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482 Matching Results
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Resonant second generation slepton production at the Tevatron
None
Date:
December 1, 2006
Creator:
Autermann, Christian Tobias
System:
The UNT Digital Library
Time-varying Reeb Graphs: A Topological Framework Supporting the Analysis of Continuous Time-varying Data
I present time-varying Reeb graphs as a topological framework to support the analysis of continuous time-varying data. Such data is captured in many studies, including computational fluid dynamics, oceanography, medical imaging, and climate modeling, by measuring physical processes over time, or by modeling and simulating them on a computer. Analysis tools are applied to these data sets by scientists and engineers who seek to understand the underlying physical processes. A popular tool for analyzing scientific datasets is level sets, which are the points in space with a fixed data value s. Displaying level sets allows the user to study their geometry, their topological features such as connected components, handles, and voids, and to study the evolution of these features for varying s. For static data, the Reeb graph encodes the evolution of topological features and compactly represents topological information of all level sets. The Reeb graph essentially contracts each level set component to a point. It can be computed efficiently, and it has several uses: as a succinct summary of the data, as an interface to select meaningful level sets, as a data structure to accelerate level set extraction, and as a guide to remove noise. I extend these uses …
Date:
November 28, 2006
Creator:
Mascarenhas, A
System:
The UNT Digital Library
Measurement of the Strange Quark Contribution to Proton Structure through Parity Violating Electron-Proton Scattering
The G0 (G-Zero) forward angle experiment completed in Hall C of the Thomas Jefferson National Accelerator Facility (TJNAF) has measured the parity violating asymmetries in elastic electron-proton scattering over a Q2 range of 0.12 < Q2 < 1.0 (GeV/c)2. A linear combination of the strange electric (GsE) and magnetic (GsM) form factors calculated from these asymmetries indicate a non-zero contribution of the strange quark to the charge and magnetization structure of the proton in the above kinematic range at a 89% confidence level. The results show a previously unmeasured Q2 dependence of the strange form factors. Combining the G0 results with previous parity violating experiments show that at Q2 = 0.1 (GeV/c)2 GsM = 0.62+-0.31 GsE = -0.013+-0.028 At intermediate Q2 of about 0.23 (GeV/c)2, a consistent value of GsM is seen compared to previous experiments, together with a measurement that may imply a negative value of GsE. For Q2 above 0.5 (GeV/c)2 a consistently positive value for the linear combination of the strange form factors is seen.
Date:
May 1, 2006
Creator:
Nakahara, Kazutaka
System:
The UNT Digital Library
Measurement of the t-tbar production cross section in p-pbar collisions at s**(1/2) = 1.96 TeV using lepton+jets events in the CDF detector at Fermilab
The top quark is the most massive fundamental particle observed so far, and the study of its properties is interesting for several reasons ranging from its possible special role in electroweak symmetry breaking to its sensitivity to physics beyond the standard model (SM). In particular, the measurement of the top quark pair production cross section {sigma}{sub t{bar t}} is of interest as a test of QCD predictions. Recent QCD calculations done with perturbation theory to next-to-leading order predict {sigma}{sub t{bar t}} with an uncertainty of less than 15%, which motivate measurements of comparable precision. In this thesis, the author reports a measurement of the cross section for pair production of top quarks in the lepton+jets channel in 318 pb{sup -1} of p{bar p} collision data at {radical}s = 1.96 TeV. The data were recorded between March 2002 and September 2004, during Run II of the Tevatron, by the CDF II detector, a general purpose detector which combines charged particle trackers, sampling calorimeters, and muon detectors. processes in which a W boson is produced in association with several jets with large transverse momentum can be misidentified at t{bar t}, since they have the same signature. In order to separate the t{bar …
Date:
December 1, 2006
Creator:
Palencia, Enrique
System:
The UNT Digital Library
Measurements of the B Production Cross Section in Proton-Antiproton Collisions at s**(1/2) = 1.96 TeV using semileptonic decays of b hadrons
The authors present a measurement of the cross section of b hadron (H{sub b}) production in p{bar p} collisions at {radical}s = 1.96 TeV using the CDF II detector at the Fermilab Tevatron. They use 83 pb{sup -1} of data taken between october 2002 and May 2003 that was collected with a trigger sensitive to high momentum muons and displaced tracks. They use partially reconstructed decays in the following modes: H{sub b} {yields} {mu}{sup -} {bar {nu}}{sub {mu}}D{sup 0}X, D{sup 0} {yields} K{sup -}{pi}{sup +}, and H{sub b} {yields} {mu}{sup -}{bar {nu}}{sub {mu}}D*{sup +} X, D*{sup +} {yields} D{sup 0}{pi}{sup +}, D{sup 0} {yields} K{sup -} {pi}{sup +}, and their charge conjugates. They correct for the backgrounds from c{bar c} and b{bar b} decays, for trigger and reconstruction efficiencies, and for detector acceptance. They report the total cross section above a minimum transverse momentum (p{sub T}) of 9 GeV/c for the rapidity range |y| {le} 0.6.
