2009 Toxic Chemical Release Inventory Report for the Emergency Planning and Community Right-to-Know Act of 1986, Title III, Section 313 (open access)

2009 Toxic Chemical Release Inventory Report for the Emergency Planning and Community Right-to-Know Act of 1986, Title III, Section 313

For reporting year 2009, Los Alamos National Laboratory (LANL) submitted a Form R report for lead as required under the Emergency Planning and Community Right-to- Know Act (EPCRA) Section 313. No other EPCRA Section 313 chemicals were used in 2009 above the reportable thresholds. This document was prepared to provide a description of the evaluation of EPCRA Section 313 chemical use and threshold determinations for LANL for calendar year 2009, as well as to provide background information about data included on the Form R reports.
Date: November 1, 2010
Creator: (ENV-ES), Environmental Stewardship Group
Object Type: Report
System: The UNT Digital Library
Development of Regional Wind Resource and Wind Plant Output Datasets: Final Subcontract Report, 15 October 2007 - 15 March 2009 (open access)

Development of Regional Wind Resource and Wind Plant Output Datasets: Final Subcontract Report, 15 October 2007 - 15 March 2009

This report describes the development of the necessary and needed wind and solar datasets used in the Western Wind and Solar Integration Study (WWSIS).
Date: March 1, 2010
Creator: 3TIER, Seattle, Washington
Object Type: Report
System: The UNT Digital Library
Epicyclic Twin-helix Magnetic Structure for Parametric-resonance Ionization Cooling (open access)

Epicyclic Twin-helix Magnetic Structure for Parametric-resonance Ionization Cooling

Para­met­ric-res­o­nance Ion­iza­tion Cool­ing (PIC) is en­vi­sioned as the final 6D cool­ing stage of a high-lu­mi­nos­i­ty muon col­lid­er. Im­ple­ment­ing PIC im­pos­es strin­gent con­straints on the cool­ing chan­nel's mag­net­ic op­tics de­sign. This paper pre­sents a lin­ear op­tics so­lu­tion com­pat­i­ble with PIC. Our so­lu­tion con­sists of a su­per­po­si­tion of two op­po­site-he­lic­i­ty equal-pe­ri­od and equal-strength he­li­cal dipole har­mon­ics and a straight nor­mal quadrupole. We demon­strate that such a sys­tem can be ad­just­ed to meet all of the PIC lin­ear op­tics re­quire­ments while re­tain­ing large ac­cep­tance.
Date: May 1, 2010
Creator: A. Afanasev, R.P. Johnson, Y.S. Derbenev, V.S. Morozov
Object Type: Article
System: The UNT Digital Library
Analysis of NSTX Upgrade OH Magnet and Center Stack (open access)

Analysis of NSTX Upgrade OH Magnet and Center Stack

The new ohmic heating (OH) coil and center stack for the National Spherical Torus Experiment (NSTX) upgrade are required to meet cooling and structural requirements for operation at the enhanced 1 Tesla toroidal field and 2 MA plasma current. The OH coil is designed to be cooled in the time between discharges by water flowing in the center of the coil conductor. We performed resistive heating and thermal hydraulic analyses to optimize coolant channel size to keep the coil temperature below 100 C and meet the required 20 minute cooling time. Coupled electromagnetic, thermal and structural FEA analyses were performed to determine if the OH coil meets the requirements of the structural design criteria. Structural response of the OH coil to its self-field and the field from other coils was analyzed. A model was developed to analyze the thermal and electromagnetic interaction of centerstack components such as the OH coil, TF inner legs and the Bellville washer preload mechanism. Torsional loads from the TF interaction with the OH and poloidal fields are transferred through the TF flag extensions via a torque transfer coupling to the rest of the tokamak structure. A 3D FEA analysis was performed to qualify this design. …
Date: November 30, 2010
Creator: A. Zolfaghari, P. Titus, J. Chrzanowski, A. Salehzadeh, F. Dahlgren
Object Type: Article
System: The UNT Digital Library
Energy Recovery Linac: 5 Cell 704 MHz SRF Cavity (open access)

