  We test different Big Bang Nucleosynthesis scenarios using the recent results
on the Cosmic Microwave Background Anisotropies provided by the BOOMERanG and
MAXIMA-1 experiments versus the observed abundances of 4He, D and 7Li. The
likelihood analysis, based on Bayesian approach, shows that, in the case of
high deuterium abundance, Y_D=(2.0\pm0.5) 10^{-4}, both standard and degenerate
BBN are inconsistent with the CMBR measurement at more than 3 \sigma. Assuming
low deuterium abundance, Y_D=(3.4\pm0.3) 10^{-5}, the standard BBN model is
still inconsistent with present observations at 2 \sigma level, while the
degenerate BBN results to be compatible. Unless systematics effects will be
found in nuclide abundances and/or in CMBR data analysis this result may be a
signal in favour of new physics like a large chemical potential of the relic
neutrino-antineutrino background.
