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Relaxed constraints on neutrino oscillation parameters

Daniela P. Kirilova·Mariana P. Panayotova
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Abstract

We study the cosmological constraints on active-sterile neutrino oscillations nu_e <-> nu_s for the case when nu_s is partially filled initially, i.e. 0 < delta N_s < 1. We provide numerical analysis of the cosmological production of He-4, in the presence of nu_e <-> nu_s oscillations, effective after neutrino decoupling, accounting for all known oscillations effects on cosmological nucleosynthesis. Cosmological constraints on oscillation parameters corresponding to higher than 5% He-4 overproduction and different non-zero initial populations of the sterile state delta N_s < 1 are calculated. These generalized cosmological constraints corresponding to delta N_s > 0 are relaxed in comparison with the delta N_s = 0 case and the relaxation is proportional to delta N_s.

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Daniela P. Kirilova, Mariana P. Panayotova. 2006-08-04. Relaxed constraints on neutrino oscillation parameters. https://doi.org/10.1088/1475-7516%2F2006%2F12%2F014

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