Spin and parity assignments for low-lying states in the odd-mass nucleus 181Ta

Abstract

Low-lying levels in the odd-mass nucleus $^{181}$Ta have been populated via nuclear resonance fluorescence using a quasi-monoenergetic, linearly polarized photon beam at the High Intensity $\gamma$-ray Source (HI$\gamma$S) facility at Duke University. The spin and parity of the levels were determined from the azimuthal intensity asymmetry of resonantly scattered $\gamma$ rays with respect to the polarization plane of the incident photon beam. The electric and magnetic dipole strengths were obtained for excitation energies from 2.2 to 3.2 MeV. The results are discussed in terms of the nuclear scissors mode.journal articl