Sivers effect in semi-inclusive deeply inelastic scattering

Abstract

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.

Comments: Small additions, Fig.2 corrected, references and one figure added, correction in Eq.(13), version accepted for publication