7,342 Matching Results

Search Results

Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron

Description: We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles (transverse momentum p{sub T} > 0.5 GeV/c, pseudorapidity |{eta}| < 1) produced in association with large transverse momentum jets ({approx}2.2 fb{sup -1}) or with Drell-Yan lepton-pairs ({approx}2.7 fb{sup -1}) in the Z-boson mass region (70 < M(pair) < 110 GeV/c{sup 2}) as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton-pair (in Drell-Yan production) or the leading jet (in high-p{sub T} jet production) in each event to define three regions of {eta}-{phi} space; toward, away, and transverse, where {phi} is the azimuthal scattering angle. For Drell-Yan production (excluding the leptons) both the toward and transverse regions are very sensitive to the underlying event. In high-p{sub T} jet production the transverse region is very sensitive to the underlying event and is separated into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam remnant and multiple parton interaction components of the scattering. The data are corrected to the particle level to remove detector effects and are then compared with several QCD Monte-Carlo models. The goal of this analysis is to provide data that can be used to test and improve the QCD Monte-Carlo models of the underlying event that are used to simulate hadron-hadron collisions.
Date: March 1, 2010
Creator: ,; Aaltonen, T.; Adelman, J.; Gonzalez, B.Alvarez; Amerio, S.; Amidei, D. et al.
Partner: UNT Libraries Government Documents Department

Diagnostics for the Biased Electrode Experiment on NSTX

Description: A linear array of four small biased electrodes was installed in NSTX in an attempt to control the width of the scrape-off layer (SOL) by creating a strong local poloidal electric field. The set of electrodes were separated poloidally by a 1 cm gap between electrodes and were located slightly below the midplane of NSTX, 1 cm behind the RF antenna and oriented so that each electrode is facing approximately normal to the magnetic field. Each electrode can be independently biased to ±100 volts. Present power supplies limit the current on two electrodes to 30 amps the other two to 10 amps each. The effect of local biasing was measured with a set of Langmuir probes placed between the electrodes and another set extending radially outward from the electrodes, and also by the gas puff imaging diagnostic (GPI) located 1 m away along the magnetic field lines intersecting the electrodes. Two fast cameras were also aimed directly at the electrode array. The hardware and controls of the biasing experiment will be presented and the initial effects on local plasma parameters will be discussed.
Date: March 20, 2009
Creator: A.L. Roquemore, S.J. Zweben, C.E. Bush, R. Kaita, R. J. Marsalsa, and R.J. Maqueda
Partner: UNT Libraries Government Documents Department

NUCLEAR WASTE GLASSES CONTINUOUS MELTING AND BULK VITRIFICAITON

Description: This contribution addresses various aspects of nuclear waste vitrification. Nuclear wastes have a variety of components and composition ranges. For each waste composition, the glass must be formulated to possess acceptable processing and product behavior defined in terms of physical and chemical properties that guarantee the glass can be easily made and resist environmental degradation. Glass formulation is facilitated by developing property-composition models, and the strategy of model development and application is reviewed. However, the large variability of waste compositions presents numerous additional challenges: insoluble solids and molten salts may segregate; foam may hinder heat transfer and slow down the process; molten salts may accumulate in container refractory walls; the glass on cooling may precipitate crystalline phases. These problems need targeted exploratory research. Examples of specific problems and their possible solutions are discussed.
Date: March 24, 2008
Creator: AA, KRUGER & PR, HRMA
Partner: UNT Libraries Government Documents Department

EMPIRICAL MODEL FOR FORMULATION OF CRYSTAL-TOLERANT HLW GLASSES

Description: Historically, high-level waste (HLW) glasses have been formulated with a low liquideus temperature (T{sub L}), or temperature at which the equilibrium fraction of spinel crystals in the melt is below 1 vol % (T{sub 0.01}), nominally below 1050 C. These constraints cannot prevent the accumulation of large spinel crystals in considerably cooler regions ({approx} 850 C) of the glass discharge riser during melter idling and significantly limit the waste loading, which is reflected in a high volume of waste glass, and would result in high capital, production, and disposal costs. A developed empirical model predicts crystal accumulation in the riser of the melter as a function of concentration of spinel-forming components in glass, and thereby provides guidance in formulating crystal-tolerant glasses that would allow high waste loadings by keeping the spinel crystals small and therefore suspended in the glass.
Date: March 7, 2012
Creator: AA, KRUGER; J, MATYAS; AR, HUCKLEBERRY; JD, VIENNA & CA, RODRIGUEZ
Partner: UNT Libraries Government Documents Department

