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Where the Sidewalk Ends: Jets and Missing Energy Search Strategies for the 7 TeV LHC (open access)

Where the Sidewalk Ends: Jets and Missing Energy Search Strategies for the 7 TeV LHC

This work explores the potential reach of the 7 TeV LHC to new colored states in the context of simplified models and addresses the issue of which search regions are necessary to cover an extensive set of event topologies and kinematic regimes. This article demonstrates that if searches are designed to focus on specific regions of phase space, then new physics may be missed if it lies in unexpected corners. Simple multiregion search strategies can be designed to cover all of kinematic possibilities. A set of benchmark models are created that cover the qualitatively different signatures and a benchmark multiregion search strategy is presented that covers these models.
Date: August 15, 2011
Creator: Alves, Daniele S.M.; Izaguirre, Eder; Wacker, Jay G. & /SLAC /Stanford U., ITP
Object Type: Article
System: The UNT Digital Library
Federal Agency Authority to Contract for Electric Power and Renewable Energy Supply (open access)

Federal Agency Authority to Contract for Electric Power and Renewable Energy Supply

None
Date: August 15, 2011
Creator: Andrews, Anthony
Object Type: Report
System: The UNT Digital Library
Improving the Top Quark Forward-Backward Asymmetry Measurement at the LHC (open access)

Improving the Top Quark Forward-Backward Asymmetry Measurement at the LHC

At the LHC, top quark pairs are dominantly produced from gluons, making it difficult to measure the top quark forward-backward asymmetry. To improve the asymmetry measurement, we study variables that can distinguish between top quarks produced from quarks and those from gluons: the invariant mass of the top pair, the rapidity of the top-antitop system in the lab frame, the rapidity of the top quark in the top-antitop rest frame, the top quark polarization and the top-antitop spin correlation. We combine all the variables in a likelihood discriminant method to separate quark-initiated events from gluon-initiated events. We apply our method on models including G-prime's and W-prime's motivated by the recent observation of a large top quark forward-backward asymmetry at the Tevatron. We have found that the significance of the asymmetry measurement can be improved by 10% to 30%. At the same time, the central values of the asymmetry increase by 40% to 100%. We have also analytically derived the best spin quantization axes for studying top quark polarization as well as spin-correlation for the new physics models.
Date: August 15, 2011
Creator: Bai, Yang & Han, Zhenyu
Object Type: Article
System: The UNT Digital Library
A Piecewise Linear Discontinuous Finite Element Spatial Discretization of the Sn Transport Equation for Polyhedral Grids in 3D Cartesian Geometry (open access)

A Piecewise Linear Discontinuous Finite Element Spatial Discretization of the Sn Transport Equation for Polyhedral Grids in 3D Cartesian Geometry

None
Date: August 15, 2011
Creator: Bailey, T S; Hawkins, W D & Adams, M L
Object Type: Article
System: The UNT Digital Library
Improving the phase stability and oxidation resistance of B-NiAl (open access)

Improving the phase stability and oxidation resistance of B-NiAl

High temperature alloys are essential to many industries that require a stable material to perform in harsh oxidative environments. Many of these alloys are suited for specific applications such as jet engine turbine blades where most other materials would either melt or oxidize and crumble (1). These alloys must have a high melting temperature, excellent oxidation resistance, good creep resistance, and decent fracture toughness to be successfully used in such environments. The discovery of Ni based superalloys in the 1940s revolutionized the high temperature alloy industry and there has been continued development of these alloys since their advent (2). These materials are capable of operating in oxidative environments in the presence of combustion gases, water vapor and at temperatures around 1050 C. Demands for increased f uel efficiency, however, has highlighted the need for materials that can be used under similar atmospheres and at temperatures in excess of 1200 C. The current Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that result in softening of the alloys above 1000 C. Therefore, recent research has been aimed at exploring and developing newer alloy systems that can meet the escalating requirements. …
Date: August 15, 2011
Creator: Brammer, Travis
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Desalination: Technologies, Use, and Congressional Issues (open access)

Desalination: Technologies, Use, and Congressional Issues

This report discusses Desalination processes that generally treat seawater or brackish water to produce a stream of freshwater, and a separate, saltier stream of water that has to be disposed.
Date: August 15, 2011
Creator: Carter, Nicole T.
Object Type: Report
System: The UNT Digital Library
Theory of Two-Magnon Raman Scattering in Iron Pnictides and Chalcogenides (open access)

