TTP06-30 Standard and ε-finite master integrals for the ρ parameter

We have constructed an ε-finite basis of master integrals for all new types of one-scale tadpoles which appear in the calculation of the four-loop QCD corrections to the electroweak ρ-parameter. Using transformation rules from the ε-finite basis to the standard minimal-number-of-lines basis, we obtain as a by-product analytical expressions for few leading terms of the ε-expansion of all members of the standard basis. The new master integrals have been computed with the help of the Pade method and by use of difference equations independently.