Nuclear structure ofY in the interacting boson-fermion model.

Unique-parity states ofY are studied in the framework of the interacting boson-fermion model (IBFM). Spin assignments for the levels of the unique-parity yrast band are proposed on the basis of nuclear systematics and the IBFM band pattern associated with coupling of a particle-type quasiparticle (g) to the SU(5) coreSr. The good fit of the experimental data with the IBFM calculations confirms the single particle character of this immediate neighbour of the doubly sub-magic nucleusZr. [ABSTRACT FROM AUTHOR]