Theory of Two-Magnon Raman Scattering in Iron Pnictides and Chalcogenides

Although the parent iron-based pnictides and chalcogenides are itinerant antiferromagnets, the use of local moment picture to understand their magnetic properties is still widespread. We study magnetic Raman scattering from a local moment perspective for various quantum spin models proposed for this new class of superconductors. These models vary greatly in the level of magnetic frustration and show a vastly different two-magnon Raman response. Light scattering by two-magnon excitations thus provides a robust and independent measure of the underlying spin interactions. In accord with other recent experiments, our results indicate that the amount of magnetic frustration in these systems may be small.
Date: August 15, 2011
Creator: Chen, C. C.
Object Type: Article
System: The UNT Digital Library
Phase-field investigation on the non-equilibrium interface dynamics of rapid alloy solidification (open access)

Phase-field investigation on the non-equilibrium interface dynamics of rapid alloy solidification

The research program reported here is focused on critical issues that represent conspicuous gaps in current understanding of rapid solidification, limiting our ability to predict and control microstructural evolution (i.e. morphological dynamics and microsegregation) at high undercooling, where conditions depart significantly from local equilibrium. More specifically, through careful application of phase-field modeling, using appropriate thin-interface and anti-trapping corrections and addressing important details such as transient effects and a velocity-dependent (i.e. adaptive) numerics, the current analysis provides a reasonable simulation-based picture of non-equilibrium solute partitioning and the corresponding oscillatory dynamics associated with single-phase rapid solidification and show that this method is a suitable means for a self-consistent simulation of transient behavior and operating point selection under rapid growth conditions. Moving beyond the limitations of conventional theoretical/analytical treatments of non-equilibrium solute partitioning, these results serve to substantiate recent experimental findings and analytical treatments for single-phase rapid solidification. The departure from the equilibrium solid concentration at the solid-liquid interface was often observed during rapid solidification, and the energetic associated non-equilibrium solute partitioning has been treated in detail, providing possible ranges of interface concentrations for a given growth condition. Use of these treatments for analytical description of specific single-phase dendritic and cellular operating point …
Date: August 15, 2011
Creator: Choi, Jeong
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Oral History Interview with Jean Mathis Lidiak, August 15, 2011 captions transcript

Oral History Interview with Jean Mathis Lidiak, August 15, 2011

Interview with Jean Mathis Lidiak, a former middle school secretary from Kerrville, Texas. Mrs. Lidiak talks about growing up in Kerrville, her family, and her work at various businesses and the Veterans Administration hospital. She also discusses her husband's education, his service in World War II, and the auto companies he worked at.
Date: August 15, 2011
Creator: Collins, Francelle Robison; Stephens, Louis; Sutton, Jeanne Schumacher & Lidiak, Jean Mathis
Object Type: Video
System: The Portal to Texas History
Oral History Interview with Jean Mathis Lidiak, August 15, 2011 transcript

Oral History Interview with Jean Mathis Lidiak, August 15, 2011

Interview with Jean Mathis Lidiak, a former middle school secretary from Kerrville, Texas. Mrs. Lidiak talks about growing up in Kerrville, her family, and her work at various businesses and the Veterans Administration hospital. She also discusses her husband's education, his service in World War II, and the auto companies he worked at.
Date: August 15, 2011
Creator: Collins, Francelle Robison; Stephens, Louis; Sutton, Jeanne Schumacher & Lidiak, Jean Mathis
Object Type: Sound
System: The Portal to Texas History
Transcript of Oral History Interview with Jean Mathis Lidiak, August 15, 2011 (open access)

Transcript of Oral History Interview with Jean Mathis Lidiak, August 15, 2011

Interview with Jean Mathis Lidiak, a former middle school secretary from Kerrville, Texas. Mrs. Lidiak talks about growing up in Kerrville, her family, and her work at various businesses and the Veterans Administration hospital. She also discusses her husband's education, his service in World War II, and the auto companies he worked at. The interview transcript includes photos of Mrs. Lidiak and her family, on pages 23-28.
Date: August 15, 2011
Creator: Collins, Francelle Robison; Stephens, Louis; Sutton, Jeanne Schumacher & Lidiak, Jean Mathis
Object Type: Text
System: The Portal to Texas History
Higgs Properties in the Fourth Generation MSSM: Boosted Signals Over the 3G Plan (open access)

