Study of parity-doublet structure in the $^{147}$La nucleus

J. Wiśniewski , W. Urban , T. Rząca-Urban , A.G. Smith , J.F. Smith , G.S. Simpson (1) , I. Ahmad , J.P. Greene

1 LPSC - Laboratoire de Physique Subatomique et de Cosmologie

The work reports several new excited states in the neutron-rich 147La nucleus, populated in spontaneous fission of 252Cf. The excitation scheme has been reinvestigated by means of γ-ray spectroscopy, using high-fold γ coincidences measured with the Gammasphere array of Ge detectors. It is shown that the 229.65-keV level has spin and parity 11/2-, which changes the 9/2- spin-parity reported in a recent evaluation and sets up the spinparity of the ground state as 5/2+. New levels allow to arrange the excitation scheme of 147La into a parity-doublet-like structure showing that the 147La nucleus may have an octupole deformation.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

J. Wiśniewski, W. Urban, T. Rząca-Urban, A.G. Smith, J.F. Smith, et al.. Study of parity-doublet structure in the $^{147}$La nucleus. 6th Workshop on Nuclear Fission and Spectroscopy of Neutron-Rich Nuclei, Mar 2017, Chamrousse, France. pp.05006, ⟨10.1051/epjconf/201819305006⟩. ⟨hal-01952146⟩