This dissertation presents a search for large extra dimensions in the single photon plus missing transverse energy final states. We use a data sample of approximately 2.7 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV (recorded with the D{sup -} detector) to investigate direct Kaluza Klein graviton production and set limits, at the 95% C.L., on the fundamental mass scale M{sub D} from 970 GeV to 816 GeV for two to eight extra dimensions.

We report results from a search for neutral Higgs bosons decaying to tau pairs produced in association with a b-quark in 1.6 fb{sup -1} of data taken from June 2006 to March 2008 with the D0 detector at Fermi National Accelerator Laboratory. The final state includes a muon, hadronically decaying tau, and jet identified as coming from a b-quark. We set cross section times branching ratio limits on production of such neutral Higgs bosons {phi} in the mass range from 90 GeV to 160 GeV. Exclusion limits are set at the 95% Confidence Level for several supersymmetric scenarios.

I describe a search for anomalous production of Z pairs through a new massive resonance X in 2.5-2.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV using the CDFII Detector at the Fermilab Tevatron. I reconstruct Z pairs through their decays to electrons, muons, and quarks. To achieve perhaps the most efficient lepton reconstruction ever used at CDF, I apply a thorough understanding of the detector and new reconstruction software heavily revised for this purpose. In particular, I have designed and employ new general-purpose algorithms for tracking at large {eta} in order to increase muon acceptance. Upon analyzing the unblinded signal samples, I observe no X {yields} ZZ candidates and set upper limits on the production cross section using a Kaluza-Klein graviton-like acceptance.

This thesis describes a search for standard model Higgs bosons decaying to W boson pairs in proton-anti-proton collisions at a center of mass energy of 1.96 TeV using the CDF II detector. The decay to W bosons is dominant for Higgs masses greater than about 135 GeV. The final state examined consists of two leptons and missing transverse energy from the leptonic decay of one or more W bosons. The signal production mechanisms included are gluon fusion, associated production with a W or Z boson, and vector boson fusion. Matrix element calculations and artificial neural networks are used to discriminate signal from background for Higgs masses in the range 110 {le} M{sub H} {le} 200 GeV. No significant excess of events is observed at any of the Higgs masses investigated. Upper limits on the standard model Higgs cross section are set at 95% confidence for each Higgs mass investigated, the most stringent limit being 1.63 times the predicted standard model cross section for a Higgs mass of 160 GeV.

We present a search for a narrow resonance in the t{bar b} mass spectrum using 1.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV recorded with the CDF II detector at the Fermilab Tevatron. We select events with a lepton, neutrino candidate, and two or three jets from which to construct the t{bar b} mass. We quantify the result using the model of a massive Standard Model-like charged-boson (W{prime}) decaying to t{bar b}, but we are generally sensitive to the presence of any narrow state decaying to the third generation. For a purely right-handed W{prime} with Standard Model couplings, we set a new limit at 95% confidence of {sigma}(p{bar p} {yields} W{prime}{sub R}) x BR(W{prime}{sub R} {yields} t{bar b}) < 0.28 pb and M{sub W{prime}{sub R}} > 800 GeV/c{sup 2}. The limit increases to M{sub W{prime}{sub R}} > 825 GeV/c{sup 2} if decay to right-handed neutrinos is forbidden. These results are shown in Table 7 and plotted in Figure 7.1. The best prior search found M{sub W{prime}} {ge} 768 GeV/c{sup 2} if leptonic decays are forbidden [16]. For a simple W{prime} model with effective coupling g{sub W{prime}}, the cross-section is proportional to g{sub W{prime}}{sup 4}. Relaxing the …

The development of advanced lithium-ion batteries is key to the success of many technologies, and in particular, hybrid electric vehicles. In addition to finding materials with higher energy and power densities, improvements in other factors such as cost, toxicity, lifetime, and safety are also required. Lithium transition metal oxide and LiFePO₄/C composite materials offer several distinct advantages in achieving many of these goals and are the focus of this report. Two series of layered lithium transition metal oxides, namely LiNi_1/3Co_1/3-yM_yMn_1/3O₂ (M=Al, Co, Fe, Ti) and LiNi_0.4Co_0.2-yM_yMn_0.4O₂ (M = Al, Co, Fe), have been synthesized. The effect of substitution on the crystal structure is related to shifts in transport properties and ultimately to the electrochemical performance. Partial aluminum substitution creates a high-rate positive electrode material capable of delivering twice the discharge capacity of unsubstituted materials. Iron substituted materials suffer from limited electrochemical performance and poor cycling stability due to the degradation of the layered structure. Titanium substitution creates a very high rate positive electrode material due to a decrease in the anti-site defect concentration. LiFePO₄ is a very promising electrode material but suffers from poor electronic and ionic conductivity. To overcome this, two new techniques have been developed to synthesize high …