Higgs Properties in the Fourth Generation MSSM: Boosted Signals Over the 3G Plan

The generalization of the MSSM to the case of four chiral fermion generations (4GMSSM) can lead to significant changes in the phenomenology of the otherwise familiar Higgs sector. In most of the 3GMSSM parameter space, the lighter CP-even h is {approx} 115-125 GeV and mostly Standard Model-like while H,A,H{sup {+-}} are all relatively heavy. Furthermore, the ratio of Higgs vevs, tan {beta}, is relatively unconstrained. In contrast to this, in the 4GMSSM, heavy fourth generation fermion loops drive the masses of h,H,H{sup {+-}} to large values while the CP-odd boson, A, can remain relatively light and tan {beta} is restricted to the range 1/2 {approx}< tan {beta} {approx}< 2 due to perturbativity requirements on Yukawa couplings. We explore this scenario in some detail, concentrating on the collider signatures of the light CP-odd Higgs at both the Tevatron and LHC. We find that while gg {yields} A may lead to a potential signal in the {tau}{sup +}{tau}{sup -} channel at the LHC, A may first be observed in the {gamma}{gamma} channel due to a highly loop-enhanced cross section that can be more than an order of magnitude greater than that of a SM Higgs for A masses of {approx} 115-120 and …
Date: August 15, 2011
Creator: Cotta, R. C.; Hewett, J. L.; Ismail, A.; Le, M. -P. & Rizzo, T. G.
Object Type: Article
System: The UNT Digital Library
New Dualities in Supersymmetric Chiral Gauge Theories (open access)

New Dualities in Supersymmetric Chiral Gauge Theories

We analyze the phase structure of supersymmetric chiral gauge theories with gauge group SU(N), an antisymmetric, and F {le} N + 3 flavors, in the presence of a cubic superpotential. When F = N + 3 the theory flows to a superconformal fixed point in the infrared, and new dual descriptions of this theory are uncovered. The theory with odd N admits a self-dual magnetic description. For general N, we find an infinite family of magnetic dual descriptions, characterized by arbitrarily large gauge groups and additional classical global symmetries that are truncated by nonperturbative effects. The infrared dynamics of these theories are analyzed using a-maximization, which supports the claim that all these theories flow to the same superconformal fixed point. A very rich phase structure is found when the number of flavors is reduced below N + 3, including a new self-dual point, transitions from conformal to confining, and a nonperturbative instability for F {le} N. We also give examples of chiral theories with antisymmetrics that have nonchiral duals.
Date: August 15, 2011
Creator: Craig, Nathaniel; /Princeton, Inst. Advanced Study /Rutgers U., Piscataway; Essig, Rouven; Hook, Anson; Torroba, Gonzalo & /Stanford U., Phys. Dept. /SLAC
Object Type: Article
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Monday, August 15, 2011 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Monday, August 15, 2011

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: August 15, 2011
Creator: DeSilver, Debi
Object Type: Newspaper
System: The Gateway to Oklahoma History
Top Quark Anomalous Couplings at the International Linear Collider (open access)

Top Quark Anomalous Couplings at the International Linear Collider

We present a study of the experimental determination of the forward-backward asymmetry in the process e{sup +}e{sup -} {yields} t{bar t} and in the subsequent t {yields} Wb decay, studied in the context of the International Linear Collider. This process probes the elementary couplings of the top quark to the photon, the Z and the W bosons at a level of precision that is difficult to achieve at hadron colliders. Measurement of the forward-backward asymmetry requires excellent b quark identification and determination of the quark charge. The study reported here is performed in the most challenging all-hadronic channel e{sup +}e{sup -} {yields} b{bar b}q{bar q}q{bar q}. It includes realistic details of the experimental environment, a full Monte Carlo simulation of the detector, based on the Silicon Detector concept, and realistic event reconstruction. The forward-backward asymmetries are determined to a precision of approximately 1% for each of two choices of beam polarization. We analyze the implications for the determination of the t{bar t}Z and Wt{bar b} couplings.
Date: August 15, 2011
Creator: Devetak, Erik; Nomerotski, Andrei & Peskin, Michael
Object Type: Article
System: The UNT Digital Library
Iraq: Map Sources. August 2011 (open access)

Iraq: Map Sources. August 2011

This report identifies online sources for maps of Iraq, including government. library, and organizational websites.
Date: August 15, 2011
Creator: Fischer, Hannan
Object Type: Report
System: The UNT Digital Library
Natural Resource Management Plan for Brookhaven National Laboratory (open access)

