New Results for a Two-Loop Massless Propagator-Type Feynman Diagram

Abstract

We consider a two-loop massless propagator-type Feynman diagram with an arbitrary (noninteger) index on the central line. We analytically prove the equality of two well-known results in the literature expressing this diagram in terms of hypergeometric functions 3F2 of the respective arguments −1 and 1. We also derive new representations for this diagram, which can be important in practical calculations.