CP violation in flavor-tagged Bs̳ --> J/[psi][phi] decays

Abstract

In this dissertation, we present the results of a time-dependent angular analysis of Bs -+ J/,0 decays performed with the use of initial-state flavor tagging. CP violation is observed in this mode through the interference of decay without net mixing and decay with net mixing, that is, Bs -- J/0 and Bs -+ B, -+ J/q0. The time-dependent angular analysis is used to extract the decay widths of the heavy and light B, eigenstates and the difference between these decay widths AF, - FL - FH. Initial-state flavor tagging is used to determine the matter-antimatter content of the B. mesons at production time. We combine flavor tagging with the angular analysis, which statistically determines the contributions of the CP-even and CP- odd components at decay time, to measure the CP-violating phase 0,. The phase 3, is expressed in terms of elements of the Cabibbo-Kobayashi-Maskawa matrix as s - arg (-VtsV4/VcsV*b), and is predicted by the Standard Model to be close to zero, O3SM = 0.02. In the measurement of AF,, we use a dataset corresponding to 1.7 fb- of luminosity, collected at the CDF experiment from proton-antiproton collisions at a center of mass energy f = 1.96 TeV. In the measurement of Ps, we use a dataset corresponding to 1.3 fb-1 of collected luminosity. We measure AF, = (0.071+0.064 ± 0.007) ps-1 using the time-dependent angular analysis. Combining the angular analysis with flavor-tagging, we find that assuming the Standard Model predictions of p/ and AF,, the probability of a deviation as large as the level of the observed data is 33%. We obtain a suite of associated results which are discussed in detail in this dissertation alongside the main results.