The investigation of spin-vibration IπK=1+1 states in deformed nuclei (150≤A≤178)

Keywords: QRPA, even-even deformed nuclei, spin-vibration, iso vector, EWSR, I"K = 1+1 states, magnetic dipole transition, resonance energy region, quasiparticle, collective, quasiparticle number. In this thesis, properties of I*K = \+\ spin-vibration states in the even-even deformed nuclei 15 Sm, 168Er and 178Hf, which are in the region of rare-earth elements, were studied using QRPA method. Contribution of Ml transition matrix element to the energy weighted sum rules and energy distribution of Ml excitation strength functions were investigated for 1+1 states, generated by the isovector spin- spin forces. It was observed that the collectivity of 1+1 states is small in the spectroscopic energy region (co < 4 MeV). Between 10-12 MeV, presence of very collective spin- vibration 1+1 states that produce magnetic dipole resonance was seen. In the lower energy, neutron-proton spin-spin interactions are quite weak since 1+1 states are two quasi-particles character. In this work the change of quasi-particle number with respect to the spin-spin interaction constant is studied, as well %m = Zİ A. The quasi-particle number in the collective states for the deformed nucleus 154Sm is calculated as an example. The numerical calculations in this thesis are performed on the basis of the Deformed Wood-Saxon potential.