Hadron pair production in semi-inclusive electron positron annihilation process at twist-4

Fragmentation functions are important quantities in describing the hadronization process in high energy reactions. They can induce various azimuthal modulations which can be measured to reveal correlations between transverse momenta and polarizations. Without introducing initial state uncertainties, electron positron annihilation process is known as an ideal process to investigate the fragmentation functions. In this paper, therefore, we calculate the hadron pair production in the semi-inclusive electron positron annihilation process e(+)+e(-) -> h(1)+h(2)+(q) over bar +X at twist-4 to study dihadron fragmentation functions. Here (q) over bar denotes an antiquark that corresponds to a jet of hadrons in experiments. Together with single hadron fragmentation functions, dihadron fragmentation functions can provide additional ways to extract nucleon parton distribution functions from the semi-inclusive deeply inelastic scattering experiments with two detected final state hadrons. We calculate the differential cross section of the hadron pair production semi-inclusive electron positron annihilation process at twist-4 level. The calculation is carried out by using the collinear expansion method. We also calculate azimuthal asymmetries in terms of dihadron fragmentation functions. Contributions from four-quark correlator are also taken into account. Both the electromagnetic and weak interactions are considered in this paper.

Automated summary

This paper focuses on the importance of fragmentation functions in high energy reactions and the method of studying fragmentation functions using electron positron annihilation process. By calculating hadron pair production in the electron positron annihilation process, dihadron fragmentation functions can be studied, providing a new way to extract nucleon parton distribution functions.