This dissertation reports on a study of search for an orbitally excited state of charmed baryons {Sigma}{sub c}{sup 0}(2800) and {Sigma}{sub c}{sup ++}(2800). They measure the widths, momentum spectrum and production cross-section for these states decaying into a {Lambda}{sub c}{sup +} and a charged {pi}. The analysis uses 230 fb{sup -1} of data collected at BABAR detector operating at PEP-II collider at Stanford Linear Accelerator Center. The data is collected in the region of {Upsilon}(4S) an {approx} 40 MeV below the resonance. {Lambda}{sub c}{sup +} baryon is reconstructed in the decay mode pK{sup -}{pi}{sup +}. The {Sigma}{sub c}(2800) baryon production at continuum is observed to be quite significant for x{sub p} > 0.7, where x{sub p} = p/{radical}E{sup 2}+M{sup 2} is the scaled momentum and varies from 0.0 to 1.0. The momentum spectrum is measured by considering the corrected yield for momentum bins above x{sub p} > 0.5 and can be parameterized very well by a Peterson function, given by: dN/dx{sub p} {proportional_to} 1/x{sub p}(1 - 1/x{sub p} - {epsilon}/1-x{sub p}){sup 2}. The values for the peterson parameter {epsilon}, are found to be 0.050 {+-} 0.010 for {Sigma}{sub c}{sup 0}(2800) and 0.057 {+-} 0.012 for {Sigma}{sub c}{sup ++}(2800). They use …

The CDF experiment has searched for production of a third generation vector leptoquark (VLQ3) in the di-tau plus di-jet channel using 322 pb{sup -1} of Run II data. We review the production and decay theory and describe the VLQ3 model we have used as a benchmark. We study the analysis, including the data sample, triggers, particle identification, and event selection. We also discuss background estimates and systematic uncertainties. We have found no evidence for VLQ3 production and have set a 95% C.L. upper limit on the pair production cross section {sigma} to 344 fb, and exclude VLQ3 in the mass range m{sub VLQ3} > 317 GeV/c{sup 2}, assuming Yang-Mills couplings and Br(LQ3 {yields} b{tau}) = 1. If theoretical uncertainties on the cross section are taken into account, the results are {sigma} < 353 fb and m{sub VLQ3} > 303 GeV/c{sup 2}. For a VLQ3 with Minimal couplings, the upper limit on the cross section is {sigma} < 493 fb ({sigma} < 554 fb) and the lower limit on the mass is m{sub VLQ3} > 251 GeV/c{sup 2} (m{sub VLQ3} > 235 GeV/c{sup 2}) for the nominal (1{sigma} varied) theoretical expectation.

All known experimental results on fundamental particles and their interactions can be described to great accuracy by a theory called the Standard Model. In the Standard Model of particle physics, the masses of particles are explained through the Higgs mechanism. The Higgs boson is the only Standard Model particle not discovered yet, and its observation or exclusion is an important test of the Standard Model. While the Standard Model predicts that a Higgs boson should exist, it does not exactly predict its mass. Direct searches have excluded a Higgs with m{sub H} < 114.4 GeV at 95% confidence level, while indirect measurements indicate that the mass should be less than 144 GeV. This analysis looks for W{sup {+-}}H {yields} {mu}{nu}{sub {mu}}b{bar b} in 1 fb{sup -1} of data collected with the D0 detector in p{bar p} collisions with {radical}s = 1.96 TeV. The analysis strategy relies on the tracking, calorimetry and muon reconstruction of the D0 experiment. The signature is a muon, missing transverse energy (E{sub T}) to account for the neutrino and two b-jets. The Higgs mass is reconstructed using the invariant mass of the two jets. Backgrounds are W{sup {+-}}b{bar b}, W{sup {+-}} c{bar c}, W{sup {+-}} + …

Since the invention of quantum mechanics, even the simplest example of collisional breakup in a system of charged particles, e{sup {minus}} + H {r_arrow} H{sup +} + e{sup {minus}} + e{sup {minus}}, has stood as one of the last unsolved fundamental problems in atomic physics. A complete solution requires calculating the energies and directions for a final state in which three charged particles are moving apart. Advances in the formal description of three-body breakup have yet to lead to a viable computational method. Traditional approaches, based on two-body formalisms, have been unable to produce differential cross sections for the three-body final state. Now, by using a mathematical transformation of the Schrodinger equation that makes the final state tractable, a complete solution has finally been achieved, Under this transformation, the scattering wave function can be calculated without imposing explicit scattering boundary conditions. This approach has produced the first triple differential cross sections that agree on an absolute scale with experiment as well as the first ab initio calculations of the single differential cross section.

