Collective properties of nucleons in the abnormal-parity states - art. no.034317

In the first part of this work, we study the quadrupole collective properti es of N-a = 2, 4, 6, and 8 nucleons occupying the abnormal-parity intruder single-particle states with high angular momenta j(a) = 9/2, 11/2, 13/2, an d 15/2. This study is essential for a detailed understanding of the contrib ution made by these nucleons to the quadrupole collectivity of the yrast st ares of deformed nuclei. The properties studied include (i) the distributio n of the angular momenta J contained in the intrinsic state of N-a particle s in the \j(a)k(a)] states, (ii) the relationship between the quadrupole mo ment Q(0)(j(a),N-a) of such an intrinsic state and the maximum angular mome ntum J(max) contained in it, (iii) the complete set of reduced quadrupole m atrix elements (J'parallel to Q parallel to J) for transitions between all the states \J] and \J'] projected from the intrinsic state, (iv) the B(E2:J -->J-2) values, (v) the transition moments Q(t)(J), and (vi) the spectrosco pic quadrupole moment Q(J). We compare these properties with similar proper ties of an intrinsic state having SU(3) symmetry which contains the same se t of angular momenta as contained in the intrinsic state of a particular nu mber of nucleons in a specific j(a) configuration. In the second part, we u se the input from the first part to study the collective properties of the coupled system of protons and neutrons in abnormal-parity states. We show t hat the SU(3)-like features observed for the individual groups of abnormal- parity nucleons become stronger for the coupled system. Finally, in the thi rd part, we consider the yrast bands of well-deformed nuclei projected from their Nilsson intrinsic states of valence nucleons in a major shell. We sp ecify the structure of the wave function of each projected yrast state \J] in terms of the nucleons in both normal- and abnormal-parity states. These wave functions can be used to determine the individual contributions of the nucleons in normal- and abnormal-parity states to any specific property of the yrast state. In particular, we calculate the transition moments Q(t)(J ) of the entire yrast band of even-even Yb160-166, Dy-156,Dy-158, Th-232, U -234, and U-236 projected from their respective Nilsson intrinsic states.