Forward-backward asymmetry in top quark production from light colored scalars in SO(10) model
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 Mtt and rapidity difference | Y|. We consider light colored sextet scalars appearing in a particular non-supersymmetric \10 grand unification model within the 126 scalar representation. These scalar states have masses in the range of 300 GeV-2 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 1σ. We find that the simultaneous fitting of the cross section, the total asymmetry and the asymmetries in different rapidity and Mtt bins gives only a marginal improvement over the SM contribution. We also study various production mechanisms of these colored sextet scalars at the LHC.