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Measurement of the top quark pair production cross-section in dimuon final states in proton-antiproton collisions at 1.96 TeV

Description: 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… more
Date: September 1, 2008
Creator: Konrath, Jens Peter
Partner: UNT Libraries Government Documents Department
open access

A measurement of the neutral current neutrino-nucleon elastic cross section at MiniBooNE

Description: 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 t… more
Date: February 1, 2008
Creator: Cox, David Christopher
Partner: UNT Libraries Government Documents Department
open access

A Study of Factorization and a Measurement of CP Violation

Description: We report on a study of the decay {bar B}{sup 0} {yields} D*{sup +} {omega}{pi}{sup -} with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232 million B{sup 0}{bar B}{sup 0} decays collected between 1999 and 2004, we measure the branching fraction {Beta}({bar B}{sup 0} {yields} D*{sup +} {omega}{pi}{sup -}) = (2.88 {+-} 0.21(stat.) {+-} 0.31(syst.)) x 10{sup -3}. We study the invariant mass spectrum of the {omega}{pi}{sup -} system in … more
Date: January 16, 2008
Creator: Dahmes, Bryan
Partner: UNT Libraries Government Documents Department
open access

Measurement of CP Violation in B0 to Phi K0, and of Branching Fraction and CP Violation in B0 to F0(980) K0(S)

Description: The authors measure the time-dependent CP asymmetry parameters in B{sup 0} {yields} K{sup +}K{sup -}K{sup 0} based on a data sample of approximately 277 million B-meson pairs recorded at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II B-meson Factory at SLAC. They reconstruct two-body B{sup 0} decays to {phi}(1020)K{sub s}{sup 0} and {phi}(1020)K{sub L}{sup 0}. Using a time-dependent maximum-likelihood fit, they measure sin2{beta}{sub eff}({phi}K{sup 0}) = 0.48 {+-} 0.28 {+-} … more
Date: March 10, 2008
Creator: Kutter, Paul E.
Partner: UNT Libraries Government Documents Department
open access

Study of CP violation in Bx to J/psi phi decays at DZero

Description: 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 lar… more
Date: December 1, 2008
Creator: Strom, Derek A.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Hadronic Mass Spectrum in B to Xulnu Decaysand Determination of the b-Quark Mass at the BaBar Experiment

Description: I present preliminary results of the measurement of the hadronic mass spectrum and its first three spectral moments in inclusive charmless semileptonic B-meson decays. The truncated hadronic mass moments are used for the first determination of the b-quark mass and the nonperturbative parameters {mu}{sub {pi}}{sup 2} and {rho}{sub D}{sup 3} in this B-meson decay channel. The study is based on 383 x 10{sup 6} B{bar B} decays collected with the BABAR experiment at the PEP-II e{sup +}e{sup -} stora… more
Date: June 26, 2008
Creator: Tackmann, Kerstin & /UC, Berkeley /SLAC
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Top Quark Mass by Dynamical Likelihood Method using the Lepton + Jets Events with the Collider Detector at Fermilab

Description: 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 qu… more
Date: February 1, 2008
Creator: Kubo, Taichi
Partner: UNT Libraries Government Documents Department
open access

A Search for Neutrinoless Tau Decays to Three Leptons

Description: Using approximately 350 million {tau}{sup +}{tau}{sup -} pair events recorded with the BaBar detector at the Stanford Linear Accelerator Center between 1999 and 2006, a search has been made for neutrinoless, lepton-flavor violating tau decays to three lighter leptons. All six decay modes consistent with conservation of electric charge and energy have been considered. With signal selection efficiencies of 5-12%, we obtain 90% confidence level upper limits on the branching fraction {Beta}({tau} {… more
Date: September 24, 2008
Creator: Kolb, Jeffrey A. & /SLAC, /Oregon U.
Partner: UNT Libraries Government Documents Department
open access

Study of the Ds+ to K+K-e+ nu Decay Channel with the BaBar Experiment

Description: Charm semileptonic decays allow a validation of lattice QCD calculations through the measurement of the hadronic form factors, which characterize the effect of strong interaction in these reactions. The accuracy of such calculations is crucial for the improvement of the test of the standard model in flavor physics. This thesis presents a study of the D{sub s}{sup +} {yields} K{sup +}K{sup -}e{sup +}{nu}{sub e} channel using 214 fb{sup -1} recorded by de BAbar experiment. For events with a K{sup… more
Date: September 9, 2008
Creator: Serrano, Justine & /Orsay, IPN /SLAC
Partner: UNT Libraries Government Documents Department
open access

Search for pair production of second generation scalar leptoquarks in ppbar collisions at the Tevatron

