Guoli Liu

Production and decay of the neutral top pion in high-energy e+ e- colliders

We study the production and decay of the neutral top-pion � 0 predicted by topcolor-assisted technicolor(TC2) theory. Our results show that, except the dominant decay modes b ¯, ¯ and gg, the � 0 t can also decay into and Z modes. It can be significantly produced at high energy e + e collider(LC) experiments via the processes e + e → � 0 and e + e → Z� 0 t. We further calculate the production cross sections of the processes e + e → � 0 → ¯ and e + e → Z� 0 → Z¯ tc. We find that the signatures of the neutral top-pion � 0 can be detected via these processes.

The flavor-changing rare top decays t→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 π t 0 and the top-Higgs h t 0 ) to the flavor-changing rare top decays t→cVV (V=W,g , γ 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 2 m W and m t . The branching ratio B r ( t → cWW ) can reach 10 −3 in the narrow range.

The rare top decay t → cg in topcolor assisted technicolor models

In the framework of topcolor-assisted technicolor(TC2) models, we calculate the contributions of flavor changing scalar couplings involved the neutral top-pion � 0 and top-Higgs h 0 to the branching ratio Br(t −→ cg). We find that the value of Br(t −→ cg) can reach 1 × 10 3 with reasonable values of the parameters in TC2 models, which may be testable in the future experiments.

The process in topcolor-assisted technicolor models

We consider the flavor changing neutral current (FCNC) process e(+)e(-) --> (t) over barc (or t (c) over bar) in the context of topcolor-assisted technicolor (TC2) models. We find that the contributions of charged scalars (technipions and top-pions) and topcolor gauge bosons are negligibly small. The neutral scalars (top-pion pi(t)(0) and top-Higgs h(t)(0)) can give significant contributions to this process. With reasonable values of the parameters in TC2 models, there will be several tens of the observable is events to be generated in the future e(+)e(-) linear colliders

Lepton flavor violating processes l(i) ---> l(j) gamma in topcolor assisted technicolor models

We consider the lepton-flavor violating(LFV) processes

The colour-singlet technipion P0 and the recent experimental results at LEPII

l_{i}\to l_{j}\gamma

Neutral top-pion and top-charm production in high energy e+e− collisions☆

in the framework of topcolor assisted technicolor(TC2) models. We find that the new gauge boson

The bound on the mass of the new gauge boson Z′ from the process μ→3e

Z^{\prime}

Detecting top-Higgs at high energy e+e− colliders☆

predicted by TC2 models can give significantly contributions to these processes via the flavor changing couplings. The present experimental bound on the LFV process

Topcolour-assisted technicolour models and the muon anomalous magnetic moment

\mu \to e\gamma