Date:
July 1, 2006
Creator:
Kraus, James Alexander
System:
The UNT Digital Library
Novel Aryne Chemistry in Organic Synthesis
Arynes are among the most intensively studied systems in chemistry. However, many aspects of the chemistry of these reactive intermediates are not well understood yet and their use as reagents in synthetic organic chemistry has been somewhat limited, due to the harsh conditions needed to generate arynes and the often uncontrolled reactivity exhibited by these species. Recently, o-silylaryl triflates, which can generate the corresponding arynes under very mild reaction conditions, have been found very useful in organic synthesis. This thesis describes several novel and useful methodologies by employing arynes, which generate from o-silylaryl triflates, in organic synthesis. An efficient, reliable method for the N-arylation of amines, sulfonamides and carbamates, and the O-arylation of phenols and carboxylic acids is described in Chapter 1. Amines, sulfonamides, phenols, and carboxylic acids are good nucleophiles, which can react with arynes generated from a-silylaryl triflates to afford the corresponding N- and O-arylated products in very high yields. The regioselectivity of unsymmetrical arynes has also been studied. A lot of useful, functional groups can tolerate our reaction conditions. Carbazoles and dibenzofurans are important heteroaromatic compounds, which have a variety of biological activities. A variety of substituted carbazoles and dibenzofwans are readily prepared in good to excellent …
Date:
December 12, 2006
Creator:
Liu, Zhijian
System:
The UNT Digital Library
Search for 3rd Generation Vector Leptoquarks in the Di-tau Di-jet Channel in Proton Antiproton Collisions at square root s = 1.96 TeV
We search for third generation vector leptoquarks (V LQ3) produced in colliding p{bar p} beams operating at {radical}s = 1.96 TeV at the CDF experiment in Run II of the Fermilab Tevatron. We use 322 pb{sup -1} of data to search for the V LQ3 signal in the di-tau plus di-jet channel. For the first time, the full matrix element is used in the Monte Carlo simulation of this signal. With no events observed in the signal region, we set a 95% C.L. upper limit on the V LQ3 pair production cross section of {sigma} < 344fb, assuming Yang-Mills couplings and Br(V LQ3 {yields} b{tau}) = 1, and a lower limit on the V LQ3 mass of m{sub V LQ3} > 317 GeV=c{sup 2}. If theoretical uncertainties on the cross section are applied in the least favorable manner the results are {sigma} < 360fb and m{sub V LQ3} > 294 GeV=c{sup 2}. The Minimal coupling V LQ3 result is an upper limit on the cross section of {sigma} < 493fb ({sigma} < 610fb) and the lower limit on the mass is m{sub V LQ3} > 251 GeV=c{sup 2} (m{sub V LQ3} > 223 GeV=c{sup 2}) for the nominal (1{sigma} varied) …
Date:
December 1, 2006
Creator:
Forrester, Stanley Scott
System:
The UNT Digital Library
Identification of electrons in the forward region of the CDF experiment for the search for electroweak top quark production
None
Date:
February 1, 2006
Creator:
Kemp, Yves
System:
The UNT Digital Library
Search for t-Channel Single Top Quark Production in p anti-p Collisions at 1.96 TeV
I have performed a search for t-channel single top quark production in p{bar p} collisions at 1.96 TeV on a 366 pb{sup -1} dataset collected with the D0 detector from 2002-2005. The analysis is restricted to the leptonic decay of the W boson from the top quark to an electron or muon, tq{bar b} {yields} lv{sub l}b q{bar b} (l = e,{mu}). A powerful b-quark tagging algorithm derived from neural networks is used to identify b jets and significantly reduce background. I further use neural networks to discriminate signal from background, and apply a binned likelihood calculation to the neural network output distributions to derive the final limits. No direct observation of single top quark production has been made, and I report expected/measured 95% confidence level limits of 3.5/8.0 pb.
