Related papers: QCD at LEP
Perturbative QCD analysis is presented of the cumulative out-of-plane momentum distribution in the near-to-planar e+e- annihilation events, K_out << Q. In this kinematical region multiple gluon radiation effects become essential. They are…
This report summarises experimental aspects of the phenomena of colour reconnection in W+W- production, concentrating on charged multiplicity and event shapes, which were carried out as part of the Phenomenology Workshop on LEP2 Physics,…
We report on recent studies of QCD performed using reanalysed e+e- annihilation data recorded at centre of mass energies 14<sqrt(s)<44 GeV by the JADE experiment operated 1979 to 1986 at the PETRA e+e- collider at DESY, Hamburg, Germany.…
We identify a class of perturbatively computable measures of interjet energy flow, which can be associated with well-defined color flow at short distances. As an illustration, we calculate correlations between event shapes and the flow of…
Six--jet events via WW pairs, $e^+e^- \ar W^+W^- \ar q_1 \overline{q_1} q_2 \overline{q_2} g g$ are studied at tree level using helicity amplitudes. This is the dominant production mechanism for six--jet final states at Lep II energy. ISR…
We employ data taken by the JADE and OPAL experiments for an integrated QCD study in hadronic e+e- annihilations at c.m.s. energies ranging from 35 GeV through 189 GeV. The study is based on jet-multiplicity related observables. The…
A summary is given of the current status of measurements of the strong coupling constant $\alpha_s$ performed at LEP. These include measurements from inclusive observables as well as from event shape variables. Recent results based on power…
In this paper I investigate the production of four quarks at LEP 200 energies. Effects due to initial state QED corrections and background diagrams, including QCD contributions, are studied and examples of results obtained with an event…
Selected topics on precision tests of the Standard Model of the Electroweak and the Strong Interaction at the LEP $e^+e^-$ collider are presented, including an update of the world summary of measurements of $\alpha_s$, representing the…
Preliminary but close to final results on the Z lineshape and Forward-Backward asymmetries from the four LEP experiments are presented. Combined values extracted from ALEPH. DELPHI, L3 and OPAL data recorded at energies around the Z pole…
Recent results on measurements of the strong coupling $\alpha_S$ from LEP are reported. These include analyses of the 4-jet rate using the Durham or Cambridge algorithm, of hadronic $Z^0$ decays with hard final state photon radiation, of…
Recent progress on the study of power corrections applied to event shape variables in deep inelastic ep scattering is discussed.
Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~ events. Spin correlations are favoured by data, and found to agree with the…
Results are presented from a study of the structure of hadronic events in high-energy e+e- interactions detected by the L3 detector at LEP. Various event shape distributions and their moments are measured at several energy points at and…
We present the QCD analysis of D-parameter distribution in near-to-planar 3-jet e+e- annihilation events. We derive the all-order resummed perturbative prediction and the leading power suppressed non-perturbative corrections both to the…
Some recent QCD results from the OPAL Collaboration are summarized. In particular: a test of color reconnection models and a search for glueballs using gluon jets with a rapidity gap; a study of unbiased gluon jet properties using a new…
We analyze the impact of using $b$-tagged samples in studying non-Abelian effects due to QCD in $e^+e^-\ar 4$jet events at $\sqrt s=M_{Z^0}$, using angular variable analyses and comparisons with $e^+e^-\ar 3 \mbox{jet}\gamma$ events. We…
Various QCD studies based on jet observables in hadronic final states in deep-inelastic scattering and hadron-hadron collisions are presented. Measured quantities are event shape variables, jet rates and jet cross sections. QCD analyses…
The program of understanding inverse-power law corrections to event shapes and energy flow observables in e+ e- annihilation to two jets and DIS (1+1) jets has been a significant success of QCD phenomenology over the last decade. The…
Resummation in QCD provides insight into the evolution of final state jets from short to long distances, and of accompanying interjet radiation. Applications to event shapes, including the recently-proposed angularities, suggest…