| 1. |
- Bhagwat, A., et al.
(författare)
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Investigation of band termination in the lower fp shell within the cranked relativistic mean field model
- 2013
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Ingår i: International Conference on Recent Trends in Nuclear Physics-2012 (ICRTNP 2012). - : AIP. - 9780735411470 ; , s. 105-108
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Konferensbidrag (refereegranskat)abstract
- The excitation energy difference (ΔE) between the terminating states built on the f7/2 n and d3/2 -1f 7/2 n+1 configurations (here, 'n' denotes the number of valence particles outside the 40Ca core and the particle hole excitation across the magic gap 20 is of proton type) in the lower fp shell are studied systematically within the framework of the cranked relativistic mean field model. The ΔE thus defined, depends predominantly on the f 7/2 - d3/2 shell gap, and its evolution as a function of neutron - proton asymmetry. The latter, in turn, depends on the isoscalar - isovector balance in the spin - orbit potential. Therefore, a systematic investigation of the difference ΔE is expected to test quantitatively the predicted shell gaps as a function of isospin. We find that: 1) the conventional NL3 parameter set over estimates the ΔE values, implying that the said shell gap is over - estimated in this parametrization and 2) the largest deviation between the calculated and the experimental values of ΔE is obtained for the nucleus with the smallest asymmetry value in the set of nuclei considered, and that the deviation decreases with increasing asymmetry, indicating that the in RMF parametrization considered, the isoscalar - isovector balance in the spin - orbit potential requires improvement. We carry out a re - fit of the RMF parameters to attempt a remedy to these two problems. We find that in addition to the binding energies and charge radii, if a constraint is put on the f7/2 - d3/2 shell gap in the fit to the Lagrangian parameters, the overall agreement of ΔE with the experiment improves significantly, without disturbing the agreement already achieved for the bulk properties of the nuclei spanning the entire periodic table. At a finer level, however, it is found that the isoscalar - isovector balance in the spin orbit interaction is required to be improved further. A detailed work in this direction is in progress.
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| 2. |
- 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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