## Abstract

We extensively reanalyze the effects of a long-lived, negatively charged massive particle, X ^{-}, on big bang nucleosynthesis (BBN). The BBN model with an X ^{-}particle was originally motivated by the discrepancy between the ^{6, 7}Li abundances predicted in the standard BBN model and those inferred from observations of metal-poor stars. In this model, ^{7}Be is destroyed via the recombination with an X ^{-}particle followed by radiative proton capture. We calculate precise rates for the radiative recombinations of ^{7}Be, ^{7}Li, ^{9}Be, and ^{4}He with X ^{-}. In 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 ^{-}mass, m_{X}≳ 100 GeV, the d-wave → 2P transition is most important for ^{7}Li and ^{7, 9}Be, unlike recombination with electrons. Our new nonresonant rate of the ^{7}Be recombination for m_{X}= 1000 GeV is more than six times larger than the existing rate. Moreover, we suggest a new important reaction for ^{9}Be production: the recombination of ^{7}Li and X ^{-}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 ^{7}Be destruction depends significantly on the charge distribution of ^{7}Be. Finally, updated constraints on the initial abundance and the lifetime of the X ^{-}are derived in the context of revised upper limits to the primordial ^{6}Li abundance. Parameter regions for the solution to the ^{7}Li problem and the primordial ^{9}Be abundances are revised.

Original language | English |
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Article number | 5 |

Journal | Astrophysical Journal, Supplement Series |

Volume | 214 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2014 Sept 1 |

## Keywords

- atomic processes
- early universe
- elementary particles
- nuclear reactions, nucleosynthesis, abundances
- primordial nucleosynthesis
- stars: abundances

## ASJC Scopus subject areas

- Astronomy and Astrophysics
- Space and Planetary Science

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