The flavor-changing rare top decays $t\to cVV$ in topcolor-assisted technicolor theory

Abstract

In the framework of topcolor-assisted technicolor (TC2) theory, we calculate the contributions of the scalars(the neutral top-pion ${\pi }_t^0$ and the top-Higgs $h_t^0$) to the flavor-changing rare top decays $t\to cVV$(V= W, g, $\gamma$ or Z). Our results show that $h_t^0$ can enhance the standard model $B_r^{SM}(t⟶cWW)$ by several orders of magnitude for most of the parameter space. The peak of the branching ratio resonance emerges when the top-Higgs mass is between $2m_W$ and $m_t$. The branching ratio $B_r(t\to cWW)$ can reach $10^{-3}$ in the narrow range.

Comments: Latex file, 11pages, 2 eps figures