Search Results

open access

First measurement of sigma (p anti-p ---> Z) . Br (Z ---> tau tau) at s**(1/2) = 1.96- TeV

Description: The authors present a measurement of the cross section for Z production times the branching fraction to {tau} leptons, {sigma} {center_dot} Br(Z {yields} {tau}{sup +}{tau}{sup -}), in p{bar p} collisions at {radical}s = 1.96 TeV in the channel in which one {tau} decays into {mu}{nu}{sub {mu}}{nu}{sub {tau}}, and the other into hadrons + {nu}{sub {tau}} or e{nu}{sub e}{nu}{sub {tau}}. The data sample corresponds to an integrated luminosity of 226 pb{sup -1} collected with the D0 detector at the … more
Date: December 1, 2004
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Partner: UNT Libraries Government Documents Department
open access

Search for first-generation scalar leptoquarks in p anti-p collisions at s**(1/2) = 1.96-TeV

Description: The authors report on a search for pair production of first-generation scalar leptoquarks (LQ) in p{bar p} collisions at {radical}s = 1.96 TeV using an integrated luminosity of 252 pb{sup -1} collected at the Fermilab Tevatron collider by the D0 detector. They observe no evidence for LQ production in the topologies arising from LQ{ovr LQ} {yields} eqeq and LQ{ovr LQ} {yields} eqvq, and derive 95% C.L. lower limits on the LQ mass as a function of {beta}, where {beta} is the branching fraction fo… more
Date: December 1, 2004
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Partner: UNT Libraries Government Documents Department
open access

Electric Reliability: Options for Electric Transmission Infrastructure Improvements

Description: The electric utility industry is inherently capital intensive. At the same time, the industry must operate under a changing and sometimes unpredictable regulatory system at both the federal and state level. The Energy Policy Act of 2005 has set in place government activities intended to relieve congestion on the transmission system. Several factors have contributed to the lack of new transmission capacity; these are outlined within this report. This report also discusses earlier pieces of energ… more
Date: December 23, 2004
Creator: Abel, Amy
Partner: UNT Libraries Government Documents Department
open access

Electric Reliability: Options for Electric Transmission Infrastructure Improvements

Description: The electric utility industry is inherently capital intensive. At the same time, the industry must operate under a changing and sometimes unpredictable regulatory system at both the federal and state level. The Energy Policy Act of 2005 has set in place government activities intended to relieve congestion on the transmission system. Several factors have contributed to the lack of new transmission capacity; these are outlined within this report. This report also discusses earlier pieces of energ… more
Date: December 23, 2004
Creator: Abel, Amy
Partner: UNT Libraries Government Documents Department
open access

Analysis of the Effect of Geometry Generated Turbulence on HCCI Combustion by Multi-Zone Modeling

Description: This paper illustrates the applicability of a sequential fluid mechanics, multi-zone chemical kinetics model to analyze HCCI experimental data for two combustion chamber geometries with different levels of turbulence: a low turbulence disc geometry (flat top piston), and a high turbulence square geometry (piston with a square bowl). The model uses a fluid mechanics code to determine temperature histories in the engine as a function of crank angle. These temperature histories are then fed into a… more
Date: December 13, 2004
Creator: Aceves, S. M.; Flowers, D. L.; Martinez-Frias, J.; Espinosa-Loza, F.; Christensen, M.; Johansson, B. et al.
Partner: UNT Libraries Government Documents Department
open access

The Impact of humidity above stratiform clouds on indirect aerosol climate forcing

Description: Some of the global warming effect of anthropogenic greenhouse gases is offset by increased solar reflection from clouds with smaller droplets that form on increased numbers of cloud condensation nuclei in polluted air. The global magnitude of the resulting indirect aerosol climate forcing is estimated to be comparable (and opposed) to the anthropogenic carbon dioxide forcing, but estimates are highly uncertain because of complexities in characterizing the physical process that determine global … more
Date: December 20, 2004
Creator: Ackerman, A. S.; Kirkpatrick, M. P.; Stevens, D. E. & Toon, O. B.
Partner: UNT Libraries Government Documents Department
open access

