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The BaBar Level 1 Drift-Chamber Trigger Upgrade With 3D Tracking

Description: At BABAR, the Level 1 Drift Chamber trigger is being upgraded to reduce increasing background rates while the PEP-II luminosity keeps improving. This upgrade uses the drift time information and stereo wires in the drift chamber to perform a 3D track reconstruction that effectively rejects background events spread out along the beam line.
Date: November 29, 2005
Creator: Chai, X.D. & U., /Iowa
Partner: UNT Libraries Government Documents Department

Properties of Exotic Charmonium-like States at CDF

Description: We report the recent evidence for a new narrow structure, Y (4140), decaying to the J/{psi}{phi} final state, in exclusive B{sup +} {yields} J/{psi}{phi}K{sup +} decays in a data sample corresponding to an integrated luminosity of 2.7 fb{sup -1} collected at the CDF II detector. This narrow structure with its mass well above open charm pairs is unlikely to be a candidate for a conventional charmonium state. From a study of the X(3872) mass and width based on the world's largest sample of X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -} decays, we find that our X(3872) signal is consistent with a single state, and leads to the most precise measurement of the X(3872) mass.
Date: June 1, 2009
Creator: Yi, Kai & U., /Iowa
Partner: UNT Libraries Government Documents Department

Exclusive B Decays into Final States with Two Charmed Baryons

Description: This Thesis presents measurements of the decays B{sup -} {yields} {Xi}{sub c}{sup 0}{bar {Lambda}}{sub c}{sup -}, {bar B}{sup 0} {yields} {Xi}{sub c}{sup +}{bar {Lambda}}{sub c}{sup -}, B{sup -} {yields} {Lambda}{sub c}{sup +}{bar {Lambda}}{sub c}{sup -} K{sup -}, and {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar {Lambda}}{sub c}{sup -} K{sub s}{sup 0} based on 228 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory.
Date: January 11, 2010
Creator: Chai, Xuedong & U., /Iowa
Partner: UNT Libraries Government Documents Department

Hadronic B Decays From BaBar

Description: We present preliminary results on hadronic decays of B mesons, based on data recorded at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II B-factory at SLAC. We measure branching fractions in CP-related analyses of B{sup -} {yields} D({yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0})K{sup -}, B{sup 0} {yields} {bar D}{sup 0}(D{sup 0})DK{sup +}{pi}{sup -} and B{sup 0} {yields} D{sub s}{sup +}a{sub 0(2)}{sup -} and in non-CP-related analyses of B{sup +} {yields} D{sup (*)+} K{sup 0}, B{sup -} {yields} D{sub s}{sup (*)-} and {phi} and B {yields} J/{Psi} {bar D}. Because the results presented in this paper are preliminary, they are based on different amount of data samples.
Date: April 17, 2006
Creator: Yi, J. & U., /Iowa State
Partner: UNT Libraries Government Documents Department

MIP Reconstruction Techniques and Minimum Spanning Tree Clustering

Description: The development of a tracking algorithm for minimum ionizing particles in the calorimeter and of a clustering algorithm based on the Minimum Spanning Tree approach are described. They do not depend on information from the central tracking system. Both are important components of a particle flow algorithm currently under development.
Date: September 12, 2005
Creator: Mader, Wolfgang F. & U., /Iowa
Partner: UNT Libraries Government Documents Department

Hyperon AND Hyperon Resonance Properties From Charm Baryon Decays At BaBar

Description: This report describes studies of hyperons and hyperon resonances produced in charm baryon decays at BABAR. Using two-body decays of the {Xi}{sub c}{sup 0} and {Omega}{sub c}{sup 0}, it is shown, for the first time, that the spin of the {omega}{sup -} is 3/2. The {Omega}{sup -} analysis procedures are extended to three-body final states and properties of the {Xi}(1690){sup 0} are extracted from a detailed isobar model analysis of the {Lambda}{sub c}{sup +} {yields} {Lambda}{bar K}{sup 0}K{sup +} Dalitz plot. The mass and width values of the {Xi}(1690){sup 0} are measured with much greater precision than attained previously. The hypothesis that the spin of the {Xi}(1690) resonance is 1/2 yields an excellent description of the data, while spin values 3/2 and 5/2 are disfavored. The {Lambda}a{sub 0}(980){sup +} decay mode of the {Lambda}{sub c}{sup +} is observed for the first time. Similar techniques are then used to study {Xi}(1530){sup 0} production in {Lambda}{sub c}{sup +} decay. The spin of the {Xi}(1530) is established for the first time to be 3/2. The existence of an S-wave amplitude in the {Xi}{sup -}{pi}{sup +} system is shown, and its interference with the {Xi}(1530){sup 0} amplitude provides the first clear demonstration of the Breit-Wigner phase motion expected for the {Xi}(1530). The {Xi}{sup -}{pi}{sup +} mass distribution in the vicinity of the {Xi}(1690){sup 0} exhibits interesting structure which may be interpreted as indicating that the {Xi}(1690) has negative parity.
Date: July 3, 2007
Creator: Ziegler, Veronique & U., /Iowa
Partner: UNT Libraries Government Documents Department

