Determination of the strong-coupling constant from the Z -boson transverse-momentum distribution

The strong-coupling constant is determined from the low-momentum region of the transverse-momentum distribution of Z bosons produced through the Drell–Yan process, using predictions at third order in perturbative QCD. The analysis employs a measurement performed in proton-antiproton collisions at a centre-of-mass energy of √(s) = 1.96 TeV with the CDF experiment. The determined value of the strong coupling at the reference scale corresponding to the Z -boson mass is α _S(m_Z)= 0.1191^+0.0013_-0.0016 .