Energy Recovery Linac: 5 Cell 704 MHz SRF Cavity

N/A
Date: January 1, 2010
Creator: A., Burrill
Object Type: Report
System: The UNT Digital Library
Energy Recovery Linac: SRF Electron Gun (open access)

Energy Recovery Linac: SRF Electron Gun

N/A
Date: January 1, 2010
Creator: A., Burrill
Object Type: Report
System: The UNT Digital Library
Energy Recovery Linac: Magnetic Measurement of the ERL Magnets (open access)

Energy Recovery Linac: Magnetic Measurement of the ERL Magnets

N/A
Date: January 1, 2010
Creator: A., Jain
Object Type: Report
System: The UNT Digital Library
Progress of Bep Treatments on Nb at JLAB (open access)

Progress of Bep Treatments on Nb at JLAB

Recent experimental results have indicated that Buffered Electropolishing (BEP) is a promising candidate for the next generation of surface treatment technique for Nb superconducting radio frequency (SRF) cavities to be used in particle accelerators. In order to lay the foundation for using BEP as the next generation surface treatment technique for Nb SRF cavities, some fundamental aspects of BEP treatments for Nb have to be investigated. In this report, recent progress on BEP study at JLab is shown. Improvements on the existing vertical BEP are made to allow water cooling from outside of a Nb single cell cavity in addition to cooling provided by acid circulation so that the temperature of the cavity can be stable during processing. Some investigation on the electrolyte mixture was performed to check the aging effect of the electrolyte. It is shown that good polishing results can still be obtained on Nb at a current density of 171 mA/cm when the BEP electrolyte was at the stationary condition and was more than 1.5 years old.
Date: May 1, 2010
Creator: A.T. Wu, S. Jin, R.A. Rimmer,X.Y. Lu, K. Zhao
Object Type: Article
System: The UNT Digital Library
Images of Quark Intrinsic Motion in Covariant Parton Model (open access)

Images of Quark Intrinsic Motion in Covariant Parton Model

We discuss the relations between TMDs and PDFs in the framework of the covariant parton model. The quark OAM and its connection to TMDs are studied as well.
Date: April 1, 2010
Creator: A.V. Efremov, P. Schweitzer, O.V. Teryaev, P. Zavada
Object Type: Article
System: The UNT Digital Library
EFFECT OF GLASS-BATCH MAKEUP ON THE MELTING PROCESS (open access)

EFFECT OF GLASS-BATCH MAKEUP ON THE MELTING PROCESS

The response of a glass batch to heating is determined by the batch makeup and in turn determines the rate of melting. Batches formulated for a high-alumina nuclear waste to be vitrified in an all-electric melter were heated at a constant temperature-increase rate to determine changes in melting behavior in response to the selection of batch chemicals and silica grain-size as well as the addition of heat-generating reactants. The type of batch materials and the size of silica grains determine how much, if any, primary foam occurs during melting. Small quartz grains, 5 {micro}m in size, caused extensive foaming because their major portion dissolved at temperatures <800 C, contributing to the formation of viscous glass forming melt that trapped evolving batch gases. Primary foam did not occur in batches with larger quartz grains, {+-}75 {micro}m in size, because their major portion dissolved at temperatures >800 C when batch gases no longer evolved. The exothermal reaction of nitrates with sucrose was ignited at a temperature as low as 160 C and caused a temporary jump in temperature of several hundred degrees. Secondary foam, the source of which is oxygen from redox reactions, occurred in all batches of a limited composition variation …
Date: December 7, 2010
Creator: AA, KRUGER & P, HRMA
Object Type: Article
System: The UNT Digital Library
HIGH ALUMINUM HLW (HIGH LEVEL WASTE ) GLASSES FOR HANFORDS WTP (WASTE TREATMENT PROJECT) (open access)

HIGH ALUMINUM HLW (HIGH LEVEL WASTE ) GLASSES FOR HANFORDS WTP (WASTE TREATMENT PROJECT)

