arXiv subjects
Publications and source records attributed to H. R. Avakian.
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.
We investigate the $sin ϕ$ azimuthal asymmetry in the semi-inclusive deep-inelastic lepton scattering off longitudinally polarized nucleon target arising from the time reversal odd structures. The order 1/Q contributions of the leading twist and twist-three distribution and fragmentation functions to that asymmetry for the certain kinematical conditions are numerically estimated.
We consider the azimuthal asymmetries in semi-inclusive deep inelastic leptoproduction arising due to both perturbative and nonperturbative effects at HERMES energies and show that the $k_T^2/Q^2$ order corrections to $< \cosϕ>$ and $< \cos2ϕ>$ are significant. We also reconsider the results of perturbative effects for $< \cosϕ>$ at large momentum transfers \cite{A1} using the more recent sets of scale-dependent distribution and fragmentation functions, which bring up to $18{%}$ difference in $< \cosϕ>$. In the same approach we calculate the $< \cos2ϕ>$ as well.