Measurement of CP violation in B0→ D∗±D∓ decays

The decay-time-dependent CP asymmetry in B0→ D∗±D∓ decays is mea- sured using a data set corresponding to an integrated luminosity of 9 fb−1 recorded by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The CP parameters are measured as$$ {\displaystyle \begin{array}{c}{S}_{D\ast D}=-0.861\pm 0.077\left(\mathrm{stat}\right)\pm 0.019\left(\mathrm{syst}\right),\\ {}\varDelta {S}_{D\ast D}=0.019\pm 0.075\left(\mathrm{stat}\right)\pm 0.012\left(\mathrm{syst}\right),\\ {}{C}_{D\ast D}=-0.059\pm 0.092\left(\mathrm{stat}\right)\pm 0.020\left(\mathrm{syst}\right),\\ {}{\varDelta C}_{D\ast D}=-0.031\pm 0.092\left(\mathrm{stat}\right)\pm 0.016\left(\mathrm{syst}\right),\\ {}{\mathcal{A}}_{D\ast D}=\kern0.75em 0.008\pm 0.014\left(\mathrm{stat}\right)\pm 0.006\left(\mathrm{syst}\right).\end{array}} $$ The analysis provides the most precise single measurement of CP violation in this decay channel to date. All parameters are consistent with their current world average values.