This paper presents the results of glass formulation development and melter testing to identify high waste loading glasses to treat high-Al high level waste (HLW) at Hanford. Previous glass formulations developed for this HLW had high waste loadings but their processing rates were lower that desired. The present work was aimed at improving the glass processing rate while maintaining high waste loadings. Glass formulations were designed, prepared at crucible-scale and characterized to determine their properties relevant to processing and product quality. Glass formulations that met these requirements were screened for melt rates using small-scale tests. The small-scale melt rate screening included vertical gradient furnace (VGF) and direct feed consumption (DFC) melter tests. Based on the results of these tests, modified glass formulations were developed and selected for larger scale melter tests to determine their processing rate. Melter tests were conducted on the DuraMelter 100 (DMIOO) with a melt surface area of 0.11 m{sup 2} and the DuraMelter 1200 (DMI200) HLW Pilot Melter with a melt surface area of 1.2 m{sup 2}. The newly developed glass formulations had waste loadings as high as 50 wt%, with corresponding Al{sub 2}O{sub 3} concentration in the glass of 26.63 wt%. The new glass formulations …
Date: January 4, 2010
Creator: AA, KRUGER; BW, BOWAN; I, JOSEPH; H, GAN; WK, KOT; KS, MATLACK et al.
Object Type: Article
System: The UNT Digital Library
MELT RATE ENHANCEMENT FOR HIGH ALUMINUM HLW (HIGH LEVEL WASTE) GLASS FORMULATION FINAL REPORT 08R1360-1 (open access)

MELT RATE ENHANCEMENT FOR HIGH ALUMINUM HLW (HIGH LEVEL WASTE) GLASS FORMULATION FINAL REPORT 08R1360-1

This report describes the development and testing of new glass formulations for high aluminum waste streams that achieve high waste loadings while maintaining high processing rates. The testing was based on the compositions of Hanford High Level Waste (HLW) with limiting concentrations of aluminum specified by the Office of River Protection (ORP). The testing identified glass formulations that optimize waste loading and waste processing rate while meeting all processing and product quality requirements. The work included preparation and characterization of crucible melts and small scale melt rate screening tests. The results were used to select compositions for subsequent testing in a DuraMelter 100 (DM100) system. These tests were used to determine processing rates for the selected formulations as well as to examine the effects of increased glass processing temperature, and the form of aluminum in the waste simulant. Finally, one of the formulations was selected for large-scale confirmatory testing on the HLW Pilot Melter (DM1200), which is a one third scale prototype of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) HLW melter and off-gas treatment system. This work builds on previous work performed at the Vitreous State Laboratory (VSL) for Department of Energy (DOE) to increase waste loading …
Date: January 4, 2010
Creator: AA, KRUGER; KS, MATLACK; W, KOT; IL, PEGG; I, JOSEPH; T, BARDAKCI et al.
Object Type: Report
System: The UNT Digital Library
TECHNICAL COMPARISON OF CANDIDATE ION EXCHANGE MEDIA FOR SMALL COLUMN ION EXCHANGE (SCIX) APPLICATIONS IN SUPPORT OF SUPPLEMENTAL LAW PRETREATMENT (open access)

TECHNICAL COMPARISON OF CANDIDATE ION EXCHANGE MEDIA FOR SMALL COLUMN ION EXCHANGE (SCIX) APPLICATIONS IN SUPPORT OF SUPPLEMENTAL LAW PRETREATMENT

At-tank supplemental pretreatment including both filtration and small column ion exchange is currently under evaluation to facilitate salt waste retrieval and processing in the Hanford tank farms. Spherical resorcinol formaldehyde (sRF) resin is the baseline ion exchange resin for use in the Waste Treatment and Immobilization Plant (WTP). This document provides background and technical rationale to assist in determining whether spherical resorcinol formaldehyde (sRF) is also the appropriate ion exchange resin for supplemental LAW pretreatment processes and compares sRF with crystalline silicotitanate (CST) as potential supplemental pretreatment ion exchange media.
Date: December 28, 2010
Creator: AA, RAMSEY & MR, THORSON
Object Type: Report
System: The UNT Digital Library
AN INTEGRATED BIOLOGICAL CONTROL SYSTEM AT HANFORD (open access)

