Nuclear physics and cosmology
- Chicago Univ., IL (USA); Fermi National Accelerator Lab., Batavia, IL (USA)
Nuclear physics has provided one of the 2 critical observational tests of all Big Bang cosmology, namely Big Bang Nucleosynthesis. Furthermore, this same nuclear physics input enables a prediction to be made about one of the most fundamental physics questions of all, the number of elementary particle families. This paper reviews the standard Big Bang Nucleosynthesis arguments. The primordial He abundance is inferred from He--C and He--N and He--O correlations. The strengthened Li constraint as well as {sup 2}D plus {sup 3}He are used to limit the baryon density. This limit is the key argument behind the need for non-baryonic dark matter. The allowed number of neutrino families, N{sub {nu}}, is delineated using the new neutron lifetime value of {tau}{sub n} = 890 {plus minus} 4s ({tau}{sub {1/2}} = 10.3 min). The formal statistical result is N{sub {nu}} = 2.6 {plus minus} 0.3 (1{sigma}) providing a reasonable fit (1.3{sigma}) to 3 families but making a fourth light (m{sub {nu}} {approx lt}10 MeV) neutrino family exceedingly unlikely ({approx gt}4.7{sigma}) (barring significant systematic errors either in D + {sup 3}He, and Li and/or {sup 4}He and/or {tau}{sub n}). It is also shown that uncertainties induced by postulating a first-order quark-hadron phase transition do not seriously affect the conclusions. 21 refs., 3 figs.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- DOE/ER; National Aeronautics and Space Administration (NASA); National Science Foundation (NSF)
- DOE Contract Number:
- AC02-76CH03000
- OSTI ID:
- 5246750
- Report Number(s):
- FNAL/C-89/254-A; CONF-890826-8; ON: DE90004972; TRN: 90-003424
- Resource Relation:
- Conference: International nuclear physics conference, Sao Paulo (Brazil), 20-26 Aug 1989
- Country of Publication:
- United States
- Language:
- English
Similar Records
Experimental, computational, and observational analysis of primordial nucleosynthesis
Experimental, computational, and observational analysis of primordial nucleosynthesis
Related Subjects
GENERAL PHYSICS
NUCLEOSYNTHESIS
COSMOLOGICAL MODELS
NEUTRINOS
NONLUMINOUS MATTER
PHASE TRANSFORMATIONS
QUARKS
ELEMENTARY PARTICLES
FERMIONS
LEPTONS
MASSLESS PARTICLES
MATHEMATICAL MODELS
POSTULATED PARTICLES
SYNTHESIS
640106* - Astrophysics & Cosmology- Cosmology