Renormalized shell model matrix elements derived from nucleon-nucleon phase shifts

We apply theG matrix elements calculated by Singh et al. (using the DWBA approach) to some spectra calculations forA=18, 19, 20 after first renormalizing the matrix elements by including second-order processes inG. The corrections introduced by the Distorted-Wave-Born-Correction Term are attractive for both the H.J. and Reid potentials. The magnitude and uncertainties in these corrections are discussed. Differences between these potentials are attributed chiefly to their different off-the-energy-shell behaviour. The results are compared to calculations with the Kuo matrix elements and with experiment.