The flavor-changing single-top quark production in the littlest Higgs model with T parity at the LHC

TL;DR

This paper investigates flavor-changing single-top quark production at the LHC within the Littlest Higgs model with T parity, highlighting how new FC interactions can significantly enhance production cross sections, especially with heavy mirror quarks.

Contribution

It provides the first detailed analysis of FC single-top production processes in the LHT model, emphasizing the dependence on mirror quark masses and potential for new physics discovery.

Findings

Cross sections depend strongly on mirror quark masses.

Processes $pp\to t\bar{c}$ and $pp\to tg$ can have large cross sections.

Observation of these processes could indicate new physics.

Abstract

The littlest Higgs model with discrete symmetry named "T-parity"(LHT) is an interesting new physics model which does not suffer strong constraints from electroweak precision data. One of the important features of the LHT model is the existence of new source of FC interactions between the SM fermions and the mirror fermions. These FC interactions can make significant loop-level contributions to the couplings $tcV$, and furthermore enhance the cross sections of the FC single-top quark production processes. In this paper, we study some FC single-top quark production processes, $pp\to t\bar{c}$ and $pp\to tV$, at the LHC in the LHT model. We find that the cross sections of these processes are strongly depended on the mirror quark masses. The processes $pp\to t\bar{c}$ and $pp\to tg$ have large cross sections with heavy mirror quarks. The observation of these FC processes at the LHC is certainly the clue of new physics, and further precise measurements of the cross scetions can provide useful information about the free parameters in the LHT model, specially about the mirror quark masses.