AN INTEGRATED BIOLOGICAL CONTROL SYSTEM AT HANFORD

In 1999 an integrated biological control system was instituted at the U.S. Department of Energy's Hanford Site. Successes and changes to the program needed to be communicated to a large and diverse mix of organizations and individuals. Efforts at communication are directed toward the following: Hanford Contractors (Liquid or Tank Waste, Solid Waste, Environmental Restoration, Science and Technology, Site Infrastructure), General Hanford Employees, and Hanford Advisory Board (Native American Tribes, Environmental Groups, Local Citizens, Washington State and Oregon State regulatory agencies). Communication was done through direct interface meetings, individual communication, where appropriate, and broadly sharing program reports. The objectives of the communication efforts was to have the program well coordinated with Hanford contractors, and to have the program understood well enough that all stakeholders would have confidence in the work performed by the program to reduce or elimated spread of radioactive contamination by biotic vectors. Communication of successes and changes to an integrated biological control system instituted in 1999 at the Department of Energy's Hanford Site have required regular interfaces with not only a diverse group of Hanford contractors (i.e., those responsible for liquid or tank waste, solid wastes, environmental restoration, science and technology, and site infrastructure), and general Hanford …
Date: February 11, 2010
Creator: AR, JOHNSON; JG, CAUDILL; RF, GIDDINGS; JM, RODRIGUEZ; RC, ROOS & JW, WILDE
Object Type: Article
System: The UNT Digital Library
Combined Tevatron upper limit on gg -> H -> W^+W^- and constraints on the Higgs boson mass in fourth-generation fermion models (open access)

Combined Tevatron upper limit on gg -> H -> W^+W^- and constraints on the Higgs boson mass in fourth-generation fermion models

We combine results from searches by the CDF and D0 collaborations for a standard model Higgs boson (H) in the process gg {yields} H {yields} W{sup +}W{sup -} in p{bar p} collisions at the Fermilab Tevatron Collider at {radical}s = 1.o6 TeV. With 4.8 fb{sup -1} of itnegrated luminosity analyzed at CDF and 5.4 fb{sup -1} at D0, the 95% Confidence Level upper limit on {sigma}(gg {yields} H) x {Beta}(H {yields} W{sup +}W{sup -}) is 1.75 pb at m{sub H} = 120 GeV, 0.38 pb at m{sub H} = 165 GeV, and 0.83 pb at m{sub H} = 200 GeV. Assuming the presence of a fourth sequential generation of fermions with large masses, they exclude at the 95% Confidence Level a standard-model-like Higgs boson with a mass between 131 and 204 Gev.
Date: May 1, 2010
Creator: Aaltonen, T.; Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Soft Electron b-Tagging (open access)

Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Soft Electron b-Tagging

We present a measurement of the top quark pair production cross section in p{bar p} collisions at {radical}s = 1.96 TeV using a data sample corresponding to 1.7 fb{sup -1} of integrated luminosity collected with the Collider Detector at Fermilab. We reconstruct t{bar t} events in the lepton+jets channel, consisting of e{nu}+jets and {mu}{nu}+jets final states. The dominant background is the production of W bosons in association with multiple jets. To suppress this background, we identify electrons from the semileptonic decay of heavy-flavor jets ('soft electron tags'). From a sample of 2196 candidate events, we obtain 120 tagged events with a background expectation of 51 {+-} 3 events, corresponding to a cross section of {sigma}{sub t{bar t}} = 7.8 {+-} 2.4 (stat) {+-} 1.6 (syst) {+-} 0.5 (lumi) pb. We assume a top-quark mass of 175 GeV/c{sup 2}. This is the first measurement of the t{bar t} cross section with soft electron tags in Run II of the Tevatron.
Date: February 1, 2010
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 Z gamma Production in pbar{p} Collisions at sqrt{s} = 1.96 TeV (open access)

