CP violation and material interaction of neutral kaons in measurements of the CKM angle γ using B ± → DK ± decays where D → K s 0 π + π −

As measurements of the CKM angleγin decays ofb-hadrons become increasingly precise, it is important to consider the impact of processes that affect secondary and tertiary decay products and can contribute to the observedCPviolation. The golden decay mode used to measureγisB→DK, whereD→Ks0π+π−. Due to the presence of aKs0meson in the final state,γmeasurements based on this mode are affected by neutral kaonCPviolation and matter regeneration, and this study examines the potential size of the impact. Previous studies determine the impact of kaonCPviolation to be a few degrees in size, but make simplifying assumptions about how experimental measurements are implemented. These assumptions are lifted in the present study, and the matter regeneration effect is included for the first time. The results are presented within the context ofγmeasurements to be made using the LHCb and Belle II detectors. It is found that the expected biases due to ignoring the effects ofCPviolation and matter regeneration in neutral kaons is small and less than 0.5° degrees in all experimental scenarios considered.