Threshold expansion of Feynman diagrams within a configuration space technique
High Energy Physics - Phenomenology
2009-10-31 v2 High Energy Physics - Experiment
High Energy Physics - Theory
Nuclear Theory
Abstract
The near threshold expansion of generalized sunset-type (water melon) diagrams with arbitrary masses is constructed by using a configuration space technique. We present analytical expressions for the expansion of the spectral density near threshold and compare it with the exact expression obtained earlier using the method of the Hankel transform. We formulate a generalized threshold expansion with partial resummation of the small mass corrections for the strongly asymmetric case where one particle in the intermediate state is much lighter than the others.
Cite
@article{arxiv.hep-ph/0003115,
title = {Threshold expansion of Feynman diagrams within a configuration space technique},
author = {S. Groote and A. A. Pivovarov},
journal= {arXiv preprint arXiv:hep-ph/0003115},
year = {2009}
}
Comments
36 pages LaTeX, 7 postscript figures included, a reference added