Description: As predicted by numerous extensions of the Standard Model, leptoquarks (LQ) are hypothetical bosons allowing lepton-quark transitions. Under the assumption that they couple only to quarks and leptons of the same generation, three generations of leptoquarks can be distinguished. The search for the pair production of second generation scalar leptoquarks has been carried out in p{bar p} collisions at {radical}s = 1.96TeV, using an integrated luminosity of 1 fb{sup -1} collected by the D0 experimen… more
Date: May 1, 2008
Creator: Calfayan, Philippe
Partner: UNT Libraries Government Documents Department
open access

Nanocrystal Bioassembly: Asymmetry, Proximity, and Enzymatic Manipulation

Description: Research at the interface between biomolecules and inorganic nanocrystals has resulted in a great number of new discoveries. In part this arises from the synergistic duality of the system: biomolecules may act as self-assembly agents for organizing inorganic nanocrystals into functional materials; alternatively, nanocrystals may act as microscopic or spectroscopic labels for elucidating the behavior of complex biomolecular systems. However, success in either of these functions relies heavily up… more
Date: May 1, 2008
Creator: Claridge, Shelley A
Partner: UNT Libraries Government Documents Department
open access

An improved Neutrino Oscillations Analysis of the MiniBooNE Data

Description: We calculate the exclusion region in the parameter space of {nu}{sub {mu}} {yields} {nu}{sub e} oscillations of the LSND type using a combined fit to the reconstructed energy distributions of neutrino candidate samples from the MiniBooNE data obtained with two different particle identification methods. The two {nu}{sub e} candidate samples are included together with a high statistics sample of {nu}{sub {mu}} events in the definition of a {chi}{sup 2} statistic which includes the correlations be… more
Date: January 1, 2008
Creator: Aguilar-Arevalo, Alexis Armando
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Top Quark Mass at CDF Using the Template Method in the Lepton + Jets Channel

Description: A measurement of the top quark mass in p{bar p} collisions at {radical}s = 1.96 TeV is presented. The analysis uses a template method, in which the overconstrained kinematics of the Lepton+Jets channel of the t{bar t} system are used to measure a single quantity, the reconstructed top quark mass, that is strongly correlated with the true top quark mass. in addition, the dijet mass of the hadronically decaying W boson is used to constrain in situ the uncertain jet energy scale in the CDF detecto… more
Date: May 1, 2008
Creator: Adelman, Jahred A.
Partner: UNT Libraries Government Documents Department
open access

Neutrino induced events in the MINOS detectors

Description: The MINOS experiment is designed to study neutrino oscillations. It uses an accelerator generated beam of neutrinos and two detectors, the smaller at a distance of 1km and the larger at 735 km. By comparing the spectrum and flavour composition of the beam at the two detectors precise determinations of the oscillation parameters are possible. This thesis concentrates on the analysis of data from the larger Far Detector. By studying the spectrum of neutral current events it is possible to look fo… more
Date: March 1, 2008
Creator: Litchfield, Reuben Phillip
Partner: UNT Libraries Government Documents Department
open access

A Simultaneous Measurement of the Branching Fractions of Ten B to Double Charm Decays

Description: This dissertation presents a simultaneous measurement of the branching fractions of ten B {yields} D{sup (*)}{bar D}{sup (*)} decays. The measurements are derived from a sample of 2.32 x 10{sup 8} B{bar B} pairs collected by the BABAR detector at the PEP-II B Factory located at Stanford Linear Accelerator Center. The branching fractions (x 10{sup -4}) are: -0.10 {+-} 0.44 {+-} 0.15 (<0.59) for B{sup 0} {yields} D{sup 0}{bar D}{sup 0}; 1.01 {+-} 1.07 {+-} 0.35 (<2.92) for B{sup 0} {yields}… more
Date: January 16, 2008
Creator: Lae, Chung Khim
Partner: UNT Libraries Government Documents Department
open access

Probing the Energy Transfer Dynamics of Photosynthetic Reaction Center Complexes Through Hole-Burning and Single-Complex Spectroscopy

Description: Photosynthesis is the process by which light energy is used to drive reactions that generate sugars to supply energy for cellular processes. It is one of the most important fundamental biological reactions and occurs in both prokaryotic (e.g. bacteria) and eukaryotic (e.g. plants and algae) organisms. Photosynthesis is also remarkably intricate, requiring the coordination of many different steps and reactions in order to successfully transform absorbed solar energy into a biochemical usable for… more
Date: May 1, 2008
Creator: Riley, Kerry
Partner: UNT Libraries Government Documents Department
open access

Inductively Coupled Plasma: Fundamental Particle Investigations with Laser Ablation and Applications in Magnetic Sector Mass Spectrometry

