Big Bang nucleosynthesis in crisis?

Journal Article · Mon Nov 27 04:00:00 EST 1995 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.75.3977· OSTI ID:147872

Hata, N; Scherrer, R J; Steigman, G; Thomas, D; Walker, T P ^[1]; Bludman, S; Langacker, P ^[2]

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1. Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States)
2. Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

A new evaluation of the constraint on the number of light neutrino species ({ital N}{sub {nu}}) from big bang nucleosynthesis suggests a discrepancy between the predicted light element abundances and those inferred from observations, unless the inferred primordial {sup 4}He abundance has been underestimated by 0.014{plus_minus}0.004 (1{sigma}) or less than 10% (95% C.L.) of {sup 3}He survives stellar processing. With the quoted systematic errors in the observed abundances and a conservative chemical evolution parametrization, the best fit to the combined data is {ital N}{sub {nu}}=2.1{plus_minus}0.3 (1{sigma}) and the upper limit is {ital N}{sub {nu}}{lt}2.6 (95% C.L.). The data are inconsistent with the standard model ({ital N}{sub {nu}}=3) at the 98.6% C.L. {copyright} {ital 1995} {ital The} {ital American} {ital Physical} {ital Society}.

• Research Organization: Ohio State University Research Foundation
• DOE Contract Number: AC02-76ER01545; AC02-76ER03071
• OSTI ID: 147872
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 22 Vol. 75; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ELEMENT ABUNDANCE
ENERGY DENSITY
HELIUM 3
HELIUM 4
INFLATIONARY UNIVERSE
NEUTRINOS
NUCLEOSYNTHESIS
STANDARD MODEL