IRON-PHOSPHATE GLASS FOR IMMOBILIZATION OF RADIOACTIVE TECHNETIUM

Description: Technetium-99 (Tc-99) can bring a serious environmental threat because of its high fission yield, long half-life, and high solubility and mobility in the ground water. The present work investigated the immobilization of Tc-99 (surrogated by Re) by heat-treating mixtures of an iron-phosphate glass with 1.5 to 6 wt.% KReO{sub 4} at {approx}1000 C. The Re retention in the glass was as high as {approx}1.2 wt. % while the loss of Re by evaporation during melting was {approx}50%. Re was uniformly distributed within the glass. The normalized Re release by the 7-day Product Consistency Test was {approx}0.39 g/m{sup 2}, comparable with that in phosphate-bonded ceramics and borosilicate glasses. These results suggest that iron-phosphate glass can provide a good matrix for immobilizing Tc-99.
Date: March 19, 2012
Creator: AA, KRUGER; PR, HRMA; K, XU; J, CHOI; W, UM & J, HEO
Partner: UNT Libraries Government Documents Department

Characterization of Environmental Stability of Pulsed Laser Deposited Oxide Ceramic Coatings

Description: A systematic investigation of candidate hydrogen permeation materials applied to a substrate using Pulsed Laser Deposition has been performed. The investigation focused on application of leading permeation-resistant materials types (oxide, carbides, and metals) on a stainless steel substrate. and evaluation of the stability of the applied coatings. Type 304L stainless steel substrates were coated with aluminum oxide, chromium oxide, and aluminum. Characterization of the coating-substrate system adhesion was performed using scratch adhesion testing and microindentation. Coating stability and environmental susceptibility were evaluated for two conditions-air at 350 degrees Celsius and Ar-H2 at 350 degrees Celsius for up to 100 hours. Results from this study have shown the pulsed laser deposition process to be an extremely versatile technology that is capable of producing a sound coating/substrate system for a wide variety of coating materials.
Date: March 2, 2004
Creator: ADAMS, THADM
Partner: UNT Libraries Government Documents Department

HIGH INTENSITY PERFORMANCE OF THE BROOKHAVEN AGS.

Description: The Brookhaven AGS provides 24 GeV protons for a multi-user program of fixed-target high energy physics experiments, such as the study of extremely rare Kaon decays. Up to 7 x 10{sup 13} protons are slowly extracted over 2.2 seconds each 5.1 seconds. The muon storage ring of the g-2 experiment is supplied with bunches of 7 x 10{sup 12} protons. Since the completion of the a 1.9 GeV Booster synchrotron and installation of a new high-power rf system and transition jump system in the AGS various modes of operation have been explored to overcome space charge limits and beam instabilities at these extreme beam intensities. Experiments have been done using barrier cavities to enable accumulation of debunched beam in the AGS as a potential path to significantly higher intensities. We report on the present understanding of intensity limitations and prospects for overcoming them.
Date: March 29, 1999
Creator: AHRENS,L. A.; ALESSI,J.; BLASKIEWICZ,M.; BRENNAN,J. M.; BROWN,K.; GARDNER,C. et al.
Partner: UNT Libraries Government Documents Department

AGS RESONANT EXTRACTION WITH HIGH INTENSITY BEAMS.

