Related papers: Determination of the QCD Coupling $\alpha_s$
In the domain of Nuclear reactions at intermediate energies, the QCD coupling constant $\alpha_s$ is large enough ($\sim$ 0.3 - 0.5) to render the perturbative calculational techniques inapplicable. In this regime the quarks are confined…
We review the determination of the strong coupling alpha_s from the comparison of the perturbative expression for the Quantum Chromodynamics static energy with lattice data. We collect here all the perturbative expressions needed to…
We discuss the new model expression $\bar{\alpha}_{an}(Q^2)$ recently obtained for the QCD running coupling with a regular ghost-free behavior in the "low $Q^2$" region. Being deduced from the standard "asymptotic-freedom" expression by…
We performed NLO QCD analysis of the nonsinglet part of the combined SLAC/BCDMS data on $F_2$ with the extraction of $\alpha_s$ and high twist contribution. It was shown that the value of $\alpha_s$ obtained in the analysis is sensitive to…
We estimate the strong coupling constant from the perturbative expansion of the plaquette. The scale is set by the 2S-1S and 1P-1S splittings in bottomonium which are computed in NRQCD on dynamical gauge configurations with nf=2 degenerate…
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…
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, accounting for the massive Wilson…
We compare lattice data for the short-distance part of the static energy in 2+1 flavor quantum chromodynamics (QCD) with perturbative calculations, up to next-to-next-to-next-to leading-logarithmic accuracy. We show that perturbation theory…
We present a new extraction of the effective strong coupling constant \alpha_{s,g_1}(Q^2). The result agrees with a previous determination and extends the measurement of the low and high Q^2 behavior of \alpha_{s,g_1}(Q^2) that was…
The strong coupling limit (beta_gauge = 0) of QCD offers a number of remarkable research possibilities, of course at the price of large lattice artifacts. Here, we determine the complete phase diagram as a function of temperature T and…
Hadronic final states with a hard isolated photon are studied using data taken at centre-of-mass energies around the mass of the Z0 boson with the OPAL detector at LEP. The strong coupling alpha S is extracted by comparing data and QCD…
The coupling constant of the strong force is determined from the transverse-momentum distribution of $Z$ bosons produced in 8 TeV proton-proton collisions at the LHC and recorded by the ATLAS experiment. The $Z$-boson cross sections are…
Using recent CLEO III results for the cross section for $e^+e^- \to {\rm hadrons}$ at seven centre-of-mass energies between 6.964 and 10.538 GeV, we derive a value for the strong coupling constant…
Using recently developed methods for the evaluation of five-loop amplitudes in perturbative QCD, corrections of order alpha_s^4 for the cross section of electron-positron annihilation into hadrons and for the decay rates of the Z-boson and…
We present the details and first results of a new strategy for the determination of $\alpha_s(m_Z)$. By simultaneously decoupling 3 fictitious heavy quarks we establish a relation between the $\Lambda$-parameters of three-flavor QCD and…
We present a new approach to determining the strong coupling $\alpha_s(Q)$, over the entire range of validity of perturbative QCD, for scales above $\Lambda_{\mathrm{QCD}}$ and up to the Planck scale $\sim1.22\cdot10^{19}$\,GeV, with the…
If quantum chromodynamics (QCD) is renormalized by minimal subtraction (MS), at higher orders, the strong coupling constant alpha_s and the quark masses m_q exhibit discontinuities at the flavour thresholds, which are controlled by…
A high precision determination of the strong coupling constant in the MS-bar scheme at the Z-mass scale, using low energy quantities, namely pion/kaon decay constants and masses, as experimental input is presented. The computation employs…
The color neutrality of hadrons is interpreted as an expression of conformal symmetry of strong interaction, the latter being signaled through the detected "walking" at low transferred momenta, $\lim_{Q^2\to 0}\alpha_s(Q^2)/\pi\to 1 $, of…
We perform pQCD analysis of the existing DIS data for charged leptons with account of corrections up to the NNLO. The parton distributions, value of strong coupling constant, and high-twist terms are extracted and their stability with…