May 16 – 20, 2022
Europe/Zurich timezone

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

May 17, 2022, 7:00 PM
Experimental poster QCD Physics Poster Session I


Stefano Camarda (CERN)


The strong force is the least known fundamental force of nature, and the effort of precisely measuring its coupling constant has a long history of at least 30 years. This contribution presents a new experimental method for determining the strong-coupling constant from the Sudakov region of the transverse-momentum distribution of Z bosons produced in hadron collisions through the Drell-Yan process. The analysis is based on predictions at third order in perturbative QCD,and employs a measurement performed in proton-proton collisions with the CDF experiment. The determined value of the strong coupling at the reference scale corresponding to the $Z$-boson mass is $\alpha_S(m_Z) = 0.1185^{+0.0014}_{-0.0015}$. This is the most precise determination achieved so far at a hadron collider. The application of this methodology at the LHC has the potential to reach sub-percent precision.

Primary authors

Giancarlo Ferrera (Università degli Studi e INFN Milano (IT)) Stefano Camarda (CERN) Matthias Schott (CERN / University of Mainz)

Presentation materials