Eur. Phys. J. A (2006) 27: 283-288
https://doi.org/10.1140/epja/i2006-08-043-4

Nuclear Physics in Astrophysics II

Exploring the Nα + 3n light nuclei via the ( ⁷Li,⁷Be) reaction

¹ INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, 95123, Catania, Italy
² Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123, Catania, Italy
³ INFN-Sezione di Catania, Via S. Sofia 64, 95123, Catania, Italy
⁴ Institut de Physique Nuclèaire, 91406, Orsay Cedex, France
⁵ Institut für Theoretische Physik, Universität Giessen, Heinrich-Buff-Ring 16, 35392, Giessen, Germany

^* e-mail: c.nociforo@gsi.de

Received: 18 June 2005
Accepted: 20 December 2005
Published online: 29 March 2006

Abstract

Experimental signatures of the dynamical correlations of a core with a single-particle neutron have been found in light neutron-rich nuclei investigated via the ( ⁷Li, ⁷Be) charge-exchange reactions at around 8MeV/u. Of particular astrophysical relevance are low-lying narrow resonances ( Γ ∼ 200keV FWHM) BSEC (Bound States Embedded in the Continuum). Because of their long lifetime BSEC states are likely to effect the capture rates in any scenario for nucleosynthesis in neutron-rich environment. They have been observed in the continuum of ¹¹Be and ¹⁵C nuclei. A microscopic nuclear structure model based on QRPA theory, which takes into account Dynamical Core Polarisation (DCP) correlations, gives a suitable description of these resonances as well as single-particle states of the studied systems. In this context, high-energy narrow structures populated in nuclei having an integer number of α-particles plus three neutrons are good BSEC candidates and can be systematically investigated.