Multiscale Technicolor Model Research Articles

Distinguishing technicolor models viatt¯production at polarized photon colliders

We study top quark pair productions at a polarized photon collider from an e{sup +}e{sup -} linear collider (LC) in various improved technicolor models, namely, the one-family walking technicolor model, the top-color-assisted technicolor model, and the top-color-assisted multiscale technicolor model. Recent constraint on the top-pion mass from the precision data of R{sub b} is considered. It is shown that, considering only the statistical errors, a polarized photon collider from a 500 GeV LC with an integrated luminosity of 500 fb{sup -1} is sufficient for distinguishing the three improved technicolor models experimentally.

The Production of Pseudo Goldstone Boson in Top Quark Rare Decay**The project supported by National Natural Science Foundation of China under Grant No. 19775012 and Natural Science Foundation of Henan Educational Committee under Grant No. 1999140013

We calculate the flavor changing decay in the framework of the topcolor assisted multiscale technicolor model. We find that (a) the branching ratio of is insensitive to and , while it increases quickly as ∊ increases; (b) for reasonable ranges of the parameters, the maximum of the branching ratio in this model may reach , seven orders larger compared to the one calculated in the standard model. This might provide an opportunity to detect the rare decay of the top quark in experiments.

Detecting Extended Technicolor Effects via the Process at High Energy e+e- Linear Collider**The project supported by National Natural Science Foundation of China, the Excellent Youth Foundation of Henan Scientific Committeeand Foundation of Henan Educational Committee

We calculate the corrections of extended technicolor (ETC) interactions to the asymmetry parameter and the polarized parameters , of the process in topcolor-assisted multiscale technicolor model. Our results show that the ETC effect on is negligibly small which can be safely ignored, and the ETC effect on may be testable at high energy linear collider (LC). For , , the relative correction of is in the range of , which will certainly be detected at the LC experiments (for example TESLA).

TC2 dynamics and top quark production at NLC

We calculate the correction of the TC2 dynamics to the production cross section of the process $e^+e^- \rightarrow t\overline{t}$ in the top color-assisted multiscale technicolor model. Our results show that the corrections mainly come from the effects of the top color gauge boson $Z^{\prime}$ in the s-channel. The total corrections to cross sections $\sigma_L$ and $\sigma_R$ are very large; this can be detected at NLC. The total corrections to the polarized parameters $P_{\mathrm{L}}^t$ and $P_{\mathrm{R}}^t$ may be observed at NLC in most of the parameter space.

TC corrections to $t \overline{t}$ production at photon colliders in topcolor-assisted multiscale technicolor model

TC(technicolor) corrections to ttI production in high-energy photon-photon collision are calculated in the topcolor-assisted multiscale technicolor(TOPCMTC) model. We find that the contribution of the technipions to the production cross section of the process γγ → tt is very small. The relative corrections to the production cross section mainly come from the top-pions, which may be observable at future e+e-. linear collider.

Corrections to theWt¯bcoupling in the top-color-assisted multiscale technicolor model

We consider the contributions of new gauge bosons to $W\overline{t}b$ coupling in the top-color-assisted multiscale technicolor model. We find that the exchange of the diagonal extended technicolor (ETC) gauge boson has no contribution to $W\overline{t}b$ coupling. Using the CERN LEP value of ${R}_{b},$ we calculate the corrections to the CKM matrix element ${V}_{\mathrm{tb}}$ which arise from the sideways ETC gauge boson and coloron exchange. We find that the $\ensuremath{\delta}{V}_{\mathrm{tb}}$ is significantly large for a certain range of the parameters which might be detected in the Fermilab Tevatron collider's run 3.