Measurement ofg-factors in160Yb by aγ-γ coincidence technique

Aγ-γ coincidence technique has been developed forg-factor measurements of short-lived nuclear states. The method involvesγ-detection in 4π geometry as well as transient magnetic fields and the recoil-distance technique. A first experiment was performed for the isotope¹⁶⁰Yb produced in the reaction⁶⁴Ni(¹⁰⁰Mo, 4n) at 430 MeV beam energy. The valueg=? 0.23(31) of the 14⁺ yrast state, which is compatible with zero, establishes thevi _13/2 quasiparticle structure to be responsible for the first backbend. A meang-factor for low spin states around the 4⁺ state,g=+0.48(26) was also derived as well as lifetimes for yrast states up toI ^π=8⁺.