violation is a necessary ingredient to create a matter-antimatter asymmetry. However, the amount of violation incorporated in the Standard Model is orders of magnitude too small to explain the observed asymmetry. This thesis documents two studies of violation with doubly charmed decays. Both were performed using Run I data collected by the LHCb experiment in collisions at the LHC. This corresponds to 1.0 fb collected at a centre-of-mass energy of 7 TeV and 2.0 fb collected at a centre-of-mass energy of 8 TeV.
The first analysis is a search for decays to two charm mesons, , where the second charm meson is either or , which are sensitive to the CKM angle \gamma. No evidence for signal is found and limits are set on twelve decay modes. The second analysis is the measurement of the asymmetry in decays. The results are
\begin{align*}
\mathcal{A}^{CP}(B^+\to D^+_{s} \overline{D}{}^0) &= (-0.4\pm 0.5\pm 0.5)%,\
\mathcal{A}^{CP}(B^+\to D^+ \overline{D}{}^0) &= (+2.3\pm 2.7\pm 0.4)%,
\end{align*}
where the first uncertainty is statistical and the second systematic. This is the first measurement of and the most precise measurement of to date. The results are consistent with symmetry.