Understanding quantum phase behavior through gamma-ray spectroscopy of 154Gd

Nuclei that undergo rapid transitions from spherical to deformed states can be modeled using quantum phase transitions. At N$=90$, discontinuous binding-energies indicate the simultaneous existence of spherical and deformed structures. To expand upon our knowledge of quantum phase transitional behavior at N$=90$, the decay of $^{154}$Eu to $^{154}$Gd was studied with the Gammasphere array at Argonne National Laboratory. The ultra high statistics data set allowed for precise determination of transition intensities between low-lying states in $^{154}$Gd important for interpretation of its structure. The new intensities will be used to re-evaluate the efficiency of various theoretical models to describe the phase and shape transition of $^{154}$Gd. This work was supported by the DOE Office of Nuclear Physics under contract DE-AC02-06CH11357 and DE-AC02-98CH10946.