Luminosity scenarios for LHCb Upgrade II

The potential HL-LHC operational scenarios for LHCb Upgrade II are reviewed. Their impact on the physics performance of the LHCb Upgrade II experiment is described considering: the total integrated luminosity to be collected; the impact of beam-crossing angles on measurements of $CP$ violation; the effects of pile-up and the size of the luminous region. A maximum instantaneous luminosity of 1.5 × 1034 cm$^{−2}$s$^{−1}$ is recommended and detectors should be designed to withstand up to 350 fb$^{−1}$ during Run 5 and 6 (400 fb$^{−1}$ in Run 1-6). The RMS of the luminous region, spatially and temporally, should be maximised. Identical crossing angles for both magnet polarities is preferred as is collection of equal integrated luminosity in each configuration. From the scenarios currently presented, a purely vertical crossing plane during collisions best meets these requirements.