Accessing Polarized Fragmentation Functions at the Unpolarized EIC and BELLE Experiments

TL;DR

This paper presents a practical method to measure polarized fragmentation functions of Lambda hyperons in unpolarized semi-inclusive deep-inelastic scattering and electron-positron annihilation, expanding the experimental avenues for probing these functions.

Contribution

It introduces a simple approach to measure azimuthal-angle-dependent polarization observables and connects them to structure and fragmentation functions at leading twist.

Findings

Method to measure azimuthal-angle-dependent polarization

Connection of observables to structure and fragmentation functions

Diversification of reactions probing polarized fragmentation functions

Abstract

We briefly report our recent progress on the study of the polarized fragmentation functions of $\Lambda$ hyperon in unpolarized semi-inclusive deep-inelastic scatterings and electron-positron annihilations at low energies. In particular, we present a simple but practical method on how to measure the azimuthal-angle-dependent longitudinal polarization and the transverse polarization inside the production plane and bridge these observables to the corresponding structure functions and fragmentation functions at the leading twist. Our work diversifies the high energy reactions that can probe the polarized fragmentation functions.