New results on catalyzed big bang nucleosynthesis with a long-lived negatively charged massive particle

It has been proposed that the apparent discrepancies between the inferred primordial abundances of Li6 and Li7 and the predictions of big bang nucleosynthesis (BBN) can be resolved by the existence of a negatively charged massive unstable supersymmetric particle (X^-) during the BBN epoch. Here, we present new BBN calculations with an X^- particle utilizing an improved nuclear reaction network including captures of nuclei by the particle, nuclear reactions and β decays of normal nuclei and nuclei bound to the X^- particles (X nuclei), and new reaction rates derived from recent rigorous quantum many-body dynamical calculations. We find that this is still a viable model to explain the observed Li6 and Li7 abundances. We also show that with the new rates the production of heavier nuclei is suppressed and there is no signature on abundances of nuclei heavier than Be in the X ^--particle catalyzed BBN model as has been previously proposed. We also consider the version of this model whereby the X^- particle decays into the present cold dark matter. We analyze this paradigm in light of the recent constraints on the dark-matter mass deduced from the possible detected events in the CDMS-II experiment. We conclude that based upon the inferred range for the dark-matter mass, only X^- decay via the weak interaction can achieve the desired Li7 destruction while also reproducing the observed Li6 abundance.