Electric Monopole and Quadrupole Matrix Elements for the Kπ=0+ Bands in 154Gd

Electric monopole and quadrupole transitions from the first and second K π =0 + band states in 154 Gd are observed through the decay of 154 Tb with a high resolution iron-free magnetic spectrometer. Electric quadrupole transition matrix elements for the β-band states are deduced from an analysis of ratios Q β g ( I β - I g ')/ eR 2 ρ( I β - I g ). The decrease of the rotation vibration interaction energy for high spin states of the β-band is discussed. Dimensionless ratios X ( I 2 - I λ ) for the second 0 + band are deduced as follows; X (0 2 -0 g )=0.056±0.009 and X (2 2 -2 β )=0.069±0.011. The branching ratio of E0 reduced transition probabilities, ρ(0 2 -0 β )/ρ(0 2 -0 g ), is found to be ≤0.3. The possibility of the second equilibrium deformation is discussed for the second K π =0 + band.