Two-loop sunset diagrams with three massive lines

In this paper, we consider the two-loop sunset diagram with two different masses, m and M  , at spacelike virtuality q2=−m2q2=−m2. We find explicit representations for the master integrals and an analytic result through O(ɛ)O(ɛ) in d=4−2ɛd=4−2ɛ space–time dimensions for the case of equal masses, m=Mm=M.