Unfolding the effects of the T=0 and T=1 parts of the two-body interaction on nuclear collectivity in the f-p shell

Calculations of the spectra of various even-even nuclei in the fp shell (Ti44, Ti46, Ti48, Cr48, and Cr50) are performed with two sets of two-body interaction matrix elements. The first set consists of the matrix elements of the FPD6 interaction. The second set has the same T=1 two-body matrix elements as the FPD6 interaction, but all the T=0 two-body matrix elements are set equal to zero (T0FPD6). Surprisingly, the T0FPD6 interaction gives a semireasonable spectrum when compared to FPD6 (or else this method would make no sense). A consistent feature for even-even nuclei, e.g., Ti44,46,48 and Cr48,50, is that the reintroduction of T=0 matrix elements makes the spectrum look more rotational than when the T=0 matrix elements are set equal to zero. The odd-odd nucleus V46 is also discussed. In general, but not always, the inclusion of T=0 two-body matrix elements enhances the B(E2) rates.