Resolving the Tevatron Top Quark Forward-Backward Asymmetry Puzzle: Fully Differential Next-to-Next-to-Leading-Order Calculation

We determine the dominant missing standard model (SM) contribution to the top quark pair forward-backward asymmetry at the Tevatron. Contrary to past expectations, we find a large, around 27%, shift relative to the well-known value of the inclusive asymmetry in next-to-leading order QCD. Combining all known standard model corrections, we find that A(FB)(SM) = 0.095 +/- 0.007. This value is in agreement with the latest DO measurement [V. M. Abazov et al. (D0 Collaboration), Phys. Rev. D 90, 072011 (2014)] A(FB)(D0) = 0.106 +/- 0.03 and about 1.5 sigma below that of CDF [T. Aaltonen et al. (CDF Collaboration), Phys. Rev. D 87, 092002 (2013)] A(FB)(CDF) = 0.164 +/- 0.047. Our result is derived from a fully differential calculation of the next-to-next-to leading order (NNLO) QCD corrections to inclusive top pair production at hadron colliders and includes-without any approximation-all partonic channels contributing to this process. This is the first complete fully differential calculation in NNLO QCD of a two-to-two scattering process with all colored partons.