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Observation of Two-Neutrino Double-Beta Decay in Xe-136 with EXO-200 (open access)

Observation of Two-Neutrino Double-Beta Decay in Xe-136 with EXO-200

We report the observation of two-neutrino double-beta decay in {sup 136}Xe with T{sub 1/2} = 2.11 {+-} 0.04(stat) {+-} 0.21(syst) x 10{sup 21} yr. This second-order process, predicted by the standard model, has been observed for several nuclei but not for {sup 136}Xe. The observed decay rate provides new input to matrix element calculations and to the search for the more interesting neutrinoless double-beta decay, the most sensitive probe for the existence of Majorana particles and the measurement of the neutrino mass scale.
Date: September 14, 2012
Creator: Ackerman, N.; Aharmim, B.; Auger, M.; Auty, D. J.; Barbeau, P. S.; Barry, K. et al.
Object Type: Article
System: The UNT Digital Library
Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope (open access)

Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope

Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 10{sup -26} cm{sup 3} s{sup -1} at 5 GeV to about 5 x 10{sup -23} cm{sup 3} s{sup -1} at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section ({approx}3 x 10{sup -26} cm{sup 3} s{sup -1} for a purely s-wave cross section), without assuming additional boost factors.
Date: September 14, 2012
Creator: Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J. et al.
Object Type: Article
System: The UNT Digital Library
Gravitomagnetism and Spinor Quantum Mechanics (open access)

Gravitomagnetism and Spinor Quantum Mechanics

We give a systematic treatment of a spin 1=2 particle in a combined electromagnetic field and a weak gravitational field that is produced by a slowly moving matter source. This paper continues previous work on a spin zero particle, but it is largely self-contained and may serve as an introduction to spinors in a Riemann space. The analysis is based on the Dirac equation expressed in generally covariant form and coupled minimally to the electromagnetic field. The restriction to a slowly moving matter source, such as the earth, allows us to describe the gravitational field by a gravitoelectric (Newtonian) potential and a gravitomagnetic (frame-dragging) vector potential, the existence of which has recently been experimentally verified. Our main interest is the coupling of the orbital and spin angular momenta of the particle to the gravitomagnetic field. Specifically we calculate the gravitational gyromagnetic ratio as g{sub g} = 1 ; this is to be compared with the electromagnetic gyromagnetic ratio of g{sub e} = 2 for a Dirac electron.
Date: September 14, 2012
Creator: Adler, Ronald J.; /Stanford U., HEPL /San Francisco State U.; Chen, Pisin; /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC; Varani, Elisa & /Unlisted
Object Type: Article
System: The UNT Digital Library
Fermi Large Area Telescope Observations of the Supernova Remnant G8.7-0.1 (open access)

Fermi Large Area Telescope Observations of the Supernova Remnant G8.7-0.1

We present a detailed analysis of the GeV gamma-ray emission toward the supernova remnant (SNR) G8.7-0.1 with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. An investigation of the relationship between G8.7-0.1 and the TeV unidentified source HESS J1804-216 provides us with an important clue on diffusion process of cosmic rays if particle acceleration operates in the SNR. The GeV gamma-ray emission is extended with most of the emission in positional coincidence with the SNR G8.7-0.1 and a lesser part located outside the western boundary of G8.7-0.1. The region of the gamma-ray emission overlaps spatially connected molecular clouds, implying a physical connection for the gamma-ray structure. The total gamma-ray spectrum measured with LAT from 200 MeV-100 GeV can be described by a broken power-law function with a break of 2.4 {+-} 0.6 (stat) {+-} 1.2 (sys) GeV, and photon indices of 2.10 {+-} 0.06 (stat) {+-} 0.10 (sys) below the break and 2.70 {+-} 0.12 (stat) {+-} 0.14 (sys) above the break. Given the spatial association among the gamma rays, the radio emission of G8.7-0.1, and the molecular clouds, the decay of p0s produced by particles accelerated in the SNR and hitting the molecular clouds naturally …
Date: September 14, 2012
Creator: Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D. et al.
Object Type: Article
System: The UNT Digital Library
Higgs, Binos and Gluinos: Split Susy within Reach (open access)

Higgs, Binos and Gluinos: Split Susy within Reach

Recent results from the LHC for the Higgs boson with mass between 142 GeV {approx}< m{sub h{sup 0}} {approx}< 147 GeV points to PeV-scale Split Supersymmetry. This article explores the consequences of a Higgs mass in this range and possible discovery modes for Split Susy. Moderate lifetime gluinos, with decay lengths in the 25 {micro}m to 10 yr range, are its imminent smoking gun signature. The 7TeV LHC will be sensitive to the moderately lived gluinos and trilepton signatures from direct electroweakino production. Moreover, the dark matter abundance may be obtained from annihilation through an s-channel Higgs resonance, with the LSP almost purely bino and mass m{sub {chi}{sub 1}{sup 0}} {approx_equal} 70 GeV. The Higgs resonance region of Split Susy has visible signatures in dark matter direct and indirect detection and electric dipole moment experiments. If the anomalies go away, the majority of Split Susy parameter space will be excluded.
Date: September 14, 2012
Creator: Alves, Daniele S.M.; Izaguirre, Eder; /SLAC /Stanford U., Phys. Dept.; Wacker, Jay G. & /SLAC /Stanford U., ITP
Object Type: Article
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Friday, September 14, 2012 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Friday, September 14, 2012

