This dissertation presents a measurement of the \(W^{\pm}Z\) production cross section and limits on anomalous triple gauge couplings in proton-proton collisions at a center of mass energy of 7 TeV using data produced by LHC collisions and acquired by the ATLAS detector in 2011. The measurement and limits probe the electroweak sector of the Standard Model at high energies and allow for generic tests for new physics that could be present at high energy scales. This analysis is also useful for understanding the ATLAS detector response in the presence of multi-lepton signatures. The dataset used corresponds to an integrated luminosity of \(1.02 fb^{−1}\). The measurement relies on the leptonic decay modes of the W and Z, resulting in final states with electrons, muons, and missing energy. Events are selected by requiring three high momentum leptons, a large missing transverse energy, a Z candidate (reconstructed from two of the leptons) with a mass consistent with the Z pole mass, and a W candidate (reconstructed from the third lepton and the missing energy) with a large transverse mass. The backgrounds to the \(W^{\pm}Z\) process are estimated using Monte Carlo simulations and Data-Driven techniques. A total of 71 \(W^{\pm}Z\) candidate events are observed in data, with 50.3 signal and 12.1 background events expected. The production cross section is extracted from these events using a maximum likelihood method, and is found to be in good agreement with the Standard Model expectation. Limits at the 95% confidence interval on anomalous triple gauge couplings are extracted from the observed event yields using a frequentist limit setting approach. / Physics

The objectives of this research were to provide a better understanding of particle motion in cascading rotary dryers. This would lead to more soundly based design procedures. Experiments were performed, to check the validity of a proposed design method for dryers operating in the under-loaded and design loaded conditions developed by Matchett and Baker, on a pilot plant rig at Teesside Polytechnic using wheat and sand in the absence of airflow. The model considers the particles to move in two parallel phases, the airborne phase contains the material in flight and the dense phase contains the remaining material which is caught on the flights and on the bottom of the drum. There is continuous Interchange of material between the two phases. A dimensionless number, dense phase velocity number 'a', has been defined which is a measure of the axial velocity of the material in the dense phase of the drum. The 'a' values were found to be in agreement with existing data and were found to be dependent on material and not on dryer speed or slope. Photographic studies of the dryer internals suggested that the assumption of a constant 0 value (measure of flight loading) In the original model was not valid and that 4) varied with number of flights. A model was developed to predict 0 which worked extremely well for large number of flights. The existing design model was therefore modified to take account of the variation In 4). However, the paired t-test Indicated that at 5% level of significance there was no difference between the original and the modified model, even though the modified model is physically more realistic. It is, however, recommended that the models be tested on a large number of flights and also large equipment, because It is expected that with a large number of flights there will be differences between the two models and the 0 model will be superior. The 'a' and am (the am value is a modified form of the 'a' value which takes into account the variation in flight loading) values were found to be Independent of operating conditions, flight angle and also dryer size but were dependent on material. The 'a' and am values were proportional to 1/number of flights. Particle motion in the dense is by bouncing, rolling and sliding, but the high dense phase velocity numbers obtained with zero flights (ar) suggested ii that rolling and sliding are the important mechanisms of the dense phase motion and may be far more important than bouncing. A model has also been developed to study the over-loaded regime. In the over-loaded regime It was found that dryer speed, slope, material and number of flights affected the dense phase motion and a simple relationship between the over-loaded dense phase velocity number (ao) and number of flights could not be developed with the limited data. Particle motion In the over-loaded regime was found to be very complex. The ao values could be predicted to within ± 35%. Estimates have been made of the transition holdup, marking the change from under-loaded to over-loaded behaviour, but It was found that the prediction of the transition holdup is also complex and could be predicted to within ± 45%. The am values could be predicted to an accuracy of ± 10%. Thus suggesting that the ao and the transition holdup numbers are not so reliable. Future work has been recommended particularly in the over-loaded regime and also on the transition region since it was found that the particle motion in these regions was complex. It has also been suggested that the models be tested in large Industrial units with and without air flow.

One of the most important issues in suspension polymerisation process is the control of the final particle size distribution (PSD) as this is an indicator for both quality and financial matters. For polymer manufacturers, a narrow PSD is always welcome. The conventional reactors, e. g. stirred tank reactors, generally produce particles of a rather broad PSD. As a result, to explore a new type of polymerisation devices becomes a challenging task. The objectives of this PhD study are to apply a novel mixing apparatus, the oscillatory baffled reactor (OBR), to batch polymerisation of MMA and Styrene (crosslinked) and to characterise all the major aspects of the OBR involved in the pioneering work, with a view to assessing its potential for industrial applications. In order to carry out such investigations, a 1.2 litre batch jacketed OBR system with temperature control and on-line data acquisition units was designed and built. In addition, an off-line image capture system was set up f or droplet studies. From heat transfer study in the OBR, it was found that the temperature profiles across and along the reactor were uniform and a heat transfer correlation was obtained. The oil-water dispersion in the OBR was then investigated for various baffle designs, dispersed phase fractions and the levels of surfactants, enabling the optimal baffle type and parameters to be identified. In order to understand the droplet behaviour in the OBR, the droplet size distribution (DSD) was examined on dispersion uniformity, oscillation time, operational conditions, baffle thickness and the level of surfactant addition. It was found that the DSDs were very uniform within the reactor and the oscillation frequency and amplitude had the same effect on controlling the DSDs. Finally, a series of PMMA and PS tests were successfully conducted in the OBR, indicating that the polymer PSD can be controlled by adjusting both oscillation conditions and the baffle orifice diameter and that the OBR has the potential to produce uniform polymer particles at high oscillation frequencies. A correlation between droplet sizes with no reaction and final polymer particle sizes was established, which can be used to predict the final polymer sizes.