Date:
June 1, 2006
Creator:
Perea, Philip Michael & /UC, Riverside
System:
The UNT Digital Library
SEARCH FOR HIGH-MASS RESONANCES DECAYING TO e-mu IN ppbar COLLISIONS AT s**(1/2) = 1.96 TeV
We describe a general search for resonances decaying to a neutral e{mu} final state in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. Using a data sample representing 344 pb{sup -1} of integrated luminosity recorded by the CDF II experiment, we compare Standard Model predictions with the number of observed events for invariant masses between 50 and 800 GeV/c{sup 2}. Finding no significant excess (5 events observed vs. 7.7 {+-} 0.8 expected for M{sub e{mu}} > 100 GeV/c{sup 2}), we set limits on sneutrino and Z' masses as functions of lepton family number violating couplings.
Date:
August 1, 2006
Creator:
Hahn, Kristian Allan
System:
The UNT Digital Library
Heat Transfer Analysis and Assessment of Kinetics Systems for PBX 9501
The study of thermal decomposition in high explosive (HE) charges has been an ongoing process since the early 1900s. This work is specifically directed towards the analysis of PBX 9501. In the early 1970s, Dwight Jaeger of Los Alamos National Laboratory (LANL) developed a single-step, two-species kinetics system that was used in the development of one of the first finite element codes for thermal analyses known as EXPLO. Jaeger's research focused on unconfined spherical samples of HE charges to determine if varied heating ramps would cause detonation or deflagration. Tarver and McGuire of Lawrence Livermore National Laboratory (LLNL) followed soon after with a three-step, four-species kinetics system that was developed for confined spheres under relatively fast heating conditions. Peter Dickson et al. of LANL then introduced a kinetics system with four steps and five species that included bimolecular products to capture the effects of the endothermic phase change that the HE undergoes. The results of four experiments are examined to study the effectiveness of these kinetics systems. The experiments are: (1) The LLNL scaled thermal explosion (STEX) experiments on confined cylindrical charges with long heating ramps in the range of 90 hours. (2) The LLNL one-dimensional time to explosion (ODTX) …
Date:
July 31, 2006
Creator:
Jorenby, Jeffrey W.
System:
The UNT Digital Library
A measurement of the top quark mass with a matrix element method
The authors present a measurement of the mass of the top quark. The event sample is selected from proton-antiproton collisions, at 1.96 TeV center-of-mass energy, observed with the CDF detector at Fermilab's Tevatron. They consider a 318 pb{sup -1} dataset collected between March 2002 and August 2004. They select events that contain one energetic lepton, large missing transverse energy, exactly four energetic jets, and at least one displaced vertex b tag. The analysis uses leading-order t{bar t} and background matrix elements along with parameterized parton showering to construct event-by-event likelihoods as a function of top quark mass. From the 63 events observed with the 318 pb{sup -1} dataset they extract a top quark mass of 172.0 {+-} 2.6(stat) {+-} 3.3(syst) GeV/c{sup 2} from the joint likelihood. The mean expected statistical uncertainty is 3.2 GeV/c{sup 2} for m{sub t} = 178 GTeV/c{sup 2} and 3.1 GeV/c{sup 2} for m{sub t} = 172.5 GeV/c{sup 2}. The systematic error is dominated by the uncertainty of the jet energy scale.
Date:
December 1, 2006
Creator:
Gibson, Adam Paul
System:
The UNT Digital Library
Under-sampling in a Multiple-Channel Laser Vibrometry System
Laser vibrometry is a technique used to detect vibrations on objects using the interference of coherent light with itself. Most vibrometry systems process only one target location at a time, but processing multiple locations simultaneously provides improved detection capabilities. Traditional laser vibrometry systems employ oversampling to sample the incoming modulated-light signal, however as the number of channels increases in these systems, certain issues arise such a higher computational cost, excessive heat, increased power requirements, and increased component cost. This thesis describes a novel approach to laser vibrometry that utilizes undersampling to control the undesirable issues associated with over-sampled systems. Undersampling allows for significantly less samples to represent the modulated-light signals, which offers several advantages in the overall system design. These advantages include an improvement in thermal efficiency, lower processing requirements, and a higher immunity to the relative intensity noise inherent in laser vibrometry applications. A unique feature of this implementation is the use of a parallel architecture to increase the overall system throughput. This parallelism is realized using a hierarchical multi-channel architecture based on off-the-shelf programmable logic devices (PLDs).
