Determination of the strong coupling constant α_S(m_Z) from measurements of inclusive W± and Z boson production cross sections in proton-proton collisions at √s = 7 and 8 TeV

Twelve measurements of inclusive cross sections of W± and Z boson production, performed in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, are compared with perturbative quantum chromodynamics calculations at next-to-next- to-leading order (NNLO) accuracy obtained with the CT₁₄, HERAPDF2.0, MMHT₁₄, and NNPDF_(3.0) parton distribution functions (PDFs). Data and theory agree well for all PDF sets, taking into account the experimental and theoretical uncertainties. A novel procedure is employed to extract the strong coupling constant at the Z pole mass from a detailed comparison of all the experimental fiducial cross sections to the corresponding NNLO theoretical predictions, yielding α_S(m_Z) = 0.1163^(+0.0024)_(−0.0031) (CT₁₄), 0.1072^(+0.0043)_(−0.0040) (HERAPDF_(2.0)), 0.1186 ± 0.0025 (MMHT₁₄), and 0.1147 ± 0.0023 (NNPDF_(3.0)). Using the results obtained with the CT₁₄ and MMHT₁₄ PDFs, which yield the most robust and stable α_S(m_Z) extractions, a value α_S(m_Z) = 0.1175^(+0.0025)_(−0.0028) is determined.