Abstract
We show that the Bogoliubov–de Gennes equations for nuclear ground-state wave functions support solutions in which the condensate has a mixture of spin-singlet and spin-triplet pairing. We find that such mixed-spin condensates do not occur when there are equal numbers of neutrons and protons, but only when there is an isospin imbalance. Using a phenomenological Hamiltonian, we predict that such nuclei may occur in the physical region within the proton dripline. We also solve the Bogoliubov–de Gennes equations with variable constraints on the spin-singlet and spin-triplet pairing amplitudes. For nuclei that exhibit this new pairing behavior, the resulting energy surface can be rather soft, suggesting that there may be low-lying excitations associated with the spin mixing.
- Received 31 March 2011
DOI:https://doi.org/10.1103/PhysRevLett.106.252502
© 2011 American Physical Society
Synopsis
Pairing in nuclei
Published 23 June 2011
Paired states between neutrons and protons were thought to only occur in nuclei beyond the proton dripline, but calculations suggest they may be seen in stable nuclei, too.
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