Related papers: Precision Measurements of alphas at HERA
Determinations of the strong coupling strength, $\alpha_s$, are summarised and a new world average value of $\alpha_s (M_Z)$ is determined, using a new method of pre-averaging results within classes of measurements like hadronic $\tau$…
Hadronic event shape distributions are determined from data in e+e- collisions between 183 and 207 GeV. From these the strong coupling alpha_s is extracted in O(alpha_s^2), NLLA and matched O(alpha_s^2)+NLLA theory. Hadronisation…
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)…
A review is presented of recent results in QCD from the H1 and ZEUS experiments at HERA, emphasizing the use of higher order calculations to describe the data.
The ZEUS inclusive differential cross-section data from HERA, for charged and neutral current processes taken with e+ and e- beams, together with differential cross-section data on inclusive jet production in e+ p scattering and dijet…
Results are presented from a study of the structure of high energy hadronic events recorded by the L3 detector at sqrt(s)>192 GeV. The distributions of several event shape variables are compared to resummed O(alphaS^2) QCD calculations. We…
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),…
We present an estimation of the strong coupling constant alphas(MZ) using, for the first time, the production of prompt photon process in proton-proton collisions at the LHC. ATLAS measurements of the inclusive isolated prompt photon cross…
Inclusive jet production is studied in neutral current deep-inelastic positron-proton scattering at large four momentum transfer squared Q^2>150 GeV^2 with the H1 detector at HERA. Single and double differential inclusive jet cross sections…
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…
The energy dependence of the electroweak gauge couplings has not been measured above the weak scale. We propose that percent-level measurements of the energy dependence of $\alpha_{1,2}$ can be performed now at the LHC and at future higher…
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…
Dijet production has been studied in neutral current deep inelastic e+p scattering for 470 < Q**2 < 20000 GeV**2 with the ZEUS detector at HERA using an integrated luminosity of 38.4 pb**{-1}. Dijet differential cross sections are presented…
We present a new determination of the strong coupling constant from lattice QCD simulations. We use four different short-distance quantities to obtain the coupling, three different (infrared) meson splittings to tune the simulation…
Recent structure function results from H1 and ZEUS are presented. The data have been recorded in e+p and e-p collisions for both Neutral Current and Charged Current reactions, covering a wide kinematic range of squared four-momentum…
I review and compare various techniques to obtain the value of the QED coupling, alpha, at the Z pole. GigaZ precisions would require a much more accurate determination than available today. A combination of the virtues of current methods…
Deep inelastic scattering cross section measurements previously published by the H1 and ZEUS collaborations are combined. The procedure takes into account the systematic error correlations in a coherent way, leading to a significantly…
We review the predictions on angular correlations and their recent experimental tests at LEP and HERA. Power behaviour of correlation functions appear for large angles and reflect the underlying fractal structure in jet evolution.…
A review is given of the latest results on jet production and studies of event shape variables in deep inelastic scattering at HERA. Jet cross sections studies for inclusive jet and dijet events are presented and compared to next-to-leading…
The latest results from the H1 and ZEUS collaborations which challenge the QCD description of high energy $ep$ collisions are presented. Data from HERA continue to provide precision measurements and are compared to the latest theoretical…