Non-perturbative Effects in $B\to X_s{l}^{+}{l}^{-}$

Abstract

The rare decay $B\to X_s{l}^{+}{l}^{-}$ provides excellent prospects for precision tests of Standard Model flavour dynamics. The process can be computed in perturbation theory with small uncertainty. However, in order to ensure a reliable theoretical prediction, also potentially important effects from non-perturbative QCD have to be controlled with sufficient accuracy. The present article summarizes recent developments related to this topic.

Comments: Invited Talk presented at the QCD Euroconference 98, Montpellier, 2-8 July 1998, 7 pages, 1 figure