Evidence of X(5) symmetry for nγ=0,1,2 bands in 104Mo -: art. no. 031301

The dynamical symmetry X(5) characterizes the critical point of phase transition between spherical and axially deformed shape in atomic nuclei. A first example of this new symmetry has been found in Sm-152 (Z=62) by Casten and Zamfir. We show that the level scheme of the transitional nucleus Mo-104 (N=62) also presents the characteristic X(5) pattern, not only in the ground-state band but also in its low-lying n(gamma)=1, K=2 and n(gamma)=2, K=4 bands. An essential point of the model leading to the X(5) symmetry, i.e., the decoupling of the gamma vibrations from the other degrees of freedom, is therefore confirmed.