Monte Carlo approach to QCD jets in the next-to-leading-logarithmic approximation

Abstract

We present a Monte Carlo model for the parton generation in the next-to-leading-logarithmic (NLL) approximation. This model provides us with the natural introduction of cross sections for nontrivial hard scatterings and it enables us to determine the scheme for the fundamental parameter \ensuremath{\Lambda} in QCD. The implementation of the NLL effects into the Monte Carlo approach is studied extensively. The stochastic treatment requires the positivity of functions for hard scatterings, two-body decays, and three-body decays. This leads to the condition of angular ordering which restricts the phase space. We apply this model to ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilation and incorporate clean three-jet events into the QCD cascade.