The MINOS Far Detector is a 5400 ton iron calorimeter located at the Soudan state park in Soudan Minnesota. The MINOS far detector can observe atmospheric neutrinos and separate charge current {nu}{sub {mu}} and {bar {nu}}{sub {mu}} interactions by using a 1.4 T magnetic field to identify the charge of the produced muon. The CPT theorem requires that neutrinos and anti-neutrinos oscillate in the same way. In a fiducial exposure of 5.0 kilo-ton years a total of 41 candidate neutrino events are observed with an expectation of 53.1 {+-} 7.6(system.) {+-} 7.2(stat.) unoscillated events or 31.6 {+-} 4.7(system.) {+-} 5.6(stat.) events with {Delta}m{sup 2} = 2.4 x 10{sup -3} eV{sup 2}, sin{sup 2}(2{theta}) = 1.0 as oscillation parameters. These include 28 events which can have there charge identified with high confidence. These 28 events consist of 18 events consistent with being produced by {nu}{sub {mu}} and 10 events being consistent with being produced by {bar {nu}}{sub {mu}}. No evidence of CPT violation is observed.

We discuss the measurement of the cross section for t{bar t} production in p{bar p} collisions at {radical}s = 1.96 TeV in e+jets final states observed at the D0 experiment at the Fermilab Tevatron. Our result is based on data collected from the June 2002 to September 2003 period of Run II of the p{bar p} Collider. In the Standard Model, the top quark is expected to decay mainly into a W boson and a b quark. The W boson can decay subsequently into a lepton and its neutrino or a q{bar q} quark-antiquark pair. In this thesis, we focus on the e{sup +} {nu}{sub e} or e{sup -} {bar {nu}}{sub e} decays of one of the W bosons and the q{bar q} decays of the other W boson in t{bar t} final states. The b, q and q' quarks appear as jets of particles in the detector, thereby defining the e+jets final state. We present two methods used for performing this measurement. The first method is based on a Random Grid Search (RGS) that minimizes the uncertainty on the extracted cross section. The variables used in the search take advantage of differences between expected background and signal processes to …

We have demonstrated that a bulk absorber coupled to a TES can serve as a good gamma-ray spectrometer. Our measured energy resolution of 70 eV at 60 keV is among the best measurements in this field. We have also shown excellent agreement between the noise predictions and measured noise. Despite this good result, we noted that our detector design has shortcomings with a low count rate and vulnerabilities with the linearity of energy response. We addressed these issues by implementation of an active negative feedback bias. We demonstrated the effects of active bias such as additional pulse shortening, reduction of TES change in temperature during a pulse, and linearization of energy response at low energy. Linearization at higher energy is possible with optimized heat capacities and thermal conductivities of the microcalorimeter. However, the current fabrication process has low control and repeatability over the thermal properties. Thus, optimization of the detector performance is difficult until the fabrication process is improved. Currently, several efforts are underway to better control the fabrication of our gamma-ray spectrometers. We are developing a full-wafer process to produce TES films. We are investigating the thermal conductivity and surface roughness of thicker SiN membranes. We are exploring alternative …

The neutral current neutrino-nucleon elastic interaction {nu} N {yields} {nu} N is a fundamental process of the weak interaction ideally suited for characterizing the structure of the nucleon neutral weak current. This process comprises {approx}18% of neutrino events in the neutrino oscillation experiment, MiniBooNE, ranking it as the experiment's third largest process. Using {approx}10% of MiniBooNE's available neutrino data, a sample of these events were identified and analyzed to determine the differential cross section as a function of the momentum transfer of the interaction, Q{sup 2}. This is the first measurement of a differential cross section with MiniBooNE data. From this analysis, a value for the nucleon axial mass M{sub A} was extracted to be 1.34 {+-} 0.25 GeV consistent with previous measurements. The integrated cross section for the Q{sup 2} range 0.189 {yields} 1.13 GeV{sup 2} was calculated to be (8.8 {+-} 0.6(stat) {+-} 0.2(syst)) x 10{sup -40} cm{sup 2}.

