Test of the Universality of Naive-time-reversal-odd Fragmentation Functions

TL;DR

This paper tests the universality of naive-time-reversal-odd fragmentation functions by examining hyperon polarization in different scattering processes, revealing sign relations that probe initial/final state interactions and factorization.

Contribution

It provides a novel test of the universality of T-odd fragmentation functions through hyperon polarization measurements in $e^+e^-$ and deep inelastic scattering.

Findings

Sign relations among observables support universality.

Initial/final state interactions influence fragmentation.

Provides a method to test factorization assumptions.

Abstract

We investigate the ''spontaneous'' hyperon transverse polarization in $e^+e^-$ annihilation and semi-inclusive deep inelastic scattering processes as a test of the universality of the naive-time-reversal-odd transverse momentum dependent fragmentation functions. We find that universality implies definite sign relations among various observables. This provides a unique opportunity to study initial/final state interaction effects in the fragmentation process and test the associated factorization.