We reconsider the effects of the radiation from the decays of unstable particles on the production and destruction of the primordial light elements, with a view to reconciling the high primordial 7Li abundance deduced from big bang nucleosynthesis (BBN), as implied by the baryon-to-photon ratio now inferred from the anisotropies of the cosmic microwave background (CMB), with the lower abundance of 7Li observed in halo stars. The potential destruction of 7Li is strongly constrained by observations of deuterium (D), 3He and 6Li. We identify ranges for the unstable particle abundance and lifetime which would deplete 7Li while remaining consistent with the abundance of 6Li. However, in these regions either the D abundance is unacceptably low or the ratio 3He/D is unacceptably large. We conclude that late particle decay is unable to explain both the discrepancy of the calculated 7Li abundance and the observed 7Li plateau. In the context of supersymmetric theories with neutralino or gravitino dark matter, we display the corresponding light-element constraints on the model parameters.
|Original language||English (US)|
|Number of pages||13|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - Jul 14 2005|
Bibliographical noteFunding Information:
We thank R. Cyburt, B. Fields, Y. Santoso and V. Spanos for collaborations on related topics. The work of K.A.O. and E.V. was supported by the Project “CNRS/USA”, and the work of K.A.O. was also supported partly by DOE grant DE-FG02-94ER-40823.