Abstract
The most recent data on the weighted transverse single spin asymmetry from HERMES and COMPASS Collaborations are analyzed within the LO parton model with unintegrated parton distribution and fragmentation functions; all transverse motions are taken into account, with exact kinematics, in the elementary interactions. The overall quality of the data is such that, for the first time, a rather well constrained extraction of the Sivers function for and quarks is possible and is performed. Comparisons with models are made. Based on the extracted Sivers functions, predictions for asymmetries at JLab are given; suggestions for further measurements at COMPASS, with a transversely polarized hydrogen target and selecting favorable kinematical ranges, are discussed. Predictions are also presented for single spin asymmetries in Drell-Yan processes at the Relativistic Heavy Ion Collider and the Facility for Antiproton and Ion Research at GSI-Darmstadt.
- Received 19 July 2005
- Corrected 14 November 2005
DOI:https://doi.org/10.1103/PhysRevD.72.094007
©2005 American Physical Society
Corrections
14 November 2005