Extracting the \(\Lambda \) Polarizing Fragmentation Function from Belle e+e− Data within the TMD Formalism

Data from the Belle Collaboration for associated production (with a light unpolarized hadron) and single-inclusive production of transversely polarized Λ -hyperons in e + e − annihilation processes allowed to extract within a TMD approach, for the first time, the Λ 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 E ff ective 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.