The CMS forward calorimeter prototype design studies and Omega(c)0 search at E781 experiment at Fermilab

Description: In the fit part, the Compact Muon Solenoid (CMS) forward calorimeter design studies are presented. The forward calorimeter consists of quartz fibers embedded in a steel absorber. Radiation damage studies of the quartz fiber and the absorber as well as the results of the first pre-production prototype PPP-I are presented. In the second part, the {Omega}{sub c}{sup 0}search studies at the SELEX (E781) experiment at FermiLab are presented. 107 {+-} 22 {Omega}{sub c}{sup 0} events are observed in three decay modes. The relative branching ratio ({Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup -}{pi}{sup +}{pi}{sup +})/{Beta}({Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +}) is measured as 2.00 {+-} 0.45(stat) {+-} 0.32(sys).
Date: May 1, 2004
Creator: Ayan, Ahmet Sedat & U., /Iowa
Partner: UNT Libraries Government Documents Department

Dalitz Plot Analyses of B- to D+ Pi- Pi-, B+ to Pi+ Pi- Pi+ and D(S)+ to Pi+ Pi- Pi+ at BaBar

Description: We report on the Dalitz plot analyses of B{sup -} {yields} D{sup +}{pi}{sup -}{pi}{sup -}, B{sup +} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +} and D{sub s}{sup +} {yields} {pi}{sup +}{pi}{sup -}{sup +}. The Dalitz plot method and the most recent BABAR results are discussed.
Date: April 10, 2012
Creator: Dong, Liaoyuan & U., /Iowa State
Partner: UNT Libraries Government Documents Department

Charm Baryon Studies at BaBar

Description: The authors present a precision measurement of the mass of the {Lambda}{sub c}{sup +} and studies of the production and decay of the {Omega}{sub c}{sup 0} and {Xi}{sub c}{sup 0} charm baryons using data collected by the BABAR experiment. To keep the systematic uncertainty as low as possible, the {Lambda}{sub c}{sup +} mass measurement is performed using the low Q-value decays, {Lambda}{sub c}{sup +} {yields} {Lambda}{sup 0} K{sub S}{sup 0}K{sup +} and {Lambda}{sub c}{sup +} {yields} {Sigma}{sup 0} K{sub S}{sup 0}K{sup +}. Several hadronic final states involving an {Omega}{sup -} and a {Xi}{sup -} hyperon are analyzed to reconstruct the {Xi}{sub c}{sup 0} and the {Omega}{sub c}{sup 0}.
Date: April 21, 2006
Creator: Ziegler, V. & U., /Iowa
Partner: UNT Libraries Government Documents Department

Heavy Flavor Spectroscopy at the Tevatron

Description: The Tevatron experiments have each accumulated about 6 fb{sup -1} of good data since the start of Run II. This large dataset provides excellent opportunities for heavy flavor spectroscopy studies at the Tevatron. This article will cover the latest {Upsilon}(nS) polarization studies as well as exotic meson spectroscopy results.
Date: May 1, 2010
Creator: Yi, Kai & U., /Iowa
Partner: UNT Libraries Government Documents Department

Electron Anomalous Magnetic Moment in Basis Light-Front Quantization Approach

Description: We apply the Basis Light-Front Quantization (BLFQ) approach to the Hamiltonian field theory of Quantum Electrodynamics (QED) in free space. We solve for the mass eigenstates corresponding to an electron interacting with a single photon in light-front gauge. Based on the resulting non-perturbative ground state light-front amplitude we evaluate the electron anomalous magnetic moment. The numerical results from extrapolating to the infinite basis limit reproduce the perturbative Schwinger result with relative deviation less than 1.2%. We report significant improvements over previous works including the development of analytic methods for evaluating the vertex matrix elements of QED.
Date: February 17, 2012
Creator: Zhao, Xingbo; U., /Iowa State; Honkanen, Heli; U., /Jyvaskyla; Maris, Pieter; Vary, James P. et al.
Partner: UNT Libraries Government Documents Department

CP violating anomalous top-quark coupling in p$\bar{p}$ collision at $\sqrt{s}=1.96$ TeV

Description: We conduct the first study of the T-odd correlations in tt events produced in p{bar p} collision at the Fermilab Tevatron collider that can be used to search for CP violation. We select events which have lepton+jets final states to identify t{bar t} events and measure counting asymmetries of several physics observables. Based on the result, we search the top quark anomalous couplings at the production vertex at the Tevatron. In addition, Geant4 development, photon identification, the discrimination of a single photon and a photon doublet from {pi}{sup 0} decay are discussed in this thesis.
Date: April 1, 2011
Creator: Lee, Sehwook & U., /Iowa State
Partner: UNT Libraries Government Documents Department

