Study of the negative-parity yrast states in odd-A Lu-isotopes

Using Particle-Rotor Model, the energy spectra and electromagnetic transiti ons of the negative-parity yrast states, before and after the band-crossing in odd-A Lu isotopes, are investigated and compared with the experimental data. It is noted that before and after the band-crossing the moment of ine rtia of the core is a smooth function of the total angular momentum I and c an be described by the ab formula; The triaxial deformation before and afte r the band-crossing determined from the calculations is appreciably differe nt for (161,163,165) Lu, while it is more or less similar for (167) Lu.