A new study of the polarized parton densities in the nucleon

We present a new next-to-leading order QCD analysis of the world data on in clusive polarized deep inelastic lepton-nucleon scattering adding to the ol d set of data the final SMC results, the HERMES proton and very recent SLAC /E155 deuteron data. We find an excellent fit to the data and present resul ts for the polarized parton densities in different factorization schemes. T hese results are in a good agreement with what follows from the theory. We have also found that the main effect of the newly incorporated data is a be tter determination of the polarized gluon density. (C) 1999 Published by El sevier Science B.V. All rights reserved.