Luminosity determination at LHCb during Run 3

The LHCb detector optimized its performance in Runs 1 and 2 by stabilizing the instantaneous luminosity during a fill by tuning the distance between the two colliding beams using a hardware-based trigger. In Run 3, the LHCb experiment has being upgraded to cope with the 5-fold increase of luminosity and now features a fully software-based trigger. A brand new luminometer, PLUME, has been installed and successfully commissioned. Additionally, new online proxies from nearly all sub-detectors are now used to provide measurements of luminosity, both integrated and per bunch-crossing. In addition, new offline counters are stored via a dedicated stream running at 30 kHz rate to allow for a precise offline calibration of the luminosity. This talk presents an overview of the new luminosity measurements at LHCb. The first results obtained using data collected during 2023 will also be shown, including the ghost charge fraction measurement using the beam-gas imaging technique.