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: September 14, 2012
Creator: Bright, James
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Altus Times (Altus, Okla.), Vol. 113, No. 76, Ed. 1 Friday, September 14, 2012 (open access)

The Altus Times (Altus, Okla.), Vol. 113, No. 76, Ed. 1 Friday, September 14, 2012

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: September 14, 2012
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
Plasmas, Dielectrics and the Ultrafast: First Science and Operational Experience at FACET (open access)

Plasmas, Dielectrics and the Ultrafast: First Science and Operational Experience at FACET

FACET (Facility for Advanced Accelerator and Experimental Tests) is an accelerator R&D test facility that has been recently constructed at SLAC National Accelerator Laboratory. The facility provides 20 GeV, 3 nC electron beams, short (20 {micro}m) bunches and small (20 {micro}m wide) spot sizes, producing uniquely high power beams. FACET supports studies from many fields but in particular those of Plasma Wakefield Acceleration and Dielectric Wakefield Acceleration. FACET is also a source of THz radiation for material studies. We present the FACET design, initial operating experience and first science from the facility.
Date: September 14, 2012
Creator: Clarke, C. I.; Adli, E.; Corde, S.; Decker, F. J.; England, R. J.; Erickson, R. et al.
Object Type: Article
System: The UNT Digital Library
Brownwood Bulletin (Brownwood, Tex.), Vol. 112, No. 287, Ed. 1 Friday, September 14, 2012 (open access)

Brownwood Bulletin (Brownwood, Tex.), Vol. 112, No. 287, Ed. 1 Friday, September 14, 2012

Weekly newspaper from Brownwood, Texas that includes local, state and national news along with advertising.
Date: September 14, 2012
Creator: Deason, Gene
Object Type: Newspaper
System: The Portal to Texas History
The Oklahoma Daily (Norman, Okla.), Vol. 98, No. 22, Ed. 1 Friday, September 14, 2012 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 98, No. 22, Ed. 1 Friday, September 14, 2012

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: September 14, 2012
Creator: Ellisor, Laney
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Kerens Tribune (Kerens, Tex.), Vol. 120, No. 37, Ed. 1 Friday, September 14, 2012 (open access)

The Kerens Tribune (Kerens, Tex.), Vol. 120, No. 37, Ed. 1 Friday, September 14, 2012

Weekly newspaper from Kerens, Texas that includes local, state and national news along with extensive advertising.
Date: September 14, 2012
Creator: Epps, Sam
Object Type: Newspaper
System: The Portal to Texas History
The Federal Communications Commission: Current Structure and Its Role in the Changing Telecommunications Landscape (open access)

The Federal Communications Commission: Current Structure and Its Role in the Changing Telecommunications Landscape

This report provides information about The Current Structure and Its Role in the Changing Telecommunications Landscape on the Federal Communications Commission. The FCC is an independent agency with its five members appointed by the president.
Date: September 14, 2012
Creator: Figliola, Patricia Moloney
Object Type: Report
System: The UNT Digital Library
Level-2 Milestone 4470: Early Users on Unclassified Sequoia Hardware (open access)

Level-2 Milestone 4470: Early Users on Unclassified Sequoia Hardware

None
Date: September 14, 2012
Creator: Fox, D. M.
Object Type: Report
System: The UNT Digital Library
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 98, No. 1, Ed. 1 Friday, September 14, 2012 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 98, No. 1, Ed. 1 Friday, September 14, 2012

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: September 14, 2012
Creator: Gibbs, Angenene
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Baytown Sun (Baytown, Tex.), Vol. 92, No. 184, Ed. 1 Friday, September 14, 2012 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 92, No. 184, Ed. 1 Friday, September 14, 2012

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: September 14, 2012
Creator: Gray, Janie
Object Type: Newspaper
System: The Portal to Texas History
Financial Services and General Government: FY2013 Appropriations (open access)

Financial Services and General Government: FY2013 Appropriations

None
Date: September 14, 2012
Creator: Hatch, Garrett L.
Object Type: Report
System: The UNT Digital Library
Howard County Junior College District Requests for Legislative Appropriations: Fiscal Years 2014 and 2015, Revised (open access)

Howard County Junior College District Requests for Legislative Appropriations: Fiscal Years 2014 and 2015, Revised

Revised report submitted by the Texas Howard County Junior College District containing background information on the school system, and summaries of requests for appropriations and expenditures for the fiscal years 2014 and 2015 with supporting documentation.
Date: September 14, 2012
Creator: Howard County Junior College District
Object Type: Book
System: The Portal to Texas History
The Jack County Herald (Jacksboro, Tex.), Vol. 67, No. 16, Ed. 1 Friday, September 14, 2012 (open access)

