The eld of particle physics explores elementary constituents of matter and interactions between them. During the last century remarkable achievements were made in this eld - smaller and smaller objects could be resolved. In this sense, the research objects gradually shifted from molecules over atoms and nucleons to point-like particles, which are assumed to be elementary. Interactions between these constituents are mediated by four fundamental forces. Three of them are described by the Standard Model of Particle Physics. Judged by its ability to describe observations and its capability to make predictions, this model is extremely successful. According to the standard model the constituents of matter are quarks and leptons. Both groups consist of six di erent species, so called avours, which may appear as particle or anti-particle. Quarks never appear as free particles. Only bound states of quark and anti-quark, called mesons, and three quarks, called baryons, are observed. The proton, for example, is composed of two up (u) and one down (d) quark. The focal point of this thesis is the B$0\atop{s}$ meson. In a nutshell, the thesis at hand has two aims: the first one is to calibrate a tagger using B$0\atop{s}$ oscillations and the second one is to improve the result (equation 1.1) on the mixing frequency itself.

Over the past decades the current theoretical description, the Standard Model of elementary particle physics, was solidified by many measurements as the basic theory describing fundamental particles and their interactions. It is extremely successful in explaining the high-precision data collected by experiments so far. The Standard Model includes several intrinsic parameters which have to be measured in experiments. Independent analyses of different physical processes can constrain those parameters. By combining those measurements physicists might be sensitive to physics beyond the Standard Model. If they are inconsistent it allows to get a hint on the theory that might supersede the Standard Model. The goal of the analysis presented in this thesis is to measure some of these parameters in the B{sub s} meson system. The B{sub s} meson, consisting of an anti-b and s quark, is not a pure mass eigenstate, thus allowing a B{sub s} meson to oscillate into its antiparticle via weak interacting processes. This is a general feature of any neutral meson. The history of meson mixing measurements is more then 50 years old. It was first observed in the kaon system. The oscillation in the B{sub d} system was measured very precisely by the B factories, whereas the oscillation frequency of the Bs was measured with more than 5[sigma] significance last year by CDF and first evidence for mixing in the D0 system was presented only this year.

The CDF collaboration has adapted several heavy flavor tagging techniques and employed them in analyses of time-dependent flavor asymmetries using data from the Tevatron Run I. The tagging algorithms were calibrated using low-P[sub t] inclusive lepton and dilepton trigger data samples. The tagging techniques were applied to a sample of [approximately] 400 B[sub d][sup 0]/[anti B][sub d][sup 0] [r-arrow] J/[psi]K[sub s][sup 0] decays and were used to measure the CP violation parameter, sin(2[beta]). Prospects for future improved measurements of the CP violation parameters at the Tevatron are briefly discussed.

This thesis reports on the final measurement of the flavor-mixing phase in decays of strange-bottom mesons (B_s) into J/psi and phi mesons performed in high-energy proton-antiproton collisions recorded by the Collider Experiment at Fermilab. Interference occurs between direct decays and decays following virtual particle-antiparticle transitions (B_s-antiB_s). The phase difference between transition amplitudes (“mixing phase”) is observable and extremely sensitive to contributions from non-standard-model particles or interactions that may be very hard to detect otherwise – a fact that makes the precise measurement of the B_s mixing phase one of the most important goals of particle physics. The results presented include a precise determination of the mixing phase and a suite of other important supplementary results. All measurements are among the most precise available from a single experiment and provide significantly improved constraints on the phenomenology of new particles and interactions.