Magnetic moments of N = 50 isotones and proton core polarization

Pulsed heavy-ion beams of 4He, 6Li, 32S and 35Cl have been used to populate isomeric states in N = 50 nuclei having a closed neutron shell and a rather pure (psup(n)sub(1/2)gsup(m)sub(9/2)) proton configuration. The g-factors of the 3.4 μs (17/2)- state in 91Nb, the 9.3 ns 11- state in 92Mo, the 10.1 μs (17/2)- state in 93Tc, the 65.5 ns 6+ state and the 68 μs 8+ state in 94Ru were measured for the first time and those of 8+ states in 90Zr and in 92Mo were remeasured with improved accuracy. The g-factors increase by (4.2+-0.8)% as the psub(1/2) proton subshell is filled and decrease by (3.5+-1.4)% as the number of protons in the gsub(9/2) shell increases from two to four. Calculations that take core polarization into account in first-order perturbation theory explain quantitatively the observed magnetic moments. One-pion exchange current contributions have also been calculated. (Auth.)