Analysis of magnetic dipole transitions between sd-shell states

Experimental values of magnetic dipole transition strengths between states of sd-shell (A = 17--39) nuclei are analyzed with one-body transition densities from complete-space 0d/sub 5/2/-1s/sub 1/2/-0d/sub 3/2/ shell-model wave functions in order to extract empirical values for the higher-order corrections to the model M1 operator. These corrections, or renormalizations, are obtained in terms of the values of the effective single-particle matrix elements which, when combined with the model transition densities, yield a minimum deviation of the model predictions for M1 strengths from a set of selected experimental values. A total of 250 experimental data are investigated. Confirmation that the particular realizations of shell-model wave functions employed in the analysis of the data yield adequate descriptions of the actual nuclear states, and that the set of experimental data provides a thorough and accurate sampling of the relevant phenomena, are prerequisites to obtaining meaningful results from this procedure. These issues are studied with a variety of tests of the internal consistency of the procedures used