Eur. Phys. J. C (2005) 44: 533-543
https://doi.org/10.1140/epjc/s2005-02380-0

Theoretical Physics

Longitudinally polarized photoproduction of inclusive hadrons at fixed-target experiments

¹ Institut für Theoretische Physik, Universität Karlsruhe, 76128, Karlsruhe, Germany
² Institut für Theoretische Physik, Universität Regensburg, 93040, Regensburg, Germany
³ Physics Department, Brookhaven National Laboratory, 11973, Upton, New York, USA
⁴ RIKEN-BNL Research Center, Brookhaven National Laboratory, 11973, 5000, Upton, New York, USA

^* e-mail: marco.stratmann@physik.uni-regensburg.de

Abstract

We present a detailed phenomenological study of spin-dependent single-inclusive high- p _T hadron photoproduction with particular emphasis on the kinematics relevant for the Compass and Hermes fixed-target experiments. We carefully examine the theoretical uncertainties associated with the only moderate transverse momenta accessible in such measurements and analyze the sensitivity of the relevant spin asymmetries to the gluon polarization in the nucleon as well as to the completely unknown parton content of circularly polarized photons.