GENERALIZED RECURRENCE RELATIONS FOR 2-LOOP PROPAGATOR INTEGRALS WITHARBITRARY MASSES

An algorithm for calculating two-loop propagator type Feynman diagrams with arbitrary masses and external momentum is proposed. Recurrence r elations allowing one to express any scalar integral in terms of basic integrals are given. A minimal set consisting of 15 essentially two-l oop and 15 products of one-loop basic integrals is found. Tensor integ rals and integrals with irreducible numerators are represented as a co mbination 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. Rev. D 54 (1996) 6479. (C) 1997 Elsevier Science B. V.