Date:
August 15, 2006
Creator:
Corey, J
System:
The UNT Digital Library
Genotyping and Bioforensics of Ricinus communis
The castor bean plant (Ricinus communis) is a member of the family Euphorbiaceae. In spite of its common name, the castor plant is not a true bean (i.e., leguminous plants belonging to the family, Fabaceae). Ricinus communis is native to tropical Africa, but because the plant was recognized for its production of oil with many desirable properties, it has been introduced and cultivated in warm temperate regions throughout the world (Armstrong 1999 and Brown 2005). Castor bean plants have also been valued by gardeners as an ornamental plant and, historically, as a natural rodenticide. Today, escaped plants grow like weeds throughout much of the southwestern United States, and castor seeds are even widely available to the public for order through the Internet. In this study, multiple loci of chloroplast noncoding sequence data and a few nuclear noncoding regions were examined to identify DNA polymorphisms present among representatives from a geographically diverse panel of Ricinus communis cultivated varieties. The primary objectives for this research were (1) to successfully cultivate castor plants and extract sufficient yields of high quality DNA from an assortment of castor cultivated varieties, (2) to use PCR and sequencing to screen available universal oligos against a small panel …
Date:
November 20, 2006
Creator:
Hinckley, A C
System:
The UNT Digital Library
High Pressure Scanning Tunneling Microscopy and High PressureX-ray Photoemission Spectroscopy Studies of Adsorbate Structure,Composition and Mobility during Catalytic Reactions on A Model SingleCrystal
Our research focuses on taking advantage of the ability of scanning tunneling microscopy (STM) to operate at high-temperatures and high-pressures while still providing real-time atomic resolution images. We also utilize high-pressure x-ray photoelectron spectroscopy (HPXPS) to monitor systems under identical conditions thus giving us chemical information to compare and contrast with the structural and dynamic data provided by STM.
Date:
May 12, 2006
Creator:
Montano, M. O.
System:
The UNT Digital Library
Understanding How Femtosecond Laser Waveguide Fabrication in Glasses Works
In order to understand the physical processes associated with fs-laser waveguide writing in glass, the effects of the laser repetition rate, the material composition and feature size were studied. The resulting material changes were observed by collecting Raman and fluorescence spectra with a confocal microscope. The guiding behavior of the waveguides was evaluated by measuring near field laser coupling profiles in combination with white light microscopy. Waveguides and Bragg gratings were fabricated in fused silica using pulse repetition rates from 1 kHz to 1 MHz and a wide range of scan speeds and pulse energies. Two types of fluorescence were detected in fused silica, depending on the fabrication conditions. Fluorescence from self trapped exciton (E{prime}{sub {delta}}) defects, centered at 550 nm, were dominant for conditions with low total doses, such as using a 1 kHz laser with a scan speed of 20 {micro}m/s and pulse energies less than 1 {micro}J. For higher doses a broad fluorescence band, centered at 650 nm, associated with non-bridging oxygen hole center (NBOHC) defects was observed. Far fewer NBOHC defects were formed with the 1 MHz laser than with the kHz lasers possibly due to annealing of the defects during writing. We also observed an …
Date:
May 11, 2006
Creator:
Reichman, W J
System:
The UNT Digital Library
Search for r-parity violating supersymmetry in multilepton final states with the D0 detector
Results obtained from a search for the trilepton signature {mu}{mu}{ell} (with {ell} = e, or {mu}) are combined with two complementary searches for the trilepton signatures ee{ell} and eer and interpreted in the framework of R-parity violating Supersymmetry. Pairwise, R-parity conserving production of the supersymmetric particles is assumed, followed by R-parity violating decays via an LL{bar E}-operator with one dominant coupling {lambda}{sub 122}. An LL{bar E}-operator couples two weak isospin doublet and one singlet (s)lepton fields and thus violates lepton number conservation. The data, collected with the D0 detector at the Fermilab proton-antiproton collider Tevatron, corresponds to an integrated luminosity of {integral} L dt = 360 {+-} 23 pb{sup -1}. No evident is observed, while 0.41 {+-} 0.11(stat) {+-} 0.07(sys) events are expected from Standard Model processes. The resulting 95% confidence level cross section limits on new physics producing a {mu}{mu}{ell} signature in the detector are of the order of 0.020 to 0.136 pb. They are interpreted in two different supersymmetry scenarios: the mSUGRA and the MSSM model. The corresponding lower limits on the masses of the lightest neutralino ({tilde {chi}}{sub 1}{sup 0}) and the lightest chargino ({tilde {chi}}{sub 1}{sup {+-}}) in case of the mSUGRA model are found to …
