Two-loop master integrals for e+e− → μ+μ− process with account of electron mass

A bstract We calculate a subset of two-loop master integrals relevant for the differential cross section of e + e − → μ + μ − process. We consider only those families for which the account of the electron mass m is necessary. Our results have the form of the Frobenius series in m with coefficients expressed via Goncharov’s polylogarithms.