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Collins effect and single spin azimuthal asymmetries in the HERMES and COMPASS experiments

A. V. Efremov·K. Goeke·P. Schweitzer
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Abstract

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 from the transversely polarized proton target are found to be about 20% for positive and neutral pions both at HERMES and COMPASS. For a longitudinally polarized target we obtain for COMPASS a sin(phi) asymmetry of 1% and a sin(2phi) asymmetry of about 3%.

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A. V. Efremov, K. Goeke, P. Schweitzer. 2004-01-22. Collins effect and single spin azimuthal asymmetries in the HERMES and COMPASS experiments. https://doi.org/10.1140/epjc%2Fs2003-01398-6

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