Systematic uncertainties in integrated luminosity measurement at CEPC

The very forward region is one of the most challenging regions to instrument at a future $e^+e^-$ collider. At CEPC, machine-detector interface includes, among others, calorimeter dedicated for precision measurement integrated luminosity per mill level or better. Here we review feasibility such precision, from point view systematic effects arising luminometer mechanical and positioning, beam-related requirements physics background two-photon processes. impact beam energy spread its uncertainty on also discussed, as well achievable with post-CDR CEPC beams.