No description available.

No description available.

Brookhaven National Laboratory experiment E949 was designed to search for the rare K meson decay K⁺ → π⁺ , neutrino, and anti-neutrino, a decay sensitive to physics beyond the Standard Model. While previous data analyses dealt with the high π⁺ momentum region accessible for this reaction, this thesis concentrates on the lower range between 140 and 199 MeV/c. Analysis of this low π⁺ momentum region was performed to search for additional evidence of the process K⁺ → π⁺, neutrino, and anti-neutrino. A blind analysis technique was used to avoid bias when developing the selection criteria used to suppress the competing background processes. The blind analysis technique was based on identifying background sources a priori and only examining the signal region once all selection criteria and background estimates had been finalized. The background estimates were performed using a technique known as a "bifurcation method", which relied on using two uncorrelated selection criteria to suppress each background source. The analysis of an exposure of 1.71 x 10¹² K⁺ decays resulted in an observation of three events with an estimated background of 0.927 ± 0.168(stat.)⁺³²⁰-₀.₂₃₇(sys.) events and a single event sensitivity of (4.28 ± 0.43)x 10-¹⁰. Using a likelihood method, the three candidate events observed here were combine with the previous E787 and E949 results, yielding a branching ratio of ϐ(K⁺ → π⁺, neutrino, and anti-neutrino decay of (1.73+1.15-1.05) x 10⁻¹⁰ at the 68% confidence level. This branching ratio is consistent with the prediction of the Standard Model, (0.85 ± 0.07) x 10⁻¹⁰.

In this thesis we examine the method of counting BB events produced in the BaBar experiment. The original method was proposed in 2000, but improvements to track reconstruction and our understanding of the detector since that date make it appropriate to revisit the B Counting method. We propose a new set of cuts designed to minimize the sensitivity to time-varying backgrounds. We find the new method counts BB events with an associated systematic uncertainty of ±0.6%.

No description available.

The neutrino fluxes from the neutral current (NC), charged current (CC), and elastic scattering (ES) neutrino interactions in the salt phase of SNO have been extracted. The signals were extracted above an energy threshold of 4MeV, which is the lowest energy threshold at which the neutrino signals have been extracted from SNO to date. To achieve this low energy threshold the internal and external radioactive background signals have also been measured. The $^{8}$B neutrino fluxes for the 4MeV threshold were found to be \begin{eqnarray*} \Phi_{CC} & = & 1.60 ~^{+0.04}_{-0.04}~(\mbox{stat}) ~^{+0.06}_{-0.06}~(\mbox{syst}) \times 10^6 \mbox{cm}^{-2} \mbox{sec}^{-1},\\ \Phi_{NC} & = & 4.84 ~^{+0.16}_{-0.16}~(\mbox{stat}) ~^{+0.29}_{-0.32}~(\mbox{syst}) \times 10^6 \mbox{cm}^{-2} \mbox{sec}^{-1},\\ \Phi_{ES} & = & 2.75 ~^{+0.23}_{-0.23}~(\mbox{stat}) ~^{+0.25}_{-0.26}~(\mbox{syst}) \times 10^6 \mbox{cm}^{-2} \mbox{sec}^{-1}. \end{eqnarray*} \noindent These results are in agreement with the values published in ~\cite{SNO3} and the NC flux is in agreement with the standard solar model calculation from ~\cite{bp2004}. The published fluxes were \begin{eqnarray*} \Phi_{CC} &= & 1.68 ~^{+0.06}_{-0.06}~(\mbox{stat}) ~^{+0.08}_{-0.09}~(\mbox{syst}) \times 10^6 \mbox{cm}^{-2} \mbox{sec}^{-1} , \\ \Phi_{NC} &= & 4.94 ~^{+0.21}_{-0.21}~(\mbox{stat}) ~^{+0.38}_{-0.34}~(\mbox{syst}) \times 10^6 \mbox{cm}^{-2} \mbox{sec}^{-1}, \\ \Phi_{ES} &= & 2.35 ~^{+0.22}_{-0.22}~(\mbox{stat}) ~^{+0.15}_{-0.15}~(\mbox{syst}) \times 10^6 \mbox{cm}^{-2} \mbox{sec}^{-1}. \end{eqnarray*} \noindent The uncertainties on the extracted NC and CC fluxes are significantly smaller than on the published values. A comparison of the total uncertainty from flux measurements presented here and those published are given below. \begin{table}[htp] \begin{center} \begin{tabular}{|c|c|c|} \hline & uncertainties presented here (\%) & uncertainties from ~\cite{SNO3} (\%) \\ \hline $\Phi_{CC}$ & $~^{+4.6}_{-4.4}$ & $~^{+5.9}_{-6.4}$ \\ \hline $\Phi_{NC}$ & $~^{+6.8}_{-7.4}$ & $~^{+8.9}_{-8.2}$ \\ \hline $\Phi_{ES}$ & $~^{+12.3}_{-12.6}$ & $~^{+11.3}_{-11.3}$ \\ \hline \end{tabular} \label{funcert1} \end{center} \end{table} The shape of the CC energy spectrum has also been extracted with the 4MeV energy threshold. The uncertainties on the extracted fluxes are smaller than what was previously published. The CC spectrum gives a measure of the neutrino energy shape distortion due to neutrino oscillations. The uncertainties on the lowest energy bins in the extracted CC spectrum are much larger than the predicted distortion. We are therefore not sensitive to the upturn in the neutrino survival probability at lower energies predicted by neutrino oscillations in the large mixing angle (LMA) region. / Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2007-12-19 13:58:16.601

No description available.