2015/09/14 by A. Warburton, Warburton, Andreas
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Particle Detector Development and Performance #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.1509.04380
openalex publication_date 2015/09/15 · openalex created_date 2024/04/11 · openalex updated_date 2026/07/28
The coupling of the strong force, αs, is deemed to be a fundamental parameter of Nature, and, beyond the quark masses, constitutes the only free parameter in the QCD Lagrangian. Provided is an overview of CERN Large Hadron Collider (LHC) measurements of αs(MZ) evaluated at the Z-boson mass and of the running of αs(Q) as a function of energy-momentum transfer Q. The measurements were performed by the ATLAS and CMS Collaborations using proton-proton (pp) collisions with centre-of-mass energies of 7 TeV and data samples with time-integrated luminosities up to 5 fb-1. Four different categories of observable were used in the described extractions of αs: inclusive jet cross sections, 3-jet to 2-jet inclusive cross-section ratios, 3-jet mass cross sections, and top-quark pair production cross sections. These results, which include the first NNLO measurement of αs at a hadron collider and the first determinations of αs at energy scales above 1 TeV, are consistent with each other, with the world-average value, and with QCD predictions of their running with Q.