We consider the evolution of the light elements (Li, Be, and B) incorporating the effects of their production by both neutrino process and cosmic-ray nucleosynthesis. We test the viability of the neutrino process to resolve the long standing problem of the 11B/10B isotopic ratio which amounts to 4 at the time of the formation of the solar system. This hypothesis may be ultimately constrained by the B/Be ratio observed in halo stars. Though we are able to obtain a solar isotopic ratio 11B/10B ≃ 4, the current paucity of data at low metallicity prevents us from making a definitive conclusion regarding the resolution of this problem. We show, however, that neutrino process nucleosynthesis leads to a relatively model independent prediction that the B/Be elemental ratio is large (> 50) at low metallicities ([Fe/H] < -3.0), if Be is produced as a secondary element (as is the case in the conventional scenario of galactic cosmic-ray nucleosynthesis).
- Cosmic rays
- Nuclear reactions, nucleosynthesis, abundances