Triaxiality-driving effect extracted by spin projection

The effect of triaxial spin projection on the potential energy surface in t he deformation parameter space (epsilon,gamma) is investigated for three nu clei; Nd-142, Er-168 and Os-188. The calculation is performed for two sets of the spherical single-particle space and an effective monopole-pairing pl us quadrupole-quadrupole interaction. The correlations taken into account b y the spin projection have an effect of driving the system toward a triaxia l deformation, irrespective of the shell fillings of the nuclei.