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Title: Big-bang nucleosynthesis with an evolving radion in the brane world scenario

Abstract

We consider the big-bang nucleosynthesis (BBN) in the brane world scenario, where all matter fields are confined on our 3-brane and the radion of the Brane evolves cosmologically. In the Einstein frame fundamental fermion masses vary and the results of standard BBN (SBBN) are modified. We can thus use the observational primordial element abundances to impose constraints on the possible variations of the radion. The possibility of using the evolving radion to resolve the discrepancies between the Wilkinson Microwave Anisotropy Probe and SBBN values of the baryon-to-photon ratio ({eta}) is also discussed. The results and constraints presented here are applicable to other models in which fundamental fermion masses vary.

Authors:
;  [1]
  1. Department of Physics, Chinese University of Hong Kong, Hong Kong (China)
Publication Date:
OSTI Identifier:
20795701
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevD.73.023509; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANISOTROPY; BARYONS; COSMOLOGY; ELEMENT ABUNDANCE; MASS; MEMBRANES; NUCLEOSYNTHESIS; PHOTONS; PROBES; RELICT RADIATION; VARIATIONS

Citation Formats

Li, B., and Chu, M.-C.. Big-bang nucleosynthesis with an evolving radion in the brane world scenario. United States: N. p., 2006. Web. doi:10.1103/PHYSREVD.73.0.
Li, B., & Chu, M.-C.. Big-bang nucleosynthesis with an evolving radion in the brane world scenario. United States. doi:10.1103/PHYSREVD.73.0.
Li, B., and Chu, M.-C.. Sun . "Big-bang nucleosynthesis with an evolving radion in the brane world scenario". United States. doi:10.1103/PHYSREVD.73.0.
@article{osti_20795701,
title = {Big-bang nucleosynthesis with an evolving radion in the brane world scenario},
author = {Li, B. and Chu, M.-C.},
abstractNote = {We consider the big-bang nucleosynthesis (BBN) in the brane world scenario, where all matter fields are confined on our 3-brane and the radion of the Brane evolves cosmologically. In the Einstein frame fundamental fermion masses vary and the results of standard BBN (SBBN) are modified. We can thus use the observational primordial element abundances to impose constraints on the possible variations of the radion. The possibility of using the evolving radion to resolve the discrepancies between the Wilkinson Microwave Anisotropy Probe and SBBN values of the baryon-to-photon ratio ({eta}) is also discussed. The results and constraints presented here are applicable to other models in which fundamental fermion masses vary.},
doi = {10.1103/PHYSREVD.73.0},
journal = {Physical Review. D, Particles Fields},
number = 2,
volume = 73,
place = {United States},
year = {Sun Jan 15 00:00:00 EST 2006},
month = {Sun Jan 15 00:00:00 EST 2006}
}
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  • We extensively reanalyze the effects of a long-lived, negatively charged massive particle, X {sup –}, on big bang nucleosynthesis (BBN). The BBN model with an X {sup –} particle was originally motivated by the discrepancy between the {sup 6,} {sup 7}Li abundances predicted in the standard BBN model and those inferred from observations of metal-poor stars. In this model, {sup 7}Be is destroyed via the recombination with an X {sup –} particle followed by radiative proton capture. We calculate precise rates for the radiative recombinations of {sup 7}Be, {sup 7}Li, {sup 9}Be, and {sup 4}He with X {sup –}. Inmore » nonresonant rates, we take into account respective partial waves of scattering states and respective bound states. The finite sizes of nuclear charge distributions cause deviations in wave functions from those of point-charge nuclei. For a heavy X {sup –} mass, m{sub X} ≳ 100 GeV, the d-wave → 2P transition is most important for {sup 7}Li and {sup 7,} {sup 9}Be, unlike recombination with electrons. Our new nonresonant rate of the {sup 7}Be recombination for m{sub X} = 1000 GeV is more than six times larger than the existing rate. Moreover, we suggest a new important reaction for {sup 9}Be production: the recombination of {sup 7}Li and X {sup –} followed by deuteron capture. We derive binding energies of X nuclei along with reaction rates and Q values. We then calculate BBN and find that the amount of {sup 7}Be destruction depends significantly on the charge distribution of {sup 7}Be. Finally, updated constraints on the initial abundance and the lifetime of the X {sup –} are derived in the context of revised upper limits to the primordial {sup 6}Li abundance. Parameter regions for the solution to the {sup 7}Li problem and the primordial {sup 9}Be abundances are revised.« less