Abstract
We consider, at order \( {\alpha}_s^2 \) in the QCD coupling, top-quark pair production in the continuum at various center-of-mass energies and b-quark pair production at the Z resonance by (un)polarized electron and positron beams. For top quarks we compute the forward-backward asymmetry with respect to the top-quark direction of flight, the associated polar angle distribution, and we analyze the effect of beam polarization on the QCD corrections to the leading-order asymmetry. We calculate also the polarized forward-backward asymmetry. For b-quark production at the Z peak we explore different definitions of AFB. In particular, we analyze b jets defined by the Durham and the flavor-kT clustering algorithms. We compute the inclusive b-jet and two-jet asymmetry with respect to the b-jet direction. For the latter asymmetry the QCD corrections to order \( {\alpha}_s^2 \) are small. That predestines it to act as a precision observable.
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Acknowledgments
This work was supported by the Natural Science Foundation of China under contract No.12205171, No.12235008.
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Bernreuther, W., Chen, L., Lu, PC. et al. Top and bottom quark forward-backward asymmetries at next-to-next-to-leading order QCD in (un)polarized electron positron collisions. J. High Energ. Phys. 2023, 94 (2023). https://doi.org/10.1007/JHEP05(2023)094
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DOI: https://doi.org/10.1007/JHEP05(2023)094