| Thème(s) : |
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Physique/Physique Nucléaire Expérimentale
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| Titre : |
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Evidence for core excitation in single-particle states of $^{19}$Na |
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| Auteur : |
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M.G. Pellegriti1, N.L. Achouri2, C. Angulo1, J.C. Angélique2, E. Berthoumieux3, E. Casarejos1, M. Couder1, T. Davinson4, C. Ghag4, A.St. Murphy4, N.A. Orr2, I. Ray5, I.G. Stefan5, P. Descouvemont6 |
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| Laboratoire : |
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| équipe(s) de recherche : |
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structure nucléaire |
| Résumé : |
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We present an experimental study of $^{19}$Na states in the excitation energy range between 2 and 3 MeV. The presence of $^{19}$Na single-particle levels at these energies was first predicted by a microscopic cluster model and then experimentally confirmed by measuring the elastic and inelastic scattering of a 66 MeV $^{18}$Ne radioactive beam on a $(CH2)_n$ target. The H($^{18}$Ne,p)$^{18}$Ne(g.s.) and H($^{18}$Ne,p')18Ne*($2^+$, 1.887 MeV) cross sections have been obtained in the laboratory angular range $\theta$_lab$ = 6.1°−18.4° and analyzed by using the R-matrix method. Two new states in $^{19}$Na have been observed at centre of mass energies $E_c.m.$ = 2.78 ± 0.01 MeV and 3.09 ± 0.05 MeV. Both resonances exhibit large widths in the $^{18}$Ne($2^+$)+p channel, and low branching ratios into the elastic channel. The reduced proton widths confirm the single-particle nature of these states, with a $^{18}$Ne($2^+$)+p structure. |
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| Type de publication : |
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Articles dans des revues avec comité de lecture |
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Date de publication
ou d'écriture : |
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2008 |
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| Nom du périodique : |
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| Physics Letters B (Phys. Lett. B) |
| Publisher |
Elsevier |
| ISSN |
0370-2693 |
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| Volume : |
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659 |
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| Page/Article : |
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864-869 |
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| Identifiant local : |
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GANIL P 08 37 |
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| Classification PACS : |
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25.60.-t; 25.60.Bx; 27.20.+n |
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| Mot(s)-clé(s) : |
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Elastic scattering – Inelastic scattering – Single-particle states |
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