Description: The Brookhaven AGS third integer resonant extraction system allows the AGS to provide high quality, high intensity 25.5 GeV/c proton beams simultaneously to four target stations and as many as 8 experiments. With the increasing intensities (over 7 x 10{sup 13} protons/pulse) and associated longer spill periods (2.4 to 3 seconds long), we continue to run with low losses and high quality low modulation continuous current beams.[1] Learning to extract and transport these higher intensity beams has required a process of careful modeling and experimentation. We have had to learn how to correct for various instabilities and how to better match extraction and the transport lines to the higher emittance beams being accelerated in the AGS. Techniques employed include ''RF'' methods to smooth out momentum distributions and fine structure. We will present results of detailed multi-particle tracking modeling studies which enabled us to develop a clear understanding of beam loss mechanisms in the transport and extraction process. We will report on our status, experiences, and the present understanding of the intensity limitations imposed by resonant extraction and transport to fixed target stations.
Date: March 29, 1999
Creator: AHRENS,L.; BROWN,K.; GLENN,J. W.; ROSER,T.; TSOUPAS,N. & VANASSELT,W.
Partner: UNT Libraries Government Documents Department

{sup 17}O NMR investigation of oxidative degradation in polymers under gamma-irradiation

Description: The {gamma}-irradiated-oxidation of pentacontane (C{sub 50}H{sub 102}) and the polymer polyisoprene was investigated as a function of oxidation level using {sup 17}O nuclear magnetic resonance (NMR) spectroscopy. It is demonstrated that by using {sup 17}O labeled O{sub 2} gas during the {gamma}-irradiation process, details about the oxidative degradation mechanisms can be directly obtained from the analysis of the {sup 17}O NMR spectra. Production of carboxylic acids is the primary oxygen-containing functionality during the oxidation of pentacontane, while ethers and alcohols are the dominant oxidation product observed for polyisoprene. The formation of ester species during the oxidation process is very minor for both materials, with water also being produced in significant amounts during the radiolytic oxidation of polyisoprene. The ability to focus on the oxidative component of the degradation process using {sup 17}O NMR spectroscopy demonstrates the selectivity of this technique over more conventional approaches.
Date: March 8, 2000
Creator: ALAM,TODD M.; CELINA,MATHIAS C.; ASSINK,ROGER A.; CLOUGH,ROGER LEE & GILLEN,KENNETH T.
Partner: UNT Libraries Government Documents Department

Hands-free operation of a small mobile robot

Description: The Intelligent Systems and Robotics Center of Sandia National laboratories has an ongoing research program in advanced user interfaces. As part of this research, promising new transduction devices, particularly hands-free devices, are being explored for the control of mobile and floor-mounted robotic systems. Brainwave control has been successfully demonstrated by other researchers in a variety of fields. In the research described here, Sandia developed and demonstrated a proof-of-concept brainwave-controlled mobile robot system. Preliminary results were encouraging. Additional work required to turn this into a reliable. fieldable system for mobile robotic control is identified. Used in conjunction with other controls, brainwave control could be an effective control method in certain circumstances.
Date: March 14, 2000
Creator: AMAI,WENDY A.; FAHRENHOLTZ,JILL C. & LEGER,CHRIS L.
Partner: UNT Libraries Government Documents Department

DESIGN AND STATUS OF THE VISA II EXPERIMENT.

Description: VISA II is the follow-up project to the successful Visible to Infrared SASE Amplifier (VISA) experiment at the Accelerator Test Facility (ATF) in Brookhaven National Lab (BNL). This paper will report the motivation for and status of the two main experiments associated with the VISA II program. One goal of VISA II is to perform an experimental study of the physics of a chirped beam SASE FEL at the upgraded facilities of the ATF. This requires a linearization of the transport line to preserve energy chirping of the electron beam at injection. The other planned project is a strong bunch compression experiment, where the electron bunch is compressed in the chicane, and the dispersive beamline transport, allowing studies of deep saturation.
Date: March 24, 2004
Creator: ANDONIAN,G. BABZIEN,MLBEN-ZVI,I. YAKIMENKO,Y. ET AL.
Partner: UNT Libraries Government Documents Department

