English
Related papers

Related papers: The QCD Running Coupling and its Measurement

200 papers

We analyze the running gauge coupling at finite temperature for QCD, using the functional renormalization group. The running of the coupling is calculated for all scales and temperatures. At finite temperature, the coupling is governed by a…

High Energy Physics - Phenomenology · Physics 2008-11-26 Jens Braun , Holger Gies

Physical quantities in QCD do not depend upon $\alpha_s(Q)$. There is no way to measure $\alpha_s(Q)$ experimentally. If those statements sound shocking, please read on. They are actually well-known facts, though ones that are constantly…

High Energy Physics - Phenomenology · Physics 2024-09-04 P. M. Stevenson

We present results for the QCD running coupling obtained from measuring the quark-gluon vertex in Landau gauge with suitable renormalisation conditions. The issue of discretisation errors arising from the fermion action is discussed.

High Energy Physics - Lattice · Physics 2008-11-26 J. I. Skullerud

We give a brief review of our recent QCD analysis carried out over the deep inelastic scattering data on F2 structure function and in the non-singlet approximation to the accuracy up to next-to-next-to-leading-order. Specifically, analysis…

High Energy Physics - Phenomenology · Physics 2010-08-05 A. V. Kotikov , V. G. Krivokhizhin , B. G. Shaikhatdenov , G. Parente

An update on the prospects for the precise measurement of the strong coupling constant alpha_S at a high energy Linear Collider via the three-jet rate is presented. In particular, the issue of the distribution of center-of-mass energies of…

High Energy Physics - Experiment · Physics 2009-11-07 Bruce A. Schumm , Andrew S. Truitt

We try to review the main current ideas and points of view on the running coupling constant in QCD. We begin by recalling briefly the classic analysis based on the Renormalization Group with some emphasis on the exact solutions of the RG…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. M. Prosperi , M. Raciti , C. Simolo

A method to determine the running of alpha from a measurement of small-angle Bhabha scattering is proposed and worked out. The method is suited to high statistics experiments at e+e- colliders, which are equipped with luminometers in the…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. B. Arbuzov , D. Haidt , C. Matteuzzi , M. Paganoni , L. Trentadue

We present a novel method for precisely determining the running QCD coupling constant $\alpha_s(Q^2)$ over a wide range of $Q^2$ from event shapes for electron-positron annihilation measured at a single annihilation energy $\sqrt{s}$. The…

High Energy Physics - Phenomenology · Physics 2019-11-20 Sheng-Quan Wang , Stanley J. Brodsky , Xing-Gang Wu , Jian-Ming Shen , Leonardo Di Giustino

We present an overview of the recent lattice determination of the QCD coupling $\alpha_s$ by the ALPHA Collaboration. The computation is based on the non-perturbative determination of the $\Lambda$-parameter of $N_{\rm f}=3$ QCD, and the…

High Energy Physics - Phenomenology · Physics 2018-12-18 Mattia Dalla Brida

We compute the running QCD coupling on the lattice by evaluating two-point and three-point off-shell gluon Green's functions in a fixed gauge and imposing non-perturbative renormalisation conditions on them. Our exploratory study is…

High Energy Physics - Lattice · Physics 2009-03-09 B. Alles , D. S. Henty , H. Panagopoulos , C. Parrinello , C. Pittori , D. G. Richards

We obtain a determination of the strong coupling alpha_s in quantum chromodynamics, by comparing perturbative calculations for the short-distance part of the static energy with lattice computations. Our result reads…

High Energy Physics - Phenomenology · Physics 2012-11-21 Xavier Garcia i Tormo

We consider a phenomenologycal parametrization of the QCD running coupling which arises from the dispersion relation respecting the holomorphic properties of the physical QCD observables in the complex momentum plane. The parameters are…

High Energy Physics - Phenomenology · Physics 2017-10-03 Cesar Ayala

We study the running of the QCD coupling with the momentum squared ($Q^2$) and the temperature scales in the high temperature limit ($T > T_{c}$), using a mass dependent renormalization scheme to build the Renormalization Group Equations.…

High Energy Physics - Phenomenology · Physics 2015-06-25 F. M. Steffens

The $\tau$ decay rate into hadrons of invariant mass smaller than $\sqrt{s_0}\gg\Lambda_{\rm QCD}$ can be calculated in QCD assuming global quark--hadron duality. It is shown that this assumption holds for $s_0>0.7$~GeV$^2$. From…

High Energy Physics - Phenomenology · Physics 2009-10-28 Maria Girone , Matthias Neubert

We propose to utilize NISQ-era quantum devices to compute short distance quantities in $(2+1)$-dimensional QED and to combine them with large volume Monte Carlo simulations and perturbation theory. On the quantum computing side, we perform…

High Energy Physics - Lattice · Physics 2023-01-04 Giuseppe Clemente , Arianna Crippa , Karl Jansen

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

The precision measurements of the strong coupling constant, alphas, and its energy-scale dependence carried out at HERA by the H1 and ZEUS Collaborations are reviewed. An average value of alphas(Mz) = 0.1186 +- 0.0011 (exp.) +- 0.0050 (th.)…

High Energy Physics - Experiment · Physics 2015-06-25 Claudia Glasman

The QCD coupling, $\alpha_s$, has a critical role in Hadron collider studies of the Standard Model Effective Field Theory (SMEFT). Patterns of measurements can be modified by local contact operators in the SMEFT that change the measured…

High Energy Physics - Phenomenology · Physics 2023-06-27 Michael Trott

Analytic QCD models are those where the QCD running coupling has the physically correct analytic behavior, i.e., no Landau singularities in the Euclidean regime. We present a simple analytic QCD model in which the discontinuity function of…

High Energy Physics - Phenomenology · Physics 2014-11-21 Carlos Contreras , Gorazd Cvetic , Olivier Espinosa , Hector E. Martinez

Multiplicity correlation measurements provide insight into the dynamics of high energy collisions. Models describing these collisions need these correlation measurements to tune the strengths of the underlying QCD processes which influence…

Nuclear Experiment · Physics 2016-04-27 K. Gulbrandsen , C. Soegaard