Multiphonon \gamma-vibrational bands in the \gamma-soft nucleus ¹³⁸Nd

H. J. Li, Z. G. Xiao, S. J. Zhu, E. Y. Yeoh, Y. X. Liu, Y. Sun, Z. Zhang, R. S. Wang, H. Yi, W. H. Yan, Q. Xu, X. G. Wu, C. Y. He, Y. Zheng, G. S. Li, C. B. Li, H. W. Li, J. J. Liu, S. P. Hu, J. L. Wang, and S. H. Yao

Accepted Tuesday Apr 30, 2013

The low spin states of 138Nd have been re-investigated via the 124Te(19F,4n1p) reaction at a beam energy of 103 MeV. The quasi-one-phonon g-vibrational band based on 1013.7 keV level has been expanded and the quasi-two-phonon g-vibrational band built on 1842.7 keV level has been proposed. A systematical comparison supports our assignments for multi-phonon g-vibrational bands in 138Nd. The characteristics of g-softness in 138Nd have been discussed. Triaxial projected shell model calculations can well describe the rotational feature of the bands, but fails to reproduce simultaneously the bandhead energies of the two g-vibrational bands if a fixed triaxial deformation is assumed.