Related papers: Status of NNLO 3-jet calculations
Precision studies of QCD at $e^+e^-$ colliders are based on measurements of event shapes and jet rates. To match the high experimental accuracy, theoretical predictions to next-to-next-to-leading order (NNLO) in QCD are needed for a…
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…
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…
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…
The strong coupling constant is a fundamental parameter of nature. It can be extracted from experiments measuring three-jet events in electron-positron annihilation. For this extraction precise theoretical calculations for jet rates and…
In this work we provide all the missing ingredients for calculating parity-violating 3-jet observables in e^+e^- collisions at next-to-leading order (NLO) including the full quark mass dependence. In particular we give explicit results for…
I review the status of fixed order jet Monte Carlos and briefly discuss the prospects for next-to-next-to-leading order calculations. I present a general purpose next-to-leading order Monte Carlo program for four jet event shape observables…
We discuss a calculation of the next-to-leading order QCD corrections to the process $e^+e^-\to 3$ jets with massive quarks, and show numerical results for the three jet fraction and the differential two jet rate.
A method based on sector decomposition has been developed to calculate the double real radiation part of the process e+e- to 3 jets at next-to-next-to-leading order. It is shown in an example that the numerical cancellation of soft and…
I report on a numerical program, which can be used to calculate any infrared safe three-jet observable in electron-positron annihilation to next-to-next-to-leading order in the strong coupling constant alpha_s. The results are compared to a…
We present in detail a calculation of the next-to-leading order QCD corrections to the process $e^+e^-\to 3$ jets with massive quarks. To isolate the soft and collinear divergencies of the four parton matrix elements, we modify the phase…
The production of the three jets in hadron-hardon collision is the first more complex process which allow us to define a branch of variables in order to do more precise measurement of the strong coupling and the parton distribution function…
Multi-jet rates at hadron colliders provide a unique possibility for probing Quantum Chromodynamics (QCD), the theory of strong interactions. By comparing theory predictions with collider data, one can directly test perturbative QCD,…
Three-jet event-shape distributions can be exploited to investigate the dependence of hadronisation effects on the colour and the geometry of the underlying hard event. We present here the first comparison of data in e+e- annihilation and…
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…
I review the state-of-the-art for fully differential numerical NNLO programs. Topics which are covered include the calculation of two-loop amplitudes, multiple polylogarithms, cancellation of infra-red divergences at NNLO and the efficient…
We present a strong coupling constant extraction at Next-to-Leading Order QCD accuracy using ATLAS Z+2,3,4 jets data. This is the first extraction using processes with a dependency to high powers of the coupling constant. We obtain values…
We present results of a next-to-leading order calculation of three jet production at hadron colliders. This calculation will have many applications. In addition to computing such three-jet observables as spectra, mass distributions, this…
We measure the strong coupling constant at NNLO corrections. We do this analysis with moments of event shape variables: thrust, C parameter, heavy jet mass, wide and total jet broadening, by fitting the L3 and DELPHI data with NNLO model.…
Recent measurements of QCD interactions involving large momentum transfers are reviewed. The status of measurements of the strong coupling constant is summarised. Recent developments in the measurement and interpretation of deep inelastic…