| 11. |
- Satula, Wojtek, et al.
(författare)
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Isospin Mixing in Nuclei around N similar or equal to Z and the Superallowed beta-decay
- 2011
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Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 42:3-4, s. 415-425
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Tidskriftsartikel (refereegranskat)abstract
- Theoretical approaches that use one-body densities as dynamical variables, such as Hartree-Fock or the density functional theory (DFT), break isospin symmetry both explicitly, by virtue of charge-dependent interactions, and spontaneously. To restore the spontaneously broken isospin symmetry, we implemented the isospin-projection scheme on top of the Skyrme-DFT approach. This development allows for consistent treatment of isospin mixing in both ground and exited nuclear states. In this study, we apply this method to evaluate the isospin impurities in ground states of even-even and odd-odd N similar or equal to Z nuclei. By including simultaneous isospin and angular-momentum projection, we compute the isospin-breaking corrections to the 0(+) -> 0(+) superallowed beta-decay.
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| 12. |
- Satula, W., et al.
(författare)
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Microscopic structure of fundamental excitations in N = Z nuclei
- 2001
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 8705:5
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Tidskriftsartikel (refereegranskat)abstract
- An extended mean-field model is presented that describes states of different isospin in odd-odd and even-even nuclei. Excitation energies of the T = 1 states in even-even as well as T = 0 and T = 1 states in odd-odd N = Z nuclei are calculated. It is shown that the structure of these states can be determined in a consistent manner when both isoscalar and isovector pairing collectivity as well as isospin projection (treated here within the isocranking approximation) are taken into account. In particular, in odd-odd N = Z nuclei, the interplay between quasiparticle excitations (relevant for the case of T = 0 states) and isorotations (relevant for the case of T = 1 states) explains the near degeneracy of these states.
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| 13. |
- Satula, W., et al.
(författare)
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Rotations in isospace : A doorway to the understanding of neutron-proton superfluidity in N = Z nuclei
- 2001
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 86:20, s. 4488-4491
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Tidskriftsartikel (refereegranskat)abstract
- The T = 2 excitations in even-even N = Z nuclei are calculated within the isospin cranked mean-held approach. The response of pairing correlations to rotation in isospace is investigated. Whereas the isovector pairing rather modestly modifies the single-particle moment of inertia in isospace, the isoscalar pairing strongly reduces its value. This reduction of the isomoments of inertia with respect to its rigid body value is a strong indicator of collective isoscalar pairing correlations. These results are further generalized yielding beautiful analogies between the role of isovector pairing for the case of spatial rotations and the role of isoscalar pairing for the case of isorotations.
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| 14. |
- Wyss, Ramon A., et al.
(författare)
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Rotating N=Z nuclei - A probe to the t=0 and t=1 pairing correlations
- 2001
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Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 32:9, s. 2457-2468
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Tidskriftsartikel (refereegranskat)abstract
- A study of heavy N=Z nuclei including t=1, t(z)=+/-1 pairing only clearly reveals the shortcoming of that model in T-z=0 nuclei. We present a simple model in which we study the response of isoscalar t=0 and isovector t=1 pairing correlations to rotational motion. In particular, we address the role played by the t=1 and t=0 pair gaps with respect to the band crossing frequency. We argue that the t=1 neutron-proton pair field is of limited importance in even-even nuclei. For the t=0 pair field, we introduce two different pairing modes. One is invariant with respect to signature symmetry and one is not. The signature conserving mode results in a delay of the band crossing frequency, whereas the signature breaking part enhances the rigidity of the moment of inertia.
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| 15. |
- Xu, F. R., et al.
(författare)
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Quadrupole pairing interaction and signature inversion
- 2000
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Ingår i: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 669:02-jan, s. 119-134
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Tidskriftsartikel (refereegranskat)abstract
- The signature inversion in the pi h(11/2) x vh(11/2) rotational bands of the odd-odd Cs and La isotopes and the pi h(11/2) x vi(13/2) bands of the odd-odd Tb, Ho and Tm nuclei is investigated using pairing and deformation self-consistent mean-field calculations, The model can rather satisfactorily account for the anomalous signature splitting provided that spin assignments in some of the bands are revised. Our calculations show that signature inversion can appear already at axially symmetric shapes. It is found that this is due to the contribution of the (lambda mu) = (22) component of the quadrupole-pairing interaction to the mean-field potential.
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