Limitations of B-meson mixing bounds on technicolor theories

Recent work by Burdman, Lane, and Rador has shown that BB̄ mixing places stringent lower bounds on the masses of topgluons and Z′ bosons in classic topcolor-assisted technicolor (TC2) models. This Letter finds analogous limits on the Z′ bosons of flavor-universal TC2 and non-commuting extended technicolor models, and compares the limits with those from precision electroweak measurements. A discussion of the flavor structure of these models (contrasted with that of classic TC2) shows that B-meson mixing is a less reliable probe of these models than of classic TC2.