Late-decaying Q-ball with BBN lifetime
  In the Affleck-Dine mechanism of baryogenesis, non-topological solitons called Q-balls can be formed. In this work we study the Q-balls which decay during the Big Bang Nucleosythesis (BBN) era. We show that such late-decaying baryonic Q-balls with lifetime of about 10^3 s can provide a new developing mechanism for the BBN through a rolling baryon to photon ratio \eta, which can naturally explain the discrepancy of BBN prediction with the WMAP data on ^7Li abundance. For the late-decaying leptonic Q-balls with lifetime of about 10^6 s, we find that their decay product, gravitino, can serve as a dark matter candidate without overclosing the universe and, at the same time, can give an explanation of the approximate equality of dark and baryon matter densities. 
Fei Wang, Jin Min Yang