First Measurement of the Angular Coefficients of Drell-Yan $e^{+}e^{-}$ pairs in the Z Mass Region from $p\bar{p}$ Collisions at $\sqrt{s}$ = 1.96 TeV

Description: We report on the first measurement of the angular distributions of final state electrons in p{bar p} {yields} {gamma}*/Z {yields} e{sup +}e{sup -} + X events produced in the Z boson mass region at {radical}s = 1.96 TeV. The data sample collected by the CDF II detector for this result corresponds to 2.1 fb{sup -1} of integrated luminosity. The angular distributions are studied as a function of the transverse momentum of the electron-positron pair and show good agreement with the Lam-Tung relation, consistent with a spin-1 description of the gluon, and demonstrate that at high values of the transverse momentum, Z bosons are produced via quark anti-quark annihilation and quark-gluon Compton processes.
Date: March 1, 2011
Creator: Aaltonen, T.; Aaltonen, T.; Phys., /Helsinki Inst. of; Alvarez Gonzalez, B.; Phys., /Oviedo U. /Cantabria Inst. of; Amerio, S. et al.
Partner: UNT Libraries Government Documents Department

Limits on Anomalous Trilinear Gauge Couplings in $Z\gamma$ Events from $p\bar{p}$ Collisions at $\sqrt{s} = 1.96$ TeV

Description: Using Z{gamma} candidate events collected by the CDF detector at the Tevatron Collider, we search for potential anomalous (non-standard-model) couplings between the Z boson and the photon. At the hard scatter energies typical of the Tevatron, standard model Z{gamma} couplings are too weak to be detected by current experiments; hence any evidence of couplings indicates new physics. Measurements are performed using data corresponding to an integrated luminosity of 4.9 fb{sup -1} in the Z {yields} {nu}{bar {nu}} decay channel and 5.1 fb{sup -1} in the Z {yields} l{sup +}l{sup -} (l = {mu}, e) decay channels. The combination of these measurements provides the most stringent limits to date on Z{gamma} trilinear gauge couplings. Using an energy scale of {Lambda} = 1.5 TeV to allow for a direct comparison with previous measurements, we find limits on the CP-conserving parameters that describe Z{gamma} couplings to be |h{sub 3}{sup {gamma},Z}| < 0.017 and |h{sub 4}{sup {gamma},Z}| < 0.0006. These results are consistent with standard model predictions.
Date: March 1, 2011
Creator: Aaltonen, T.; Aaltonen, T.; Phys., /Helsinki Inst. of; Alvarez Gonzalez, B.; Phys., /Oviedo U. /Cantabria Inst. of; Amerio, S. et al.
Partner: UNT Libraries Government Documents Department

Measurement of Event Shapes in Proton-Antiproton Collisions at Center-of-Mass Energy 1.96 TeV

Description: A study of event shape observables in proton-antiproton collisions at {radical}s = 1.96 TeV is presented. The data for this analysis were recorded by the CDF II detector at the Tevatron collider. The variables studied are the transverse thrust and thrust minor, both defined in the plane perpendicular to the beam direction. The observables are measured using energies from unclustered calorimeter cells. In addition to studies of the differential distributions, we present the dependence of event shape mean values on the leading jet transverse energy. Data are compared with pythia Tune A and to resummed parton level predictions that were matched to fixed order results at NLO accuracy (NLO+NLL). Predictions from pythia Tune A agree fairly well with the data. However, the underlying event contributes significantly to these observables, making it difficult to make direct comparisons to the NLO+NLL predictions, which do not account for the underlying event. To overcome this difficulty, we introduce a new observable, a weighted difference of the mean values of the thrust and thrust minor, which is less sensitive to the underlying event, allowing for a comparison with NLO+NLL. Both pythia Tune A and the NLO+NLL calculations agree well within the 20% theoretical uncertainty with the data for this observable, indicating that perturbative QCD successfully describes shapes of the hadronic final states.
Date: March 1, 2011
Creator: Aaltonen, T.; Aaltonen, T.; Phys., /Helsinki Inst. of; Alvarez Gonzalez, B.; Phys., /Oviedo U. /Cantabria Inst. of; Amerio, S. et al.
Partner: UNT Libraries Government Documents Department