In a universe dominated by matter, the source of CP violation may explain one of the greatest mysteries in particle physics: what happened to the antimatter? The Standard Model successfully describes CP violation in the B{sup +} and B{sub d}{sup 0} systems, yet insufficiently accounts for the observed matter-antimatter asymmetry. The Standard Model predicts a small value of CP violation in the B{sub s}{sup 0} meson system, which has only recently been experimentally tested. A measurement of large, anomalous CP violation in the B{sub s}{sup 0} system would be a clear indication of new physics sources beyond the Standard Model. This dissertation describes a study of CP violation in approximately 2000 B{sub s}{sup 0} {yields} J/{psi}{phi} decays reconstructed in a 2.8 fb{sup -1} data sample collected by the D0 Run II detector at Fermi National Accelerator Laboratory in Batavia, Illinois. This data was provided by p{bar p} collisions at {radical}s = 1.96 TeV delivered by the Tevatron accelerator between April 2002 and August 2007. Flavor-tagged B{sub s}{sup 0} {yields} J/{psi}({mu}{sup +}{mu}{sup -}){phi}(K{sup +}K{sup -}) decays and an angular analysis are used to study the time evolution of the final state angular distributions. From this analysis, we measure the width difference …

We study the behavior of charged particles produced in association with Drell-Yan lepton-pairs in the region of the Z-boson in proton-antiproton collisions at 1.96 TeV. We use the direction of the Z-boson in each event to define 'toward', 'away', and 'transverse' regions. For Drell-Yan production (excluding the leptons) both the 'toward' and 'transverse' regions are very sensitive to the 'underlying event', which is defined as everything except the two hard scattered components. The data are corrected to the particle level and are then compared with several PYTHIA models (with multiple parton interactions) and HERWIG (without multiple parton interactions) at the particle level (i.e. generator level). The data are also compared with a previous analysis on the behavior of the 'underlying event' in high transverse momentum jet production. The goal is to produce data that can be used by the theorists to tune and improve the QCD Monte-Carlo models of the 'underlying event' that are used to simulate hadron-hadron collisions.

We report on a measurement of the rapidity distribution, d{sigma}/dy, for Z=Drell-Yan {yields} ee events produced in p{bar p} collisions at {radical}s = 1.96 TeV. The data sample consists of 2.13 fb{sup -1} corresponding to about 160,000 Z/Drell-Yan {yields} ee candidates in the Z boson mass region collected by the Collider Detector at Fermilab. The d{sigma}/dy distribution, which is measured over the full kinematic range for e{sup +}e{sup -} pairs in the invariant mass range 66 < M{sub ee} < 116 GeV/c{sup 2}, is compared with theory predictions. There is good agreement between the data and predictions of Quantum Chromodynamics in Next to Leading Order with the CTEQ6.1M Parton Distribution Functions.

This thesis describes a measurement of the average proper decay time of the B{sub c}{sup {+-}} mesons, the ground state of bottom and charm quark bound states. The lifetime measurement is carried out in the decay modes B{sub c}{sup {+-}} {yields} J/{psi} + e{sup {+-}} + X and B{sub c}{sup {+-}} {yields} J/{psi} + {mu}{sup {+-}} + X, where the J/{psi} decays as J/{psi} {yields} {mu}{sup +}{mu}{sup -} and the X are unmeasured particles such as {nu}{sub e} or {nu}{sub {mu}}. The data are collect by the CDF II detector which measures the properties of particles created in {radical}s = 1.96 TeV p{bar p} collisions delivered by the Fermilab Tevatron. This measurement uses {approx} 1 fb{sup -1} of integrated luminosity. The measured average proper decay time of B{sub c}{sup {+-}} mesons, {tau} = 0.475{sub -0.049}{sup +0.053}(stat.) {+-} 0.018(syst.) ps, is competitive with the most precise measurements in the world and confirms previous measurements and theoretical predictions.