Measurement of Z gamma Production in pbar{p} Collisions at sqrt{s} = 1.96 TeV

The production rate and kinematics of photons produced in association with Z bosons are studied using 2 fb{sup -1} of p{bar p} collision data collected at the Collider Detector at Fermilab. The cross section for p{bar p} {yields} {ell}{sup +}{ell}{sup -}{gamma} + X (where the leptons {ell} are either muons or electrons with dilepton mass M{sub {ell}{ell}} > 40 GeV/c{sup 2}, and where the photon has transverse energy E{sub T}{sup {gamma}} > 7 GeV and is well separated from the leptons) is 4.6 {+-} 0.2 (stat) {+-} 0.3 (syst) {+-} 0.3 (lum) pb, which is consistent with standard model expectations. We use the photon ET distribution from Z{gamma} events where the Z has decayed to {mu}{sup +}{mu}{sup -}, e{sup +}e{sup -}, or {nu}{bar {nu}} to set limits on anomalous (non-standard-model) trilinear couplings between photons and Z bosons.
Date: April 1, 2010
Creator: Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type: Article
System: The UNT Digital Library
Observation of Single Top Quark Production and Measurement of |Vtb| with CDF (open access)

Observation of Single Top Quark Production and Measurement of |Vtb| with CDF

We report the observation of electroweak single top quark production in 3.2 fb{sup -1} of p{bar p} collision data collected by the Collider Detector at Fermilab at {radical}s = 1.96 TeV. Candidate events in the W+jets topology with a leptonically decaying W boson are classified as signal-like by four parallel analyses based on likelihood functions, matrix elements, neural networks, and boosted decision trees. These results are combined using a super discriminant analysis based on genetically evolved neural networks in order to improve the sensitivity. This combined result is further combined with that of a search for a single top quark signal in an orthogonal sample of events with missing transverse energy plus jets and no charged lepton. We observe a signal consistent with the standard model prediction but inconsistent with the background-only model by 5.0 standard deviations, with a median expected sensitivity in excess of 5.9 standard deviations. We measure a production cross section of 2.3{sub -0.5}{sup +0.6}(stat + sys) pb, extract the CKM matrix element value |V{sub tb}| = 0.91{sub -0.11}{sup +0.11}(stat + sys) {+-} 0.07(theory), and set a lower limit |V{sub tb}| > 0.71 at the 95% confidence level, assuming m{sub t} = 175 GeV/c{sup 2}.
Date: April 1, 2010
Creator: Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type: Article
System: The UNT Digital Library
Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron (open access)

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

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 …
Date: March 1, 2010
Creator: Aaltonen, T.; Adelman, J.; Gonzalez, B.Alvarez; Amerio, S.; Amidei, D.; Anastassov, A. et al.
Object Type: Article
System: The UNT Digital Library
Improved Search for a Higgs Boson Produced in Association with Z->l+l- in proton antiproton Collisions at sqrt(s) = 1.96 TeV (open access)

Improved Search for a Higgs Boson Produced in Association with Z->l+l- in proton antiproton Collisions at sqrt(s) = 1.96 TeV

We present a search for the standard model Higgs boson produced with a Z boson in 4.1 fb{sup -1} of data collected with the CDF II detector at the Tevatron. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the Z boson to electrons or muons, we set 95% credibility level upper limits on the ZH production cross section times the H {yields} b{bar b} branching ratio. Improved analysis methods enhance signal sensitivity by 20% relative to previous searches beyond the gain due to the larger data sample. At a Higgs boson mass of 115 GeV/c{sup 2} we set a limit of 5.9 times the standard model value.
Date: September 1, 2010
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Object Type: Article
System: The UNT Digital Library
Search for the supersymmetric partner of the top quark in ppbar collisions at sqrt(s) = 1.96 TeV (open access)

Search for the supersymmetric partner of the top quark in ppbar collisions at sqrt(s) = 1.96 TeV