CROSS SECTION MEASUREMENTS IN THE MAIN INJECTOR PARTICLE PRODUCTION (FNAL-E907) EXPERIMENT AT 58 GEV ENERGY

Description: Cross-sections are presented for 58 GeV {pi}, K, and p on a wide range of nuclear targets. These cross-sections are essential for determining the neutrino flux in measurements of neutrino cross-sections and oscillations. The E907 Main Injector Particle Production (MIPP) experiment at Fermilab is a fixed target experiment for measuring hadronic particle production using primary 120 GeV/c protons and secondary {pi}, K, and p beams. The particle identification is made by dE/dx in a time projection chamber, and by time-of-flight, differential Cherenkov and ring imaging Cherenkov detectors, which together cover a wide range of momentum from 0.1 GeV/c up to 120 GeV/c. MIPP targets span the periodic table, from hydrogen to uranium, including beryllium and carbon. The MIPP has collected {approx} 0.26 x 10{sup 6} events of 58 GeV/c secondary particles produced by protons from the main injector striking a carbon target.
Date: December 1, 2009
Creator: Gunaydin, Yusuf Oguzhan & U., /Iowa
Partner: UNT Libraries Government Documents Department

Observation of $t$-channel electroweak top quark production

Description: The top quark is the heaviest known fundamental particle, with a mass of 172.0{sub -1.3}{sup +0.9}GeV. This is nearly twice the mass of the second heaviest known particle, the Z boson, and roughly the mass of a gold atom. Because of its unusually large mass, studying the top quark may provide insight into the Higgs mechanism and other beyond the standard model physics. Only two accelerators in the world are powerful enough to produce top quarks. The Tevatron, which first accelerated protons in 1983, has produced almost 400,000 top quarks, roughly half at each of its two detectors: DO and CDF. The LHC is a much newer accelerator which currently has accumulated about 0.5% as much data as the Tevatron. However, when running at full luminosity, the LHC is capable of producing a top quark about once every second and will quickly surpass the Tevatron as the leading producer of top quarks. This analysis uses data from the D0 detector at the Tevatron, which are described in chapter 3. Top quarks are produced most often in pairs of top and anti-top quarks through an interaction of the strong force. This production mode was first observed in 1995 at the Tevatron. However, top quarks can also be produced though an electroweak interaction, which produces just one top quark. This production mode was first observed at the Tevatron in 2008. Single top quark production can occur in different channels. In this analysis, a measurement of the cross section of the t-channel production mode is performed. This measurement uses 5.4 fb{sup -1} of data and uses the technique of boosted decision trees in order to separate signal from background events. The t-channel cross section is measured to be: {sigma}(p{bar p} {yields} tqb + X) = 3.03{sub -0.66}{sup +0.78}pb (0.0.1). Additional cross section measurements ...
Date: April 1, 2011
Creator: Triplett, Nathan & U., /Iowa State
Partner: UNT Libraries Government Documents Department

Realistic Two-body Interactions in Many-nucleon Systems: Correlated Motion beyond Single-particle Behavior

Description: In the framework of the theory of spectral distributions we perform an overall comparison of three modern realistic interactions, CD-Bonn, CD-Bonn+3terms, and GXPF1 in a broad range of nuclei in the upper fp shell and study their ability to account for the development of isovector pairing correlations and collective rotational motion in many-particle nuclear systems. Our findings reveal a close similarity between CD-Bonn and CD-Bonn+3terms, while both interactions possess features different from the ones of GXPF1. The GXPF1 interaction is used to determine the strength parameter of a quadrupole term that augments an isovector-pairing model interaction with Sp(4) dynamical symmetry, which in turn is shown to yield a reasonable agreement with the experimental low-lying energy spectra of {sup 58}Ni and {sup 58}Cu.
Date: June 27, 2006
Creator: Sviratcheva, K.D.; Draayer, J.P. & /Louisiana State U. /Iowa State U. /LLNL, Livermore /SLAC
Partner: UNT Libraries Government Documents Department

Electron in a transverse harmonic cavity

Description: We employ Hamiltonian light-front quantum field theory in a basis function approach to solve the non-perturbative problem of an electron in a strong scalar transverse confining potential. We evaluate both the invariant mass spectra and the anomalous magnetic moment of the lowest state for this two-scale system. The weak external field limit of the anomalous magnetic moment agrees with the result of QED perturbation theory within the anticipated accuracy.
Date: October 27, 2010
Creator: Honkanen, H.; Maris, P.; Vary, J.P.; U., /Iowa State; Brodsky, S.J. & /SLAC
Partner: UNT Libraries Government Documents Department

