Performance Demonstration Program Plan for Nondestructive Assay of Drummed Wastes for  the TRU Waste Characterization Program (open access)

Performance Demonstration Program Plan for Nondestructive Assay of Drummed Wastes for the TRU Waste Characterization Program

Each testing and analytical facility performing waste characterization activities for the Waste Isolation Pilot Plant (WIPP) participates in the Performance Demonstration Program (PDP) to comply with the Transuranic Waste Acceptance Criteria for the Waste Isolation Pilot Plant (WAC) (DOE/WIPP-02-3122) and the Quality Assurance Program Document (QAPD) (CBFO-94-1012). The PDP serves as a quality control check for data generated in the characterization of waste destined for WIPP. Single blind audit samples are prepared and distributed to each of the facilities participating in the PDP. The PDP evaluates analyses of simulated headspace gases, constituents of the Resource Conservation and Recovery Act (RCRA), and transuranic (TRU) radionuclides using nondestructive assay (NDA) techniques.
Date: April 1, 2009
Creator: /A, N
Object Type: Report
System: The UNT Digital Library
Buffer Chemical Polishing and RF Testing of the 56 MHz SRF Cavity (open access)

Buffer Chemical Polishing and RF Testing of the 56 MHz SRF Cavity

N/A
Date: January 1, 2009
Creator: A., Burrill
Object Type: Report
System: The UNT Digital Library
IBS and Potential Luminosity Improvement for RHIC Operation Below Transition Energy (open access)

IBS and Potential Luminosity Improvement for RHIC Operation Below Transition Energy

N/A
Date: January 1, 2009
Creator: A., Fedotov
Object Type: Report
System: The UNT Digital Library
Issues Concerning High Current Low Energy Electron Beams Required for Ion Cooling between EBIS LINAC and Booster (open access)

Issues Concerning High Current Low Energy Electron Beams Required for Ion Cooling between EBIS LINAC and Booster

N/A
Date: March 1, 2009
Creator: A., Hershcovitch
Object Type: Report
System: The UNT Digital Library
RF and structural characterization of new SRF films (open access)

RF and structural characterization of new SRF films

In the past years, energetic vacuum deposition methods have been developed in different laboratories to improve Nb/Cu technology for superconducting cavities. Jefferson Lab is pursuing energetic condensation deposition via Electron Cyclotron Resonance. As part of this study, the influence of the deposition energy on the material and RF properties of the Nb thin film is investigated. The film surface and structure analyses are conducted with various techniques like X-ray diffraction, Transmission Electron Microscopy, Auger Electron Spectroscopy and RHEED. The microwave properties of the films are characterized on 50 mm disk samples with a 7.5 GHz surface impedance characterization system. This paper presents surface impedance measurements in correlation with surface and material characterization for Nb films produced on copper substrates with different bias voltages and also highlights emerging opportunities for developing multilayer SRF films with a new deposition system.
Date: September 1, 2009
Creator: A.-M. Valente-Feliciano,H. L. Phillips,C. E. Reece,X. Zhao,D. Gu,R. Lukaszew,B. Xiao,K. Seo
Object Type: Article
System: The UNT Digital Library
Astrophysical Gyrokinetics: Kinetic and Fluid Turbulent Cascades In Magentized Weakly Collisional Plasmas (open access)

Astrophysical Gyrokinetics: Kinetic and Fluid Turbulent Cascades In Magentized Weakly Collisional Plasmas

This paper presents a theoretical framework for understanding plasma turbulence in astrophysical plasmas. It is motivated by observations of electromagnetic and density fluctuations in the solar wind, interstellar medium and galaxy clusters, as well as by models of particle heating in accretion disks. All of these plasmas and many others have turbulentmotions at weakly collisional and collisionless scales. The paper focuses on turbulence in a strong mean magnetic field. The key assumptions are that the turbulent fluctuations are small compared to the mean field, spatially anisotropic with respect to it and that their frequency is low compared to the ion cyclotron frequency. The turbulence is assumed to be forced at some system-specific outer scale. The energy injected at this scale has to be dissipated into heat, which ultimately cannot be accomplished without collisions. A kinetic cascade develops that brings the energy to collisional scales both in space and velocity. The nature of the kinetic cascade in various scale ranges depends on the physics of plasma fluctuations that exist there. There are four special scales that separate physically distinct regimes: the electron and ion gyroscales, the mean free path and the electron diffusion scale. In each of the scale ranges separated …
Date: April 23, 2009
Creator: A.A. Schekochihin, S.C. Cowley, W. Dorland, G.W. Hammett, G.G. Howes, E. Quataert, and T. Tatsuno
Object Type: Report
System: The UNT Digital Library
Diagnostics for the Biased Electrode Experiment on NSTX (open access)

