Symmetry Breaking by Proton-Neutron Pairing

Abstract

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.

7 pages 9 figures

Cited by in corpus (9)

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• Self-consistent symmetries in the proton-neutron Hartree-Fock-Bogoliubov approach
• Pairing theory of the symmetry energy
• Different particle alignments in N \approx Z Ru isotopes studied by the shell model
• Nuclear masses near N = Z from Nilsson-Strutinsky calculations with pairing corrections beyond BCS from an isospin-conserving pairing force
• Isoscalar and isovector neutron-proton pairing