Expansion by regions: revealing potential and Glauber regions automatically
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When performing asymptotic expansions using the strategy of expansion by regions, it is a non-trivial task to find the relevant regions. The recently published Mathematica code asy.m automates this task, but it has not been able to detect potential regions in threshold expansions or Glauber regions. In this work we present an algorithm and its implementation in the update asy2.m which also reveals potential and Glauber regions automatically.
KeywordsDelta Function Parametric Representation Loop Momentum Feynman Integral Collinear Region
This work is supported by the Deutsche Forschungsgemeinschaft Sonderforschungsbereich/Transregio 9 “Computergestützte Theoretische Teilchenphysik”. The work of A.S. and V.S. is also supported by the Russian Foundation for Basic Research through grant 11-02-01196. The authors thank M. Beneke and A. Pak for helpful discussions.