Transversity and inclusive two-pion production

Abstract

A model for dihadron fragmentation functions is briefly outlined, that describes the fragmentation of a quark in two unpolarized hadrons. The parameters are tuned to the output of the PYTHIA event generator for two-hadron semi-inclusive production in deep inelastic scattering at HERMES. Then, predictions are made for the unknown polarized fragmentation function and the related single-spin asymmetry in the azimuthal distribution of ${\pi }^{+}{\pi }^{-}$ pairs in semi-inclusive deep inelastic scattering on transversely polarized targets at HERMES and COMPASS. This asymmetry can be used to extract the quark transversity distribution.

Comments: 4 pages, 4 composite figures, talk presented at the 17th International Spin Physics Symposium (SPIN2006), Kyoto (Japan), October 2-7, 2006