Isobaric multiplet yrast energies and isospin nonconserving forces.

The isovector and isotensor energy differences between yrast states of isobaric multiplets in the lower half of the pf region are quantitatively reproduced in a shell model context. The isospin nonconserving nuclear interactions are found to be at least as important as the Coulomb potential. Their isovector and isotensor channels are dominated by J=2 and J=0 pairing terms, respectively. The results are sensitive to the radii of the states, whose evolution along the yrast band can be accurately followed.