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arXiv · hep-ph/9308278

Zeros of tree amplitudes at rest and symmetries of mechanical systems

M. V. Libanov·V. A. Rubakov·S. V. Troitsky
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Abstract

We consider the tree amplitudes of production of $n_2$ scalar particles by $n_1$ particles of another kind, where both initial and final particles are at rest and on mass shell, in a model of two scalar fields with $O(2)$ symmetric interaction and unequal masses. We find that these amplitudes are zero except for the lowest possible $n_1$ and $n_2$, and that the cancellation of the corresponding Feynman graphs occurs due to a special symmetry of the classical mechanical counterpart of this theory. This feature is rather general and is inherent in various other scalar field theories.

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M. V. Libanov, V. A. Rubakov, S. V. Troitsky. 1993-08-16. Zeros of tree amplitudes at rest and symmetries of mechanical systems. https://doi.org/10.1016/0370-2693(93)91796-p

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