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arXiv · 0805.1752

The Gluon Distribution Function and Factorization in Feynman Gauge

J. C. Collins·T. C. Rogers
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Abstract

A complication in proving factorization theorems in Feynman gauge is that individual graphs give a super-leading power of the hard scale when all the gluons inducing the hard scattering are longitudinally polarized. With the aid of an example in gluon-mediated deep inelastic scattering, we show that, although the super-leading terms cancel after a sum over graphs, there is a residual non-zero leading term from longitudinally polarized gluons. This is due to the non-zero transverse momenta of the gluons in the target. The non-cancellation, due to the non-Abelian property of the gauge group, is necessary to obtain the correct form of the gluon distribution function as a gauge-invariant matrix element.

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J. C. Collins, T. C. Rogers. 2008-09-03. The Gluon Distribution Function and Factorization in Feynman Gauge. https://doi.org/10.1103/physrevd.78.054012

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