Signature of Long-lived Relic Particles onPrimordial Light Element Abundances inBig Bang Nucleosynthesis

摘要

The standard Big Bang nucleosynthesis model predicts primordial light element abun-dances which are rather consistent with those derived from astronomical observations. However, observed abundances of ~7Li in metal-poor halo stars are a factor of ～three smaller and those of ~6Li in some of the stars are a factor of ～1000 larger than respective predictions for the cosmological baryon density determined with WMAP data. We summarize latest results of three cosmological scenarios beyond the standard model of particle physics in which light element abundances are affected, i.e., 1. the radiative decay of long-lived particles, 2. the existence of long-lived negatively charged massive particles, and 3. the existence of long-lived strongly interacting massive particles.