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Search for neutral Higgs bosons decaying to tau pairs produced in association with b-quarks at s**(1/2)=1.96 TeV

Description: 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 l… more
Date: December 1, 2008
Creator: Herner, Kenneth Richard
Partner: UNT Libraries Government Documents Department
open access

Measurement of top quark mass in the all hadronic channel in s**(1/2) = 1.96 TeF, ppbar collisions at D0

Description: A measurement of the top quark mass in proton-antiproton collisions at {radical}s = 1.96 TeV using 1040fb{sup -1} of data collected in D detector at Fermilab is presented. This analysis focuses on the all-hadronic decay mode of the top quark and therefore only events with six or more calorimeter jets in the final state are considered.
Date: May 1, 2008
Creator: Lam, David Wai Kui & U., /Notre Dame
Partner: UNT Libraries Government Documents Department
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Search for Large Extra Dimensions via Single Photons Plus Missing Energy Final States at s^(1/2) = 1.96 TeV

Description: 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.
Date: December 1, 2008
Creator: Carrera, Edgar Fernando
Partner: UNT Libraries Government Documents Department
open access

MEASUREMENT OF Z + GAMMA PRODUCTION AND SEARCH FOR ANOMALOUS TRIPLE GAUGE COUPLINGS IN PROTON-ANTIPROTON COLLISIONS AT s**(1/2) = 1.96 TEV

Description: The author presents a measurement of p{bar p} {yields} Z{gamma} + X {yields} e{sup +}e{sup -}{gamma} + X production using proton-antiproton collisions data collected at the Collider Detector at Fermilab at a center of mass energy of 1.96 TeV. Z{gamma} production provides a direct test of the triple neutral gauge couplings. A measurement of Z{gamma} production cross section and search for anomalous ZZ{gamma} and Z{gamma}{gamma} couplings are presented. The data presented are from 1.1 fb{sup -1} … more
Date: January 1, 2008
Creator: Deng, Jianrong & U., /Duke
Partner: UNT Libraries Government Documents Department
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Search for standard model Higgs bosons decaying to w-boson pairs in proton-anti-proton collisions at s**(1/2) = 1.96 TeV

Description: 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, a… more
Date: December 1, 2008
Creator: Hidas, Dean Andrew & U., /Duke
Partner: UNT Libraries Government Documents Department
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Measurement of sigma(ppbar->Z) Br(Z->tau+tau-) and search for Higgs bosons decaying to tau+tau- at s**(1/2) = 1.96 TeV

Description: The resonant production of tau-lepton pairs is as interesting for the study of Standard Model (SM) physics as the production of lighter leptons pairs. For new phenomena, such as Higgs boson production or in case new particles beyond the SM would arise, the detection of (resonant) pairs of tau leptons becomes much more interesting. This is due to the fact that tau leptons are much heavier than the other leptons, which increases the chance that these new phenomena would be observed first in this … more
Date: January 1, 2008
Creator: Galea, Cristina Florina & U., /Nijmegen
Partner: UNT Libraries Government Documents Department
open access

A Measurement of the t anti-t Production Cross Section in p anti-p Collisions at s**(1/2) = 1.96-TeV using Soft Muon Tagging

Description: I present a measurement of the t{bar t} production cross section at {radical}s = 1.96 TeV using 2034 pb{sup -1} of CDF Run II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes a t {yields} Wb branching fraction of 100 percent. Events consistent with t{bar t} decay are found by identifying jets containing heavy-flavor semileptonic decays to muons. The dominant backgrounds are evaluated directly from the … more
Date: May 1, 2008
Creator: Grundler, Ulysses A.
Partner: UNT Libraries Government Documents Department
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t anti-t production cross section measurement using soft electron tagging in p anti-p collisions at s**(1/2) = 1.96-TeV

Description: 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. T… more
Date: September 1, 2008
Creator: Chou, John Paul & U., /Harvard
Partner: UNT Libraries Government Documents Department
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Measurement of Inclusive Jet Cross Sections in Z/gamma*(->e+e-) + jets Production in ppbar Collisions at s**(1/2) = 1.96 TeV with the CDF Detector

Description: This Ph.D. thesis presents the measurement of inclusive jet cross sections in Z/{gamma}* {yields} e{sup +}e{sup -} events using 1.7 fb{sup -1} of data collected by the upgraded CDF detector during the Run II of the Tevatron. The Midpoint cone algorithm is used to search for jets in the events after identifying the presence of a Z/{gamma}* boson through the reconstruction of its decay products. The measurements are compared to next-to-LO (NLO) pQCD predictions for events with one and two jets in… more
Date: April 1, 2008
Creator: Salto Bauza, Oriol
Partner: UNT Libraries Government Documents Department
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Search for 1st Generation Leptoquarks in the eejj channel with the DZero experiment

Description: An evidence of the existence of leptoquarks (LQ) would prove the validity of various extensions of the Standard Model of Particle Physics (SM). The search for first generation leptoquarks presented in this dissertation has been performed by analyzing a 1.02 fb{sup -1} sample of data collected by the D0 detector, events with a final state comprising two light jets and two electrons. The absence of an excess of events in comparison to SM expectations leads to exclude scalar LQ masses up to 292 Ge… more
Date: September 1, 2008
Creator: Barfuss, Anne-Fleur
Partner: UNT Libraries Government Documents Department
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Search for W' -> tbbar in ppbar Collisions at sqrt(s)=1.96 TeV