Date:
November 1, 2006
Creator:
Kaefer, Daniela
System:
The UNT Digital Library
Measurement of the front back asymmetry in top-antitop quark pairs produced in proton-antiproton collisions at center of mass energy = 1.96 TeV
Quarks, along with leptons and force carrying particles, are predicted by the Standard Model to be the fundamental constituents of nature. In distinction from the leptons, the quarks interact strongly through the chromodynamic force and are bound together within the hadrons. The familiar proton and neutron are bound states of the light ''up'' and ''down'' quarks. The most massive quark by far, the ''top'' quark, was discovered by the CDF and D0 experiments in March, 1995. The new quark was observed in p{bar p} collisions at 1.8 TeV at the Fermilab Tevatron. The mass of the top quark was measured to be 176 {+-} 13 GeV/c{sup 2} and the cross section 6.8{sub -2.4}{sup +3.6} pb. It is the Q = 2/3, T{sub 3} = +1/2 member of the third generation weak-isospin doublet along with the bottom quark. The top quark is the final Standard Model quark to be discovered. Along with whatever is responsible for electroweak symmetry breaking, top quark physics is considered one of the least understood sectors of the Standard Model and represents a front line of our understanding of particle physics. Currently, the only direct measurements of top quark properties come from the CDF and D0 experiments …
Date:
January 1, 2006
Creator:
Schwarz, Thomas A.
System:
The UNT Digital Library
Structure, ionic Conductivity and mobile Carrier Density in Fast Ionic Conducting Chalcogenide Glasses
This thesis consists of six sections. The first section gives the basic research background on the ionic conduction mechanism in glass, polarization in the glass, and the method of determining the mobile carrier density in glass. The proposed work is also included in this section. The second section is a paper that characterizes the structure of MI + M{sub 2}S + (0.1 Ga{sub 2}S{sub 3} + 0.9 GeS{sub 2}) (M = Li, Na, K and Cs) glasses using Raman and IR spectroscopy. Since the ionic radius plays an important role in determining the ionic conductivity in glasses, the glass forming range for the addition of different alkalis into the basic glass forming system 0.1 Ga{sub 2}S{sub 3} + 0.9 GeS{sub 2} was studied. The study found that the change of the alkali radius for the same nominal composition causes significant structure change to the glasses. The third section is a paper that investigates the ionic conductivity of MI + M{sub 2}S + (0.1Ga{sub 2}S{sub 3} + 0.9 GeS{sub 2}) (M = Li, Na, K and Cs) glasses system. Corresponding to the compositional changes in these fast ionic conducting glasses, the ionic conductivity shows changes due to the induced structural changes. …
Date:
December 12, 2006
Creator:
Yao, Wenlong
System:
The UNT Digital Library
First search at CDF for the Higgs boson decaying to a W-boson pair in proton-antiproton collisions at the center-of-mass energy of 1.96 TeV
By way of retaining the gauge invariance of the Standard Model (SM) and giving masses to the W{sup {+-}} and Z{sup 0} bosons and the fermions, the Higgs mechanism predicts the existence of a neutral scalar bosonic particle, whose mass is not exactly known. The Higgs boson is the only experimentally unconfirmed SM particle to date. This thesis documents a search for the Higgs boson in p{bar p} collisions at {radical}s = 1.96 TeV at the Tevatron, using 360 {+-} pb {sup -1} data collected by the Run II Collider Detector at Fermilab (CDF II), as part of the most important quest for contemporary particle physicists. The search was for a Higgs boson decaying to a pair of W{sup {+-}} bosons, where each W boson decays to an electron, a muon or a tau that further decays to an electron or a muon with associated neutrinos. Events with two charged leptons plus large missing energy were selected in data triggered on a high p{sub t} lepton and compared to the signal and backgrounds modeled using Monte Carlo and jet data. No signal-like excess was observed in data. Therefore, upper limits on the HWW production cross-section in the analyzed mass range …
Date:
December 1, 2006
Creator:
Chuang, Shan-Huei S.
System:
The UNT Digital Library
A search for double-charged Higgs bosons at the Tevatron
We search for the pair production of doubly charged Higgs particles followed by the lepton-flavor violating decay of each Higgs into electron-and-tau and muon-and-tau pairs using 350 pb{sup -1} of data collected by the CDF II experiment at the Fermilab Tevatron. Separate searches investigate cases where three or four final state leptons are detected, and the limits for each exclusive decay mode reflect the combined results of both searches. Assuming the H{sup {+-}{+-}}{sub L} decays exclusively into like sign electron-and-tau pairs, we set a lower limit on its mass of 114 GeV/c2 at the 95 % confidence level. In the case of exclusive muon-and-tau decays, we set a lower mass limit of 112 GeV/c2 also at the 95% confidence level.
