The Sivers function is extracted from HERMES data on single spin asymmetries in semi-inclusive deeply inelastic scattering. Our analysis use a simple Gaussian model for the distribution of transverse parton momenta, together with the flavor dependence given by the leading 1/Nc approximation and a neglect of the Sivers antiquark distribution. We find that within the errors of the data these approximations are sufficient.
@article{arxiv.hep-ph/0509076,
title = {Sivers effect in semi-inclusive deeply inelastic scattering},
author = {J. C. Collins and A. V. Efremov and K. Goeke and S. Menzel and A. Metz and P. Schweitzer},
journal= {arXiv preprint arXiv:hep-ph/0509076},
year = {2009}
}
Comments
Small additions, Fig.2 corrected, references and one figure added, correction in Eq.(13), version accepted for publication