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arXiv · hep-ph/0106059

Kinematical twist-3 effects in DVCS as a quark spin rotation

A. V. Radyushkin·C. Weiss
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Abstract

We point out that the kinematical twist-3 contributions to the DVCS amplitude, required to restore electromagnetic gauge invariance of the twist-2 amplitude up to O(t/q^2), can be understood as a spin rotation applied to the twist-2 quark density matrix in the target. This allows for a compact representation of the twist-3 effects, as well as for a simple physical interpretation.

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A. V. Radyushkin, C. Weiss. 2001-06-05. Kinematical twist-3 effects in DVCS as a quark spin rotation. https://doi.org/10.1103/physrevd.64.097504

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