Metrological Uncertainties in the Integrated Luminosity Measurement with the Updated Design of a Detector at CEPC

In order to measure integrated luminosity with the required precision of 10⁻⁴ at the Z⁰ pole, the proposed CEPC e⁺e⁻ collider requires a luminometer, a specially designed calorimeter placed in the very forward region to identify Bhabha scattering at low polar angles. Usually, such a device is placed at the outgoing beams, to keep the spatial symmetries of the head-on collisions at accelerators with a nonzero crossing angle. At CEPC it is currently proposed to place the luminometer on the z-axis. We review the feasibility of measurement of the integrated luminosity at the Z⁰ pole with the required precision, focusing on the luminometer centered around the z-axis and the post-CDR beam properties.