%0 Journal Article %T Isovector Pairing in Odd-A Proton-Rich Nuclei %A Jonathan Engel %A Karlheinz Langanke %A Petr Vogel %J Physics %D 1998 %I arXiv %R 10.1016/S0370-2693(98)00477-8 %X A simple model based on the group SO(5) suggests that both the like-particle and neutron-proton components of isovector pairing correlations in odd-A nuclei are Pauli blocked. The same effect emerges from Monte Carlo Shell-model calculations of proton-rich nuclei in the full fp shell. There are small differences between the two models in their representation of the effects of an odd nucleon on the competition between like-particle and neutron-proton pairing, but they can be understood and reduced by using a two-level version of the SO(5) model. On the other hand, in odd-odd nuclei with N not equal to Z SO(5) disagrees more severely with the shell model because it incorrectly predicts ground-state isospins. The shell model calculations for any fp-shell nuclei can be extended to finite temperature, where they show a decrease in blocking. %U http://arxiv.org/abs/nucl-th/9803018v1