A measurement of alpha(s) from the scaling violation in e(+)e(-) annihilation

摘要

The hadronic fragmentation functions of the various quark flavours and of gluons are measured in a study of the inclusive hadron production from Z(0) decays with the DELPHI detector and are compared with the fragmentation functions measured elsewhere at energies between 14 GeV and 91 GeV. A large scaling violation is observed, which is used to extract the strong coupling constant from a fit using a numerical integration of the second order DGLAP evolution equations. The result is alpha(s)(M-Z) = 0.124(-0.007)(+0.006) (exp) +/- 0.009(theory) where the first error represents the experimental uncertainty and the second error is due to the factorization and renormalization scale dependence. (C) 1997 Elsevier Science B.V.