Collins effect and single spin azimuthal asymmetriesin the HERMES and COMPASS experiments
Joint Institute for Nuclear Research, 141980, Dubna, Russia
2 Institut für Theoretische Physik II, Ruhr-Universität Bochum, 44780, Bochum, Germany
Predictions are made for single spin azimuthal asymmetries due to the Collins effect in pion production from semi-inclusive deeply inelastic scattering off transversely and longitudinally polarized targets for the HERMES and COMPASS experiments. The x-dependence of the asymmetries is evaluated using the parton distribution functions from the chiral quark-soliton model. The overall normalization of the predicted asymmetries is determined by the information on the Collins fragmentation function extracted from previous HERMES data on azimuthal asymmetries from a longitudinally polarized target. The single spin asymmetries A UT from the transversely polarized proton target are found to be about for positive and neutral pions both at HERMES and COMPASS. For a longitudinally polarized target we obtain for COMPASS and .
© Springer-Verlag, 2003