English
Related papers

Related papers: Determination of the QCD Coupling $\alpha_s$

200 papers

The current status of measurements of the strong coupling constant from different reactions is reviewed. Including new results presented at the 1996 ICHEP conference, a global average alpha_s(Mz) = 0.118 +- 0.003 is obtained.

High Energy Physics - Experiment · Physics 2007-05-23 Michael Schmelling

The strong coupling, $\alpha_s$, governs perturbative Quantum Chromodynamics (QCD) and is one of the free parameters of the Standard Model. We introduce a new method that allows a precise extraction of $\alpha_s(m_Z)$ from dimensionless…

High Energy Physics - Phenomenology · Physics 2020-05-28 Diogo Boito , Vicent Mateu

Measurements which probe the energy dependence of $\alpha_s$, the coupling strength of the strong interaction, are reviewed. Jet counting in $e^+ e^-$ annihilation, combining results obtained in the centre of mass energy range from 22 to…

High Energy Physics - Experiment · Physics 2011-07-19 Siegfried Bethke

We review the ALPHA collaboration strategy for obtaining the QCD coupling at high scale. In the three-flavor effective theory it avoids the use of perturbation theory at $\alpha > 0.2$ and at the same time has the physical scales small…

In this talk we present a determination of the strong coupling constant $\alpha_\text{s}$ and its energy-scale dependence based on a next-to-next-to-leading order (NNLO) QCD analysis of dijet production. Using the invariant mass of the…

High Energy Physics - Phenomenology · Physics 2025-07-03 João Pires

Global fits for precision determinations of parton distributions, together with the highly correlated strong coupling $\alpha_s$, are presented up to next-to-next-to-leading order (NNLO) of QCD utilizing most world data (charm and jet…

High Energy Physics - Phenomenology · Physics 2014-05-23 Pedro Jimenez-Delgado , Ewald Reya

We present a determination of the strong coupling constant $\alpha_s(m_Z)$ based on the NNPDF3.1 determination of parton distributions, which for the first time includes constraints from jet production, top-quark pair differential…

High Energy Physics - Phenomenology · Physics 2018-07-10 Richard D. Ball , Stefano Carrazza , Luigi Del Debbio , Stefano Forte , Zahari Kassabov , Juan Rojo , Emma Slade , Maria Ubiali

We present a new determination of the strong coupling constant from lattice QCD simulations. We use four different short-distance quantities to obtain the coupling, three different (infrared) meson splittings to tune the simulation…

High Energy Physics - Lattice · Physics 2016-08-24 C. T. H. Davies , K. Hornbostel , G. P. Lepage , P. McCallum , J. Shigemitsu , J. Sloan

We reanalyze deep inelastic scattering data of BCDMS Collaboration by including proper cuts of ranges with large systematic errors. We perform also the fits of high statistic deep inelastic scattering data of BCDMS, SLAC, NM and BFP…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. G. Krivokhijine , A. V. Kotikov

Hadronic event shape distributions from e+e- annihilation measured by the OPAL experiment at centre-of-mass energies between 91 GeV and 209 GeV are used to determine the strong coupling {\alpha}S. The results are based on QCD predictions…

High Energy Physics - Experiment · Physics 2015-05-20 The OPAL Collaboration

We make a critical analysis on the free parameters of the Cornell potential $-4\alpha_{s}/3r+br+c$ and provide a parameterisation space for the strong coupling constant $\alpha_{s}$ and the constant shift $c$ for choosing linear part as…

High Energy Physics - Phenomenology · Physics 2022-12-06 Krishna Kingkar Pathak , Satyadeep Bhattacharya , Tapashi Das

We present a determination of the strong coupling $\alpha_s(m_Z)$ from a global dataset including both fixed-target and collider data from deep-inelastic scattering and a variety of hadronic processes, with a simultaneous determination of…

The current phenomenological determinations of $\alpha_s(M_\tau)$ and $\alpha_s(M_Z)$ are shown to be only marginally consistent with the QCD evolution of the strong coupling constant between $M_Z$ and $M_\tau$. This motivates a revised…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. G. Steele , V. Elias

The latest experimental and theoretical developments in the high-precision determination of the strong coupling $\alpha_s$ are briefly reviewed. Six groups of observables: (i) lattice QCD data, (ii) hadronic $\tau$ decays, (iii)…

High Energy Physics - Experiment · Physics 2018-06-19 David d'Enterria

The strong coupling alpha_s is a fundamental parameter of the Standard Model. In comparison to parameters like alpha_em and M_Z it is relatively poorly known. However the precision of alpha_s measurements has improved dramatically in recent…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. J. Stirling

Deep inelastic scattering data on F2 structure function from various fixed-target experiments were analyzed in the non-singlet approximation with a next-to-next-to-leading-order accuracy. The study of high statistics deep inelastic…

High Energy Physics - Phenomenology · Physics 2014-11-20 B. G. Shaikhatdenov , A. V. Kotikov , V. G. Krivokhizhin , G. Parente

Twelve measurements of inclusive cross sections of W$^\pm$ and Z boson production, performed in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, are compared with perturbative quantum chromodynamics calculations at…

High Energy Physics - Experiment · Physics 2020-06-09 CMS Collaboration

We determine the value of the strong coupling $\alpha_\text{s}$ and study its running over a wide range of scales as probed by the dijet production process at hadron colliders, based on an NNLO QCD analysis of LHC dijet data. From a large…

We present a new determination of the strong coupling constant $\alpha_s$ from a global QCD analysis CT25 of parton distribution functions (PDFs) that incorporates high-precision experimental measurements from the Run-2 of the Large Hadron…

High Energy Physics - Phenomenology · Physics 2026-03-18 Alim Ablat , Sayipjamal Dulat , Marco Guzzi , Joey Huston , Kirtimaan Mohan , Pavel Nadolsky , Dan Stump , C. -P. Yuan

The results of a recent next-to-leading order QCD analysis of the world data on polarized deep inelastic scattering are reported. New parameterizations are derived for the quark and gluon distributions and the value of $\alpha_s(M_z^2)$ is…

High Energy Physics - Phenomenology · Physics 2010-11-19 Johannes Blümlein , Helmut Böttcher