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arXiv · 1408.3233

Boundary terms in quantum field theory and the spin structure of QCD

Peter Lowdon
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Abstract

Determining how boundary terms behave in a quantum field theory (QFT) is crucial for understanding the dynamics of the theory. Nevertheless, boundary terms are often neglected using classical-type arguments which are no longer justified in the full quantum theory. In this paper we address this problem by establishing a necessary and sufficient condition for arbitrary spatial boundary terms to vanish in a general QFT. As an application of this condition we examine the issue of whether the angular momentum operator in Quantum Chromodynamics (QCD) has a physically meaningful quark-gluon decomposition. Using this condition it appears as though this is not the case, and that it is in fact the non-perturbative QCD structure which prevents the possibility of such a decomposition.

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Peter Lowdon. 2014-11-26. Boundary terms in quantum field theory and the spin structure of QCD. https://doi.org/10.1016/j.nuclphysb.2014.11.004

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