Measurement of integrated $C\!P$ asymmetries in $\Lambda_b^0\to ph^-$ decays with the full Run 1+2 dataset from LHCb

In this thesis, a search for $C\!P$ violation in $\Lambda_b^0\to pK^-$ and $\Lambda_b^0\to pK^-$ 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, $\Lambda_b^0$ production, as well as detection asymmetries of final-state particles are needed to extract the physical $C\!P$ asymmetries and are determined in this thesis. The $C\!P$ asymmetries corresponding to the Run 1 dataset are measured to be \begin{align*} A_{C\!P}(pK^-) &= (0.09 \pm 1.53 \pm 0.72)\%, \\ A_{C\!P}(p\pi^-) &= (-0.52 \pm 1.89 \pm 0.56)\%, \end{align*} 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 $C\!P$ asymmetries corresponding to the Run 2 dataset are measured to be \begin{align*} A_{C\!P}(pK^-) &= (-1.45 \pm 0.75 \pm 0.43)\%, \\ A_{C\!P}(p\pi^-) &= (0.34 \pm 0.95 \pm 0.43)\%. \end{align*} When combining the values from Run 1 and Run 2 the following values are found \begin{align*} A_{C\!P}(pK^-) &= (-1.12 \pm 0.67 \pm 0.36)\%, \\ A_{C\!P}(p\pi^-) &= (0.15 \pm 0.85 \pm 0.36)\%, \end{align*} which are the world-best measurements of these asymmetries from a single experiment to date, and are compatible with the $C\!P$ symmetry conservation hypothesis within $1.5\sigma$ and $0.2\sigma$, respectively.