Assessing Terrorist Motivations for Attacking Critical "Chemical" Infrastructure

Description: Certain types of infrastructure--critical infrastructure (CI)--play vital roles in underpinning our economy, security, and way of life. One particular type of CI--that relating to chemicals--constitutes both an important element of our nation's infrastructure and a particularly attractive set of potential targets. This is primarily because of the large quantities of toxic industrial chemicals (TICs) it employs in various operations and because of the essential economic functions it serves. This… more
Date: December 14, 2004
Creator: Ackerman, G.; Bale, J. & Moran, K.
Partner: UNT Libraries Government Documents Department
open access

B physics: measurement of the j/psi meson and b-hadron production cross sections in p anti-p collisions at s**(1/2) = 1960 gev

Description: The authors present a new measurement of the inclusive and differential production cross sections of J/{psi} mesons and b-hadrons in proton-antiproton collisions at {radical}s = 1960 GeV. The data correspond to an integrated luminosity of 39.7 pb{sup -1} collected by the CDF Run II detector. They find the integrated cross section for inclusive J/{psi} production for all transverse momenta from 0 to 20 GeV/c in the rapidity range |y| < 0.6 to be 4.08 {+-} 0.02(stat){sub -0.33}{sup +0.36}(syst… more
Date: December 23, 2004
Creator: Acosta, D.
Partner: UNT Libraries Government Documents Department
open access

Top physics: search for anomalous kinematics in t anti-t dilepton events at cdf ii

Description: We report on a search for anomalous kinematics of t{bar t} dilepton events in p{bar p} collisions at {radical}s = 1.96 TeV using 193 pb{sup -1} of data collected with the CDF II detector. We developed a new a priori technique designed to isolate the subset in a data sample revealing the largest deviation from standard model (SM) expectations and to quantify the significance of this departure. In the four-variable space considered, no particular subset shows a significant discrepancy and we find… more
Date: December 14, 2004
Creator: Acosta, D.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the J/psi meson and b-hadron production cross sections in p anti-p collisions at s(NN)**(1/2) = 1960-GeV

Description: We present a new measurement of the inclusive and differential production cross sections of J/{psi} mesons and b-hadrons in proton-antiproton collisions at {radical}s = 1960 GeV. The data correspond to an integrated luminosity of 39.7 pb{sup -1} collected by the CDF Run II detector. We find the integrated cross section for inclusive J/{psi} production for all transverse momenta from 0 to 20 GeV/c in the rapidity range |y| < 0.6 to be 4.08 {+-} 0.02(stat){sub -0.33}{sup +0.36}(syst) {mu}b. We… more
Date: December 1, 2004
Creator: Acosta, D.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M. G.; Ambrose, D. et al.
Partner: UNT Libraries Government Documents Department
open access

Measurements of bottom anti-bottom azimuthal production correlations in proton - anti-proton collisions at s**(1/2) = 1.8-TeV

Description: The authors have measured the azimuthal angular correlation of b{bar b} production, using 86.5 pb{sup -1} of data collected by Collider Detector at Fermilab (CDF) in p{bar p} collisions at {radical}s = 1.8 TeV during 1994-1995. In high-energy p{bar p} collisions, such as at the Tevatron, b{bar b} production can be schematically categorized into three mechanisms. The leading-order (LO) process is ''flavor creation'', where both b and {bar b} quarks substantially participate in the hard scatterin… more
Date: December 1, 2004
Creator: Acosta, D.; Affolder, Anthony A.; Albrow, M. G.; Ambrose, D.; Amidei, D.; Anikeev, K. et al.
Partner: UNT Libraries Government Documents Department
open access

Solvation!

