Extracting the $\Lambda$ Polarizing Fragmentation Function from Belle $e^+e^-$ Data Within the TMD Formalism

TL;DR

This paper extracts the $\Lambda$ polarizing fragmentation function from Belle $e^+e^-$ data using a TMD formalism, providing new insights into hyperon polarization phenomena in high-energy collisions.

Contribution

It presents the first extraction of the $\Lambda$ polarizing fragmentation function within a TMD approach from $e^+e^-$ data, incorporating recent theoretical developments.

Findings

First extraction of $\Lambda$ polarization function from Belle data.

Comparison between TMD and SCET-based analyses.

Preliminary results showing consistency with theoretical models.

Abstract

Data from the Belle Collaboration for associated production (with a light unpolarized hadron) and single-inclusive production of transversely polarized $\Lambda$-hyperons in $e^+e^-$ annihilation processes allowed to extract within a TMD approach, for the first time, the $\Lambda$ polarizing fragmentation function. Recent theoretical developments on the computation of cross sections for single-inclusive hadron production in $e^+e^-$ annihilation processes, within a Soft Collinear Effective Theory approach, combined with the CSS formalism for the double-hadron production case, can be used to perform a renewed analysis, adopting a full TMD factorization scheme. Preliminary results and a comparison between the two analyses are presented.