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arXiv · hep-ph/9209287

Summing one-loop graphs in a theory with broken symmetry

B. H. Smith
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Abstract

The method suggested by Lowell Brown for calculating multi-particle threshold amplitudes is extended to the one-loop level in scalar theories with broken reflection symmetry. A result for the threshold amplitude for multiparticle production is derived. It is also shown that the tree-level amplitude for 2 on-mass-shell particles producing $n$ particles vanishes at the kinematical threshold for $n>2$

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B. H. Smith. 1992-09-28. Summing one-loop graphs in a theory with broken symmetry. https://doi.org/10.1103/physrevd.47.3518

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