Probing the topcolor-assisted technicolor model via the single t-quark production at Hadron colliders

TL;DR

This paper investigates how the TC2 model affects single top-quark production at hadron colliders, finding that loop corrections are small but tree-level FC couplings can significantly enhance production cross sections, especially via resonant effects.

Contribution

It provides a systematic analysis of the TC2 model's impact on single top-quark production, highlighting the potential for observable enhancements through tree-level FC couplings at the LHC.

Findings

Loop corrections to Wtb coupling are small and negative.

Tree-level FC couplings can significantly enhance cross sections.

Resonant effects from top-pions can increase production rates.

Abstract

In this paper, we systematically study the contribution of the TC2 model to the single t-quark production at the Hadron colliders, specially at the LHC. The TC2 model can contribute to the cross section of the single t-quark production in two different ways. First, the existence of the top-pions and top-higgs can modify the $Wtb$ coupling via their loop contributions, and such modification can cause the correction to the cross sections of all three production modes. Our study shows that this kind of correction is negative and very small in all cases. Thus it is difficult to observe such correction even at the LHC. On the other hand, there exist the tree-level FC couplings in the TC2 model which can also contribute to the cross sections of the $tq$ and $t\bar{b}$ production processes. The resonant effect can greatly enhance the cross sections of the $tq$ and $t\bar{b}$ productions. The first evidence of the single t-quark production has been reported by the $D0$ collaboration and the measured cross section for the single t-quark production of $\sigma(p\bar{p}\to tb+X,tqb+X)$ is compatible at the 10% level with the standard model prediction. Because the light top-pion can make great contribution to the $t\bar{b}$ production, the top-pion mass should be very large in order to make the predicted cross section in the TC2 model be consistent with the Tevatron experiments. More detailed information about the top-pion mass and the FC couplings in the TC2 model should be obtained with the running of the LHC.