Two-Loop Kite Master Integral for a Correlator of Two Composite Vertices

Abstract

We consider a two-loop propagator-type Feynman integral with two composite external vertices as a function of two Bjorken variables $$x$$ , $$y$$ , arbitrary indices $${{n}_{i}}$$ of propagators and space-time dimension $$D$$ . The integral is evaluated in terms of a hypergeometric double series. We find a chain of reductions of this double series to simpler functions in some physically interesting situations. The Mellin moments of the integral are also considered.