The purpose of this investigation was to determine the energy absorption characteristics of plastically deformed inclined struts under impact loading. This information is needed to provide a usable method by which designers and analysts of shipping casks for radioactive or fissile materials can determine the energy absorption capabilities of external longitudinal fins on cylindrical casks under specified impact conditions. A survey of technical literature related to experimental determination of the dynamic plastic behavior of struts revealed no information directly applicable to the immediate problem, especially in the impact velocity ranges desired, and an experimental program was conducted to obtain the needed data. Mild-steel struts with rectangular cross sections were impacted by free-falling weights dropped from known heights. These struts or fin specimens were inclined at five different angles to simulate different angles of impact that fins on a shipping cask could experience under certain accident conditions. The resisting force of the deforming strut was measured and recorded as a function of time by using load cells instrumented with resistance strain gage bridges, signal conditioning equipment, an oscilloscope, and a Polaroid camera. The acceleration of the impacting weight was measured and recorded as a function of time during the latter portion …

Experimental, numerical, and analytical work has shown that the response of a shell to a distributed force wave possesses unique characteristics which are dependent on the nature of structure attached to the shell. Specific characteristics which influence the response are the distribution of the discontinuities around the circumference (periodic/aperiodic), the impedance of the discontinuities relative to that of the shell, and the type of impedance (mass or stiffness). Traditional shell theory predicts low frequency, radial-dominated structural mode shapes of a shell with a sinusoidal distribution of displacement amplitudes. Due to the orthogonal nature of these mode shapes, the response of the structure to a traveling radial force wave with sinusoidal content at a given harmonic is due solely to the response of the mode shape with harmonic content of the same order. Introduction of impedance discontinuities to a shell yield complex mode shapes, which may be characterized by the summation of several harmonic components. These modes are no longer orthogonal in the presence of discontinuities, yielding harmonic content across various modal orders. As a result, a purely sinusoidal forcing function can excite several modes of the structure. Structural scattering as discussed in this paper refers to the phenomena in which …

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A measurement of the top quark mass with the matrix element method in the lepton + jets final state in D0 Run II is presented. Events with single isolated energetic charged lepton (electron or muon), exactly four calorimeter jets, and significant missing transverse energy are selected. Probabilities used to discriminate between signal and background are assumed to be proportional to differential cross-sections, calculated using event kinematics and folding in object resolutions and parton distribution functions. The event likelihoods constructed using these probabilities are varied with the top quark mass, m{sub t}, and the jet energy scale, JES, to give the smallest possible combined statistical + JES uncertainty.

This project will develop an analytical tool to calculate performance of HMX based PBXs in the skid test. The skid-test is used as a means to measure sensitivity for large charges in handling situations. Each series of skid tests requires dozens of drops of large billets. It is proposed that the reaction (or lack of one) of PBXs in the skid test is governed by the mechanical properties of the binder. If true, one might be able to develop an analytical tool to estimate skid test behavior for new PBX formulations. Others over the past 50 years have tried to develop similar models. This project will research and summarize the works of others and couple the work of 3 into an analytical tool that can be run on a PC to calculate drop height of HMX based PBXs. Detonation due to dropping a billet is argued to be a dynamic thermal event. To avoid detonation, the heat created due to friction at impact, must be conducted into the charge or the target faster than the chemical kinetics can create additional energy. The methodology will involve numerically solving the Frank-Kamenetskii equation in one dimension. The analytical problem needs to be bounded …

A digital network of 24 seismograph stations was operated from September 15, 1987 to September 30, 1988, by Lawrence Livermore National Laboratory and Unocal as part of the Salton Sea Scientific Drilling Project to study seismicity related to tectonics and geothermal activity near the drilling site. More than 2001 microearthquakes were relocated in this study in order to image any pervasive structures that may exist within the Salton Sea geothermal field. First, detailed velocity models were obtained through standard 1-D inversion techniques. These velocity models were then used to relocate events using both single event methods and Double-Differencing, a joint hypocenter location method. An anisotropic velocity model was built from anisotropy estimates obtained from well logs within the study area. During the study period, the Superstition wills sequence occurred with two moderate earthquakes of MS 6.2 and MS 6.6. These moderate earthquakes caused a rotation of the stress field as observed from the inversion of first motion data from microearthquakes at the Salton Sea geothermal field. Coulomb failure analysis also indicates that microearthquakes occurring after the Superstition Hills sequence are located within a region of stress increase suggesting stress triggering caused by the moderate earthquakes.

