https://doi.org/10.1140/epjc/s10052-017-5340-5
Regular Article - Theoretical Physics
Determination of the strong coupling constant 
from measurements of the total cross section for top–antitop-quark production
1
Institute for Particle Physics, ETH Zurich, Zurich, Switzerland
2
Max-Planck-Institute of Physics, Munich, Germany
3
CERN, Theoretical Physics Department, 1211, Geneva 23, Switzerland
4
CNRS, UMR 7589, LPTHE, 75005, Paris, France
* e-mail: bethke@mpp.mpg.de
Received:
25
August
2017
Accepted:
27
October
2017
Published online:
18
November
2017
We present a determination of the strong coupling constant using inclusive top-quark pair production cross section measurements performed at the LHC and at the Tevatron. Following a procedure first applied by the CMS Collaboration, we extract individual values of from measurements by different experiments at several centre-of-mass energies, using QCD predictions complete in NNLO perturbation theory, supplemented with NNLL approximations to all orders, and suitable sets of parton distribution functions. The determinations are then combined using a likelihood-based approach, where special emphasis is put on a consistent treatment of theoretical uncertainties and of correlations between various sources of systematic uncertainties. Our final combined result is 
.
© The Author(s), 2017
