Show simple item record

dc.contributor.authorBarbagallo, Massimo
dc.contributor.authorMusumarra, A.
dc.contributor.authorCosentino, L.
dc.contributor.authorCalviño Tavares, Francisco
dc.contributor.authorCasanovas Hoste, Adrià
dc.contributor.authorCortés Rossell, Guillem Pere
dc.contributor.authorTarifeño Saldivia, Ariel Esteban
dc.contributor.otherUniversitat Politècnica de Catalunya. Departament de Física
dc.contributor.otherUniversitat Politècnica de Catalunya. Institut de Tècniques Energètiques
dc.date.accessioned2016-11-23T09:49:13Z
dc.date.available2016-11-23T09:49:13Z
dc.date.issued2016-10-03
dc.identifier.citationBarbagallo, M., Musumarra, A., Cosentino, L., Calviño, F., Casanovas, A., Cortes, G., Tarifeño, A. Be-7(n,alpha)He-4 reaction and the cosmological lithium problem: measurement of the cross section in a wide energy range at n_TOF at CERN. "Physical review letters", 3 Octubre 2016, vol. 117, núm. 15, p. 152701-1-152701-7.
dc.identifier.issn0031-9007
dc.identifier.urihttp://hdl.handle.net/2117/97084
dc.description.abstractThe energy-dependent cross section of the Be7(n,alpha)He4 reaction, of interest for the so-called cosmological lithium problem in big bang nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of Be7 and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure Be7, and a specifically designed experimental setup. Coincidences between the two alpha particles have been recorded in two Si-Be7-Si arrays placed directly in the neutron beam. The present results are consistent, at thermal neutron energy, with the only previous measurement performed in the 1960s at a nuclear reactor. The energy dependence reported here clearly indicates the inadequacy of the cross section estimates currently used in BBN calculations. Although new measurements at higher neutron energy may still be needed, the n_TOF results hint at a minor role of this reaction in BBN, leaving the long-standing cosmological lithium problem unsolved.
dc.language.isoeng
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/3.0/es/
dc.subjectÀrees temàtiques de la UPC::Física
dc.subjectÀrees temàtiques de la UPC::Energies::Energia nuclear
dc.subject.lcshNeutrons
dc.subject.lcshNuclear reactors
dc.subject.lcshChemical elements
dc.subject.otherCosmological
dc.subject.otherNuclear
dc.subject.otherCross section
dc.subject.otherNeutron
dc.subject.othernTOF
dc.subject.otherCERN
dc.titleBe-7(n,alpha)He-4 reaction and the cosmological lithium problem: measurement of the cross section in a wide energy range at n_TOF at CERN
dc.typeArticle
dc.subject.lemacNeutrons
dc.subject.lemacReactors nuclears
dc.subject.lemacElements químics
dc.contributor.groupUniversitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
dc.identifier.doi10.1103/PhysRevLett.117.152701
dc.relation.publisherversionhttp://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.152701
dc.rights.accessOpen Access
local.identifier.drac19100146
dc.description.versionPostprint (published version)
dc.relation.projectidinfo:eu-repo/grantAgreement/MICINN/1PE/FPA2014-52823-C2-2-P
dc.relation.projectidinfo:eu-repo/grantAgreement/EC/FP7/605203/EU/solving CHAllenges in Nuclear DAta/CHANDA
local.citation.authorBarbagallo, M.; Musumarra, A.; Cosentino, L.; Calviño, F.; Casanovas, A.; Cortes, G.; Tarifeño, A.
local.citation.publicationNamePhysical review letters
local.citation.volume117
local.citation.number15
local.citation.startingPage152701-1
local.citation.endingPage152701-7


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record

Attribution-NonCommercial-NoDerivs 3.0 Spain
Except where otherwise noted, content on this work is licensed under a Creative Commons license : Attribution-NonCommercial-NoDerivs 3.0 Spain