TY - JOUR
T1 - Big-bang nucleosynthesis in comparison with observed helium and deuterium abundances
T2 - Possibility of a nonstandard model
AU - Ichimasa, R.
AU - Nakamura, R.
AU - Hashimoto, M.
AU - Arai, K.
PY - 2014/7/21
Y1 - 2014/7/21
N2 - Comparing the latest observed abundances of He4 and D, we make a χ2 analysis to see whether it is possible to reconcile primordial nucleosynthesis using the up-to-date nuclear data of NACRE II and the mean life of neutrons. If we adopt the observational data of He4 by Izotov et al. [Astron. Astrophys. 558, A57 (2013)], we find that it is impossible to get a reasonable agreement with the standard big-bang nucleosynthesis. However, by including degenerate neutrinos, we succeed in obtaining consistent constraints between the neutrino degeneracy and the baryon-to-photon ratio from a detailed comparison of calculated abundances with the observational data of He4 and D: the baryon-to-photon ratio in units of 10-10 is found to be in the range 6.02η10 6.54 for the specified parameters of neutrino degeneracy.
AB - Comparing the latest observed abundances of He4 and D, we make a χ2 analysis to see whether it is possible to reconcile primordial nucleosynthesis using the up-to-date nuclear data of NACRE II and the mean life of neutrons. If we adopt the observational data of He4 by Izotov et al. [Astron. Astrophys. 558, A57 (2013)], we find that it is impossible to get a reasonable agreement with the standard big-bang nucleosynthesis. However, by including degenerate neutrinos, we succeed in obtaining consistent constraints between the neutrino degeneracy and the baryon-to-photon ratio from a detailed comparison of calculated abundances with the observational data of He4 and D: the baryon-to-photon ratio in units of 10-10 is found to be in the range 6.02η10 6.54 for the specified parameters of neutrino degeneracy.
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U2 - 10.1103/PhysRevD.90.023527
DO - 10.1103/PhysRevD.90.023527
M3 - Article
AN - SCOPUS:84904861586
SN - 1550-7998
VL - 90
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 2
M1 - 023527
ER -