Interference Fragmentation Functions and the Nucleon's Transversity

Abstract

We introduce twist-two quark interference fragmentation functions in helicity density matrix formalism and study their physical implications. We show how the nucleon's transversity distribution can be probed through the final state interaction between two mesons ($π^+π^-$, $K\bar K$, or $πK$) produced in the current fragmentation region in deep inelastic scattering on a transversely polarized nucleon.

Figures (2)

• Figure 1: Hard scattering diagram for $\pi^+\pi^- (K\overline{K})$ production in the current fragmentation region of electron scattering from a target nucleon. In perturbative QCD the diagram (from bottom to top) factors into the products of distribution function, hard scattering, fragmentation function, and final state interaction. Helicity density matrix labels are shown explicitly.
• Figure 2: The factor, $\sin\delta_0 \sin\delta_1 \sin(\delta_0-\delta_1)$, as a function of the invariant mass $m$ of two-pion system. The data on $\pi\pi$ phase shifts are taken from Ref. martin74.