Big Bang nucleosynthesis in crisis?
نویسندگان
چکیده
A new evaluation of the constraint on the number of light neutrino species (N) from big bang nucleosynthesis suggests a discrepancy between the predicted light element abundances and those inferred from observations, unless the inferred primordial 4 He abundance has been underestimated by 0.014 0.004 (1) or less than 10% (95%C.L.) of 3 He survives stellar processing. With the quoted systematic errors in the observed abundances and a conservative chemical evolution parameterization, the best t to the combined data is N = 2:1 0:3 (1) and the upper limit is N < 2:6 (95% C.L.). The data are inconsistent with the Standard Model (N = 3) at the 98.6% C.L.
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ورودعنوان ژورنال:
- Physical review letters
دوره 75 22 شماره
صفحات -
تاریخ انتشار 1995