Leading and higher twist contributions in semi-inclusive e+e-   annihilation at high energies
  By applying the collinear expansion to the semi-inclusive hadron production process $e^++e^-\to h+\bar q(jet)+X$ at high energies, we construct a theoretical framework where the leading and higher twist contributions at the leading perturbative QCD can be calculated systematically. With this framework, we calculate the contributions up to twist-3 for spin-0, spin-1/2 and spin-1 hadrons respectively. We present the results for the hadronic tensors, the differential cross sections, the azimuthal asymmetries, and the polarizations of the hadrons. 
Shu-Yi Wei, Kai-bao Chen, Yu-kun Song, Zuo-tang Liang
hep-ph