One-loop photonic corrections to Bhabha scattering in d=4-2ε dimensions

The luminosity measurement at the projected International Linear e+e- Collider ILC is planned to be performed with forward Bhabha scattering with an accuracy of the order of 10-4. A theoretical prediction of the differential cross-section has to include one-loop weak corrections, with leading higher order terms, and the complete two-loop QED corrections. Here, we present the weak part and the virtual one-loop photonic corrections. For the photonic corrections, the expansions in ε=(4-d)/2 are derived with inclusion of the terms of order ε in order to match the two-loop accuracy. For the photonic box master integral in d dimensions we compare several different methods of evaluation. (orig.)