Transverse momentum dependent fragmentation functions from recent BELLE data

A new formalism for the factorization of the cross section for single-hadron production in e(+)e(-) annihilations, differential in z(h), P-T, and thrust, is applied to the phenomenological analysis of data recently measured by the BELLE Collaboration. Within this scheme the e(+)e(-) -> hX cross section can be recast in the convolution of a perturbatively calculable coefficient and a universal transverse-momentum-dependent fragmentation function. While performing a next-to-leading-order calculation of the perturbative part of the process to next-to-leading logarithmic accuracy, we examine and thoroughly discuss the suitability of a number of possible Ansatze to model the nonperturbative part of this universal transverse-momentum-dependent fragmentation function, showing the extent to which present experimental data can actually constrain its shape and functional form in terms of z(h), P-T, and thrust.