Related papers: The Four-Jet Rate in e+e- Annihilation
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…
We calculate the rate for $e^+e^-$ annihilation into four jets at next-to-leading order in perturbative QCD, but omitting terms that are suppressed by one or more powers of $1/\Nc^2$, where $\Nc$ is the number of colors. The…
Results from the study of jets in hadronic final states produced in e+e- annihilation at sqrt(s)=14 to 209 GeV are discussed. Precise measurements of the strong coupling alpha_S at many points of sqrt(s) provide convincing evidence for the…
We present for the first time resummed predictions at NLO + NLL' accuracy for the Durham jet-resolution scales $y_{n,n+1}$ in multijet production in $e^+e^-$ collisions. Results are obtained using an implementation of the well known CAESAR…
High precision analyses of experimental data for e+ e- annihillation, such as determination of jet rates or event shape observables, call for complete next-to-next-to-leading order (NNLO) perturbative QCD predictions. In this talk, we…
We report on the next-to-leading order QCD calculation for e+ e- --> 4 jets. We explain some modern techniques which have been used to calculate the one-loop amplitudes efficiently. We further report on the general purpose numerical program…
We present a complete calculation of the photon +~1 jet rate in $e^+e^-$ annihilation up to ${\cal O}(\alpha \alpha_{s})$. Although formally of next-to-leading order in perturbation theory, this calculation contains several ingredients…
We present the first determination of the strong coupling constant from the three-jet rate in e+e- annihilation at LEP, based on a next-to-next-to-leading order (NNLO) perturbative QCD prediction. More precisely, we extract alpha_s by…
We calculate the cross section for $e^+ e^-$ annihilation into three jets for massive quarks at next-to-leading order in perturbative QCD, both on and off the $Z$ resonance. Our computation allows the implementation of any jet clustering…
Next-to-leading order calculations for heavy quark three-jet production in e+e- annihilation are reviewed. Their applications for the measurement of the b-quark mass at LEP/SLC and for the test of flavour independence of the strong coupling…
The production of four jets in electron-positron annihilation allows for measuring the strong coupling and the underlying group structure of the strong interaction simultaneously. This requires next-to-leading order perturbative prediction…
We report on the general purpose numerical program MERCUTIO, which can be used to calculate any infrared safe four-jet quantity in electron-positron annihilation at next-to-leading order. The program is based on the dipole formalism and…
We compute for the first time the production rate for four jets in electron-positron annihilation at next-to-next-to-leading order. Our calculation exhibits the highest final-state jet multiplicity considered at this perturbative accuracy…
We calculate the average multiplicity of jets in e+e- annihilation as a function of both the jet resolution parameter, y_cut, and the thrust T. Our result resums to all orders the leading and next-to-leading logarithms in y_cut and 1-T, and…
We present the results of a calculation of the rate for the annihilation of an $e^+e^-$ pair into a jet containing an energetic photon and a single further jet at order $\alpha \alpha_{s}$. By comparing these results with the existing data…
A complete numerical solution of the evolution equation for parton multiplicities in quark and gluon jets with initial conditions at threshold is presented. Data on both hadron and jet multiplicities in e+e- annihilation are well described…
We report next-to-leading order perturbative QCD predictions of 4 jet event shape variables for the process e+e- \to 4 jets obtained using the general purpose Monte Carlo EERAD2. This program is based on the known `squared' one loop matrix…
We present a calculation of the differential two jet cross section in e^+e^- annihilation through next-to-next-to-leading order in the strong coupling constant alpha_s. The calculation is performed using a new method for dealing with real…
We analyze the effects of jet algorithms on each factorized part of the dijet cross sections in $e^+ e^-$ scattering using the soft-collinear effective theory. The jet function and the soft function with a cone-type jet algorithm and the…
Data recorded by the JADE experiment at the PETRA e^+e^- collider were used to measure the event shape observables thrust, heavy jet mass, wide and total jet broadening and the differential 2-jet rate in the Durham scheme. For the latter…