Be-7 (n,p)Li-7 Reaction and the Cosmological Lithium Problem

Author(s)

, L. Damone, M. Barbagallo, M. Mastromarco, A. Mengoni, L. Cosentino, E. Maugeri, S. Heinitz, D. Schumann, R. Dressler, F. Käppeler, N. Colonna, P. Finocchiaro, J. Andrzejewski, J. Perkowski, A. Gawlik, O. Aberle, S. Altstadt, M. Ayranov, L. Audouin, M. Bacak, J. Balibrea-Correa, J. Ballof, V. Becares, F. Becvar, C. Beinrucker, G. Bellia, A. P. Bernardes, E. Berthoumieux, J. Billowes, M. J. G. Borge, D. Bosnar, A. Brown, M. Brugger, M. Busso, M. Caamano, F. Calvino, M. Calviani, D. Cano-Ott, R. Cardella, A. Casanovas, D. M. Castelluccio, Y. H. Chen, H. Leeb, M. Mirea, A. Pavlik, S. Schmidt, A. Wallner, C. Weiss, C. Wolf, T. Wright

Abstract

We report on the measurement of the Be-7(n,p)Li-7 cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at CERN. This reaction plays a key role in the lithium yield of the big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and they showed a large discrepancy between each other. The measurement was performed with a Si telescope and a high-purity sample produced by implantation of a Be-7 ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low energy, relative to current evaluations, in the region of BBN interest, the present results are consistent with the values inferred from the time-reversal Li-7(p,n)Be-7 reaction, thus yielding only a relatively minor improvement on the so-called cosmological lithium problem. The relevance of these results on the near-threshold neutron production in the p + Li-7 reaction is also discussed.

Organisation(s)

Isotope Physics

External organisation(s)

Università degli Studi di Bari Aldo Moro, European Organization for Nuclear Research (CERN), Paul Scherrer Institute, Karlsruher Institut für Technologie, Medical University of Lodz, Johann Wolfgang Goethe-Universität Frankfurt am Main, European Commission, Centre National De La Recherche Scientifique (CNRS), Technische Universität Wien, Centro de Investigaciones Energeticas Medioambientales y Tecnológica, Charles University Prague, Università degli Studi di Catania, French Alternative Energies and Atomic Energy Commission (CEA), University Hospital Centre Zagreb, Università degli Studi di Perugia, Universidade de Santiago de Compostela (USC), Universitat Politècnica de Catalunya, Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Bari, Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Bologna, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, INFN Laboratori Nazionali del Sud, University of York, Australian National University, University of Manchester, Centre National de la Recherche Scientifique (CNRS), Strasbourg , Central Manchester University Hospitals, National Institute for Nuclear Physics

Journal

Physical Review Letters

Volume

121

No. of pages

7

ISSN

0031-9007

DOI

https://doi.org/10.1103/PhysRevLett.121.042701

Publication date

07-2018

Peer reviewed

Yes

Austrian Fields of Science 2012

103014 Nuclear physics

Keywords

ASJC Scopus subject areas

General Physics and Astronomy

Portal url

https://ucrisportal.univie.ac.at/en/publications/eec743db-25bd-4e6a-adf2-ce9f265afd6d