Model-Independent Measurement of the CKM Angle y in B±?[h+h-?+?-]Dh'±(h=K,?) Decays at LHCb and BESIIII

This book presents a striking demonstration of the synergies that exist between particle-physics experiments. A measurement is reported of the weak-phase ?, which is a fundamental parameter of the Standard Model and can be regarded as quantifying the amount of CP violation that is allowed by the theory. The parameter is measured through a determination of b-meson decays collected by the LHCb experiment at CERN. The b-mesons are reconstructed in a decay to a charm meson and a pion or a kaon, and the charm meson is itself reconstructed in one of two four-body final states (KK?? or ????). This is the first time these decay modes have been used in a ? measurement, which is itself a notable achievement of the thesis study. In order to interpret the measured observables in a theoretically clean manner, it is necessary to have knowledge of the dynamics of the charm-hadron decays. This knowledge is obtained from a study of charm-meson pair production in e+e- collisions at the psi(3770) resonance, using data collected by the BESIII experiment in Beijing. The quantum-correlations present in these decays give unique access to the required information, which is then imported back into the LHCb measurement. The precision obtained on ?is competitive with the most sensitive individual measurements so far performed of this parameter in other decay modes.