Diagnostics for the Biased Electrode Experiment on NSTX

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
Object Type: Article
System: The UNT Digital Library
CRYSTALLIZATION IN HIGH-LEVEL WASTE GLASSES U.S. DEPARTMENT OF ENERGY OFFICE OF RIVER PROTECTION WTP ENGINEERING DIVISION (open access)

CRYSTALLIZATION IN HIGH-LEVEL WASTE GLASSES U.S. DEPARTMENT OF ENERGY OFFICE OF RIVER PROTECTION WTP ENGINEERING DIVISION

Various circumstances influence crystallization in glassmaking, for example: (1) crystals nucleate and grow before the glass-forming melt occurs; (2) crystals grow or dissolve in flowing melt and during changing temperature; (3) crystals move under the influence of gravity; (4) crystals agglomerate and interact with gas bubbles; (5) high-level wastes (HLW) are mixtures of a large number of components in unusual proportions; (6) melter processing of HLW and the slow cooling of HLW glass in canisters provides an opportunity for a variety of crystalline forms to precipitate; (7) settling of crystals in a HLW glass melter may produce undesirable sludge at the melter bottom; and (8) crystallization of the glass product may increase, but also ruin chemical durability. The conclusions are: (1) crystal growth and dissolution typically proceed in a convective medium at changing temperature; (2) to represent crystallization or dissolution the kinetics must be expressed in the form of rate equations, such as dC/dt = f(C,T) and the temperature dependence of kinetic coefficients and equilibrium concentrations must be accounted for; and (3) non-equilibrium phenomena commonly occur - metastable crystallization, periodic distribution of crystals; and dendritic crystal growth.
Date: August 19, 2009
Creator: AA, KRUGER & PR, HRMA
Object Type: Article
System: The UNT Digital Library
CRYSTALLIZATION IN MULTICOMPONENT GLASSES (open access)

CRYSTALLIZATION IN MULTICOMPONENT GLASSES

In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.
Date: October 8, 2009
Creator: AA, KRUGER & PR, HRMA
Object Type: Article
System: The UNT Digital Library
DM100 AND DM1200 MELTER TESTING WITH HIGH WASTE LOADING GLASS FORMULATIONS FOR HANFORD HIGH-ALUMINUM HLW STREAMS (open access)

DM100 AND DM1200 MELTER TESTING WITH HIGH WASTE LOADING GLASS FORMULATIONS FOR HANFORD HIGH-ALUMINUM HLW STREAMS

This Test Plan describes work to support the development and testing of high waste loading glass formulations that achieve high glass melting rates for Hanford high aluminum high level waste (HLW). In particular, the present testing is designed to evaluate the effect of using low activity waste (LAW) waste streams as a source of sodium in place ofchemical additives, sugar or cellulose as a reductant, boehmite as an aluminum source, and further enhancements to waste processing rate while meeting all processing and product quality requirements. The work will include preparation and characterization of crucible melts in support of subsequent DuraMelter 100 (DM 100) tests designed to examine the effects of enhanced glass formulations, glass processing temperature, incorporation of the LAW waste stream as a sodium source, type of organic reductant, and feed solids content on waste processing rate and product quality. Also included is a confirmatory test on the HLW Pilot Melter (DM1200) with a composition selected from those tested on the DM100. This work builds on previous work performed at the Vitreous State Laboratory (VSL) for Department of Energy's (DOE's) Office of River Protection (ORP) to increase waste loading and processing rates for high-iron HLW waste streams as well …
Date: December 30, 2009
Creator: AA, KRUGER; KS, MATLACK; WK, KOT; IL, PEGG & I, JOSEPH
Object Type: Report
System: The UNT Digital Library
INCONEL 690 CORROSION IN WTP (WASTE TREATMENT PLANT) HLW (HIGH LEVEL WASTE) GLASS MELTS RICH IN ALUMINUM & BISMUTH & CHROMIUM OR ALUMINUM/SODIUM (open access)

