Spectral Analysis of Gluonic Pole Matrix Elements

LP Gamberg, A Mukherjee, PJ Mulders - arXiv preprint arXiv:0807.1138, 2008 - arxiv.org
LP Gamberg, A Mukherjee, PJ Mulders
arXiv preprint arXiv:0807.1138, 2008arxiv.org
We use a spectator framework to investigate the spectral properties of quark-quark-gluon
correlators and use this to study gluonic pole matrix elements. Such matrix elements appear
in principle both for distribution functions such as the Sivers function and fragmentation
functions such as the Collins function. We find that the contribution of the gluonic pole matrix
element in fragmentation functions vanishes. This outcome is important in the study of
universality for fragmentation functions.
We use a spectator framework to investigate the spectral properties of quark-quark-gluon correlators and use this to study gluonic pole matrix elements. Such matrix elements appear in principle both for distribution functions such as the Sivers function and fragmentation functions such as the Collins function. We find that the contribution of the gluonic pole matrix element in fragmentation functions vanishes. This outcome is important in the study of universality for fragmentation functions.
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