# Transversity 2022

May 23 – 27, 2022
Almo Collegio Borromeo, Pavia, Italy
Europe/Rome timezone

## Transverse $Lambda$-hyperon polarization in e+e- annihilation processes within the TMD formalism.

May 24, 2022, 4:30 PM
15m
Almo Collegio Borromeo, Pavia, Italy

#### Almo Collegio Borromeo, Pavia, Italy

P.zza Borromeo 9 27100 Pavia Italy
Standard talk

### Speaker

Marco Zaccheddu (Istituto Nazionale di Fisica Nucleare)

### Description

Data from Belle Collaboration for associated (with a light unpolarized hadron) and single-inclusive production of transversely polarized $\Lambda$-hyperons in $e^+e^-$ annihilation processes allowed to extract, for the first time, the $\Lambda$ polarizing fragmentation function, by adopting a simplified TMD approach. Recent theoretical developments on the computation of cross sections for single-inclusive hadron production in $e^+e^-$ annihilation, within a Soft Collinear Effective Theory approach, combined with the CSS formalism for the double-hadron production case, have been used to perform a renewed analysis, adopting a proper TMD factorization scheme. A detailed a comparison with the former analysis will be discussed. Preliminary estimates for the transverse $\Lambda$ polarization at OPAL and at $\sqrt s = M_Z$ will also be presented.

### Primary authors

Marco Zaccheddu (Istituto Nazionale di Fisica Nucleare) Umberto D'Alesio (Istituto Nazionale di Fisica Nucleare) Leonard Gamberg (Penn State University) Francesco Murgia (Istituto Nazionale di Fisica Nucleare)