Emerging collectivity and phase transition in mass A$\approx$150 region. New information for Nd isotopes

Abstract

Low and medium spin excitations in $^{146,148,150,152}$Nd isotopes, populated in $β^-$ decay of corresponding Pr isotopes or in prompt-$γ$ fission of $^{252}$Cf have been studied using Gammasphere array of Ge spectrometers. 159 new levels, including two new isomers, 305 new $γ$ transitions and 83 new spin-parity assignments were added in the four studied nuclei. The structure of excited levels in the studied Nd isotopes is discussed using phenomenological classifications and systematics and compared to calculations reported in other works. Particular attention is paid to $0^+$ and $2^+$ excitations related to the emerging quadrupole collectivity and to the role of the 11/2$^-$[505] neutron extruder in the process.