Threshold expansion of the sunset diagram
High Energy Physics - Phenomenology
2010-11-15 v2 High Energy Physics - Theory
Abstract
By use of the threshold expansion we develop an algorithm for analytical evaluation, within dimensional regularization, of arbitrary terms in the expansion of the (two-loop) sunset diagram with general masses m_1, m_2 and m_3 near its threshold, i.e. in any given order in the difference between the external momentum squared and its threshold value, (m_1+m_2+m_3)^2. In particular, this algorithm includes an explicit recurrence procedure to analytically calculate sunset diagrams with arbitrary integer powers of propagators at the threshold.
Keywords
Cite
@article{arxiv.hep-ph/9903328,
title = {Threshold expansion of the sunset diagram},
author = {A. I. Davydychev and V. A. Smirnov},
journal= {arXiv preprint arXiv:hep-ph/9903328},
year = {2010}
}
Comments
26 pages (23 pages in LaTeX and 3 PS figures), a typo in eq.(23) corrected; final version to appear in Nucl.Phys.B