Fermionic NNLO contributions to Bhabha scattering

Abstract

We derive the two-loop corrections to Bhabha scattering from heavy fermions using dispersion relations. The double-box contributions are expressed by three kernel functions. Convoluting the perturbative kernels with fermionic threshold functions or with hadronic data allows to determine numerical results for small electron mass me, combined with arbitrary values of the fermion mass mf in the loop, m2 e ≪ s, t,m2 f , or with hadronic insertions. We present numerical results for mf = mμ,m ,mtop at typical small- and large-angle kinematics ranging from 1 GeV to 500 GeV.