Testing new physics models by top charge asymmetry and polarization at the LHC

Abstract

As a top quark factory, the LHC can test new physics models used to explain the top quark forward-backward asymmetry ${A}_{\mathrm{FB}}^{t}$ measured at the Tevatron. In this work we perform a comparative study for two such models: the ${W}^{\ensuremath{'}}$ model and the color triplet diquark ($\ensuremath{\phi}$) model. Requiring these models to explain ${A}_{\mathrm{FB}}^{t}$ and also satisfy the top pair production rate measured at the Tevatron, we examine their contributions to the LHC observables such as the polarizations and charge asymmetries in top quark productions and the charge asymmetry in ${W}^{\ensuremath{'}}$ (or $\ensuremath{\phi}$) pair production. We find that these observables can be enhanced to their observable levels and current LHC measurement on the top charge asymmetry has already tightly constrained the ${W}^{\ensuremath{'}}$ model. We also find that each observable shows different characteristics in different models, which can be utilized to discriminate the models.