariant quasiparticle phonon model that takes into account the symmetry-restoring as well as 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 $^{152}$Sm core nucleus. The results were compared to the experimentally known $M$1 excitations at 2-3 MeV. A reasonably good agreement in the total transition strength, the centroid energy, and the resonance width was obtained.