Description: This dissertation consists of two closely related parts: theory development and coding of correlation effects in a model potential for solvation, and study of solvent effects on chemical reactions and processes. The effective fragment potential (EFP) method has been re-parameterized, using density functional theory (DFT), more specifically, the B3LYP functional. The DFT based EFP method includes short-range correlation effects; hence it is a first step in incorporating the treatment of correlat… more
Date: December 19, 2004
Creator: Adamovic, Ivana
Partner: UNT Libraries Government Documents Department
open access

K(892)* resonance production in Au+Au and p+p collisions at {radical}s{sub NN} = 200 GeV at RHIC

Description: The short-lived K(892)* resonance provides an efficient tool to probe properties of the hot and dense medium produced in relativistic heavy-ion collisions. We report measurements of K* in {radical}s{sub NN} = 200 GeV Au+Au and p+p collisions reconstructed via its hadronic decay channels K(892)*{sup 0} {yields} K{pi} and K(892)*{sup +-} {yields} K{sub S}{sup 0}{pi}{sup +-} using the STAR detector at RHIC. The K*{sup 0} mass has been studied as function of p{sub T} in minimum bias p + p and centr… more
Date: December 9, 2004
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
Partner: UNT Libraries Government Documents Department
open access

Design, Construction, and Operation of a Laboratory Scale Reactorfor the Production of High-Purity, Isotopically Enriched Bulksilicon

Description: The design and operation of a recirculating flow reactor designed to convert isotopically enriched silane to polycrystalline Si with high efficiency and chemical purity is described. The starting material is SiF{sub 4}, which is enriched in the desired isotope by a centrifuge method and subsequently converted to silane. In the reactor, the silane is decomposed to silicon on the surface of a graphite starter rod (3 mm diameter) heated to 700-750 C. Flow and gas composition (0.3-0.5% silane in hy… more
Date: December 20, 2004
Creator: Ager, J. W., III; Beeman, J. W.; Hansen, W. L. & Haller, E. E.
Partner: UNT Libraries Government Documents Department
open access

The Effect of Individual Versus Collective Creative Problem Solving Experiences on Fourth- and Fifth-grade Students' Compositional Products.

Description: The purpose of the study was to explore the effects that individual vs. collective structured creative musical problem solving tasks had on students' compositional products. Subjects in a convenience sample of 32 fourth-graders and 32 fifth-graders were randomly assigned to either the individual or collective condition. The 3 treatment sessions were characterized by an open-ended creative problem solving task, which included questions intended to guide subjects through 3 stages of the creative … more
Date: December 2004
Creator: Aguilar, Beatriz E.
Partner: UNT Libraries
open access

Aging in the large CDF axial drift chamber

Description: The Central Outer Tracker (COT) is a large axial drift chamber in the Collider Detector at Fermilab operating with a gas mixture that is 50/50 argon/ethane with an admixture of 1.7% isopropanol. In its first two years of operation the COT showed unexpected aging with the worst parts of the chamber experiencing a gain loss of {approx}50% for an accumulated charge of {approx}35 mC/cm. By monitoring the pulse height of hits on good tracks, it was possible to determine the gain as a function of tim… more
Date: December 1, 2004
Creator: Allspach, D.; Ambrose, D.; Binkley, M.; Bromberg, C.; Burkett, K.; Kephart, R. et al.
Partner: UNT Libraries Government Documents Department
open access

YUMMY: The Yucca Mountain MCNP-Library

Description: Point-wise libraries provided with the MCNP code contain neutron data for a limited number of temperatures. However, it is important to have the option of using data from a wide range of temperatures for transport calculations. For this purpose, a multi-temperature, ACE-format neutron library was generated for 134 nuclides, as requested by Yucca Mountain Project (YMP) staff. The library is referred to as YUMMY (YUcca Mountain MCNP-librarY). The neutron cross section data are based on ENDF/B-V o… more
Date: December 10, 2004
Creator: Alpan, FA
Partner: UNT Libraries Government Documents Department
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