INCONEL 690 CORROSION IN WTP (WASTE TREATMENT PLANT) HLW (HIGH LEVEL WASTE) GLASS MELTS RICH IN ALUMINUM & BISMUTH & CHROMIUM OR ALUMINUM/SODIUM

Metal corrosion tests were conducted with four high waste loading non-Fe-limited HLW glass compositions. The results at 1150 C (the WTP nominal melter operating temperature) show corrosion performance for all four glasses that is comparable to that of other typical borosilicate waste glasses, including HLW glass compositions that have been developed for iron-limited WTP streams. Of the four glasses tested, the Bi-limited composition shows the greatest extent of corrosion, which may be related to its higher phosphorus content. Tests at higher suggest that a moderate elevation of the melter operating temperature (up to 1200 C) should not result in any significant increase in Inconel corrosion. However, corrosion rates did increase significantly at yet higher temperatures (1230 C). Very little difference was observed with and without the presence of an electric current density of 6 A/inch{sup 2}, which is the typical upper design limit for Inconel electrodes. The data show a roughly linear relationship between the thickness of the oxide scale on the coupon and the Cr-depletion depth, which is consistent with the chromium depletion providing the material source for scale growth. Analysis of the time dependence of the Cr depletion profiles measured at 1200 C suggests that diffusion of Cr …
Date: November 5, 2009
Creator: AA, KRUGER; Z, FENG; H, GAN & IL, PEGG
Object Type: Report
System: The UNT Digital Library
SUMMARY REPORT DIRECT PUSH TECHNOLOGY BOREHOLES FOR GEOPHYSICAL LOGGING 200-IS-1 OPERABLE UNIT FY2008 (open access)

SUMMARY REPORT DIRECT PUSH TECHNOLOGY BOREHOLES FOR GEOPHYSICAL LOGGING 200-IS-1 OPERABLE UNIT FY2008

None
Date: February 10, 2009
Creator: AK, LEE
Object Type: Report
System: The UNT Digital Library
Ground motion modeling of Hayward fault scenario earthquakes II:Simulation of long-period and broadband ground motions (open access)

Ground motion modeling of Hayward fault scenario earthquakes II:Simulation of long-period and broadband ground motions

We simulate long-period (T > 1.0-2.0 s) and broadband (T > 0.1 s) ground motions for 39 scenarios earthquakes (Mw 6.7-7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions compared with neglecting the influence of creep. Nevertheless, the scenario earthquakes generate strong shaking throughout the San Francisco Bay area with about 50% of the urban area experiencing MMI VII or greater for the magnitude 7.0 scenario events. Long-period simulations of the 2007 Mw 4.18 Oakland and 2007 Mw 4.5 Alum Rock earthquakes show that the USGS Bay Area Velocity Model version 08.3.0 permits simulation of the amplitude and duration of shaking throughout the San Francisco Bay area, with the greatest accuracy in the Santa Clara Valley (San Jose area). The ground motions exhibit a strong sensitivity to the rupture length (or magnitude), hypocenter (or rupture directivity), and slip distribution. The ground motions display a much weaker sensitivity to the rise time and rupture speed. Peak velocities, peak accelerations, and spectral accelerations from the synthetic broadband ground motions are, on average, slightly higher than the …
Date: November 4, 2009
Creator: Aagaard, B T; Graves, R W; Rodgers, A; Brocher, T M; Simpson, R W; Dreger, D et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the $\ttbar$ Production Cross Section in 2 fb$^{-1}$ of $\ppbar$ Collisions at $\sqrt{s}=1.96$ TeV Using Lepton Plus Jets Events with Soft Muon b-Tagging (open access)

Measurement of the $\ttbar$ Production Cross Section in 2 fb$^{-1}$ of $\ppbar$ Collisions at $\sqrt{s}=1.96$ TeV Using Lepton Plus Jets Events with Soft Muon b-Tagging

