B Lambda_b and Charm Results from the Tevatron

Recent results on $B_d$, $B_u^{\pm}$, $B_s$, $\Lambda_b$ and Charm hadrons are reported from $\approx$ 75pb$^{-1}$ and $\approx$ 40 pb$^{-1}$ of data accumulated at the upgraded CDF and D0 experiments at the Fermilab Tevatron $\bar{p}-p$ collider, during Run-II. These include lifetime and mass measurements of $B$ and Charm hadrons, searches for rare decays in charm and $B$ hadrons and CP-violation in Charm decays. Results relevant to CP-violation in B-decays are also reported.Comment: 10 pages, 8 figures (+ 1 photo) Physics in Collision 2003 PNC FRAT0

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

Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron

The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of $\sqrt s =1.96$ TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is $A_{\mathrm{FB}}^{t\bar{t}} = 0.128 \pm 0.025$. The combined inclusive and differential asymmetries are consistent with recent standard model predictions

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

The Level-3 Trigger at the CDF Experiment at Tevatron Run II

We describe the filtering and analysis software running in the Collider Detector at Fermilab (CDF) Run II Level-3 trigger, as well as the client- and event-driven data hub system. These systems constitute critical components of the data acquisition system of the CDF detector. The Level-3 trigger is responsible for reconstructing the events and forming the final trigger decision. The consumer-server/logger (CSL) system receives the accepted physics events from multiple connections and writes them to disk in multiple streams, while distributing them to online analysis programs (consumers). Since 2001, the system has been running successfully at high throughput rates: the Level-3 trigger reduces the event rate from 350 Hz to about 100 Hz with an average event size of 150 kB, while the CSL is able to process up to 22 MB/s of constant event logging. We describe these systems in detail and report on their current performance. We briefly outline upgrade plans for the remainder of Tevatron Run II. © 2005 IEEE.F.I. 1,7370info:eu-repo/semantics/publishe

High-precision measurement of the W boson mass with the CDF II detector

The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, MW, using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera–electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain MW=80,433.5±6.4stat±6.9syst=80,433.5±9.4 MeV/c2, the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega–electron volts; c, speed of light in a vacuum). This measurement is in significant tension with the standard model expectation.ISSN:0036-8075ISSN:1095-920