Sum frequency generation (SFG), a second-order nonlinear optical process, is electric-dipole forbidden in systems with inversion symmetry. As a result, it has been used to study chiral media and interfaces, systems intrinsically lacking inversion symmetry. This thesis describes recent progresses in the applications of and new insights into SFG from chiral media and interfaces. SFG from solutions of chiral amino acids is investigated, and a theoretical model explaining the origin and the strength of the chiral signal in electronic-resonance SFG spectroscopy is discussed. An interference scheme that allows us to distinguish enantiomers by measuring both the magnitude and the phase of the chiral SFG response is described, as well as a chiral SFG microscope producing chirality-sensitive images with sub-micron resolution. Exploiting atomic and molecular parity nonconservation, the SFG process is also used to solve the Ozma problems. Sum frequency vibrational spectroscopy is used to obtain the adsorption behavior of leucine molecules at air-water interfaces. With poly(tetrafluoroethylene) as a model system, we extend the application of this surface-sensitive vibrational spectroscopy to fluorine-containing polymers.

This thesis reports the HAPPEX measurement of the parity-violating asymmetry for longitudinally polarized electrons elastically scattered from protons in a liquid hydrogen target. The measurement was carried out in Hall A at Thomas Jefferson National Accelerator Facility using a beam energy E = 3 GeV and scattering angle <θ{sub lab}> = 6◦. The asymmetry is sensitive to the weak neutral form factors from which we extract the strange quark electric and magnetic form factors (G{sup s}{sub E} and G{sup s}{sub M}) of the proton. The measurement was conducted during two data-taking periods in 2004 and 2005. This thesis describes the methods for controlling the helicity-correlated beam asymmetries and the analysis of the raw asymmetry. The parity-violating asymmetry has been measured to be A{sub PV} = −1.14± 0.24 (stat)±0.06 (syst) ppm at <Q{sup 2}> = 0.099 GeV{sup 2} (2004), and A{sub PV} = −1.58±0.12 (stat)±0.04 (syst) ppm at <Q{sup 2}> = 0.109 GeV{sup 2} (2005). The strange quark form factors extracted from the asymmetry are G{sup s}{sub E} + 0.080G{sup s}{sub M} = 0.030 ± 0.025 (stat) ± 0.006 (syst) ± 0.012 (FF) (2004) and G{sup s}{sub E} +0.088G{sup s}{sub M} = 0.007±0.011 (stat)±0.004 (syst)±0.005 (FF) (2005). These results place the …

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A preliminary measurement of the t{bar t} production cross section at {radical}s = 1.96 TeV is presented. The {mu}-plus-jets final state is analyzed in a data sample of 94 pb{sup -1} and a total of 14 events are selected with a background expectation of 11.7 {+-} 1.9 events. The measurement yields: {sigma}{sub p{bar p} {yields} t{bar t} + X} = 2.4{sub -3.5}{sup +4.2}(stat.){sub -2.6}{sup +2.5}(syst.) {+-} 0.3(lumi.) pb. The analysis, being part of a larger effort to re-observe the top quark in Tevatron Run II data and to measure the production cross section, is combined with results from all available analyses channels. The combined result yields: {sigma}{sub p{bar p}} {yields} t{bar t} + X = 8.1{sub -2.0}{sup +2.2}(stat.){sub -1.4}{sup +1.6}(syst.) {+-} 0.8(lumi.) pb.

This document describes the measurements of the branching fractions and isospin violations of the radiative electroweak penguin decays B {yields} ({rho}/{omega}){gamma} at the asymmetric-energy e{sup +}e{sup -} PEP-II collider with the BABAR detector. Together with the previously measured branching fractions of the decays B {yields} K*{gamma} the ratio of CKM-matrix elements |V{sub td}/V{sub ts}| are extracted and the length of the far side of the unitarity triangle is determined.

We have measured the top quark mass with the dynamical likelihood method. The data corresponding to an integrated luminosity of 1.7fb{sup -1} was collected in proton antiproton collisions at a center of mass energy of 1.96 TeV with the CDF detector at Fermilab Tevatron during the period March 2002-March 2007. We select t{bar t} pair production candidates by requiring one high energy lepton and four jets, in which at least one of jets must be tagged as a b-jet. In order to reconstruct the top quark mass, we use the dynamical likelihood method based on maximum likelihood method where a likelihood is defined as the differential cross section multiplied by the transfer function from observed quantities to parton quantities, as a function of the top quark mass and the jet energy scale(JES). With this method, we measure the top quark mass to be 171.6 {+-} 2.0 (stat.+ JES) {+-} 1.3(syst.) = 171.6 {+-} 2.4 GeV/c{sup 2}.

