Measurement of CKM-Angle Gamma with Charmed BO Meson Decays

摘要

This thesis reports measurements of the time-dependent CP asymmetries in fully reconstructed B(sup 0) (yields) (D(sup (*)(-+)) and B(sup 0) (yields) D(sup (-+)) (rho)(sup (+-))) decays in approximately 232 million (Upsilon)(4S) (yields) B(bar B) events, collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the Stanford Linear Accelerator Center in California. The phenomenon of CP violation allows one to distinguish between matter and antimatter, and, as such, is one of the essential ingredients needed to explain the apparent abundance of matter over antimatter in the universe. The Standard Model describes the observed elementary particles in terms of three generations of quarks and leptons, as well as the weak, electromagnetic, and strong interactions between them. In the Standard Model, CP violation is incorporated in the Cabibbo-Kobayashi-Maskawa (CKM) matrix, which describes the weak interactions between the quarks. The weak interactions between quarks are described by coupling constants that are functions of three real parameters and one irreducible complex phase. The magnitude of all CP violating effects in the Standard Model is related to this complex phase. The measurement of the CP violating phase of the CKM matrix is an important part of the present scientific program in particle physics. Violation of the CP symmetry manifests itself as a non-zero area of the Unitarity Triangle. The Unitarity Triangle needs to be overconstrained by experimental measurements in order to demonstrate that the CKM mechanism is the correct explanation of this phenomenon. No stringent measurement of the CKM-angle (gamma) is yet available.