Magnetic moment and lifetime measurements of Coulomb-excited states in 106Cd

Background: The Cd isotopes are well studied, but experimental data for the rare isotopes are sparse. At energies above the Coulomb barrier, higher states become accessible. Purpose: Remeasure and supplement existing lifetimes and magnetic moments of low-lying states in Cd 106 . Methods: In an inverse kinematics reaction, a Cd 106 beam impinging on a C 12 target was used to Coulomb excite the projectiles. The high recoil velocities provide a unique opportunity to measure g factors with the transient-field technique and to determine lifetimes from lineshapes by using the Doppler-shift-attenuation method. Large-scale shell-model calculations were carried out for Cd 106 . Results: The g factors of the 2 + 1 and 4 + 1 states in Cd 106 were measured to be g(2 + 1 )=+0.398(22) and g(4 + 1 )=+0.23(5) . A lineshape analysis yielded lifetimes in disagreement with published values. The new results are τ(Cd 106 ;2 + 1 )=7.0(3)ps and τ(Cd 106 ;4 + 1 )=2.5(2)ps . The mean life τ(Cd 106 ;2 + 2 )=0.28(2)ps was determined from the fully-Doppler-shifted γ line. Mean lives of τ(Cd 106 ;4 + 3 )=1.1(1)ps and τ(Cd 106 ;3 − 1 )=0.16(1)ps were determined for the first time. Conclusions: The newly measured g(4 + 1 ) of Cd 106 is found to be only 59% of the g(2 + 1 ) . This difference cannot be explained by either shell-model or collective-model calculations.