The Jack County Herald (Jacksboro, Tex.), Vol. 67, No. 16, Ed. 1 Friday, September 14, 2012

Weekly newspaper from Jacksboro, Texas that includes local, state, and national news along with advertising.
Date: September 14, 2012
Creator: Hudson, Pam
Object Type: Newspaper
System: The Portal to Texas History
Taxes and the Economy: An Economic Analysis of the Top Tax Rates Since 1945 (open access)

Taxes and the Economy: An Economic Analysis of the Top Tax Rates Since 1945

This report attempts to clarify whether or not there is an association between the tax rates of the highest income taxpayers and economic growth. Data is analyzed to illustrate the association between the tax rates of the highest income taxpayers and measures of economic growth.
Date: September 14, 2012
Creator: Hungerford, Thomas L.
Object Type: Report
System: The UNT Digital Library
[Recording of Pouring Tea: Black Gay Men of the South Tell Their Tales] captions transcript

[Recording of Pouring Tea: Black Gay Men of the South Tell Their Tales]

Video recording of a one-man show performed by E. Patrick Johnson based on his book, Sweet Tea: Black Gay Men of the South. The show discusses coming-of-age in the South, religion, sex, transgenderism, love stories, and coming out; it is based on oral histories collected from a variety of black gay men raised in the southeastern United States.
Date: September 14, 2012
Creator: Johnson, E. Patrick, 1967-
Object Type: Video
System: The UNT Digital Library
Magneto-optical Signatures of a Cascade of Transitions in La 1.875Ba 0.125CuO 4 (open access)

Magneto-optical Signatures of a Cascade of Transitions in La 1.875Ba 0.125CuO 4

Recent experiments on the original cuprate high temperature superconductor, La{sub 2-x}Ba{sub x}CuO{sub 4}, revealed a remarkable sequence of phase transitions. Here we investigate such crystals with polar Kerr effect which is sensitive to time-reversal-symmetry breaking. Concurrent birefringence measurements accurately locate the structural phase transitions from high-temperature tetragonal to low temperature orthorhombic, and then to lower temperature tetragonal, at which temperature a strong Kerr signal onsets. Hysteretic behavior of the Kerr signal suggests that time-reversal symmetry is already broken well above room temperature, an effect that was previously observed in high quality YBa{sub 2}Cu{sub 3}O{sub 6+x} crystals.
Date: September 14, 2012
Creator: Karapetyan, Hovnatan; Hucker, M.; Gu, G. D.; Tranquada, J. M.; Fejer, M. M.; Xia, Jing et al.
Object Type: Article
System: The UNT Digital Library
Solid State Marx Modulators for Emerging Applications (open access)

Solid State Marx Modulators for Emerging Applications

Emerging linear accelerator applications increasingly push the boundaries of RF system performance and economics. The power modulator is an integral part of RF systems whose characteristics play a key role in the determining parameters such as efficiency, footprint, cost, stability, and availability. Particularly within the past decade, solid-state switch based modulators have become the standard in high-performance, high power modulators. One topology, the Marx modulator, has characteristics which make it particularly attractive for several emerging applications. This paper is an overview of the Marx topology, some recent developments, and a case study of how this architecture can be applied to a few proposed linear accelerators.
Date: September 14, 2012
Creator: Kemp, M.A.
Object Type: Article
System: The UNT Digital Library
Soil Composition, Area 6 of the Nevada National Security Site (open access)

Soil Composition, Area 6 of the Nevada National Security Site

None
Date: September 14, 2012
Creator: Knight, K B
Object Type: Report
System: The UNT Digital Library
Formic Acid Free Flowsheet Development To Eliminate Catalytic Hydrogen Generation In The Defense Waste Processing (open access)

Formic Acid Free Flowsheet Development To Eliminate Catalytic Hydrogen Generation In The Defense Waste Processing

The Defense Waste Processing Facility (DWPF) processes legacy nuclear waste generated at the Savannah River Site (SRS) during production of plutonium and tritium demanded by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass canisters is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides. Testing was initiated to determine whether the elimination of formic acid from the DWPF's chemical processing flowsheet would eliminate catalytic hydrogen generation. Historically, hydrogen is generated in chemical processing of alkaline High Level Waste sludge in DWPF. In current processing, sludge is combined with nitric and formic acid to neutralize the waste, reduce mercury and manganese, destroy nitrite, and modify (thin) the slurry rheology. The noble metal catalyzed formic acid decomposition produces hydrogen and carbon dioxide. Elimination of formic acid by replacement with glycolic acid has the potential to eliminate the production of catalytic hydrogen. Flowsheet testing was performed to develop the nitric-glycolic acid flowsheet as an alternative to the nitric-formic flowsheet currently being processed at the DWPF. This new …
Date: September 14, 2012
Creator: Lambert, Dan P.; Stone, Michael E.; Newell, J. David; Fellinger, Terri L. & Bricker, Jonathan M.
Object Type: Article
System: The UNT Digital Library