$B \to \eta' X_s$ in the Standard Model
  We study $B \to \eta' X_s$ within the framework of the Standard Model. Several mechanisms such as $b \to \eta' s g$ from the QCD anomaly, and $b \to \eta's $ and $B\to \eta' s \bar q$ from four-quark operators are treated simultaneously. We find that the first mechanism give a significant contribution to the branching ratio for $B\to \eta' X_s$, while the other two mechanisms account for about 15% of the experimental value. The Standard Model prediction for $B\to \eta' X_s$ is consistent with the CLEO data. 
Xiao-Gang He (NTU) and Guey-Lin Lin (NCTU)