Partonic Pole Matrix Elements for Fragmentation

TL;DR

A model-independent analysis of collinear three-parton correlation functions for fragmentation shows that the so-called partonic pole matrix elements vanish, which sheds new light on the understanding of transverse single spin asymmetries in various hard semi-inclusive reactions.

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.

Figures (2)

• Figure 1: Kinematics of the $qgq$ correlator in Eq. (\ref{['e:qgq']}). The wiggly line with the open circle indicates the component $F^{-i}_a$ of the gluon field strength tensor.
• Figure 2: Kinematics of the $ggg$ correlator in Eq. (\ref{['e:ggg']}). The wiggly lines with the open circles indicate the different components of the gluon field strength tensor.