Forward Neutron Production at the Fermilab Main Injector

Description: We have measured cross sections for forward neutron production from a variety of targets using proton beams from the Fermilab Main Injector. Measurements were performed for proton beam momenta of 58 GeV/c, 84 GeV/c, and 120 GeV/c. The cross section dependence on the atomic weight (A) of the targets was found to vary as A{sup a} where a is 0.46 {+-} 0.06 for a beam momentum of 58 GeV/c and 0.54 {+-} 0.05 for 120 GeV/c. The cross sections show reasonable agreement with FLUKA and DPMJET Monte Carlos. Comparisons have also been made with the LAQGSM Monte Carlo. The MIPP (Main Injector Particle Production) experiment (FNAL E907) [1] acquired data in the Meson Center beam line at Fermilab. The primary purposes of the experiment were to investigate scaling laws in hadron fragmentation [2], to obtain hadron production data for the NuMI (Neutrinos at the Main Injector [3]) target to be used for calculating neutrino fluxes, and to obtain inclusive pion, neutron, and photon production data to facilitate proton radiography [4]. While there is considerable data available on inclusive charged particle production [5], there is little data on neutron production. In this article we present results for forward neutron production using proton beams of 58 GeV/c, 84 GeV/c, and 120 GeV/c on hydrogen, beryllium, carbon, bismuth, and uranium targets, and compare these data with predictions from Monte Carlo simulations.
Date: October 1, 2010
Creator: Nigmanov, T.S.; U., /Michigan; Rajaram, D.; U., /Michigan; Longo, M.J.; U., /Michigan et al.
Partner: UNT Libraries Government Documents Department

The Radiation Dose Measurement System for the BaBar Electromagnetic Calorimeter

Description: An array of 116 p-channel radiation sensitive MOSFET transistors (RadFETs) has been operational for the past 6 years at the BaBar experiment at the PEP-II asymmetric B-Factory at the Stanford Linear Accelerator Center (SLAC). This system maps the integrated dose absorbed by different regions of the Electromagnetic Calorimeter (EMC) during the running of the experiment. We report on the design and implementation of the system and finally, the performance of the monitoring system during the last 6 years of BaBar data-taking.
Date: August 14, 2006
Creator: Khan, A.; U., /Brunel; Meyer, W.T.; U., /Iowa State; Stelzer, J.; /Stanford U., Phys. Dept. et al.
Partner: UNT Libraries Government Documents Department

Charged Kaon Mass Measurement using the Cherenkov Effect

Description: The two most recent and precise measurements of the charged kaon mass use X-rays from kaonic atoms and report uncertainties of 14 ppm and 22 ppm yet differ from each other by 122 ppm. We describe the possibility of an independent mass measurement using the measurement of Cherenkov light from a narrow-band beam of kaons, pions, and protons. This technique was demonstrated using data taken opportunistically by the Main Injector Particle Production experiment at Fermi National Accelerator Laboratory which recorded beams of protons, kaons, and pions ranging in momentum from +37 GeV/c to +63 GeV/c. The measured value is 491.3 {+-} 1.7 MeV/c{sup 2}, which is within 1.4{sigma} of the world average. An improvement of two orders of magnitude in precision would make this technique useful for resolving the ambiguity in the X-ray data and may be achievable in a dedicated experiment.
Date: September 1, 2009
Creator: Graf, N.; U., /Indiana; Lebedev, A.; /Harvard U., Phys. Dept.; Abrams, R.J.; U., /Michigan et al.
Partner: UNT Libraries Government Documents Department

The CMS barrel calorimeter response to particle beams from 2-GeV/c to 350-GeV/c

Description: The response of the CMS barrel calorimeter (electromagnetic plus hadronic) to hadrons, electrons and muons over a wide momentum range from 2 to 350 GeV/c has been measured. To our knowledge, this is the widest range of momenta in which any calorimeter system has been studied. These tests, carried out at the H2 beam-line at CERN, provide a wealth of information, especially at low energies. The analysis of the differences in calorimeter response to charged pions, kaons, protons and antiprotons and a detailed discussion of the underlying phenomena are presented. We also show techniques that apply corrections to the signals from the considerably different electromagnetic (EB) and hadronic (HB) barrel calorimeters in reconstructing the energies of hadrons. Above 5 GeV/c, these corrections improve the energy resolution of the combined system where the stochastic term equals 84.7 {+-} 1.6% and the constant term is 7.4 {+-} 0.8%. The corrected mean response remains constant within 1.3% rms.
Date: January 1, 2009
Creator: Abdullin, S.; /Moscow, ITEP; Abramov, V.; /Serpukhov, IHEP; Acharya, B.; Inst., /Tata et al.
Partner: UNT Libraries Government Documents Department