• Citer

Impact of the phonon coupling on the dipole strength and radiative neutron capture

par Avdeenkov, A.V.;Goriely, Stéphane ;Kamerdzhiev, S.
Référence Journal of the Korean Physical Society, 59, page (967-970)
Publication Publié, 2011

Article révisé par les pairs

• Détails
• Contenu

Résumé :

The E1 strength functions and radiative capture cross sections for several compound Sn isotopes, including unstable 132Sn and 150Sn, have been calculated using the self-consistent microscopic theory. In addition to the standard RPA or QRPA approaches, the method includes the quasiparticle-phonon coupling and the single-particle continuum. The results obtained show that the phonon contribution significantly affects the pygmy dipole resonance, which is of particular relevance for a proper description of the radiative neutron capture. The impact of the phonon coupling on the pygmy dipole resonance and the radiative neutron capture cross sections increases with the (N -Z) difference. For example, in the (0-10) MeV interval the full theory gives 17% of the energy- weighted sum rule for 150Sn and 2:8% for 124Sn, whereas the continuum QRPA approach gives 5:1% and 1:7%, respectively. These results indicate the importance the self-consistent calculation can have, especially when applied to neutron-rich nuclei of astrophysical interest. The comparison with the widely-used phenomenological Generalized Lorentzian approach shows that the (Q)RPA approach gives an increase in the neutron capture cross section by a factor of 2 for 132Sn and a factor of 10 for 150Sn and that the inclusion of the phonon coupling still increases these cross sections even furhter, by a factor of 2-3.