Double-spin cos(phi) Asymmetry in Semi-inclusive Electroproduction

Abstract

We consider the double-spin cos(phi) asymmetry for pion electroproduction in semi-inclusive deep inelastic scattering of longitudinally polarized leptons off longitudinally polarized protons. We estimate the size of the asymmetry in the approximation where all twist-3 interaction-dependent distribution and fragmentation functions are set to zero. In that approximation at HERMES kinematics a sizable negative cos(phi) double-spin asymmetry for pi+ electroproduction is predicted.

Comments: LaTeX, 5 pages, 2 figures. Minor changes, figure modified. Final version to appear in Phys.Lett. B