Nuclear reaction uncertainties, massive gravitino decays and the cosmological lithium problem

Journal Article · Fri Oct 01 00:00:00 EDT 2010 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2010/10/032· OSTI ID:22275361

Cyburt, Richard H. ^[1]; Ellis, John ^[2]; Fields, Brian D. ^[3]; Luo, Feng; Olive, Keith A. ^[4]

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1. Joint Institute for Nuclear Astrophysics (JINA), National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, MI 48824 (United States)
2. TH Division, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland)
3. Center for Theoretical Astrophysics, Departments of Astronomy and of Physics, University of Illinois, Urbana, IL 61801 (United States)
4. School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

We consider the effects of uncertainties in nuclear reaction rates on the cosmological constraints on the decays of unstable particles during or after Big-Bang nucleosynthesis (BBN). We identify the nuclear reactions due to non-thermal hadrons that are the most important in perturbing standard BBN, then quantify the uncertainties in these reactions and in the resulting light-element abundances. These results also indicate the key nuclear processes for which improved cross section data would allow different light-element abundances to be determined more accurately, thereby making possible more precise probes of BBN and evaluations of the cosmological constraints on unstable particles. Applying this analysis to models with unstable gravitinos decaying into neutralinos, we calculate the likelihood function for the light-element abundances measured currently, taking into account the current experimental errors in the determinations of the relevant nuclear reaction rates. We find a region of the gravitino mass and abundance in which the abundances of deuterium, {sup 4}He and {sup 7}Li may be fit with χ{sup 2} = 5.5, compared with χ{sup 2} = 31.7 if the effects of gravitino decays are unimportant. The best-fit solution is improved to χ{sup 2} ∼ 2.0 when the lithium abundance is taken from globular cluster data. Some such re-evaluation of the observed light-element abundances and/or nuclear reaction rates would be needed if this region of gravitino parameters is to provide a complete solution to the cosmological {sup 7}Li problem.

• OSTI ID: 22275361
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2010, Issue 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
COMPARATIVE EVALUATIONS
COSMOLOGY
CROSS SECTIONS
DEUTERIUM
ELEMENT ABUNDANCE
GRAVITONS
HADRONS
HELIUM 4
LIMITING VALUES
LITHIUM
LITHIUM 7
MATHEMATICAL SOLUTIONS
NEUTRALINOS
NUCLEAR REACTIONS
NUCLEOSYNTHESIS