I present a measurement of the t{bar t} differential cross section, d{sigma}/dM{sub t{bar t}}, in p{bar p} collisions at {radical}s = 1.96 TeV using 2.7 fb{sup -1} of CDF II data. I find that d{sigma}/dM{sub t{bar t}} is consistent with the Standard Model expectation, as modeled by PYTHIA with CTEQ5L parton distribution functions. I set limits on the ratio {kappa}/M{sub Pl} in the Randall-Sundrum model by looking for Kaluza Klein gravitons which decay to top quarks. I find {kappa}/M{sub Pl} > 0.16 at the 95% confidence level.

In 1995 the last missing member of the known families of quarks, the top quark, was discovered by the CDF and D0 experiments at the Tevatron, a proton-antiproton collider at Fermilab near Chicago. Until today, the Tevatron is the only place where top quarks can be produced. The determination of top quark production and properties is crucial to understand the Standard Model of particle physics and beyond. The most striking property of the top quark is its mass--of the order of the mass of a gold atom and close to the electroweak scale--making the top quark not only interesting in itself but also as a window to new physics. Due to the high mass, much higher than of any other known fermion, it is expected that the top quark plays an important role in electroweak symmetry breaking, which is the most prominent candidate to explain the mass of particles. In the Standard Model, electroweak symmetry breaking is induced by one Higgs field, producing one additional physical particle, the Higgs boson. Although various searches have been performed, for example at the Large Electron Positron Collider (LEP), no evidence for the Higgs boson could yet be found in any experiment. At the …

We present a search for high-mass resonances decaying into two leptons of different flavor: e{mu}, e{tau}, and {mu}{tau}. These resonances are predicted by several models beyond the standard model, such as the R-parity-violating MSSM. The search is based on 1 fb{sup -1} of data collected at the Collider Detector at Fermilab (CDF II) in proton anti-proton collisions. Our observations are consistent with the standard model expectations. The results are interpreted to set 95% C.L. upper limits on {sigma} x BR of {tilde {nu}}{sub {tau}} {yields} e{mu}, e{tau}, {mu}{tau}.

This dissertation describes a search for the associated production of the supersymmetric particles, the chargino and the neutralino, through their R-parity conserving decays to three leptons and missing energy. This search is carried out using the data collected at the CDF experiment at the Tevatron {radical}s = 1.96 TeV p{bar p} collider at Fermilab. The results are obtained by combining five independent channels with varying signal to background ratio. Overall, a total of 6.4 {+-} 1.1 background events from standard model processes and 11.4 {+-} 1.1 signal events for a particular choice of mSUGRA model parameters are expected. The observation of 7 events in data is consistent with the standard model background expectation, and the mSUGRA model is constrained. Limits are set on the cross section of Chargino-Neutralino pair production, and a limit on the mass of the chargino is extracted. A method of obtaining model-independent results is also discussed.

We measure the production cross section of t{bar t} events in p{bar p} collisions at {radical}s = 1.96 TeV. The data was collected by the CDF experiment in Run 2 of the Tevatron accelerator at the Fermi National Accelerator Laboratory between 2002 and 2007. 1.7 fb{sup -1} of data was recorded during this time period. We reconstruct t{bar t} events in the lepton+jets channel, whereby one W boson - resulting from the decay of the top quark pairs - decays leptonically and the other hadronically. The dominant background to this process is the production of W bosons in association with multiple jets. To distinguish t{bar t} from background, we identify soft electrons from the semileptonic decay of heavy flavor jets produced in t{bar t} events. We measure a cross section of {sigma}{sub p{bar p}} = 7.8 {+-} 2.4(stat) {+-} 1.6(syst) {+-} 0.5(lumi).

The Neutrino Factory has been proposed as a facility to provide an intense source of neutrinos suitable for the measurement of neutrino oscillation parameters and a possible CP violating phase to unprecedented precision. In the Neutrino Factory, neutrinos are produced by the decay of a muon beam with 20-50 GeV per muon. Initially, the muon beam occupies a large volume in phase space, which must be reduced before the beam can be accelerated. The proposed method to achieve this is to use a solenoidal ionisation colling channel.

