B -> eta ' X-s in the standard model

We study B --> eta'X-s within the framework of the Standard Model. Several mechanisms such as b --> eta'sg through the QCD anomaly, and b --> eta's an d B --> eta's (q) over bar arising from four-quark operators are treated si multaneously. Using QCD equations of motion, we relate the effective Hamilt onian for the first mechanism to that for the latter two. By incorporating next-to-leading-logarithmic(NLL) contributions, the first mechanism is show n to give a significant branching ratio for B --> eta'X-s, while the other two mechanisms account for about 15% of the experimental value. The Standar d Model prediction for B --> eta'X-s is consistent with the CLEO data. (C) 1999 Elsevier Science B.V. All rights reserved.