QCD Corrections to Four-jet Production and Three-jet Structure in e+ e- annihilation
Stefan Weinzierl, David A. Kosower
TL;DR
The paper presents MERCUTIO, a general-purpose NLO tool for infrared-safe four-jet observables in electron-positron annihilation that employs the dipole subtraction method with phase-space remapping to enhance Monte Carlo efficiency. It implements the Catani–Seymour dipole formalism and provides cross-checks for the four-jet fraction and the D-parameter, while also enabling studies of three-jet substructure through observables like jet broadening and softest-jet explanarity. The authors report results at parton level, verify consistency with existing codes, and introduce previously uncalculated observables, demonstrating MERCUTIO’s versatility for precision QCD predictions in e+e− annihilation. This work offers a robust framework for fixed-order jet phenomenology and serves as a tool for cross-validation in the field.
Abstract
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 uses a remapping of phase-space in order to improve the efficiency of the Monte Carlo integration. Numerical results are given for the four-jet fraction and the D-parameter. These results are compared with already existing ones in the literature and serve as a cross-check. The program can also be used to investigate the internal structure of three-jet events at NLO. We give results for previously uncalculated observables: the jet broadening variable and the softest-jet explanarity.