Level schemes of163, 165Yb and backbending behaviour of neutron deficient Yb-isotopes

Abstract

High spin states in 163,165yb have been populated using (160, xn) reactions with 152,154Sm targets. Several rotational bands are observed and the lifetime of highly converted transitions have been measured utilizing a solenoid-Si(Li) spectrometer and Ge(Li) detectors.The i13/2 and 3/2-[521] bands do not backbend, whereas the 5/2 [523] bands do, indicating additional processes besides the rotational alignment of one i13/2 neutron pair that are responsible for the backbending.