We present a measurement of the t{bar t} production cross section in p{bar p} collisions at {radical}s = 1.96 TeV using events containing a high transverse momentum electron or muon, three or more jets, and missing transverse energy. Events consistent with t{bar t} decay are found by identifying jets containing candidate heavy-flavor semileptonic decays to muons. The measurement uses a CDF Run II data sample corresponding to 2 fb{sup -1} of integrated luminosity. Based on 248 candidate events with three or more jets and an expected background of 79.5 {+-} 5.3 events, we measure a production cross section of 9.1 {+-} 1.6 pb.
Date: January 1, 2009
Creator: Aaltonen, T.
Object Type: Article
System: The UNT Digital Library
Observation of exclusive charmonium production and gamma gamma ---> mu+mu- in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Observation of exclusive charmonium production and gamma gamma ---> mu+mu- in p anti-p collisions at s**(1/2) = 1.96-TeV

We have observed the reactions p + {bar p} {yields} p + X + {bar p}, with X being a centrally produced J/{psi}, {psi}(2S) or {chi}{sub c0}, and {gamma}{gamma} {yields} {mu}{sup +}{mu}{sup -}, in proton-antiproton collisions at {radical}s = 1.96 TeV using the Run II Collider Detector at Fermilab. The event signature requires two oppositely charged muons, each with pseudorapidity |{eta}| < 0.6, with M{sub {mu}{mu}} {element_of} [3.0; 4.0] GeV/c{sup 2} and either no other particles, or one additional photon, detected. The J/{psi} and the {psi}(2S) are prominent, on a continuum consistent with the QED process {gamma}{gamma} {yields} {mu}{sup +}{mu}{sup -}. Events with a J/{psi} and an associated photon candidate are consistent with exclusive {chi}{sub c0} production through double pomeron exchange. The exclusive vector meson production is as expected for elastic photoproduction, {gamma} + p {yields} J/{psi}({psi}(2S)) + p, which is observed here for the first time in hadron-hadron collisions. The cross sections d{sigma}/dy|y = 0 for p + {bar p} {yields} p + X + {bar p} with X = J/{psi},{psi}(2S) or {chi}{sub c0} are 3.92 {+-} 0.62 nb, 0.53 {+-} 0.14 nb, and 76 {+-} 14 nb respectively. The cross section for the continuum, with |{eta}({mu}{sup {+-}})| < …
Date: February 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M. G.; Alvarez Gonzalez, B.; Amerio, S. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the top quark mass at CDF using the `neutrino phi weighting' template method on a lepton plus isolated track sample (open access)

Measurement of the top quark mass at CDF using the `neutrino phi weighting' template method on a lepton plus isolated track sample

We present a measurement of the top quark mass with t{bar t} dilepton events produced in p{bar p} collisions at the Fermilab Tevatron ({radical}s = 1.96 TeV) and collected by the CDF II detector. A sample of 328 events with a charged electron or muon and an isolated track, corresponding to an integrated luminosity of 2.9 fb{sup -1}, are selected as t{bar t} candidates. To account for the unconstrained event kinematics, we scan over the phase space of the azimuthal angles ({phi}{sub {nu}1}, {phi}{sub {nu}2}) of neutrinos and reconstruct the top quark mass for each {phi}{sub {nu}1}, {phi}{sub {nu}2} pair by minimizing a {chi}{sup 2} function in the t{bar t} dilepton hypothesis. We assign {chi}{sup 2}-dependent weights to the solutions in order to build a preferred mass for each event. Preferred mass distributions (templates) are built from simulated t{bar t} and background events, and parameterized in order to provide continuous probability density functions. A likelihood fit to the mass distribution in data as a weighted sum of signal and background probability density functions gives a top quark mass of 165.5{sub -3.3}{sup +3.4}(stat.){+-}3.1(syst.) GeV/c{sup 2}.
Date: January 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D. et al.
Object Type: Article
System: The UNT Digital Library
Measurements of the top-quark mass using charged particle tracking (open access)

