• charm
• CP violation
• detection asymmetry
• experimental particles physics
• LHCb
• neutral kaons

This thesis presents a high precision measurement of the asymmetry in detecting neutral kaons, K0 and K0bar, produced in charm hadrons decays. The analysis utilises data from pp collisions at a centre-of-mass energy of 13 TeV, collected with the LHCb detector during Run 2 (2016- 2018). The dataset includes approximately 50 million D+ —> KS0 pi+ signal candidates and 30 million D+ —> phi pi+ signal candidates.
This work is relevant for the search for CP-violating asymmetries in charm hadron decays. Precisely determining all charge asymmetric contributions, such as production and detector-induced effects, is essential to accurately measure CP violation. This is achieved by exploiting specific calibration channels, some of which include a neutral kaon in the final state.
This thesis models and quantifies the contribution to the neutral kaon detection asymmetry arising from the interference between the Cabibbo-Favoured and Doubly Cabibbo-Suppressed harm hadron decay amplitudes to final states containing a neutral kaon. It reports the first measurement of confidence intervals in the two-dimensional space of the parameters governing this interference, r and delta, for the D+ —> KS0 pi+ decay mode.
Additionally, the thesis presents the measurement of the direct CP asymmetry in the D+ —> phi pi+ channel, using the full LHCb Run 2 dataset. Both statistical and systematic uncertainties are assessed, slightly improving the result of the published LHCb analysis.