Generalized recurrence relations for two-loop propagator integrals with arbitrary masses

An algorithm for calculating two-loop propagator type Feynman diagrams with arbitrary masses and external momentum is proposed. Recurrence relations allowing one to express any scalar integral in terms of basic integrals are given. A minimal set consisting of 15 essentially two-loop and 15 products of one-loop basic integrals is found. Tensor integrals and integrals with irreducible numerators are represented as a combination of scalar ones with a higher space-time dimension which are reduced to the basic set by using the generalized recurrence relations proposed in Phys