Using approximately 1.3 fb{sup -1} of data collected by the D0 detector between 2002 and 2006, the lifetime of the B{sub c}{sup {+-}} meson is studied in the B{sub c}{sup {+-}} {yields} J/{psi}{mu}{sup {+-}} + X final state. Using an unbinned likelihood simultaneous fit to J/{psi} + {mu} invariant mass and lifetime distributions, a signal of 810 {+-} 80(stat.) candidates is estimated and a lifetime measurement made of: {tau}(B{sub c}{sup {+-}}) = 0.448{sub -0.036}{sup +0.038}(stat) {+-} 0.032(sys) ps.

The lifetime of the Λ⁰_b baryon (consisting of u, d and b quarks) is the theoretically most interesting of all b-hadron lifetimes. The lifetime of Λ⁰_b probes our understanding of how baryons with one heavy quark are put together and how they decay. Experimentally however, measurements of the Λ⁰_b lifetime have either lacked precision or have been inconsistent with one another. This thesis describes the measurement of Λ⁰_b lifetime in proton-antiproton collisions with center of mass energy of 1.96 TeV at Fermilab's Tevatron collider. Using 1070 ± 60pb^-1 of data collected by the Collider Detector at Fermilab (CDF), a clean sample of about 3,000 fully-reconstructed Λ⁰_b →Λ_c⁺π^- decays (with Λ⁺_c subsequently decaying via Λ⁺_c → p⁺ K^- π⁺) is used to extract the lifetime of the Λ⁰_b baryon, which is found to be cτ(Λ⁰_b) = 422.8 ± 13.8(stat) ± 8.8(syst)μm. This is the most precise measurement of its kind, and is even better than the current world average. It also settles the recent controversy regarding the apparent inconsistency between CDF's other measurement and the rest of the world.

The authors present the first measurement of the top quark mass using simultaneously data from two decay channels. They use a data sample of {radical}s = 1.96 TeV collisions with integrated luminosity of 1.9 fb{sup -1} collected by the CDF II detector. They select dilepton and lepton + jets channel decays of t{bar t} pairs and reconstruct two observables in each topology. They use non-parametric techniques to derive probability density functions from simulated signal and background samples. The observables are the reconstructed top quark mass and the scalar sum of transverse energy of the event in the dilepton topology and the reconstructed top quark mass and the invariant mass of jets from the W boson decay in lepton + jets channel. They perform a simultaneous fit for the top quark mass and the jet energy scale which is constrained in situ by the hadronic W boson resonance from the lepton + jets channel. Using 144 dilepton candidate events and 332 lepton + jets candidate events they measure: M{sub top} = 171.9 {+-} 1.7 (stat. + JES) {+-} 1.1 (other sys.) GeV/c{sup 2} = 171.9 {+-} 2.0 GeV/c{sup 2}. The measurement features a robust treatment of the systematic uncertainties, correlated between …

Particle physics deals with the fundamental building blocks of matter and their interactions. The vast number of subatomic particles can be reduced to twelve fundamental fermions, which interact by the exchange of spin-1 particles as described in the Standard Model (SM) of particle physics. The SM provides the best description of the subatomic world to date, despite the fact it does not include gravitation. Following the relation {lambda} = h/p, where h is Planck's constant, for the examination of physics at subatomic scales with size {lambda} probes with high momenta p are necessary. These high energies are accessible through particle colliders. Here, particles are accelerated and brought to collision at interaction points at which detectors are installed to record these particle collisions. Until the anticipated start-up of the Large Hadron Collider at CERN, the Tevatron collider at Fermilab near Chicago is the highest energy collider operating in the world, colliding protons and anti-protons at a center-of-mass energy of {radical}s = 1.96 TeV. Its two interaction points are covered by the multi purpose particle detectors D0 and CDF. During the first data-taking period, known as Run I, the Tevatron operated at a center-of-mass energy of 1.8 TeV. This run period lasted …

The production cross section for t{bar t} pairs decaying into two lepton final states was measured using data from the D0 detector at Fermilab. The measurement was made using a lepton+track selection, where one lepton is fully identified and the second lepton is observed as an isolated track. This analysis is designed to complement similar studies using two fully identified leptons [1]. The cross section for the lepton+track selection was found to be {sigma} = 5.2{sub -1.4}{sup +1.6}(stat){sub -0.8}{sup +0.9}(syst) {+-} 0.3(lumi) pb. The combined cross section using both the lepton+track data and the data from the electron+electron, electron+muon, and muon+muon samples is: {sigma} = 6.4{sub -0.9}{sup +0.9}(stat){sub -0.7}{sup +0.8}(syst) {+-} 0.4(lumi) pb.