Measurements of the top-quark mass using charged particle tracking

We present three measurements of the top-quark mass in the lepton plus jets channel with approximately 1.9 fb{sup -1} of integrated luminosity collected with the CDF II detector using quantities with minimal dependence on the jet energy scale. One measurement exploits the transverse decay length of b-tagged jets to determine a top-quark mass of 166.9{sub -8.5}{sup +9.5} (stat) {+-} 2.9 (syst) GeV/c{sup 2}, and another the transverse momentum of electrons and muons from W-boson decays to determine a top-quark mass of 173.5{sub -8.9}{sup +8.8} (stat) {+-} 3.8 (syst) GeV/c{sup 2}. These quantities are combined in a third, simultaneous mass measurement to determine a top-quark mass of 170.7 {+-} 6.3 (stat) {+-} 2.6 (syst) GeV/c{sup 2}.
Date: October 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D. et al.
Object Type: Article
System: The UNT Digital Library
Search for charged Higgs bosons in decays of top quarks in p anti-p collisions at s**(1/2) = 1.96 TeV (open access)

Search for charged Higgs bosons in decays of top quarks in p anti-p collisions at s**(1/2) = 1.96 TeV

We report on the first direct search for charged Higgs bosons in decays of top quarks in p{bar p} collisions at {radical}s = 1.96 TeV. The search uses a data sample corresponding to an integrated luminosity of 2.2 fb{sup -1} collected by the CDF II detector at Fermilab, and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t{bar t} candidates. We observe no evidence of charged Higgs bosons in top quark decays. Hence, 95% upper limits on the top quark decay branching ratio are placed at {Beta}(t {yields} H{sup +}b) < 0.1 to 0.3 for charged Higgs boson masses of 60 to 150 GeV/c{sup 2}, assuming {Beta}(H{sup +} {yields} c{bar s}) = 1.0. The upper limits on {Beta}(t {yields} H{sup +}b) can also be used as model-independent limits on the decay branching ratio of top quarks to generic scalar charged bosons beyond the standard model.
Date: July 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the Inclusive Isolated Prompt Photon Cross Section in ppbar Collisions at sqrt{s} = 1.96 TeV using the CDF Detector (open access)

Measurement of the Inclusive Isolated Prompt Photon Cross Section in ppbar Collisions at sqrt{s} = 1.96 TeV using the CDF Detector

A measurement of the cross section for the inclusive production of isolated photons by the CDF experiment at the Fermilab Tevatron collider is presented. The measurement covers the pseudorapidity region |{eta}{sup {gamma}}| < 1.0 and the transverse energy range E{sub T}{sup {gamma}} > 30 GeV and is based on 2.5 fb{sup -1} of integrated luminosity. The sample is almost a factor of seven larger than those used for recent published results and extends the E{sub T}{sup {gamma}} coverage by 100 GeV. The result agrees with next-to-leading order perturbative QCD calculations within uncertainties over the range 50 < E{sub T}{sup {gamma}} < 400 GeV, though the energy spectrum in the data shows a steeper slope at lower E{sub T}{sup {gamma}}.
Date: October 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the Lambda_b Lifetime in Lambda_b -> Lambda_c+ pi- Decays in p-pbar Collisions at sqrt(s) = 1.96 TeV (open access)

Measurement of the Lambda_b Lifetime in Lambda_b -> Lambda_c+ pi- Decays in p-pbar Collisions at sqrt(s) = 1.96 TeV

We report a measurement of the lifetime of the {Lambda}{sub b}{sup 0} baryon in decays to the {Lambda}{sub c}{sup +} {pi}{sup -} final state in a sample corresponding to 1.1 fb{sup -1} collected in p{bar p} collisions at {radical}s = 1.96 TeV by the CDF II detector at the Tevatron collider. Using a sample of about 3000 fully reconstructed {Lambda}{sub b}{sup 0} events we measure {tau}({Lambda}{sub b}{sup 0}) = 1.401 {+-} 0.046 (stat) {+-} 0.035 (syst) ps (corresponding to c{tau}({Lambda}{sub b}{sup 0}) = 420.1 {+-} 13.7 (stat) {+-} 10.6 (syst) {micro}m, where c is the speed of light). The ratio of this result and the world average B{sup 0} lifetime yields {tau}({Lambda}{sub b}{sup 0})/{tau}(B{sup 0}) = 0.918 {+-} 0.038 (stat and syst), in good agreement with recent theoretical predictions.
Date: December 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the WW+WZ Production Cross Section Using the Lepton+Jets Final State at CDF II (open access)

