Low and high energy limits of particle spectra in QCD jets
Sergio Lupia - Wolfgang Ochs
Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, Föhringer Ring 6, D-80805 München, Germany (e-mail: lupia@mppmu.mpg.de, wwo@mppmu.mpg.de)
Received: 14 April 1997
Abstract
Charged particle energy spectra in e+e- annihilation are compared with the
analytical predictions from the QCD evolution equation in the
Modified Leading Log Approximation.
With the nonperturbative initial condition shifted down to threshold as
suggested by the Local Parton Hadron Duality picture a good description of
the data from the lowest
up to highest available energies results. The
two essential parameters in this approach
are determined from a moment analysis.
The sensitivity of the fit to the running of 
and to
the number of active flavours (including a light gluino) is demonstrated.
For very high energies the theory predicts a scaling behaviour in
certain rescaled variables
("
-scaling''). The data show an approximate behaviour of this type
in the present energy range and come close to the predicted asymptotic
scaling function for the small particle energies.
Copyright Springer-Verlag