MINOS is a long baseline neutrino oscillation experiment. A manmade beam of predominantly muon neutrinos is detected both 1 km and 735 km from the production point by two functionally identical detectors. A comparison of the energy spectra measured by the two detectors shows the energy-dependent disappearance of muon neutrinos characteristic of oscillations and allows a measurement of the parameters governing the oscillations. This thesis presents work leading to measurements of disappearance in the 6% {bar {nu}}{sub {mu}} background in that beam. A calibration is developed to correct for time-dependent changes in the responses of both detectors, reducing the corresponding uncertainty on hadronic energy measurements from 1.8% to 0.4% in the near detector and from 0.8% to 0.4% in the far detector. A method of selecting charged current {bar {nu}}{sub {mu}} events is developed, with purities (efficiencies) of 96.5% (74.4%) at the near detector, and 98.8% (70.9%) at the far detector in the region below 10 GeV reconstructed antineutrino energy. A method of using the measured near detector neutrino energy spectrum to predict that expected at the far detector is discussed, and developed for use in the {bar {nu}}{sub {mu}} analysis. Sources of systematic uncertainty contributing to the oscillation measurements …

This thesis describes investigations of the first set of orbitally excited (L = 1) states for both the B{sub d}{sup 0} and B{sub s}{sup 0} meson systems (B**{sub d} and B**{sub s}). The data sample corresponds to 1.35 fb{sup -1} of integrated luminosity, collected in 2002-2006 by the D0 detector, during the Run IIa operation of the Tevatron p{bar p} colliding beam accelerator. The B**{sub d} states are fully reconstructed in decays to B{sup (*)+} {pi}{sup -}, with B{sup (*)+} {yields} {gamma} J/{psi}K{sup +}, J/{psi} {yields} {mu}{sup +}{mu}{sup -}, yielding 662 {+-} 91 events, and providing the first strong evidence for the resolution of two narrow resonances, B{sub 1} and B*{sub 2}. The masses are extracted from a binned {chi}{sup 2} fit to the invariant mass distribution, giving M(B{sub 1}) = 5720.7 {+-} 2.4(stat.) {+-} 1.3(syst.) {+-} 0.5 (PDG) MeV/c{sup 2} and M(B*{sub 2}) = 5746.9 {+-} 2.4(stat.) {+-} 1.0(syst.) {+-} 0.5(PDG) MeV/c{sup 2}. The production rate of narrow B**{sub d} {yields} B{pi} resonances relative to the B{sup +} meson is determined to be [13.9 {+-} 1.9(stat.) {+-} 3.2(syst.)]%. The same B{sup +} sample is also used to reconstruct the analogous states in the B{sub s}{sup 0} system, in decays …

Elementary particle physics tries to find an answer to no minor question: What is our universe made of? To our current knowledge, the elementary constituents of matter are quarks and leptons, which interact via four elementary forces: electromagnetism, strong force, weak force and gravity. All forces, except gravity, can be described in one framework, the Standard Model of particle physics. The model's name reflects its exceptional success in describing all available experimental high energy physics data to high precision up to energies of about 100 GeV. An exception is given by the neutrino masses but even these can be integrated into the model. The Standard Model is based on the requirement of invariance of all physics processes under certain fundamental symmetry transformations. The consideration of these symmetries leads naturally to the correct description of the electromagnetic, weak and strong forces as the exchange of interaction particles, the gauge bosons. However, this formalism has the weakness that it only allows for massless particles. In order to obey the symmetries, a way to introduce the particle masses is given by the Higgs mechanism, which predicts the existence of the only particle of the Standard Model which has yet to be observed: the …