Measurement of integrated CP asymmetries in Lb0->ph− decays with the full Run 1+2 dataset from LHCb

In this thesis, a search for CP violation in Lb0->pK− and Lb0->ppi− decays using the full Run 1+2 dataset gathered by the LHCb experiment is presented. The sample corresponds to an integrated luminosity of 9 fb−1 of proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV, collected between 2011 and 2018. Several corrections accounting for particle identification, trigger, Lb0 production, as well as detection asymmetries of final-state particles are needed to extract the physical CP asymmetries and are determined in this thesis. The CP asymmetries corresponding to the Run 1 dataset are measured to be ACP(pK−) = (0.09 ± 1.53 ± 0.72)%, ACP(ppi−) = (−0.52 ± 1.89 ± 0.56)%, where the first uncertainty is statistical and the second systematic. The results are compatible with the ones from a previous iteration of the analysis and supersede them thanks to a significant reduction in the systematic uncertainties. The CP asymmetries corresponding to the Run 2 dataset are measured to be ACP(pK−) = (−1.45 ± 0.75 ± 0.43)%, ACP(ppi−) = (0.34 ± 0.95 ± 0.43)%. When combining the values from Run 1 and Run 2 the following values are found ACP(pK−) = (−1.12 ± 0.67 ± 0.36)%, ACP(ppi−) = (0.15 ± 0.85 ± 0.36)%, which are the world-best measurements of these asymmetries from a single experiment to date, and are compatible with the CP symmetry conservation hypothesis within 1.5σ and 0.2σ, respectively.