A solution of the large discrepancy existing between inclusive and exclusive measurements of the Li-8 + He-4 -> B-11 + n reaction cross section at E-cm < 3 MeV is evaluated. This problem has profound astrophysical relevance for this reaction is of great interest in big bang and r-process nucleosynthesis. By means of a novel technique, a comprehensive study of all existing Li-8 + He-4 -> B-11 + n cross section data is carried out, setting up a consistent picture in which all the inclusive measurements provide the reliable value of the cross section. New unambiguous signatures of the strong branch pattern non-uniformities, near the threshold of higher B-11 excited levels, are presented and their possible origin, in terms of the cluster structure of the involved excited states of B-11 and (12)Bnuclei, is discussed.
Solving the large discrepancy between inclusive and exclusive measurements of the 8Li+4He --> 11B + n reaction cross section at astrophysical energies
CHERUBINI, SILVIO;LAMIA, LIVIO;MUSUMARRA, Agatino;ROMANO, Stefano;
2009-01-01
Abstract
A solution of the large discrepancy existing between inclusive and exclusive measurements of the Li-8 + He-4 -> B-11 + n reaction cross section at E-cm < 3 MeV is evaluated. This problem has profound astrophysical relevance for this reaction is of great interest in big bang and r-process nucleosynthesis. By means of a novel technique, a comprehensive study of all existing Li-8 + He-4 -> B-11 + n cross section data is carried out, setting up a consistent picture in which all the inclusive measurements provide the reliable value of the cross section. New unambiguous signatures of the strong branch pattern non-uniformities, near the threshold of higher B-11 excited levels, are presented and their possible origin, in terms of the cluster structure of the involved excited states of B-11 and (12)Bnuclei, is discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
