Shell model configurations in the 2 1 + state in 46 Ca from a g-factor measurement

The g factor of the first excited 2 + state in 46 Ca has been remeasured with better accuracy than previously obtained, g(2 + , 46 Ca) =− 0.26(6). The experiment utilized the transient field technique combined with Coulomb excitation in inverse kinematics. This result was analyzed in terms of shell model plus deformed core calculations. The positive g factors of the 2 + states in 42 Ca and 44 Ca suggest that the 2 + state wave functions require significant particle–hole excitations of the Z = 20, N = 20 core. The new data for 46 Ca show that (fp) 6 configurations dominate near the shell closure at 48 Ca and indicate that core excitation plays a lesser role than was hitherto believed.