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

TL;DR

This paper compares two new physics models, W'-model and diquark model, using top charge asymmetry and polarization measurements at the LHC to test their validity and distinguish between them.

Contribution

It provides a comparative analysis of two models explaining the Tevatron top asymmetry using LHC observables, highlighting their potential for discrimination.

Findings

LHC measurements can constrain the W'-model.

Observables show different characteristics in each model.

Top charge asymmetry can be enhanced to observable levels.

Abstract

As a top quark factory, the LHC can test the new physics models used to explain the top quark forward-backward asymmetry A^t_FB measured at the Tevatron. In this work we perform a comparative study for two such models: the W'-model and the color triplet diquark (\phi) model. Requiring these models to explain A^t_FB and also satisfy the top pair production rate measured at the Tevatron, we examine their contributions to the LHC observables such as the polarization and charge asymmetry in top quark and W' (or \phi) productions. We find that these observables can be enhanced to the observable level and the current LHC measurement on the top charge asymmetry can already tightly constrain the W'-model. We also find that each observable shows different characteristics in different models, which can be utilized to discriminate the models.