The β-Decay Properties of Scissors Mode 1[sup +] States in [sup 164]Er

Abstract

The beta decay properties of collective I^K = 1*1 states in doubly even deformed Er nuclei are investigated in the framework of the rotational invariant random-phase approximation. It is shown that an essential decrease of the rate of the allowed P-decay to the excited l*-states as compared with that to the ground state may be due to the orbital nature of the states. The model Hamiltonian includes restoring rotational invariance of the deformed single particle Hamiltonian forces and the spin-spin interactions. The analytical expressions for the Gamov-Teller (G-T) and Fermi (F) decay matrix elements are derived. The single-particle energies were obtained from the Warsaw deformed Woods-Saxon potential with deformation parameter S2 =0.24.The numerical residts for P* transition from Tm to Er indicate the importance of using rotational invariant Hamiltonian to explain experimental data.