Decaying neutrino and a high cosmological baryon density

Abstract The low second acoustic peak in the recent Boomerang data may indicate a cosmological baryon density which is larger than allowed by standard big bang nucleosynthesis. We show that the decay of the tau-neutrino: ν τ → ν e + φ , where ν e is the electron neutrino and φ is a scalar, essentially can assure agreement between BBN calculations and light element observations for a large baryon density.