Primordial lithium: New reaction rates, new abundances, new constraints
Newly measured nuclear reaction rates for /sup 3/H(..cap alpha..,..gamma..)/sup 7/Li (higher than previous values) and /sup 7/Li(p,..cap alpha..)/sup 4/He (lower than previous values) are shown to increase the /sup 7/Li yield from big bang nucleosynthesis for lower baryon to photon ratio (eta less than or equal to 4 x 10/sup -10/); the yield for higher eta is not affected. New, independent determinations of Li abundances in extreme Pop II stars are in excellent agreement with the earlier work of the Spites and give continued confidence in the use of /sup 7/Li in big bang baryon density determinations. The new /sup 7/Li constraints imply a lower limit on eta of 2 x 10/sup -10/ and an upper limit of 5 x 10/sup -10/. This lower limit to eta is concordant with that obtained from considerations of D + /sup 3/He. The upper limit is consistent with, but even more restrictive than, the D bound. With the new rates, any observed primordial Li/H ratio below 10/sup -10/ would be inexplicable by the standard big bang nucleosynthesis. A review is made of the strengths and possible weaknesses of utilizing conclusions drawn from big bang lithium considerations. An appendix discusses the null effect of a factor of 32 increase in the experimental rate for the D(d,..gamma..)/sup 4/He reaction. 28 refs., 1 fig.
- Research Organization:
- Chicago Univ., IL (USA); Fermi National Accelerator Lab., Batavia, IL (USA); Ohio State Univ., Columbus (USA)
- DOE Contract Number:
- AC02-76CH03000
- OSTI ID:
- 6773232
- Report Number(s):
- FNAL/Pub-87/16-A; ON: DE87005401
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
ALKALI METAL ISOTOPES
ALPHA REACTIONS
CHARGED-PARTICLE REACTIONS
COSMOLOGICAL MODELS
DEUTERIUM TARGET
DEUTERON REACTIONS
ELECTROMAGNETIC RADIATION
GAMMA RADIATION
HELIUM 3 TARGET
IONIZING RADIATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
LITHIUM 7
LITHIUM ISOTOPES
MATHEMATICAL MODELS
NUCLEAR REACTIONS
NUCLEI
NUCLEOSYNTHESIS
ODD-EVEN NUCLEI
RADIATIONS
REACTION KINETICS
STABLE ISOTOPES
SYNTHESIS
TARGETS
TRITIUM TARGET