Precision calculation of the γ-Z interference effect in the SLC/LEP luminosity process

We calculate the O(α) YFS exponentiated contribution of the Z boson, δZ, to the SLC/LEP luminosity process of low-angle Bhabha scattering. We realize our results via Monte Carlo methods and discuss their role in the theoretical uncertainty of the luminosity measurement. In the angular range 1.5°–3° we estimate the total precision of our results for δZ as 0.015%; in the angular range 3°–6° we estimate the total precision of our results for δZ as 0.09%. This represents a clear improvement over what is currently available in the literature, with which we make many cross-checks.