QCD corrections to four-jet production and three-jet structure in e+e- annihilation -: art. no. 054028

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. [S0556-2821(99)02313-9].