Odd-spin yrast states as multiple quadrupole-phonon excitations
  The wavefunctions of the lowest odd spin positive parity yrast states in the IBA are shown to be nearly pure multiple quadrupole-phonon excitations even outside the three dynamical symmetries. The empirical data for collective nuclei with 30 < Z < 80 confirm these predictions. The quadrupole-phonon purity of the 2^+_1 state can be measured from E2-branching ratios of the 3^+_1 state. These data show a high correlation to the 2^+_1 Q-phonon purity deduced from the E2-decay of 2^+ states. 
N. Pietralla (1), P. von Brentano (1), T. Otsuka (2), R.F. Casten (3)   ((1) Institut f\"ur Kernphysik, Universit\"at zu K\"...