Top Quark Pair Production and Asymmetry at the Tevatron and LHC in Left-Right Models

摘要

In light of the recent measurements of the top quark forward-backwardasymmetry at the Fermilab Tevatron experiment, which in some regions of theparameter space shows a discrepancy of 3$\sigma$ compared to the SM prediction,we analyze top quark pair production and asymmetry in the context of left-rightmodels both at the Tevatron and LHC. We use the minimal manifest left-rightmodel and an asymmetric left-right model where gauge couplings and flavormixing in the right-handed sector are allowed to differ from those in theleft-handed sector. We explore the consequences of including effects from $W_R$and $Z_R$ gauge bosons, consistent with phenomenological constraints from mesonmixing and new bounds from ATLAS and CMS, for the $t \bar{t}$ cross section,invariant mass distribution and forward-backward asymmetry at the Tevatron, andpredict their values at the LHC. We show that, choosing parameter benchmarksfor the model while preserving agreement with collider, electroweak precision,and flavor violation data, the generic left-right model cannot account for thelarge deviations of the observed asymmetry at the Tevatron and also that itpredicts very small charge asymmetries at the LHC.