High-energy break-up of 6Li as a tool to study the Big-Bang nucleosynthesis reaction 2H(alpha,gamma)6Li

Abstract

The recently claimed observations of non-negligible amounts of 6Li in old halo stars have renewed interest in the Big-Bang Nucleosynthesis (BBN) of 6Li. One important ingredient in the predicted BBN abundance of 6Li is the low-energy 2H(alpha,gamma)6Li cross section. Up to now, the only available experimental result for this cross section showed an almost constant astrophysical S-factor below 400 keV, contrary to theoretical expectations. We report on a new measurement of the 2H(alpha,gamma)6Li reaction using the break-up of 6Li at 150 A MeV. Even though we cannot separate experimentally the Coulomb contribution from the nuclear one, we find clear evidence for Coulomb-nuclear interference by analyzing the scattering-angular distributions. This is in-line with our theoretical description which indicates a drop of the S_24-factor at low energies as predicted also by most other models. Consequently, we find even lower upper limits for the calculated primordial 6Li abundance than before.

12 pages, 11 figures, LaTeX, submitted to Phy. Rev. C

References in corpus (6)

• Big Bang Nucleosynthesis Constraints on Hadronically and Electromagnetically Decaying Relic Neutral Particles
• A Bitter Pill: The Primordial Lithium Problem Worsens
• Line shift, line asymmetry, and the 6Li/7Li isotopic ratio determination
• Population III Generated Cosmic Rays and the Production of Li6
• 6Li/7Li estimates for metal-poor stars
• Is 6-Li in metal-poor halo stars produced in situ by solar-like flares?

Cited by in corpus (11)

• Standard big bang nucleosynthesis and primordial CNO Abundances after Planck
• Primordial nucleosynthesis
• LUNA: Status and Prospects
• Unified description of ${}^6$Li structure and deuterium-${}^4$He dynamics with chiral two- and three-nucleon forces
• {Once more about astrophysical $S$ factor for the $\alpha +d\to {}^6\mathrm{Li}+\gamma$ reaction
• Ab initio prediction of the ${}^4\mathrm{He}(d,\gamma ){}^6\mathrm{Li}$ big bang radiative capture
• Neutron-induced background by an alpha-beam incident on a deuterium gas target and its implications for the study of the 2H(alpha,gamma)6Li reaction at LUNA
• Destruction of 7Be in big bang nucleosynthesis via long-lived sub-strongly interacting massive particles as a solution to the Li problem
• The $\alpha +d\to {}^6\mathrm{Li}+\gamma$ astrophysical $S$-factor and its implications for Big Bang Nucleosynthesis
• Primordial Nucleosynthesis
• Transfer reactions as a Tool in Nuclear Astrophysics