High-spin states in odd-odd 164Lu

High-spin states in odd-odd 164Lu have been studied using 19F and 23Na induced fusion-evaporation reactions. Three strongly coupled rotational bands have been established and three decoupled bands were tentatively assigned to 164Lu. The band crossing frequencies, energy signature splittings, and relative transition probabilities were deduced from experimental data and compared with neighboring even-even and odd-A nuclei. An anomalously large band crossing frequency was observed in the excited band, and a pronounced signature inversion was observed in the yrast band of 164Lu. These anomalies may be associated with residual neutron-proton interactions.