Jul 6 – 13, 2022
Bologna, Italy
Europe/Rome timezone

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

Jul 7, 2022, 3:35 PM
Room 1 (Europa Auditorium)

Room 1 (Europa Auditorium)

Parallel Talk Strong interactions and Hadron Physics Strong interactions and Hadron Physics


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.

In-person participation Yes

Primary authors

Giancarlo Ferrera (Istituto Nazionale di Fisica Nucleare) Stefano Camarda (CERN) Matthias Schott (Uni. Mainz)

Presentation materials