Related papers: Hadronic Z- and tau-Decays in Order alpha_s^4
In this lecture I present a pedagogical introduction to the low-energy phenomenology of light flavors. The renormalization scheme freedom in defining QCD parameters is discussed. It is shown in some details how one can extract an accurate…
We present a strong coupling constant extraction at Next-to-Leading Order QCD accuracy using ATLAS Z+2,3,4 jets data. This is the first extraction using processes with a dependency to high powers of the coupling constant. We obtain values…
We present a new determination of the strong coupling constant alpha_s through the scaling violations in the fragmentation functions for charged pions, charged kaons, and protons. In our fit we include the latest e+e- annihilation data from…
We review the current status of the high order perturbative QCD evaluation of the hadronic decay rates of the Z and Higgs bosons. A systematic classification of the various types of QCD corrections to $O(\alpha_s^2)$ and $O(\alpha_s^3)$ is…
Details are provided how GAPP evaluates the strong coupling constant from Z and tau decays and the corresponding uncertainties.
An update of measurements of the strong coupling constant $\alpha_s$ is given, representing the status of September 2002. The results convincingly prove the energy dependence of $\alpha_s$ and are in excellent agreement with the…
We first give a brief overview of the charmed baryon spectroscopy and discuss their possible structure and spin-parity assignments in the quark model. With the new Belle measurement of the widths of $\Sigma_c(2455)$ and $\Sigma_c(2520)$ and…
We extract the strong coupling $\alpha_s(m_\tau^2)$ from the recently updated ALEPH non-strange spectral functions obtained from hadronic $\tau$ decays. We apply a self-consistent analysis method, first tested in the analysis of OPAL data,…
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…
A novel method to extract the QCD coupling alpha_s from the energy evolution of the moments of the parton-to-hadron fragmentation functions at low fractional hadron momentum z, is presented. The evolution of the moments (multiplicity, peak,…
We recalculate the hadronic contribution to the effective electromagnetic coupling constant $\alpha(M^2_Z)$ using quasi-analytical approximations for the cross-section of $e^{+}e^{-} \to hadrons$ proposed earlier by one of the…
The pure leptonic or semileptonic character of tau decays makes them a good laboratory to test the structure of the weak currents and the universality of their couplings to the gauge bosons. The hadronic tau decay modes constitute an ideal…
We report a measurement of the strong coupling constant, $\alpha_s(M_Z)$, extracted from inclusive jet production in $p\bar{p}$ collisions at $\sqrt{s}=$1800 GeV. The QCD prediction for the evolution of $\alpha_s$ with jet transverse energy…
We provide an overview of recent determinations of the strong coupling, $\alpha_s$, from hadronic $\tau$ decays. We contrast two analysis methods, the "truncated-OPE approach" and the "DV-model approach," highlighting the assumptions going…
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…
The tau hadronic width provides a determination of the strong coupling constant alpha_s at low energies, since it can be related to a weighted integral of the Adler function in the complex energy plane. Using Operator Product Expansion, one…
The inclusive cross sections of W$^+$, W$^-$, and Z boson production from 34 different measurements performed in proton-(anti)proton collisions at center-of-mass energies $\sqrt{s}$ = 1.8--13 TeV, are compared to perturbative QCD…
We perform an extraction of alpha_s based on sum rules involving isovector hadronic tau decay data. The particular sum rules employed are constructed specifically to suppress contributions associated with poorly known higher dimension…
The QCD coupling alpha_s is determined at NLO*+NMLLA accuracy from the comparison of experimental jet data to theoretical predictions of the energy-evolution of the parton-to-hadron fragmentation function moments (multiplicity, peak, width,…
We find the effective neutral current in the heavy top quark limit up to and including the terms of order $\alpha_s^3$. The result is then employed to compute the correction of the same order to the axial part of the Z decay rate into…