Speaker
Description
Recent BELLE measurements provide the cross section for single hadron production in e+e- annihilations, differential in the hadron transverse momentum with respect to the thrust axis. Universality breaking effects due to process-dependent soft factors make it very difficult to relate this cross section to that corresponding to hadron-pair production in e+e- annihilations, where TMD fragmentation functions are defined through the so-called "square-root definition". I will examine this correspondence in the framework of CSS factorization and provide the sketch of a scheme that might allow to relate 1-jet to 2-jet e+e- cross sections, neatly separating soft and collinear non-perturbative effects from the terms which can be calculated using a perturbative approach.