Measurements of Direct CP Violating Asymmetries in Charmless Decays of Strange Bottom Mesons and Bottom Baryons

Description: We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb{sup -1} of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A{sub CP}(B{sub s}{sup 0} {yields} K{sup -}{pi}{sup +}) = +0.39 {+-} 0.15 (stat) {+-} 0.08 (syst), and botton baryons, A{sub CP}({Lambda}{sub b}{sup 0} {yields} p{pi}{sup -}) = + 0.03 {+-} 0.17 (stat) {+-} 0.05 (syst) and A{sub CP} ({Lambda}{sub b}{sup 0} {yields} pK{sup -}) = +0.37 {+-} 0.17 (stat) {+-} 0.03 (syst). In addition, they measure CP violation in B{sup 0} {yields} K{sup +}{pi}{sup -} decays with 3.5{sigma} significance, A{sub CP} (B{sup 0} {yields} K{sup +}{pi}{sup -}) = -0.086 {+-} 0.023 (stat) {+-} 0.009 (syst), in agreement with the current world average. Measurements of branching fractions of B{sub s}{sup 0} {yields} K{sup +}K{sup -} and B{sup 0} {yields} {pi}{sup +}{pi}{sup -} decays are also updated.
Date: March 1, 2011
Creator: Aaltonen, T.; Aaltonen, T.; Phys., /Helsinki Inst. of; Alvarez Gonzalez, B.; Phys., /Oviedo U. /Cantabria Inst. of; Amerio, S. et al.
Partner: UNT Libraries Government Documents Department

Combined CDF and D0 Upper Limits on Standard Model Higgs Boson Production with up to 8.2 fb$^{-1}$ of Data

Description: We combine results from CDF and D0's direct searches for the standard model (SM) Higgs boson (H) produced in p{bar p} collisions at the Fermilab Tevatron at {radical}s = 1.96 TeV. The results presented here include those channels which are most sensitive to Higgs bosons with mass between 130 and 200 GeV/c{sup 2}, namely searches targeted at Higgs boson decays to W{sup +}W{sup -}, although acceptance for decays into {tau}{sup |+} {tau}{sup -} and {gamma}{gamma} is included. Compared to the previous Tevatron Higgs search combination, more data have been added and the analyses have been improved to gain sensitivity. We use the MSTW08 parton distribution functions and the latest gg {yields} H theoretical cross section predictions when testing for the presence of a SM Higgs boson. With up to 7.1 fb{sup -1} of data analyzed at CDF, and up to 8.2 fb{sup -1} at D0, the 95% C.L. upper limits on Higgs boson production is a factor of 0.54 times the SM cross section for a Higgs boson mass of 165 GeV/c{sup 2}. We exclude at the 95% C.L. the region 158 < m{sub H} < 173 GeV/c{sup 2}.
Date: March 1, 2011
Creator: Aaltonen, T.; Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M. et al.
Partner: UNT Libraries Government Documents Department

Search for a heavy particle decaying to a top quark and a light quark in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV

Description: We present a search for a new heavy particle M produced in association with a top quark, p{bar p} {yields} t(M {yields} {bar t}q) or p{bar p} {yields} {bar t}({bar M} {yields} t{bar q}), where q stands for up quarks and down quarks. Such a particle may explain the recent anomalous measurements of top-quark forward-backward asymmetry. If the light-flavor quark (q) is reconstructed as a jet (j), this gives a {bar t}+j or t+j resonance in t{bar t}+jet events, a previously unexplored experimental signature. In a sample of events with exactly one lepton, missing transverse momentum and at least five jets, corresponding to an integrated luminosity of 8.7 fb{sup -1} collected by the CDF II detector, we find the data to be consistent with the standard model. We set cross-section upper limits on the production (p{bar p} {yields} Mt or {bar M} {bar t}) at 95% confidence level from 0.61 pb to 0.02 pb for M masses ranging from 200 GeV/c{sup 2} to 800 GeV/c{sup 2}, respectively.
Date: March 1, 2012
Creator: Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Partner: UNT Libraries Government Documents Department

