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Related papers: Review on alpha_s at LEP

200 papers

In this paper we fix our attention, on hadron structure, and show that also the strong interaction strength alpha_S, ordinarily called the "(perturbative) coupling--constant square}", can be evaluated within our theory, and found to…

General Physics · Physics 2011-04-15 Erasmo Recami , Tonin-Zanchin , Antonino Del Popolo , Mario Gambera

The size of non-perturbative corrections to event shape observables is predicted to fall like a power of the inverse centre of mass energy. These power corrections are investigated for different observables from e+e-annihilation and…

High Energy Physics - Phenomenology · Physics 2009-10-30 Daniel Wicke

We briefly review some of the lower-energy constraints to the perturbative behaviour of the strong coupling $\alpha_s$, with some emphasis on the determination coming from the energy between two static sources calculated on the lattice.

High Energy Physics - Phenomenology · Physics 2015-06-18 Xavier Garcia i Tormo

Hadronic tau decays offer the possibility of determining the strong coupling alpha_s at relatively low energy. Precisely for this reason, however, good control over the perturbative QCD corrections, the non-perturbative condensate…

High Energy Physics - Phenomenology · Physics 2013-02-12 Matthias Jamin

Measurements of \alpha_s from event shapes in e^{+} e^{-} annihilation are discussed including recent determinations using experimentally optimized scales, studies of theoretically motivated scale setting prescriptions, and recently…

High Energy Physics - Experiment · Physics 2012-08-27 DELPHI Collaboration

We show that any determination of the strong coupling $\alpha_s$ from a process which depends on parton distributions, such as hadronic processes or deep-inelastic scattering, generally does not lead to a correct result unless the parton…

High Energy Physics - Phenomenology · Physics 2020-03-18 Stefano Forte , Zahari Kassabov

We study the moments of hadronic event shapes in $e^+e^-$ annihilation within the context of next-to-next-to-leading order (NNLO) perturbative QCD predictions combined with non-perturbative power corrections in the dispersive model. This…

High Energy Physics - Phenomenology · Physics 2014-11-20 T. Gehrmann , M. Jaquier , G. Luisoni

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…

High Energy Physics - Experiment · Physics 2007-05-23 Philip Reeves

We present the first determination of the strong coupling constant from a fit of next-to-next-to-leading order QCD predictions to event-shape variables, measured in $e^+e^-$ annihilations at LEP. The data have been collected by the ALEPH…

High Energy Physics - Phenomenology · Physics 2008-12-30 G. Dissertori , A. Gehrmann-De Ridder , T. Gehrmann , E. W. N. Glover , G. Heinrich , H. Stenzel

Event Shape Data from $e^+e^-$ annihilation into hadrons collected by the JADE experiment at centre-of-mass energies between 14 GeV and 44 GeV are used to determine the strong coupling $\alpha_S$. QCD predictions complete to…

High Energy Physics - Experiment · Physics 2010-04-15 S. Bethke , S. Kluth , C. Pahl , J. Schieck , the JADE Collaboration

Studies of event shape observables at PETRA and LEP energies are presented. Previously published determinations of the strong coupling constant \alpha_s at \sqrt{s} = 35 and 44 GeV are complemented using new resummed QCD calculations for…

High Energy Physics - Experiment · Physics 2009-10-31 P. A. Movilla Fernández

Concepts and results of determinations of the strong coupling constant in hadron collisions are discussed. A recent alpha_s result from the inclusive jet cross section in pp-bar collisions at sqrt(s)=1.96 TeV is presented which is based on…

High Energy Physics - Experiment · Physics 2011-06-28 M. Wobisch

I review the theoretical status of hadronization corrections to hadronic event observables and discuss their impact on the determination of $\alpha_s$.

High Energy Physics - Phenomenology · Physics 2007-05-23 V. M. Braun

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,…

High Energy Physics - Phenomenology · Physics 2014-10-20 David d'Enterria , Redamy Pérez-Ramos

Power corrections to hadronic event shapes are estimated using a recently suggested relationship between perturbative and non-perturbative effects in QCD. The infrared cutoff dependence of perturbative calculations is related to…

High Energy Physics - Phenomenology · Physics 2009-10-28 B. R. Webber

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…

High Energy Physics - Experiment · Physics 2009-02-09 The OPAL Collaboration , G. Abbiendi

We have applied so-called `optimised' perturbation theory to resolve the renormalisation-scale (mu) ambiguity of exact O(alpha_s^2) QCD calculations of event shape observables in e+e- --> hadrons. We fitted the optimised predictions for 15…

High Energy Physics - Phenomenology · Physics 2009-10-28 P. N. Burrows , H. Masuda , D. Muller , Y. Ohnishi

Hadronic event shape distributions from e+e- annihilation measured by the OPAL experiment at centre-of-mass energies between 91 GeV and 209 GeV are used to determine the strong coupling {\alpha}S. The results are based on QCD predictions…

High Energy Physics - Experiment · Physics 2015-05-20 The OPAL Collaboration

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…

High Energy Physics - Phenomenology · Physics 2009-11-07 S. Albino , M. Klasen , S. Soldner-Rembold

Event shape data from e+e- annihilation into hadrons collected by the JADE experiment between sqrt(s)=14 and 44 GeV are used to determine the strong coupling alpha_S. QCD predictionscomplete to next-to-next-to-leading order (NLLO),…

High Energy Physics - Experiment · Physics 2009-06-01 S. Kluth