Description: Particle size effects and elemental fractionation in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) are investigated with nanosecond and femtosecond laser ablation, differential mobility analysis, and magnetic sector ICP-MS. Laser pulse width was found to have a significant influence on the LA particle size distribution and the elemental composition of the aerosol and thus fractionation. Emission from individual particles from solution nebulization, glass, and a pressed… more
Date: August 18, 2008
Creator: Saetveit, Nathan Joe
Partner: UNT Libraries Government Documents Department
open access

Quantum Dynamical Behaviour in Complex Systems - A Semiclassical Approach

Description: One of the biggest challenges in Chemical Dynamics is describing the behavior of complex systems accurately. Classical MD simulations have evolved to a point where calculations involving thousands of atoms are routinely carried out. Capturing coherence, tunneling and other such quantum effects for these systems, however, has proven considerably harder. Semiclassical methods such as the Initial Value Representation (SC-IVR) provide a practical way to include quantum effects while still utilizing… more
Date: May 22, 2008
Creator: Gliebe, Cheryn E & Ananth, Nandini
Partner: UNT Libraries Government Documents Department
open access

The Differential cross section distribution of Drell-Yan dielectron pairs in the z boson mass region

Description: 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} … more
Date: November 1, 2008
Creator: Han, Jiyeon
Partner: UNT Libraries Government Documents Department
open access

Study of B_s Mixing at the D-Zero Detector at Fermilab Using the Semi-leptonic Decay B_s -> D_s mu nu X

Description: B{sub s}{sup 0} mixing studies provide a precision test of Charge-Parity violation in the Standard Model. A measurement of {Delta}m{sub s} constrains elements of the CKM quark rotation matrix [1], providing a probe of Standard Model Charge-Parity violation. This thesis describes a study of B{sub s}{sup 0} mixing in the semileptonic decay B{sub s}{sup 0} {yields} D{sub s}{sup -} {mu}{sup +}{nu}X, where D{sub s}{sup -} {yields} {phi}{pi}{sup -}, using data collected at the D-Zero detector at Ferm… more
Date: June 1, 2008
Creator: Anzelc, Meghan
Partner: UNT Libraries Government Documents Department
open access

Search for High-Mass Resonances Decaying into Leptons of Different Flavor (e mu, e tau, mu tau) in p anti-p Collisions at sqrt(s) = 1.96 TeV

Description: 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 … more
Date: October 1, 2008
Creator: Tu, Yanjun
Partner: UNT Libraries Government Documents Department
open access

Measurement of the inclusive jet cross section in proton-antiproton collisions at the center-of-mass energy of 1.96 TeV

Description: This thesis studies the high-energy collisions of protons and antiprotons. The data used in the measurement were collected during 2004-2005 with the D0 detector at the Tevatron Collider of the Fermi National Accelerator Laboratory and correspond to 0.7 fb{sup -1} of integrated luminosity. High energy hadron collisions usually produce collimated sprays of particles called jets. The energy of the jets is measured using a liquid Argon-Uranium calorimeter and the production angle is determined with… more
Date: July 1, 2008
Creator: Voutilainen, Mikko Antero & /Saclay, /Helsinki Inst. of Phys. /Helsinki U. of Tech. /Nebraska U.
Partner: UNT Libraries Government Documents Department
open access

Implementation of an interactive matching scheme for the Kapchinskij-Vladimirskij equations in the WARP code

Description: The WARP code is a robust electrostatic particle-in-cell simulation package used to model charged particle beams with strong space-charge forces. A fundamental operation associated with seeding detailed simulations of a beam transport channel is to generate initial conditions where the beam distribution is matched to the structure of a periodic focusing lattice. This is done by solving for periodic, matched solutions to a coupled set of ODEs called the Kapchinskij-Vladimirskij (KV) envelope equ… more
Date: April 15, 2008
Creator: Chilton, Sven H.
Partner: UNT Libraries Government Documents Department
open access

WW production cross section measurement and limits on anomalous trilinear gauge couplings at sqrt(s) = 1.96-TeV

Description: The cross section for WW production is measured and limits on anomalous WW{gamma} and WWZ trilinear gauge couplings are set using WW {yields} ee/e{mu}/{mu}{mu} events collected by the Run II D0 detector at the Fermilab Tevatron Collider corresponding to 1 fb{sup -1} of integrated luminosity at {radical}s = 1.96 TeV. Across the three final states, 108 candidate events are observed with 40.8 {+-} 3.8 total background expected, consistent with {sigma}(p{bar p} {yields} WW) = 11.6 {+-} 1.8(stat) {+… more
Date: April 1, 2008
Creator: Cooke, Michael P. & U., /Rice
Partner: UNT Libraries Government Documents Department
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