O(α2) next-to-leading photonic corrections to small-angle Bhabha scattering in the structure function formalism

A general method for computing O(α2) and higher-order next-to-leading photonic corrections is presented and applied to the precision calculation of the small-angle Bhabha scattering cross section in the phase-space region of interest for the luminosity measurement at LEP. The formulation is based on a proper matching of exact O(α) results with higher-order corrections in the Structure Function formalism. The results of the approach are analytically compared with theoretical calculations, both for s- and t-channel processes, available for simple Event Selections. Numerical predictions for realistic Event Selections are also provided and critically compared with the ones existing in the literature.