title: Partonic pole matrix elements for fragmentation.
abstract: A model-independent analysis of collinear three-parton correlation functions for fragmentation is performed. By investigating their support properties it is shown, in particular, that the so-called partonic pole matrix elements vanish. This sheds new light on the understanding of transverse single spin asymmetries in various hard semi-inclusive reactions. Moreover, it gives additional strong evidence for the universality of transverse-momentum-dependent fragmentation functions.
authors.affiliation: Institut für Theoretische Physik II, Ruhr-Universität Bochum, 44780 Bochum, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Meissner
authors.forename: A
authors.initials: A
authors.lastname: Metz