Charm CP violation measurements with KS0 final states at LHCb

The LHCb collaboration achieved the world's most precise measurement of the ACP(D0 -> KS0 KS0) parameter using data collected during Run 2 (2015–2018), reaching a precision of 1.3% and observing compatibility with the absence of CP violation at a significance of 2.4σ.Following a major Upgrade I, LHCb resumed operations in 2022 with a completely overhauled tracking system and a novel triggerless readout architecture, capable of reconstructing events at the full LHC bunch crossing rate of 30 MHz.This thesis presents the design and optimization of dedicated KS0 triggers, aimed at enhancing the LHCb online selection efficiency of D0 -> KS0 KS0 decays.The new triggers have been commissioned with early Run 3 data; performed tests confirm the feasibility of this new trigger strategy, never implemented before at a hadron collider.With the availability of larger samples, the impact on signal efficiency has been evaluated, leading to a fourfold enhancement for the target decay D0 -> KS0 KS0.These performances motivated an early ACP(D0 -> KS0 KS0) measurement performed on 6 fb-1 of data collected by LHCb in 2024, that already surpassed the precision of the previous measurement.This measurement is a remarkable result, being the most precise determination of this parameter to date, and demonstrating the effectiveness of the new triggers in enhancing the physics reach of the LHCb experiment.