Related papers: The QCD Running Coupling
Transport properties of a thermal medium determine how its conserved charge densities (for instance the electric charge, energy or momentum) evolve as a function of time and eventually relax back to their equilibrium values. Here the…
We analyse the data for the proton structure function $F_2$ over the entire $Q^2$ domain, including especially low $Q^2$, in terms of perturbative and non-perturbative QCD contributions. The small distance configurations are given by…
In the framework of analytic approach to QCD, which has been recently intensively developed, the dependence of nonperturbative contributions in a running coupling of strong interaction on initial perturbative approximation to 3-loop order…
Quantum chromodynamics predicts that the interaction between its fundamental constituents, quarks and gluons, can lead to different states of strongly interacting matter, dependent on its temperature and baryon density. We first survey the…
The resolution of Dyson-Schwinger equations leads to the freezing of the QCD running coupling (effective charge) in the infrared, which is best understood as a dynamical generation of a gluon mass function, giving rise to a momentum…
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.…
The QCD coupling $\alpha_s$ is extracted from the energy evolution of the first two moments (multiplicity and mean) of the parton-to-hadron fragmentation functions at low fractional hadron momentum $z$. Comparisons of the experimental…
We report our finding of a two scale cut off structure in the infrared nonperturbative dynamics of Pade couplant QCD, in the flavor states $N_{f} \le 8$. We argue that these two NPQCD momentum scales $Q_{c}(Y_{1})$ and $Q_{c}(Y_{2})$ can be…
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…
We give an overview of recent progress into the infrared structure of QCD based on the gauge/gravity correspondence and light-front quantization, where the color confining interaction for mesons and baryons is determined by an underlying…
We determine the strong coupling constant $\alpha_s$ from the static QCD potential by matching a theoretical calculation with a lattice QCD computation. We employ a new theoretical formulation based on the operator product expansion, in…
The normalization of the gluon condensate and of renormalon-related power corrections in QCD is computed under the assumption that their ``perturbative'' part dominates over any eventual extra contribution from the non-trivial vacuum. The…
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…
Quark-hadron duality is an interesting and potentially very useful phenomenon, as it relates the properly averaged hadronic data to a perturbative QCD result in some kinematic regions. While duality is well established experimentally, our…
I discuss finite-temperature gauge theories as a framework to describe the quark-gluon plasma in the regime of high temperature where the gauge coupling is small, $g << 1$. I review recent progress in the understanding of the long-range…
Despite quantum chromodynamics (QCD) being established as the theory of the strong interaction and its many successes since then, significant challenges in our understanding of hadron physics remain. The lack of a full understanding for how…
The strong coupling constant alpha_s(mu_0), taken at a fixed reference scale mu_0, is the single free parameter of QCD and should be known to the highest available precision. The value of alpha_s should also be determined with good accuracy…
This chapter, to appear in the section on QCD under extreme conditions within the Encyclopedia of Nuclear Physics, aims to provide a pedagogical introduction to the physics of quarks and gluons in the presence of high temperature, nonzero…
We estimate the QCD effective charge $\alpha_s$ in the low-energy region by exploiting the conventional meson spectrum within a relativistic quantum-field model based on analytic confinement. The ladder Bethe-Salpeter equation is solved for…
Quantum chromodynamics is the theory of the strong interaction between quarks and gluons; the coupling strength of the interaction, $\alpha_S$, is the least precisely-known of all interactions in nature. An extraction of the strong coupling…