Top decay in topcolor-assisted technicolor

Conventional technicolor models with light charged technipions (πT±) lead to an unacceptably large contribution to t → πT+b decay rate. Topcolor-assisted technicolor models also have additional PGBs called top-pions (πt+-) which may contribute to this decay. We study the potentially dangerous mixing of charged top-pion and technipions in toy models of ‘natural’ topcolor-assisted technicolor. We find that the t → πt,T+b decay rate in such models can be within experimental limits due to a combination of heavy top-pion and small πt - πT mixing.