Date:
January 1, 2006
Creator:
Baraoiant, Sasha
System:
The UNT Digital Library
Exclusive interactions in p anti-p collisions at s**(1/2) = 1.96 TeV
This thesis presents two exclusive production processes in p{bar p} collisions at {radical}s = 1.96 TeV, using the Collider Detector Facility at Fermi National Accelerator Laboratory. An observation of exclusive e{sup +}e{sup -} production through {gamma}{gamma} {yields} e{sup +}e{sup -} is presented, as well as evidence for exclusive production of {gamma}{gamma} through gg {yields} {gamma}{gamma} (via a quark loop). The exclusive e{sup +}e{sup -} production observation is based on 16 candidate events, with a background estimate of 2.1{sub -0.3}{sup +0.7}. Each event has an e{sup +}e{sup -} pair (E{sub T} (e) > 5 GeV, |{eta}(e)| < 2) and nothing else observable in the CDF detector. The measured cross section is 1.6{sub -0.3}{sup +0.5}(stat) {+-} 0.3(sys) pb, while the predicted cross section is 1.711 {+-} 0.008 pb. The kinematic properties of the events are consistent with the predictions of the LPAIR Monte Carlo. The evidence for exclusive {gamma}{gamma} production consists of 3 candidate events, with a background estimate of 0.0{sub -0.0}{sup +0.2} events. Each event has two photons (E{sub T}{gamma}) > 5 GeV, |{eta}({gamma})| < 1 and nothing else observable in the CDF detector. The measured cross section for these events is 0.14{sub -0.04}{sup +0.14}(stat) {+-} (sys) pb. It agrees with …
Date:
May 1, 2006
Creator:
Hamilton, Andrew & U., /Alberta
System:
The UNT Digital Library
The Node Monitoring Component of a Scalable Systems Software Environment
This research describes Fountain, a suite of programs used to monitor the resources of a cluster. A cluster is a collection of individual computers that are connected via a high speed communication network. They are traditionally used by users who desire more resources, such as processing power and memory, than any single computer can provide. A common drawback to effectively utilizing such a large-scale system is the management infrastructure, which often does not often scale well as the system grows. Large-scale parallel systems provide new research challenges in the area of systems software, the programs or tools that manage the system from boot-up to running a parallel job. The approach presented in this thesis utilizes a collection of separate components that communicate with each other to achieve a common goal. While systems software comprises a broad array of components, this thesis focuses on the design choices for a node monitoring component. We will describe Fountain, an implementation of the Scalable Systems Software (SSS) node monitor specification. It is targeted at aggregate node monitoring for clusters, focusing on both scalability and fault tolerance as its design goals. It leverages widely used technologies such as XML and HTTP to present an interface …
Date:
August 9, 2006
Creator:
Miller, Samuel James
System:
The UNT Digital Library
Optimization of the signal selection of exclusively reconstructed decays of B0 and B/s mesons at CDF-II
The work presented in this thesis is mainly focused on the application in a {Delta}m{sub s} measurement. Chapter 1 starts with a general theoretical introduction on the unitarity triangle with a focus on the impact of a {Delta}m{sub s} measurement. Chapter 2 then describes the experimental setup, consisting of the Tevatron collider and the CDF II detector, that was used to collect the data. In chapter 3 the concept of parameter estimation using binned and unbinned maximum likelihood fits is laid out. In addition an introduction to the NeuroBayes{reg_sign} neural network package is given. Chapter 4 outlines the analysis steps walking the path from the trigger level selection to fully reconstructed B mesons candidates. In chapter 5 the concepts and formulas that form the ingredients to an unbinned maximum likelihood fit of {Delta}m{sub s} ({Delta}m{sub d}) from a sample of reconstructed B mesons are discussed. Chapter 6 then introduces the novel method of using neural networks to achieve an improved signal selection. First the method is developed, tested and validated using the decay B{sup 0} {yields} D{pi}, D {yields} K{pi}{pi} and then applied to the kinematically very similar decay B{sub s} {yields} D{sub s}{pi}, D{sub s} {yields} {phi}{pi}, {phi} {yields} …
Date:
June 1, 2006
Creator:
Doerr, Christian
System:
The UNT Digital Library