Related papers: The QCD Running Coupling
We report on recent experimental and theoretical developments in our understanding of the QCD running coupling \alpha_s in QCD's nonperturbative regime. They allow us to analytically compute the hadron mass spectrum, with \Lambda_s the only…
The potential between infinitely heavy quarks in a color singlet state is of fundamental importance in QCD. While the confining long distance part is inherently non-perturbative, the short-distance (Coulomb-like) regime is accessible…
Establishing an explicit connection between the long distance physics of confinement and the dynamical interactions of quarks and gluons at short distances has been a long-sought goal of quantum chromodynamics. Using holographic QCD, we…
Quantum chromodynamics is the quantum gauge field theory that describes the strong interactions. This article reviews the basic structure, successes and challenges of quantum chromodynamics as it manifests itself at short and long…
We present a one-loop calculation of a gauge invariant QCD beta function. Using both momentum and temperature renormalization group equations we investigate the running coupling in the magnetic sector as a function of temperature and…
We compute the fermionic contribution to the strong coupling $\alpha_{qq}$ extracted from the static force in Lattice QCD up to order $g^4$ in perturbation theory. This allows us to subtract the leading fermionic lattice artifacts from…
We study the strong interactions among the heavy bottom spin--1/2 $\Sigma_b$ baryon, nucleon and $B$ meson as well as the heavy charmed spin--1/2 $\Sigma_c$ baryon, nucleon and $D$ meson in the context of QCD sum rules. We calculate the…
Multi-hadronic events produced in e+e- collisions provide an excellent laboratory to study QCD, the theory of strong interactions, and in particular to determine the strong coupling parameter alpha_s and demonstrate its predicted behavior…
In this chapter we introduce the $\theta$-dependence and the topological properties of QCD, features of the strongly interacting sector which give rise to the strong CP problem in the more general context of the Standard Model of particle…
We discuss the determination of the strong coupling $\alpha_\mathrm{\overline{MS}}^{}(m_\mathrm{Z})$ or equivalently the QCD $\Lambda$-parameter. Its determination requires the use of perturbation theory in $\alpha_s(\mu)$ in some scheme,…
Quantum Chromodynamics (QCD) is the fundamental theory of strong interactions. It describes the behavior of quarks and gluons which are the smallest known constituents of nuclear matter. The difficulties in solving the theory at low…
In the nearly twenty years that have elapsed since its discovery, the gauge-gravity correspondence has become established as an efficient tool to explore the physics of a large class of strongly-coupled field theories. A brief overview is…
The static QCD force from the lattice can be used to extract $\Lambda_{\overline{\textrm{MS}}}$, which determines the running of the strong coupling. Usually, this is done with a numerical derivative of the static potential. However, this…
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…
The Quantum Chromodynamics (QCD) coupling, $\alpha_s$, is not a physical observable of the theory since it depends on conventions related to the renormalization procedure. We introduce a definition of the QCD coupling, denoted by…
A model is introduced with a massive scalar coupling to the Yang--Mills term in four--dimensional gauge theory. It is shown that the resulting potential of colour sources consists of a short range Coulomb interaction and a long range…
We briefly review some of the lower-energy constraints to the perturbative behaviour of the strong coupling $\alpha_s$, with some emphasis on the determination coming from the energy between two static sources calculated on the lattice.
According to the present understanding, the observed diversity of the strong interaction phenomena is described by Quantum Chromodynamics, a gauge field theory with only very few parameters. One of the fundamental questions in this context…
The strong coupling constant is an important parameter which can help us to understand the strong decay behaviors of baryons. In our previous work, we have analyzed strong vertices $\Sigma_{c}^{*}ND$, $\Sigma_{b}^{*}NB$, $\Sigma_{c}ND$,…
The prediction of the strong coupling constant in grand unified theories is reviewed, first in the standard model, then in the supersymmetric version. Various corrections are considered. The predictions in both supergravity-induced and…