Related papers: The strong coupling from tau decays without prejud…
The ALEPH data on hadronic tau-decay is throughly analysed in the framework of QCD. The perturbative calculations are performed in 1-4-loop approximation. The analytical properties of the polarization operators are used in the whole complex…
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 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 latest experimental and theoretical developments in the high-precision determination of the strong coupling $\alpha_s$ are briefly reviewed. Six groups of observables: (i) lattice QCD data, (ii) hadronic $\tau$ decays, (iii)…
We extract the value of the strong coupling constant alpha_s from a single-parameter pointlike fit to the photon structure function F_2^gamma at large x and Q^2 and from a first five-parameter full (pointlike and hadronic) fit to 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…
It has been shown in recent analyses by ALEPH [1] and OPAL [2] that precision QCD tests are possible with hadronic tau decays by comparing spectral moments of the hadronic decay ratio of the tau with QCD calculations. In principle e+e- data…
Hadronic tau decay precision data are analyzed with account of both perturbative and power corrections of high orders within QCD. It is found that contributions of high order power corrections are essential for extracting a numerical value…
The recent update of the strange spectral function and the moments of the invariant mass distribution by the OPAL collaboration from hadronic tau decay data are employed to determine |V_us| as well as m_s. Our result,…
We have reevaluated the hadronic contribution to the anomalous magnetic moment of the muon (g-2) and to the running of the QED fine structure constant alpha(s) at s=M_Z**2. We incorporated new data from hadronic tau decays, recently…
We present a determination of the strong coupling constant $\alpha_s(m_Z)$ using inclusive top-quark pair production cross section measurements performed at the LHC and at the Tevatron. Following a procedure first applied by the CMS…
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…
We present an explicit demonstration that a determination of the strong coupling constant $\alpha_s(m_Z)$ from deep-inelastic scattering and hadron collider data without a simultaneous determination of the parton distribution functions…
We discuss sum-rule determinations of $\alpha_s$ from non-strange hadronic $\tau$-decay data. We investigate, in particular, the reliability of the assumptions underlying the "truncated OPE strategy," which specifies a certain treatment of…
The leptonic decays of the tau lepton provide relevant tests on the structure of the weak currents and the universality of their couplings to the gauge bosons. The hadronic tau decay modes constitute an ideal tool for studying low--energy…
The first complete calculation of the quadratic quark mass correction to the correlator of the two currents relevant for the strangeness-changing semihadronic tau-decay rate is presented including its real part at the four-loop level. This…
The results of two methods to extract the strong coupling constant, $\alpha_s$, are reviewed for the LEP experiments. In the first, scaling violations in the scaled momentum distributions of charged particles at LEP and at lower energy…
The $\tau$ decay rate into hadrons of invariant mass smaller than $\sqrt{s_0}\gg\Lambda_{\rm QCD}$ can be calculated in QCD assuming global quark--hadron duality. It is shown that this assumption holds for $s_0>0.7$~GeV$^2$. From…
We have determined the strong coupling alpha-s from a comprehensive study of energy-energy correlations (EEC) and their asymmetry (AEEC) in hadronic decays of Z0 bosons collected by the SLD experiment at SLAC. The data were compared with…
We perform a precise extraction of the QCD coupling at the $\tau$-mass scale, $\alpha_s(m_\tau)$, from a new vector isovector spectral function which combines ALEPH and OPAL distributions for the dominant channels, $\tau\to\pi…