Chongxing Yue

Non-universal gauge bosons Z′ and lepton flavor-violating tau decays

Abstract There are many models beyond the standard model predicting the existence of non-universal gauge bosons Z ′, which can give rise to very rich phenomena. We calculate the contributions of the non-universal gauge bosons Z ′, predicted by topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models, to the lepton flavor-violating tau decays τ → l i γ and τ → l i l j l k . We find that the branching ratio B r ( τ → l i l j l k ) is larger than that of the process τ → l i γ in all of the parameter space. Over a sizable region of the parameter space, we have B r ( τ → l i l j l k )∼10 −8 , which may be detected in the future experiments.

Reexamination of the constraint on top-color-assisted technicolor models from R b

Recent study on the charged top-pion correction to

Lepton flavor violating Z→lilj in flavor-universal topcolor-assisted technicolor☆

{R}_{b}

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

shows that it is negative and large, so that the precision experimental value of

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

{R}_{b}

Top quark associated production of the neutral top pion at high energy e + e − colliders

gives rise to a severe constraint on the top-color-assisted technicolor models such that the top-pion mass should be of the order of 1 TeV. In this paper, we restudy this constraint by further taking account the extended technicolor gauge boson correction which is positive. With this positive contribution to

Testing technicolor models in top quark pair production at high energy photon colliders

{R}_{b},

THE DISCUSSION OF ELECTROWEAK PARAMETERS IN TECHNICOLOR MODELS WITH A SCALAR DOUBLET

the constraint on the top-color-assisted technicolor models from

THE DYNAMICAL MODELS AND THE

{R}_{b}

Z \rightarrow b\bar{b}

changes significantly. The top-pion mass is allowed to be in the region of a few hundred GeV depending on the models.