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arXiv · hep-ph/9908384

Covariance of Light-Front Models: Pair Current

J. P. B. C de Melo·T. Frederico·H. W. L. Naus·P. U. Sauer
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Abstract

We compute the "+" component of the electromagnetic current of a composite spin-one two-fermion system for vanishing momentum transfer component $q^+=q^0+q^3$. In particular, we extract the nonvanishing pair production amplitude on the light-front. It is a consequence of the longitudinal zero momentum mode, contributing to the light-front current in the Breit-frame. The covariance of the current is violated, if such pair terms are not included in its matrix elements. We illustrate our discussion with some numerical examples.

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J. P. B. C de Melo, T. Frederico, H. W. L. Naus, P. U. Sauer. 1999-08-17. Covariance of Light-Front Models: Pair Current. https://doi.org/10.1016/s0375-9474(99)00371-1

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