Nuclear astrophysics at LUNA and the big bang nucleosynthesis
by
Carlo Gustavino(INFN - Sezione di Roma1)
→
Europe/Rome
Aula Conversi (Dipartimento di Fisica - Ed G.Marconi)
Aula Conversi
Dipartimento di Fisica - Ed G.Marconi
Description
Big Bang Nucleosynthesis (BBN) theory describes the formation of light isotopes such as D, 3He, 4He, 6Li and 7Li in the first minutes of cosmic time. Their abundance depends on the competition between the universal expansion rate and the yields of relevant nuclear reactions. As the universal expansion rate depends on the density of relativistic particles, the abundances of light isotopes allows to constrain the number of neutrinos species, provided that the knowledge of the relevant nuclear processes is accurate enough. The uncertainty of the computed deuterium abundance is mainly due to the poor knowledge of the 2H(p,g)3He cross section at BBN energies. This reaction is presently studied at the underground Gran Sasso Laboratory (LNGS) with the LUNA accelerator. The impact of this forthcoming LUNA measurement in cosmology, in neutrino physics and in nuclear physics will be discussed. In this seminar will be also shown the first direct measurement of the 2H(a,g)6Li cross section at big bang energies, recently performed at LUNA. This reaction dominates the production of primordial 6Li. The measurement result with respect to the primordial lithium problem will be discussed.
