47 research outputs found

### Present and Future CP Measurements

We review theoretical and experimental results on CP violation summarizing
the discussions in the working group on CP violation at the UK phenomenology
workshop 2000 in Durham.Comment: 104 pages, Latex, to appear in Journal of Physics

### Lectures in relativistic quantum mechanics: an introductory course for postgraduates in particle physics

This book is based on a series of lectures taught by the author to all incoming first year Oxford University postgraduates in experimental particle physics. It begins by deriving the Dirac equation and incorporating the electro-magnetic interaction and calculating several bread and butter processes at tree level using the Feynman Stueckelberg approach: Mott scattering, electron-electron scattering, electron-positron scattering, Compton scattering, Bremsstrahlung and electron-positron to muon-anti-muon. The intention is for the student to become fluent in detail with all the steps leading to the calculation of these processes. Every step is motivated using the most basic arguments

### Measurement of the CP violating phase [beta]s in B_s^0 [rightarrow] J/[psi][phi] decays

The CP violating phase βJ/ψφs is measured in decays of B0s → J/ψφ. This measurement uses 5.2 fb-1 of data collected in √—s = 1.96 TeV p̅p collisions at the Fermilab Tevatron with the CDF Run-II detector. CP violation in the B0s-̅B0sbar system is predicted to be very small in the Standard Model. However, several theories beyond the Standard Model allow enhancements to this quantity by heavier, New Physics particles entering second order weak mixing box diagrams. Previous measurements have hinted at a deviation from the Standard Model expectation value for βJ/ψφs with a significance of approximately 2σ. The measurement described in this thesis uses the highest statistics sample available to date in the B0s rightarrow; J/ψφ decay channel, where J/ψ → μ+ μ− and φ → K+K−. Furthermore, it contains several improvements over previous analyses, such as enhanced signal selection, fully calibrated particle ID and flavour tagging, and the inclusion of an additional decay component in the likelihood function. The added decay component considers S-wave states of KK pairs in the B0s → J/ψK+K− channel. The results are presented as 2-dimensional frequentist confidence regions for βJ/ψφs and ΔΓ (the width difference between the B0s mass eigenstates), and as a confidence interval for βJ/ψφs of [0.02,0.52] Ｕ [1.08, 1.55] at the 68 % confidence level. The measurement of the CP violating phase obtained in this thesis is complemented by the world's most precise measurement of the lifetime τs = 1.53 ± 0.025 (stat.) ± 0.012 (syst.) ps and decay width difference ΔΓ = 0.075 ± 0 .035 (stat.) ± 0.01 (syst.) ps−1 of the B0s meson, with the assumption of no CP violation.This thesis is not currently available in OR