• DOI:10.1007/JHEP05(2023)094
• Corpus ID: 256389605

Top and bottom quark forward-backward asymmetries at next-to-next-to-leading order QCD in (un)polarized electron positron collisions

@article{Bernreuther2023TopAB,
  title={Top and bottom quark forward-backward asymmetries at next-to-next-to-leading order QCD in (un)polarized electron positron collisions},
  author={Werner Bernreuther and Long-Bin Chen and Peng-Cheng Lu and Zong-Guo Si},
  journal={Journal of High Energy Physics},
  year={2023},
  volume={2023},
  pages={1-23}
}

• W. Bernreuther, Long-Bin Chen, +1 author Z. Si
• Published 30 January 2023
• Physics
• Journal of High Energy Physics

We consider, at order α s 2 $$ {\alpha}_s^2 $$ 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 A _FB. In particular, we analyze b jets defined by the Durham and the flavor- k _ T 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 α s 2 $$ {\alpha}_s^2 $$ are small. That predestines it to act as a precision observable.