Single target-spin asymmetries in semi-inclusive pion electroproduction on longitudinally polarized protons

We evaluate the single target-spin sin(phi_h) and sin(2φ_h) azimuthal asymmetries in the semi-inclusive deep inelastic lepton scattering off longitudinally polarized proton target under HERMES kinematic conditions. A good agreement with the HERMES data can be achieved using only the twist-2 distribution and fragmentation functions.