%0 Journal Article %T Symmetry Breaking by Proton-Neutron Pairing %A S. Frauendorf %A J. A. Sheikh %J Physics %D 2000 %I arXiv %R 10.1238/Physica.Topical.088a00162 %X The symmetries of the $t=1$ and $t=0$ pair-fields are different. The consequences for rotational spectra are discussed. For $t=1$, the concept of spontaneous breaking and subsequent restoration of the isospin symmetry turns out to be important. It permits us to describe the proton-neutron pair-correlation within the conventional frame of pairing between like particles. The experimental data are consistent with the presence of a $t=1$ field at low spin in $N\approx Z$ nuclei. For a substantial $t=0$ field, the spectra of even-even and odd-odd $N\approx Z$ nuclei become similar. The possibility of a rotationally induced $ J=1$ pair-field at high spin is considered. %U http://arxiv.org/abs/nucl-th/0001039v1