The authors present a preliminary measurement of CP-violating parameters S and C from fits of the time-dependence of B{sup 0} meson decays to {eta}'K{sub L}{sup 0}. The data were recorded with the BABAR detector at PEP-II and correspond to 232 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation through the {Upsilon}(4S) resonance. By fitting the time-dependent CP asymmetry of the reconstructed B{sup 0} {yields} {eta}'K{sub L}{sup 0} events, they find S = 0.60 {+-} 0.31 {+-} 0.04 and C = 0.10 {+-} 0.21 {+-} 0.03, where the first error quoted is statistical and the second is systematic. They also perform a combined fit using both {eta}'K{sub S}{sup 0} and {eta}'K{sub L}{sup 0} data, and find S = 0.36 {+-} 0.13 {+-} 0.03 and C = -0.16 {+-} 0.09 {+-} 0.02.

The authors present measurements of time-dependent CP-violation asymmetries for the decays B{sup 0} {yields} {eta}'K{sup 0}. The data sample corresponds to 347 million B{bar B} pairs produced by e{sup +}e{sup -} annihilation at the {Upsilon}(4S) resonance in the PEP-II collider, and collected with the BABAR detector. The preliminary results are S = 0.55 {+-} 0.11 {+-} 0.02, and C = -0.015 {+-} 0.07 {+-} 0.03, where the first error quoted is statistical, the second systematic.

This thesis describes a high-quality, high-precision method for the data analysis of an interesting elementary particle reaction. The data was collected at the Japanese B-meson factory KEKB with the Belle detector, one of the most successful large-scale experiments worldwide. CP violation is a subtle quantum effect that makes the world look different when simultaneously left and right and matter and antimatter are exchanged. This being a prerequisite for our own world to have developed from the big bang, there are only a few experimental indications of such effects, and their detection requires very intricate techniques. The discovery of CP violation in B meson decays garnered Kobayashi and Maskawa, who had predicted these findings as early as 1973, the 2008 Nobel prize in physics. This thesis describes in great detail what are by far the best measurements of branching ratios and CP violation parameters in two special reactions with two charm mesons in the final state. It presents an in-depth but accessible overview of the theory, phenomenology, experimental setup, data collection, Monte Carlo simulations, (blind) statistical data analysis, and systematic uncertainty studies.

The authors present an updated measurement of the time-dependent CP-violating asymmetry in B{sup 0} {yields} K{sub S}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0} decays based on 347 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The authors obtain the CP asymmetries S{sub f} = -0.66 {+-} 0.26 {+-} 0.08 and C{sub f} = -0.14 {+-} 0.22 {+-} 0.05, where the first uncertainties are statistical and the second systematic.