Azimuthal Dependence of DIS with Spin-1 Target
We study DIS with a spin-1 hadron or a nucleus polarized in arbitrary direction. The differential cross-section in this case will have an azimuthal dependence. We derive the dependence by including contributions from twist-2- and twist-3 QCD operators. The twist-3 contribution is computed at tree-level. A spin-1 hadron or nucleus can have nonzero tensor polarization. We find that all structure functions related to the tensor-polarization of the initial hadron can be extracted by study the azimuthal dependence. A nonzero result of the structure functions of a nucleus from experiment will indicate nontrivial inner structure of the nucleus.