Description: 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 … more
Date: December 1, 2008
Creator: Cully, James Clark
Partner: UNT Libraries Government Documents Department
open access

Observations and Measurements of Orbitally Excited L=1 B Mesons at the D0 Experiment

Description: 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… more
Date: September 1, 2008
Creator: Williams, Mark Richard James
Partner: UNT Libraries Government Documents Department
open access

Study on the top quark pair production mechanism in 1.96 TeV proton-antiproton collisions

Description: The study of the top quark pair production mechanism in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV is described. The main subjects are the measurements of the top quark pair production cross section, the top quark mass and a search for a new particle decaying to the top quark pair. The analyses are based on 1.9 fb{sup -1} of data collected by the Collider Detector at Fermilab (CDF) Run II experiment between March 2002 and May 2007, using the lepton+jets events. The meas… more
Date: March 1, 2008
Creator: Naganoma, Junji & U., /Waseda
Partner: UNT Libraries Government Documents Department
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Measurement of electroweak single top quark production in proton-antiproton collisions at 1.96 TeV

Description: The top quark is an extremely massive fundamental particle that is predominantly produced in pairs at particle collider experiments. The Standard Model of particle physics predicts that top quarks can also be produced singly by the electroweak force; however, this process is more difficult to detect because it occurs at a smaller rate and is more difficult to distinguish from background processes. The cross section of this process is related to the Cabbibo-Kobayashi-Maskawa matrix element |V{su… more
Date: May 1, 2008
Creator: Dong, Peter Joseph
Partner: UNT Libraries Government Documents Department
open access

Investigations of the R5(SixGe1-x)4 Intermetallic Compounds by X-Ray Resonant Magnetic Scattering

Description: The XRMS experiment on the Gd{sub 5}Ge{sub 4} system has shown that, below the Neel temperature, T{sub N} = 127 K, the magnetic unit cells is the same as the chemical unit cell. From azimuth scans and the Q dependence of the magnetic scattering, all three Gd sites in the structure were determined to be in the same magnetic space group Pnma. The magnetic moments are aligned along the c-axis and the c-components of the magnetic moments at the three different sites are equal. The ferromagnetic sla… more
Date: August 18, 2008
Creator: Tan, Lizhi
Partner: UNT Libraries Government Documents Department
open access

Search for Higgs Boson Production in Association with a W Boson in 1.96-TeV Proton - Antiproton Collisions

Description: 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{su… more
Date: February 1, 2008
Creator: Masubuchi, Tatusya
Partner: UNT Libraries Government Documents Department
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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
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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

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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Search for pair production of scalar top quarks decaying to a tau lepton and a b quark in 1.96 TeV ppbar collisions

Description: I present the results of a search for pair production of scalar top quarks ({tilde t}{sub 1}) in an R-parity violating supersymmetric scenario using 322 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected by the upgraded Collider Detector at Fermilab. I assume each {tilde t}{sub 1} decays into a {tau} lepton and a b quark, with branching ratio {beta}, and search for final states containing either an electron or a muon from a leptonic {tau} decay, a hadronically decaying {tau} l… more
Date: May 1, 2008
Creator: Khotilovich, Vadim, G. & A-M, /Texas
Partner: UNT Libraries Government Documents Department
open access

Measurement of the top-antitop quark pair differential cross section with respect to the invariant mass of the pair in proton-antiproton collisions at a center of mass energy of 1.96 TeV

Description: 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} &gt… more
Date: October 1, 2008
Creator: Bridgeman, Alice
Partner: UNT Libraries Government Documents Department
open access

Study of the heavy flavour fractions in z+jets events from proton-antiproton collisions at energy = 1.96 TeV with the CDF II detector at the Tevatron collider

Description: The Standard Model of field and particles is the theory that provides the best description of the known phenomenology of the particle physics up to now. Data collected in the last years, mainly by the experiments at the big particle accelerators (SPS, LEP, TEVATRON, HERA, SLAC), allowed to test the agreement between measurements and theoretical calculations with a precision of 10{sup -3} {divided_by} 10{sup -4}. The Standard Model is a Quantum Field Theory based on the gauge symmetry group SU(3… more
Date: June 1, 2008
Creator: Mastrandrea, Paolo & U., /Siena
Partner: UNT Libraries Government Documents Department
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A measurement of hadron production cross sections for the simulation of accelerator neutrino beams and a search for muon-neutrino to electron-neutrino oscillations in the delta m**2 about equals 1-eV**2 region

Description: A measurement of hadron production cross-sections for the simulation of accelerator neutrino beams and a search for muon neutrino to electron neutrino oscillations in the {Delta}m{sup 2} {approx} 1 eV{sup 2} region. This dissertation presents measurements from two different high energy physics experiments with a very strong connection: the Hadron Production (HARP) experiment located at CERN in Geneva, Switzerland, and the Mini Booster Neutrino Experiment (Mini-BooNE) located at Fermilab in Bata… more
Date: January 1, 2008
Creator: Schmitz, David W.
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
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