6533b828fe1ef96bd12879e2

RESEARCH PRODUCT

Threshold expansion of the sunset diagram

Andrei I. DavydychevAndrei I. DavydychevVladimir A. Smirnov

subject

High Energy Physics - TheoryPhysicsNuclear and High Energy PhysicsParticle physicsDiagramMathematical analysisFOS: Physical sciencesPropagatorSunsetMomentumHigh Energy Physics - PhenomenologyDimensional regularizationHigh Energy Physics - Phenomenology (hep-ph)High Energy Physics - Theory (hep-th)IntegerOrder (group theory)

description

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.

https://doi.org/10.1016/s0550-3213(99)00269-2