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 ^ { 4 } He , D and ^ { 7 } Li .
The likelihood analysis , based on Bayesian approach , shows that , in the case of high deuterium abundance , Y _ { D } = ( 2.0 { \pm } 0.5 ) 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 { \pm } 0.3 ) 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 .