How neutrino oscillations can induce an effective neutrino number of less than three during big bang nucleosynthesis
- School of Physics, Research Centre for High Energy Physics, The University of Melbourne, Parkville 3052 (Australia)
Ordinary-sterile neutrino oscillations can generate significant neutrino asymmetry in the early Universe. In this paper we extend this work by computing the evolution of neutrino asymmetries and light element abundances during the big bang nucleosynthesis (BBN) epoch. We show that a significant electron-neutrino asymmetry can be generated in a way that is approximately independent of the oscillation parameters {delta}m{sup 2} and sin{sup 2}2{theta} for a range of parameters in an interesting class of models. The numerical value of the asymmetry leads to the {ital prediction} that the effective number of neutrino flavors during BBN is either about 2.5 or 3.4, depending on the sign of the asymmetry. Interestingly, one class of primordial deuterium abundance data favors an effective number of neutrino flavors during the epoch of BBN of less than 3. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 545076
- Journal Information:
- Physical Review, D, Vol. 56, Issue 10; Other Information: PBD: Nov 1997
- Country of Publication:
- United States
- Language:
- English
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