Measurement of 𝘾𝙋 violation in the decay 𝘽0→𝘿∗±𝘿∓ with data from the LHCb experiment

Abstract

This thesis presents the first LHCb measurement of 𝐶𝑃 violation in 𝐵0 → 𝐷∗±𝐷∓ decays. Due to the 𝑏 → 𝑐𝑐𝑑 transition, 𝐵0 → 𝐷∗±𝐷∓ decays give access to higher-order Standard Model contributions. The decay-time-dependent measurement is performed on a dataset 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 observables are measured with an unbinned maximum likelihood fit as 𝑆𝐷∗𝐷 = −0.861 ± 0.077 (stat) ± 0.019 (syst), Δ𝑆𝐷∗𝐷 = 0.019 ± 0.075 (stat) ± 0.012 (syst), 𝐶𝐷∗𝐷 = −0.059 ± 0.092 (stat) ± 0.020 (syst), Δ𝐶𝐷∗𝐷 = −0.031 ± 0.092 (stat) ± 0.016 (syst), 𝐴𝐷∗𝐷 = 0.008 ± 0.014 (stat) ± 0.006 (syst). To date, the analysis is the most precise single measurement of 𝐶𝑃 violation in this decay channel. All parameters are consistent with their current world average values.