Shedding light on the tt̄ asymmetry: The photon handle

Abstract

We investigate a charge asymmetry in tt̄γ production at the LHC that provides complementary information to the measured asymmetries in tt̄ production. We estimate the experimental uncertainty in its measurement at the LHC with 8TeV and 14TeV. We argue that, for new physics models that simultaneously reproduce the asymmetry excess in tt̄ production at the Tevatron and the SM-like asymmetry at the LHC, the measurement in tt̄γ production at the LHC is likely to deviate from the SM prediction. In two new physics models studied in detail we find that the deviations could be significant and observable at the 14TeV run. © The Authors.