TY  - JOUR
AU  - Mangano, G.
AU  - Miele, G.
AU  - Pastor, S.
AU  - Pisanti, O.
AU  - Sarikas, S.
PY  - 2012
DA  - 2012//
TI  - Updated BBN bounds on the cosmological lepton asymmetry for non-zero theta(13)
T2  - Phys. Lett. B
JO  - Physics Letters B
SP  - 1
EP  - 5
VL  - 708
IS  - 1-2
PB  - Elsevier Science Bv
KW  - Neutrinos
KW  - Physics of the early Universe
KW  - Primordial asymmetries
AB  - We discuss the bounds on the cosmological lepton number from Big Bang Nucleosynthesis (BBN), in light of recent evidences for a large value of the neutrino mixing angle theta(13), sin(2) theta(13) greater than or similar to 0.01 at 2 sigma. The largest asymmetries for electron and mu, tau neutrinos compatible with He-4 and H-2 primordial yields are computed versus the neutrino mass hierarchy and mixing angles. The flavour oscillation dynamics is traced till the beginning of BBN and neutrino distributions after decoupling are numerically computed. The latter contains in general, non-thermal distortion due to the onset of flavour oscillations driven by solar squared mass difference in the temperature range where neutrino scatterings become inefficient to enforce thermodynamical equilibrium. Depending on the value of theta(13), this translates into a larger value for the effective number of neutrinos, N-eff. Upper bounds on this parameter are discussed for both neutrino mass hierarchies. Values for N-eff which are large enough to be detectable by the Planck experiment are found only for the (presently disfavoured) range sin(2) theta(13) <= 0.01.
SN  - 0370-2693
UR  - http://arxiv.org/abs/1110.4335
UR  - https://doi.org/10.1016/j.physletb.2012.01.015
DO  - 10.1016/j.physletb.2012.01.015
LA  - English
N1  - WOS:000301310000001
ID  - Mangano_etal2012
ER  -