This thesis describes the development, calibration and performance evaluation of an Opposite-side b flavor tagger using K mesons at a p{bar p} hadron collider. In particular, this work is performed using data collected by the Collider Detector at Fermilab (CDF) during the Run II of the Tevatron hadron collider running at {radical}s = 1.96 TeV. b flavor tagging consists of the determination of the flavor of the b quark contained within a hadron. This information is vital to perform any time-dependent measurement involving flavor asymmetries in b hadron decays and flavor oscillations, where it is necessary to know whether a b or {bar b} was contained in a hadron when it was produced. Although at a hadron collider the biggest challenge is probably to perform an effective selection of interesting events in real time and with the best signal-to-background ratio, the statistical significance of any time-dependent measurement is proportional to the effectiveness with which the selected data sample is tagged.

The search for and study of flavor oscillations in the neutral B{sub s}B{sub s} meson system is an experimentally challenging task. It constitutes a flagship analysis of the Tevatron physics program. In this dissertation, they develop an analysis of the time-dependent B{sub s} flavor oscillations using data collected with the CDF detector. The data samples are formed of both fully and partially reconstructed B meson decays: B{sub s} {yields} D{sub s}{pi}({pi}{pi}) and B{sub s} {yields} D{sub s}lv. A likelihood fitting framework is implemented and appropriate models and techniques developed for describing the mass, proper decay time, and flavor tagging characteristics of the data samples. The analysis is extended to samples of B{sup +} and B{sup 0} mesons, which are further used for algorithm calibration and method validation. The B mesons lifetimes are extracted. The measurement of the B{sup 0} oscillation frequency yields {Delta}m{sub d} = 0.522 {+-} 0.017 ps{sup -1}. The search for B{sub s} oscillations is performed using an amplitude method based on a frequency scanning procedure. Applying a combination of lepton and jet charge flavor tagging algorithms, with a total tagging power {epsilon}'D{sup 2} of 1.6%, to a data sample of 355 pb{sup -1}, a sensitivity of 13.0 ps{sup -1} is achieved. They develop a preliminary same side kaon tagging algorithm, which is found to provide a superior tagging power of about 4.0% for the B{sub s} meson species. A study of the dilution systematic uncertainties is not reported. From its application as is to the B{sub s} samples the sensitivity is significantly increased to about 18 ps{sup -1} and a hint of a signal is seen at about 175. ps{sup -1}. They demonstrate that the extension of the analysis to the increasing data samples with the inclusion of the same side tagging algorithm is capable of providing an observation of B{sub s} mixing beyond the standard model expectation. They show also that the improved knowledge of {Delta}m{sub s} has a considerable impact on constraining the CKM matrix elements.

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 BaBar experiment measures CP violation in the B meson system by analyzing the decays of B0B̄0 pairs in which one of the mesons decays into a CP eigenstate. By measuring the decay time distribution separately for B0 and B̄0 decays the CP violating asymmetry and sin 2[beta] can be measured. In order to measure the decay time distribution for the B0 and B̄0 decays, it is necessary to identify the flavor, or tag, of the second B meson. The flavor of the B meson is identified by an algorithm which analyzes physical processes which carry flavor information from its decay. Analyzing new physical processes could potentially improve the efficiency of the tagging algorithm. I tested the effect of adding subtaggers which estimated the flavor of the tag B based on the flavor or the charge of its D0 or Ds daughters. However due to the low yields and high backgrounds of reconstructed D0 and Ds candidates, these subtaggers were not effective at making a net contribution to the tagging process.

In 1947, the first of what have come to be known as "strange particles" were detected. As the number and variety of these particles proliferated, physicists began to try to make sense of them. Some seemed to have masses about 900 times that of the electron, and existed in both charged and neutral varieties. These particles are now called kaons (or K mesons), and they have become the subject of some of the most exciting research in particle physics. Kaon Physics at the Turn of the Millennium presents cutting-edge papers by leading theorists and experimentalists that synthesize the current state of the field and suggest promising new directions for the future study of kaons. Topics covered include the history of kaon physics, direct CP violation in kaon decays, time reversal violation, CPT studies, theoretical aspects of kaon physics, rare kaon decays, hyperon physics, charm: CP violation and mixing, the physics of B mesons, and future opportunities for kaon physics in the twenty-first century.

This book attempts to explain why 'string theory' may provide the comprehensive underlying theory that describes and explains our world. It is an enthusiastic view of how compactified string/M-theories (plus data that may be reachable) seem to have the possibilities of leading to a comprehensive underlying theory of particle physics and cosmology, perhaps soon. We are living in a hugely exciting era for science, one during which it may be possible to achieve a real and true understanding of our physical world.

The conference covered both the experimental and theoretical progress in the field of heavy quark physics and is of interest to readers who wish to stay current with the forefront of research in this field.