Unpolarized and Polarized Parton Distributions
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Abstract:
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Our present knowledge of the parton structure of unpolarized hadrons
and photons will be briefly recapitulated, with particular emphasis on
what we have learned from HERA and what this might imply for the unknown
small-x region, x<10**-5. Although our understanding of polarized parton
distributionss has been enormously improved during the past decade, some
of them are not accessible to present experiments and accelerators. The
importance of future experiments at polarized colliders such as RHIC and
in particular of a polarized HERA collider will be emphasized.