Forward-backward asymmetry in top quark production from light colored scalars in SO(10) model

TL;DR

This paper explores how light colored scalars in a specific SO(10) grand unification model can explain the observed forward-backward asymmetry in top quark production at Tevatron, fitting experimental data within uncertainties.

Contribution

It introduces a non-supersymmetric SO(10) model with light colored scalars that can account for top quark asymmetry measurements, linking grand unification to collider phenomenology.

Findings

Scalar contributions explain asymmetry within 1σ

Marginal improvement over Standard Model fits

Analysis of scalar production mechanisms at LHC

Abstract

The forward-backward asymmetry in top pair production at Tevatron has been reconfirmed by the CDF collaboration with 5.3 fb^{-1} of accumulated data. These measurements also report that the asymmetry is the largest in regions of high invariant mass M_{t\bar{t}} and rapidity difference |\Delta Y|. We consider light colored sextet scalars appearing in a particular non-supersymmetric \10 grand unification model within the \bar{126} scalar representation. These scalar states have masses in the range of 300 \text{GeV}-2 \text{TeV} consistent with the requirements of gauge coupling unification and bounds on the proton lifetime. The cross section and the total asymmetry can be simultaneously explained with the contributions of these scalars within 1$\sigma$. We find that the simultaneous fitting of the cross section, the total asymmetry and the asymmetries in different rapidity and M_{t\bar{t}} bins gives only a marginal improvement over the SM contribution. We also study various production mechanisms of these colored sextet scalars at the LHC.