First identification of excited states in the T-z=1/2 nucleus Zr-81 - art.no. 024310

The reaction Ni-58(Si-28, alpha n gamma) at 90 MeV of projectile energy has been used to populate the T-z = 1/2 nucleus Zr-81. gamma rays have been de tected with the GASP array, and charged particles with the ISIS Silicon bal l. The charged particle information allowed unambiguous assignment of gamma rays to Zr-81. TWO rotational band structures with both signatures have be en observed. They are discussed by comparison with similar bands in the N = 41 isotones and in T-z = 1/2 nuclei from the A approximate to 80 region, a nd on the basis of the cranked shell model and interacting boson-fermion mo del calculations.