Precise measurement of the $W$-boson mass with the CDF II detector

Description: We have measured the W-boson mass M{sub W} using data corresponding to 2.2 fb{sup -1} of integrated luminosity collected in p{bar p} collisions at {radical}s = 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470 126 W {yields} e{nu} candidates and 624 708 W {yields} {mu}{nu} candidates yield the measurement M{sub W} = 80 387 {+-} 12{sub stat} {+-} 15{sub syst} = 80 387 {+-} 19 MeV/c{sup 2}. This is the most precise measurement of the W-boson mass to date and significantly exceeds the precision of all previous measurements combined.
Date: March 1, 2012
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Partner: UNT Libraries Government Documents Department

A Search for dark matter in events with one jet and missing transverse energy in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV

Description: We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp collisions at {radical}s = 1.96 TeV corresponding to an integrated luminosity of 6.7 fb{sup -1} recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of 5 GeV/c{sup 2}, and on spin-dependent interactions up to masses of 200 GeV/c{sup 2}.
Date: March 1, 2012
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Partner: UNT Libraries Government Documents Department

Search for Scalar Top Quark Production in $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV

Description: We report on a search for the supersymmetric partner of the top quark (scalar top) decaying into a charm quark and a neutralino in p{bar p} collisions at {radical}s = 1.96 TeV. The data sample, collected by the CDF II detector at the Fermilab Tevatron, corresponds to an integrated luminosity of 2.6 fb{sup -1}. Candidate events are selected by requiring two or more jets and a large imbalance in the transverse momentum. To enhance the analysis sensitivity, at least one of the jets is required to be identified as originating from a charm quark using an algorithm specifically designed for this analysis. The selected events are in good agreement with standard model predictions. In the case of large mass splitting between the scalar top quark and the neutralino we exclude a scalar top quark mass below 180 GeV/c{sup 2} at 95% confidence level.
Date: March 1, 2012
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Partner: UNT Libraries Government Documents Department

Search for the Standard Model Higgs Boson Produced in Association with a $Z$ Boson in $p\bar{p}$ Collisions at $\sqrt{s} = 1.96$ TeV

Description: We present a search for the standard model Higgs boson produced in association with a Z boson, using up to 7.9 fb{sup -1} of integrated luminosity from p{bar p} collisions collected with the CDF II detector. We utilize several novel techniques, including multivariate lepton selection, multivariate trigger parametrization, and a multi-stage signal discriminant consisting of specialized functions trained to distinguish individual backgrounds. By increasing acceptance and enhancing signal discrimination, these techniques have significantly improved the sensitivity of the analysis above what was expected from a larger dataset alone. We observe no significant evidence for a signal, and we set limits on the ZH production cross section. For a Higgs boson with mass 115 GeV/c{sup 2}, we expect (observe) a limit of 3.9 (4.8) times the standard model predicted value, at the 95% credibility level.
Date: March 1, 2012
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Partner: UNT Libraries Government Documents Department

Search for Standard Model Higgs Boson Production in Association with a W Boson at CDF

Description: We present a search for standard model Higgs boson production in association with a W boson in proton-antiproton collisions (p{bar p} {yields} W{sup {+-}}H {yields} {ell}{nu}b{bar b}) at a center of mass energy of 1.96 TeV. The search employs data collected with the CDF II detector which correspond to an integrated luminosity of approximately 1 fb{sup -1}. We select events consistent with a signature of a single lepton (e{sup {+-}}/{mu}{sup {+-}}), missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with a secondary vertex tagging method and a neural network filter technique. The observed number of events and the dijet mass distributions are consistent with the standard model background expectations, and we set 95% confidence level upper limits on the production cross section times branching ratio ranging from 3.9 to 1.3 pb for Higgs boson masses from 110 to 150 GeV/c{sup 2}, respectively.
Date: March 1, 2008
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Partner: UNT Libraries Government Documents Department