Measurement of the WW+WZ Production Cross Section Using the Lepton+Jets Final State at CDF II

We report two complementary measurements of the diboson (WW + WZ) cross section in the final state consisting of an electron or muon, missing transverse energy, and jets, performed using p{bar p} collision data at {radical}s = 1.96 TeV collected by the Collider Detector at Fermilab. The first method uses the dijet invariant mass distribution while the second method uses more of the kinematic information in the event through matrix-element calculations of the signal and background processes and has a higher sensitivity. The result from the second method has a signal significance of 5.4{sigma} and is the first observation of WW + WZ production using this signature. Combining the results from both methods gives {sigma}{sub WW+WZ} = 16.0 {+-} 3.3 pb, in agreement with the standard model prediction.
Date: November 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type: Article
System: The UNT Digital Library
Search for Anomalous Production of Events with Two Photons and Additional Energetic Objects at CDF (open access)

Search for Anomalous Production of Events with Two Photons and Additional Energetic Objects at CDF

The authors present results of a search for anomalous production of two photons together with an electron, muon, {tau} lepton, missing transverse energy, or jets using p{bar p} collision data from 1.1-2.0 fb{sup -1} of integrated luminosity collected by the Collider Detector at Fermilab (CDF). The event yields and kinematic distributions are examined for signs for new physics without favoring a specific model of new physics. The results are consistent with the standard model expectations. The search employs several new analysis techniques that significantly reduce instrumental backgrounds in channels with an electron and missing transverse energy.
Date: October 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type: Article
System: The UNT Digital Library
Search for Supersymmetry with Gauge-Mediated Breaking in Diphoton Events with Missing Transverse Energy at CDF II (open access)

Search for Supersymmetry with Gauge-Mediated Breaking in Diphoton Events with Missing Transverse Energy at CDF II

The authors present the results of a search for supersymmetry with gauge-mediated breaking and {tilde {chi}}{sub 1}{sup 0} {yields} {gamma}{tilde G} in the {gamma}{gamma} + missing transverse energy final state. In 2.6 {+-} 0.2 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV recorded by the CDF II detector they observe no candidate events, consistent with a standard model background expectation of 1.4 {+-} 0.4 events. They set limits on the cross section at the 95% C.L. and place the world's best limit of 149 GeV/c{sup 2} on the {tilde {chi}}{sub 1}{sup 0} mass at {tau}{sub {tilde {chi}}{sub 1}{sup 0}} << 1 ns. They also exclude regions in the {tilde {chi}}{sub 1}{sup 0} mass-lifetime plane of {tau}{sub {tilde {chi}}{sub 1}{sup 0}} {approx}< 2 ns.
Date: October 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type: Article
System: The UNT Digital Library
Search for Technicolor Particles Produced in Association with a W Boson at CDF (open access)

Search for Technicolor Particles Produced in Association with a W Boson at CDF

We present a search for the technicolor particles {rho}{sub T} and {pi}{sub T} in the process p{bar p} {yields} {rho}{sub T} {yields} W{pi}{sub T} at a center of mass energy of {radical}s = 1.96 TeV. The search uses a data sample corresponding to approximately 1.9 fb{sup -1} of integrated luminosity accumulated by the CDF II detector at the Fermilab Tevatron. The event signature we consider is W {yields} {ell}{nu} and {pi}{sub T} {yields} b{bar b}, b{bar c} or b{bar u} depending on the {pi}{sub T} charge. We select events with a single high-p{sub T} electron or muon, large missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with multiple b-tagging algorithms. The observed number of events and the invariant mass distributions are consistent with the standard model background expectations, and we exclude a region at 95% confidence level in the {rho}{sub T}-{pi}{sub T} mass plane. As a result, a large fraction of the region m({rho}{sub T}) = 180-250 GeV/c{sup 2} and m({pi}{sub T}) = 95-145 GeV/c{sup 2} is excluded.
Date: December 1, 2009
Creator: Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type: Article
System: The UNT Digital Library