Big Bang6Li nucleosynthesis studied deep underground (LUNA collaboration)
| Autor: | C. G. Bruno, H. Costantini, Tamás Szücs, V. Mossa, A. Bellini, M. Erhard, G. Gervino, A. Boeltzig, C. Gustavino, Oscar Straniero, Daniel Bemmerer, M. P. Takács, Carlo Broggini, David Scott, Marialuisa Aliotta, A. Guglielmetti, Z. Elekes, A. Formicola, Gy. Gyürky, E. Somorjai, Antonio Caciolli, P. Corvisiero, Zs. Fülöp, Davide Trezzi, Rosanna Depalo, C. Mazzocchi, Michele Marta, M. Junker, A. Lemut, Thomas Davinson, Paolo Prati, F. Ferraro, R. Menegazzo, F. R. Pantaleo, F. Cavanna, M. Anders, C. Rossi Alvarez |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Big Bang
Nuclear reaction Physics e Underground 010308 nuclear & particles physics Astronomy and Astrophysics Astrophysics Big Bang Nucleosynthesis 01 natural sciences Cosmology Nuclear physics Stars Big Bang nucleosynthesis Nuclear Astrophysics Big Bang Nucleosynthesis 6Li abundanc e Underground Nucleosynthesis 6Li abundanc 0103 physical sciences Nuclear Astrophysics Nuclear astrophysics Nuclide 6Li abundance Underground 010306 general physics |
| Popis: | The correct prediction of the abundances of the light nuclides produced during the epoch of Big Bang Nucleosynthesis (BBN) is one of the main topics of modern cosmology. For many of the nuclear reactions that are relevant for this epoch, direct experimental cross section data are available, ushering the so-called “age of precision”. The present work addresses an exception to this current status: the 2H(α,γ)6Li reaction that controls 6Li production in the Big Bang. Recent controversial observations of 6Li in metal-poor stars have heightened the interest in understanding primordial 6Li production. If confirmed, these observations would lead to a second cosmological lithium problem, in addition to the well-known 7Li problem. In the present work, the direct experimental cross section data on 2H(α,γ)6Li in the BBN energy range are reported. The measurement has been performed deep underground at the LUNA (Laboratory for Underground Nuclear Astrophysics) 400 kV accelerator in the Laboratori Nazionali del Gran Sasso, Italy. The cross section has been directly measured at the energies of interest for Big Bang Nucleosynthesis for the first time, at E c m = 80, 93, 120, and 133 keV. Based on the new data, the 2H(α,γ)6Li thermonuclear reaction rate has been derived. Our rate is even lower than previously reported, thus increasing the discrepancy between predicted Big Bang 6Li abundance and the amount of primordial 6Li inferred from observations. |
| Databáze: | OpenAIRE |
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