Q-ball evolution, B-ball baryogenesis and the fB problem

We consider some of the issues surrounding the formation and evolution ofQ-balls in the MSSM and its extensions. The ratio of the baryon number packedinto Q-balls to that outside, f_{B}, plays a fundamental role in determiningthe relationship of dark matter to the baryon number in the Universe atpresent. The final value of f_{B} will depend upon the details of the formationof Q-balls from the collapse of the Affleck-Dine condensate and upon thesubsequent evolution of the ensemble of Q-balls. We discuss the implicationsfor neutralino dark matter in the gravity-mediated scenario and show that alight neutralino is necessary in most cases to account for the baryon to darkmatter ratio, with an NMSSM singlino LSP of mass m_{\chi} \lae 20 \GeV being afavoured candidate.Comment: 26 pages, LaTe