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Statut |
Confirmé |
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Série |
NUC-THEO |
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Domaines |
nucl-th |
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Date |
Jeudi 16 Mars 2017 |
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Heure |
11:30 |
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Institut |
IPN |
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Salle |
IPN, Bâtiment 100, salle A 015 |
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Nom de l'orateur |
Scamps |
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Prenom de l'orateur |
Guillaume |
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Addresse email de l'orateur |
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Institution de l'orateur |
Center for Computational Sciences, University of Tsukuba, Japan |
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Titre |
Gauge angle dependency in fusion and transfer reactions, restoration of broken symmetries in dynamical calculation |
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Résumé |
Heavy ion transfer reactions are an ideal tool to study the pair correlations.
New experimental data show that the probability to transfer a pair of neutrons
is enhanced compared to the expected value in the uncorrelated limit or pure
sequential transfer.
In order to understand this enhancement, the Time-dependent Hartree-Fock (TDHF)
with BCS pairing has been studied but this approach cannot reproduce the
experimental data. To go beyond this approach, we use the Time-dependent
Hartree-Fock-Bogoliubov (TDHFB) theory. The calculation is done with a Gogny
interaction in a hybrid basis of two-dimensional harmonic oscillator eigen-
functions and a one-dimensional Lagrange mesh. With that model, the Josephson
effect is quantitatively described in the reaction 20O+20O as well as the
dependency of the Nucleus-Nucleus potential with respect to the Gauge angle.
The restoration of the gauge angle symmetry is then studied with a projection
method. The accuracy of this method is discussed in a simple model.
As a complementary method, the coupled-channels formalism is used. A phenomeno-
logical approach is used consisting in fitting the transfer coupling to reproduce the experimental data for the 40Ca+96Zr and 60Ni+116Sn systems. We investigate two different mechanisms for the pair transfer: a pure sequential transfer hypothesis and a sequential plus direct pair transfer hypothesis. We discuss the validity of the perturbative approach and highlight the effect of high-order terms. In this simple model, it is find that the direct pair transfer give a better reproduction of the experimental data at energies close to the coulomb barrier. Finally, we use the coupled-channels approach to achieve a simultaneous description of the fusion cross sections and the transfer probabilities for the 40Ca+96Zr reaction. |
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Numéro de preprint arXiv |
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Commentaires |
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Fichiers attachés |
- 2017_03_16_G_Scamps.pdf (209052 bytes)
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