A COMPARISON OF MEASURED JET CROSS-SECTIONS WITH QCD CALCULATIONS FOR E+ E- ANNIHILATION

The cross sections for 2-, 3- and 4-jet production have been determined with the JADE detector, sited on the e+ e- -storage ring PETRA. Data at square-root s = 14, 22, 35 and 44GeV were compared to two O(alpha-s2) QCD calculations. A first analysis was performed with uncorrected data using the O(alpha-s2) 3-jet matrix element calculation of Ellis, Ross and Terrano and the Lund String Monte Carlo program. In a second analysis the calculation of Kramer and Lampe was compared to corrected data. Both approaches gave a poor description of the data when the square of the momentum transfer Q2 = s was used as the scale of the running coupling constant. The description improved when the renormalization scale was adjusted to the process studied. The data were used to fix the best renormalization scale.