FEYN CALC SYMBOL

D0


is the Passarino-Veltman D_0 function. The convention for the arguments is that if the denominator of the integrand has the form ([q^2-m1^2] [(q+p1)^2-m2^2] [(q+p2)^2-m3^2] [(q+p3)^2-m4^2] ), the first six arguments of D0 are the scalar products p10 = p1^2, p12 = (p1-p2)^2, p23 = (p2-p3)^2, p30 = p3^2, p20 = p2^2, p13 = (p1-p3)^2.