New results for a two-loop massless propagator-type Feynman diagram
  We consider the two-loop massless propagator-type Feynman diagram with an arbitrary (non-integer) index on the central line. We analytically prove the equality of the two well-known results existing in the literature which express this diagram in terms of ${}_3F_2$-hypergeometric functions of argument $-1$ and $1$, respectively. We also derive new representations for this diagram which may be of importance in practical calculations. 
A. V. Kotikov and S. Teber
hep-th cond-mat.mes-hall hep-ph math-ph math.MP