The strong coupling constant alpha_S is the least well known of all constants of nature, which play a role in the Standard Model (SM) of
particle physics and related fields such as cosmology and astrophysics. For many searches for new physics beyond the SM as well as for some important precision tests of the SM using collider data the uncertainty on the value of ?? is a limiting factor. In recent years progress in theoretical predictions of Quantum Chromodynamics (QCD), and the availability of collider data at the highest energies has led to many improved determinations of alpha_S. The current world average quotes an uncertainty of less than 1%. However, there are noticeable discrepancies between different categories of
determinations of alpha_S, which may limit the ultimate precision of future world averages. We plan to bring together in this workshop the
leading experts on determinations of alpha_S from theory and experiment and all important categories. With presentations of the latest results and intense discussion by all participants we will focus on a global view of advantages and problems of each method.
| Overview and Introduction |
| Pre-2019 summaries of $α_s$ PoS(ALPHAS2019)001 pdf |
| $a_S$ from $e^+e^-$ hadronic and tau pair final states |
| Old and new observables for $α_S$ from $e^+e^-$ to hadrons PoS(ALPHAS2019)002 pdf |
| $a_S$ from energy-energy correlations and jet rates in $e^+e^-$ collisions PoS(ALPHAS2019)003 pdf |
| The strong coupling from $e^+e^-$ to hadrons PoS(ALPHAS2019)004 pdf |
| $a_S$ from soft QCD jet fragmentation functions PoS(ALPHAS2019)005 pdf |
| $a_S$ from electroweak observables |
| The QCD coupling $αs$ (Q2)at all momentum scales and the elimination of renormalization scale uncertainties PoS(ALPHAS2019)006 pdf |
| Higgs-boson, tau-lepton, and Z-boson decay ratesin fourth order and the five-loop $β$ function of QCD PoS(ALPHAS2019)007 pdf |
| High-precision $α_S$ from W and Z hadronic decays PoS(ALPHAS2019)008 pdf |
| $a_S$ at hadron colliders |
| $α_s$ from jets in $pp$ collisions PoS(ALPHAS2019)009 pdf |
| Jet substructure and a possible determination of the QCD coupling PoS(ALPHAS2019)010 pdf |
| Extractions of the QCD coupling in ATLAS PoS(ALPHAS2019)011 pdf |
| $a_S$ determinations from CMS PoS(ALPHAS2019)012 pdf |
| $a_S$ extraction from inclusive W and Z cross sections in pp collisions at the LHC PoS(ALPHAS2019)013 pdf |
| Determination of $a_S(m_Z)$ from the Z-boson transverse momentum distribution PoS(ALPHAS2019)014 pdf |
| $a_S$ from DIS & PDFs |
| $a_S$ from pdfs PoS(ALPHAS2019)015 pdf |
| $a_S$, ABM PDFs, and heavy-quark masses PoS(ALPHAS2019)016 pdf |
| $a_S$ from H1 jets PoS(ALPHAS2019)017 pdf |
| $a_S$ from tau decays |
| $a_S$ from non-strange hadronic tau decays PoS(ALPHAS2019)018 pdf |
| QCD coupling: scheme variations and tau decays PoS(ALPHAS2019)019 pdf |
| $a_S$: Lattice OCD |
| The 2019 lattice FLAG $a_S$ average PoS(ALPHAS2019)020 pdf |
| Strong coupling constant from moments of quarkonium correlators PoS(ALPHAS2019)021 pdf |
| $a_S$ from the ALPHA collaboration (part I) PoS(ALPHAS2019)022 pdf |
| $a_S$ from the ALPHA collaboration (part II) PoS(ALPHAS2019)023 pdf |
| $a_S$ from the QCD static energy PoS(ALPHAS2019)024 pdf |
| $a_S$ determination from static QCD potential with renormalon subtraction PoS(ALPHAS2019)025 pdf |
| Conclusion |
| $\alpha_s$(2019) discussions summary PoS(ALPHAS2019)026 pdf |