We present a search for the lightest supersymmetric partner of the top quark in proton-antiproton collisions at a center-of-mass energy {radical}s = 1.96 TeV. This search was conducted within the framework of the R-parity conserving minimal supersymmetric extension of the standard model, assuming the stop decays dominantly to a lepton, a sneutrino, and a bottom quark. We searched for events with two oppositely-charged leptons, at least one jet, and missing transverse energy in a data sample corresponding to an integrated luminosity of 1 fb{sup -1} collected by the CDF experiment. No significant evidence of a stop quark signal was found. Exclusion limits at 95% confidence level in the stop quark versus sneutrino mass plane are set. Stop quark masses up to 180 GeV/c{sup 2} are excluded for sneutrino masses around 45 GeV/c{sup 2}, and sneutrino masses up to 116 GeV/c{sup 2} are excluded for stop quark masses around 150 GeV/c{sup 2}.
Date: September 1, 2010
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Object Type: Article
System: The UNT Digital Library
First Measurement of the Ratio sigma_(t-tbar) / sigma_(Z/\gamma*->ll) and Precise Extraction of the t-tbar Cross Section (open access)

First Measurement of the Ratio sigma_(t-tbar) / sigma_(Z/\gamma*->ll) and Precise Extraction of the t-tbar Cross Section

We report a measurement of the ratio of the t{bar t} to Z/{gamma}* production cross sections in {radical}s = 1.96 TeV p{bar p} collisions using data corresponding to an integrated luminosity of up to 4.6 fb{sup -1}, collected by the CDF II detector. The t{bar t} cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/{gamma}* {yields} ll cross section predicted by the standard model, the extracted t{bar t} cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result {sigma}{sub t{bar t}} = 7.70 {+-} 0.52 pb, for a top-quark mass of 172.5 GeV/c{sup 2}.
Date: April 1, 2010
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the $B^-$ lifetime using a simulation free approach for trigger bias correction (open access)

Measurement of the $B^-$ lifetime using a simulation free approach for trigger bias correction

The collection of a large number of B hadron decays to hadronic final states at the CDF II detector is possible due to the presence of a trigger that selects events based on track impact parameters. However, the nature of the selection requirements of the trigger introduces a large bias in the observed proper decay time distribution. A lifetime measurement must correct for this bias and the conventional approach has been to use a Monte Carlo simulation. The leading sources of systematic uncertainty in the conventional approach are due to differences between the data and the Monte Carlo simulation. In this paper they present an analytic method for bias correction without using simulation, thereby removing any uncertainty between data and simulation. This method is presented in the form of a measurement of the lifetime of the B{sup -} using the mode B{sup -} {yields} D{sup 0}{pi}{sup -}. The B{sup -} lifetime is measured as {tau}{sub B{sup -}} = 1.663 {+-} 0.023 {+-} 0.015 ps, where the first uncertainty is statistical and the second systematic. This new method results in a smaller systematic uncertainty in comparison to methods that use simulation to correct for the trigger bias.
Date: April 1, 2010
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the Top Quark Mass and ppbar -> ttbar Cross Section in the All-Hadronic Mode with the CDFII Detector (open access)

Measurement of the Top Quark Mass and ppbar -> ttbar Cross Section in the All-Hadronic Mode with the CDFII Detector

We present a measurement of the top quark mass and of the top-antitop pair production cross section using p{bar p} data collected with the CDF II detector at the Tevatron Collider at the Fermi National Accelerator Laboratory and corresponding to an integrated luminosity of 2.9 fb{sup -1}. We select events with six or more jets satisfying a number of kinematical requirements imposed by means of a neural network algorithm. At least one of these jets must originate from a b quark, as identified by the reconstruction of a secondary vertex inside the jet. The mass measurement is based on a likelihood fit incorporating reconstructed mass distributions representative of signal and background, where the absolute jet energy scale (JES) is measured simultaneously with the top quark mass. The measurement yields a value of 174.8 {+-} 2.4(stat+JES){sub -1.0}{sup +1.2}(syst)GeV/c{sup 2}, where the uncertainty from the absolute jet energy scale is evaluated together with the statistical uncertainty. The procedure measures also the amount of signal from which we derive a cross section, {sigma}{sub t{bar t}} = 7.2 {+-} 0.5(stat) {+-} 1.0(syst) {+-} 0.4(lum) pb, for the measured values of top quark mass and JES.
Date: February 1, 2010
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of et al.
Object Type: Article
System: The UNT Digital Library