First observation of yrast band in odd-odd N=91 162Lu nucleus

High Spin states of the odd-odd 162Lu nucleus have been studied via 147Sm (19F, 4n��) reaction at 90 MeV beam energy. Level scheme for yrast band based on ��[h11/2]v[i13/2] configuration was established. This band shows the signature inversion in energy before bandbending generally appeared in this mass region. It is stressed that the signature splitting in 162Lu is bigger than that in 160Tm which could be understood in the framework of the cranked shell model if taking positive ��-triaxiality into account.