MINOS (Main Injector Neutrino Oscillation Search), is a long baseline neutrino experiment designed to search for neutrino oscillations using two detectors at Fermi National Accelerator Laboratory, IL (Near Detector) and Soudan, MN (Far Detector). It will study {nu}{sub {mu}} {yields} {nu}{sub {tau}} oscillations and make a measurement on the oscillation parameters, {Delta}m{sub 23}{sup 2} and sin{sup 2} 2{theta}{sub 23}, via a {nu}{sub {mu}} beam made at Fermilab. Charge current neutrino interactions in the MINOS detectors are of three types: quasi-elastic scattering (QEL), resonance scattering (RES) and deep inelastic scattering (DIS). Of these, quasi-elastic scattering leaves the cleanest signal with just one {mu} and one proton in the final state, thus rendering the reconstruction of the neutrino energy more accurate. This thesis will outline a method to separate QEL events from the others in the two detectors and perform a calculation of {Delta}m{sub 23}{sup 2} and sin{sup 2} 2{theta}{sub 23} using those events. The period under consideration was May 2005 to February 2006. The number of observed quasi-elastic events with energies below 10 GeV was 29, where the expected number was 60 {+-} 3. A fit to the energy distribution of these events gives {Delta}m{sub 23}{sup 2} = 2.91{sub -0.53}{sup +0.49}(stat){sub …

In this work the S-wave component of the K{pi} amplitude from decay of D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +} it is directly measured. The data come from the Fermilab E831/FOCUS experiment. The amplitude measurement is made using the partial wave analysis without any preliminary assumption about the nature of the S-wave component of the K{pi} system. The phase and magnitude of the S-wave amplitude are generic functions to be determined directly through the Dalitz plot fit. For the sake of comparison, our results the same decay is analyzed using the isobar model, which is the standard way to analyze the Dalitz plot. The data fit obtained with the partial wave analysis is better than the data fit from the isobar model. The phase variation with respect to the invariant mass K{pi} is compared with the measurement of the phase {delta}{sub I=1/2}{sup 0} (m{sub K{pi}}) from K{pi} {yields} K{pi} scattering. The difference between both analysis is discussed considering: a difference in the composition of the isospin components I = 1/2 and I = 3/2 of the K{pi} system between D{sup +} decay and the K{pi} {yields} K{pi} scattering; and the final state interaction involving all particles from decay.

We have searched for the Standard Model Higgs boson production in association with a W{sup {+-}} boson. This search is based on the data collected between February 2002 and May 2007, corresponding to an integrated luminosity of 1.9 fb{sup -1} collected by the Collider Detector at Fermilab (CDF) at the Tevatron which is a p{bar p} collider at a center of mass energy 1.96 TeV. W+Higgs channel is one of the most promising channels for the Higgs search at Tevatron in the low Higgs mass region (m{sub H} &lt; 135 GeV/c{sup 2}), where Higgs boson decays into b{bar b} dominantly. The detection of lepton from the W boson decay makes the W+Higgs events much cleaner than the direct Higgs production events which have the largest production cross section. Experimentally we select events with a high p{sub T} lepton, high missing transverse energy and two b-quark jets. This signature is same as for the W+jets background which has a huge cross section. To reduce the W+jets background, b-jet identification algorithms are applied to at least one jet. The expected signal events in 1.9fb{sup -1} are 1.82 {+-} 0.15 and 1.68 {+-} 0.20 for one b-tagged events and two b-tagged events, respectively. …

To monitor in-flight damage and reduce life-cycle costs associated with CFRP composite aircraft, an autonomous built-in structural health monitoring (SHM) system is preferred over conventional maintenance routines and schedules. This thesis investigates the use of ultrasonic guided waves and piezoelectric transducers for the identification and localization of damage/defects occurring within critical components of CFRP composite aircraft wings, mainly the wing skin-to-spar joints. The guided wave approach for structural diagnostics was demonstrated by the dual application of active and passive monitoring techniques. For active interrogation, the guided wave propagation problem was initially studied numerically by a semi-analytical finite element method, which accounts for viscoelastic damping, in order to identify ideal mode-frequency combinations sensitive to damage occurring within CFRP bonded joints. Active guided wave tests across three representative wing skin-to-spar joints at ambient temperature were then conducted using attached Macro Fiber Composite (MFC) transducers. Results from these experiments demonstrate the importance of intelligent feature extraction for improving the sensitivity to damage. To address the widely neglected effects of temperature on guided wave base damage identification, analytical and experimental analyses were performed to characterize the influence of temperature on guided wave signal features. In addition, statistically-robust detection of simulated damage in a CFRP …