Abstract

A [special characters omitted] meson can oscillate into its anti-particle, the [special characters omitted] meson, before decaying. CP violation in this system is made possible by the presence of amplitudes from both mixed and unmixed [special characters omitted] meson decays. The CP violating phase β _s appears in the interference between the decay amplitudes. The quantity sin(2β_s) is expected to be small in the standard model. Thus, measuring a large value for sin(2β _s) would be an unequivocal sign of new physics participation in the [special characters omitted] mixing loop diagram.

In this thesis, we present a latest measurement of sin(2β _s), using 5.2 fb^–1 of data collected at CDF from pp¯ collisions at a center of mass energy of [special characters omitted] = 1.96 TeV. A time-dependent angular analysis, with the production flavor of the [special characters omitted] meson identified with flavor tagging methods, is used to extract sin(2β _s) from ∼6500 [special characters omitted] → J/ψ&phis; decays. Other parameters of interest, such as the [special characters omitted] lifetime and the decay width difference ΔΓ between the heavy and light [special characters omitted] mass eigenstates are determined to high precision. Also, the effect of potential contributions to the final state from [special characters omitted] → J/ψf₀ and [special characters omitted] → J/ψK⁺K ^– decays is considered for the first time.

We present 68% and 95% confidence regions in the β _s – ΔΓ plane. The probability that the observed central value is a fluctuation of the data from the standard model expected value of β_s is calculated to be 44%. The observed confidence region shows better agreement with the standard model prediction than previous measurements.