SPECTROSCOPY OF Y-88 HOMOLOGOUS LEVELS

The Zr-91((p) over right arrow, alpha)Y-88 reaction has been studied a t incident energy of 22 MeV using a polarized proton source and a Q3D spectrometer. The differential cross sections and asymmetries for tran sitions to levels of Y-88 homologous to the lowest excitation energy s tates of Y-87 have been measured and interpreted both in terms of the experimental differential cross sections and asymmetries of the parent Y-87 states and by means of the finite-range distorted wave Born appr oximation theory using conventional Woods-Saxon alpha-particle potenti al. The advantage of the concept of homology consists in having to dea l with a unique l-transfer, that given by the transition to the corres ponding parent state. In order to validate the concept of homology as a spectroscopic tool to identify spin, parity and dominant configurati on of highly excited states in ((p) over right arrow, alpha) reaction on odd mass target nuclei, shell model calculations have been performe d. Several new attributions of spin and parity for Y-88 residual nucle us are proposed.