Deformation dependence of low lying<i>M</i>1 strengths in even Nd isotopes

Abstract

Measurements of the linear polarization of resonantly scattered photons have been used for model independent parity assignments in nuclear resonance fluorescence experiments (NRF). Previous NRF investigations of the even-even Nd isotopes were completed by polarization measurements on the transitional nucleus $^{146}\mathrm{Nd}$. With these new parity assignments the systematics of low lying M1 strengths can be studied along the transition from spherical to deformed nuclear shapes. The total M1 strength in the excitation energy range of 2--4 MeV in the investigated even-even Nd isotopes increases proportionally to the square of the deformation parameter. These findings represent a reliable confirmation of the results recently reported for the Sm isotopes by the Darmstadt group. This deformation dependence can be explained by various recent theoretical approaches.