Related papers: World Summary of $\alpha_s$ (2012)
Recent determinations of alphas(Mz) from the H1 and ZEUS Collaborations using inclusive-jet cross-section measurements in neutral current deep inelastic scattering at high Q2 are presented. A combined value of alphas(mz)=0.1198 +- 0.0019…
We have studied hadronic events from e+e- annihilation data at centre-of-mass energies from 91 to 209 GeV. We present distributions of event shape observables and their moments at each energy and compare with QCD Monte Carlo models. From…
Motivated by recent preliminary results from the SLD Collaboration on the measurement of angle-dependent B-Bbar energy correlations in Z^0 -> b bbar events, we propose a class of observables that can be computed as a power expansion in the…
We present a measurement of the strong coupling alpha_S using data collected with the JADE detector at centre-of-mass energies between 14 and 44 GeV. The three-jet rate as a function of the transition parameter ycut is determined using the…
Employing the heavy quark expansion model with the kinetic scheme, we evaluate $\alpha_S(m_c^2)$, the strong coupling constant at the charm quark mass $m_c$ with data on inclusive semileptonic decays of charmed mesons. Using the…
An overview of precision determinations of the strong coupling constant, as well as the top, bottom and charm quark masses is presented.
We present a state-of-the-art analysis on determining the strong coupling constant $\alpha_s(m_Z)$ from available $e^+e^-$ data for the Heavy Jet Mass (HJM) distribution. Dijet resummation is supplemented with additional resummation of…
We use the available data on e+ e- -> hadrons to determine the value of the QED coupling at the Z pole. The inclusion of recent preliminary BES-II data in the analysis is found to reduce the ambiguity in the determination of the coupling,…
The value of $\alpha_s(m_Z)=0.106\pm 0.005$ is obtained in a scheme of sum rules for the leptonic constants of the vector $nS$-levels in the heavy $(\bar b b)$-quarkonium.
The status of determinations of the strong coupling constant based on lattice QCD is reviewed.
We discuss the extraction of alpha_s using isovector hadronic tau decay data and sum rules constructed specifically to suppress contributions associated with poorly known higher dimension condensates. We show, first, that problems with the…
In this contribution we explore one of the many possibilities of determining the strong coupling constant $\alpha_S$ at hadron colliders. The method considered is quite unique compared to other methods in that the value of $\alpha_S$ is…
The strong coupling constant alpha_S is determined using recently re-analysed e+e- annihilation data collected by the JADE experiment at sqrt{s}= 14 to 44 GeV. The measurements are based on O(alpha_S**2)+NLLA predictions for various event…
We update a previous N$^3$LL$^\prime$+${\cal O}(\alpha_s^3)$ determination of the strong coupling from a global fit to thrust data by including newly available perturbative ingredients, upgrading the renormalization scales to include a…
Two recent measurements of inclusive jet, 2-jet and 3-jet cross sections in deep-inelastic $ep$ scattering from the H1 collaboration are presented. The measurements are performed at low $5<Q^2<100$ GeV$^2$ and high $150<Q^2<15000$ GeV$^2$…
The finite energy sum rule extraction of the strong coupling {\alpha}_s from hadronic {\tau} decay data provides one of its most precise experimental determinations. As precision improves, small non-perturbative effects become increasingly…
The strong coupling $\alpha_s$ is determined with high precision from fits to lattice QCD simulations on the static energy. Our theoretical setup relies on R-improving the three-loop fixed-order prediction for the static energy by removing…
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 study of the energy dependence of event shape observables is presented. The strong coupling constant \alpha_s has been determined from the mean values of six event shape observables. Power corrections, employed for the measurement of…
The coupling of the strong force, $\alpha_s$, is deemed to be a fundamental parameter of Nature, and, beyond the quark masses, constitutes the only free parameter in the QCD Lagrangian. Provided is an overview of CERN Large Hadron Collider…