In the context of topcolor-assisted technicolor (TC2) models, we examine the flavor changing (FC) Z decay $Z\to b\bar{ s}(\bar{ b}s)$ and calculate the contributions of the new particles predicted by TC2 models to the branching ratio Br($Z\to b\bar{ s}+\bar{ b}s$). We find that the contributions mainly come from the top-pions. In most of the parameter space, the Br($Z\to b\bar{ s}+\bar{ b}s$) can reach $10^{ -5}$, which may be detected in near future experiments such as Giga-Z version of the TESLA. Thus, the FC Z decay $Z\to b\bar{ s}(\bar{ b}s)$ can be used to test TC2 models.
Categories: hep-ph