Natural Resource Management Plan for Brookhaven National Laboratory

This comprehensive Natural Resource Management Plan (NRMP) for Brookhaven National Laboratory (BNL) was built on the successful foundation of the Wildlife Management Plan for BNL, which it replaces. This update to the 2003 plan continues to build on successes and efforts to better understand the ecosystems and natural resources found on the BNL site. The plan establishes the basis for managing the varied natural resources located on the 5,265 acre BNL site, setting goals and actions to achieve those goals. The planning of this document is based on the knowledge and expertise gained over the past 10 years by the Natural Resources management staff at BNL in concert with local natural resource agencies including the New York State Department of Environmental Conservation, Long Island Pine Barrens Joint Planning and Policy Commission, The Nature Conservancy, and others. The development of this plan is an attempt at sound ecological management that not only benefits BNL's ecosystems but also benefits the greater Pine Barrens habitats in which BNL is situated. This plan applies equally to the Upton Ecological and Research Reserve (Upton Reserve). Any difference in management between the larger BNL area and the Upton Reserve are noted in the text. The purpose …
Date: August 15, 2011
Creator: Green, T.
Object Type: Report
System: The UNT Digital Library
Built-in and Induced Polarization Across LaAlO3/SrTiO3 Heterojunctions (open access)

Built-in and Induced Polarization Across LaAlO3/SrTiO3 Heterojunctions

Ionic crystals terminated at oppositely charged polar surfaces are inherently unstable and expected to undergo surface reconstructions to maintain electrostatic stability. Essentially, an electric field that arises between oppositely charged atomic planes gives rise to a built-in potential that diverges with thickness. Here we present evidence of such a built-in potential across polar LaAlO{sub 3} thin films grown on SrTiO{sub 3} substrates, a system well known for the electron gas that forms at the interface. By performing tunneling measurements between the electron gas and metallic electrodes on LaAlO{sub 3} we measure a built-in electric field across LaAlO{sub 3} of 80.1 meV/{angstrom}. Additionally, capacitance measurements reveal the presence of an induced dipole moment across the heterostructure. We forsee use of the ionic built-in potential as an additional tuning parameter in both existing and novel device architectures, especially as atomic control of oxide interfaces gains widespread momentum.
Date: August 15, 2011
Creator: Guneeta, Singh-Bhalla
Object Type: Article
System: The UNT Digital Library
Dissecting the Wjj Anomaly: Diagnostic Tests of a Leptophobic Z' (open access)

Dissecting the Wjj Anomaly: Diagnostic Tests of a Leptophobic Z'

We examine the scenario where a leptophobic Z{prime} boson accounts for the excess of events in the Wjj channel as observed by CDF. We assume generation independent couplings for the Z{prime} and obtain allowed regions for the four hadronic couplings using the measured cross section as well as constraints from dijet production at UA2. These coupling regions translate into well-determined rates for the associated production of Z/{gamma} + Z{prime} at the Tevatron and LHC, as well as W + Z{prime} at the LHC,that are directly correlated with the Wjj rate observed at the Tevatron. The Wjj rate at the LHC is large and this channel should be observed soon once the SM backgrounds are under control. The rates for Z/{gamma} + Z{prime} associated production are smaller, and these processes should not yet have been observed at the Tevatron given the expected SM backgrounds. In addition, we show that more coupling information is obtainable from the M{sub WZ{prime}} distribution. Once detected, these processes will provide further valuable information on the Z{prime} boson couplings.
Date: August 15, 2011
Creator: Hewett, J. L. & Rizzo, T. G.
Object Type: Article
System: The UNT Digital Library
Electric Field Penetration in Au/Nb:SrTiO3 Schottky Junctions Probed by Bias-Dependent Internal Photoemission (open access)

Electric Field Penetration in Au/Nb:SrTiO3 Schottky Junctions Probed by Bias-Dependent Internal Photoemission

Electric field penetration into the metallic side of a Schottky junction is in principle a universal phenomenon, the magnitude of which increases with the semiconductor permittivity. Here, we quantitatively probe this effect using bias-dependent internal photoemission spectroscopy at the Schottky junction between a large dielectric permittivity semiconductor SrTiO{sub 3} and gold. A clear linear reduction of the barrier height with increasing interface electric field was observed, highlighting the importance of field penetration into the gold. The interfacial permittivity of SrTiO{sub 3} at the interface is reduced from the bulk value, reflecting intrinsic suppression at the interface.
Date: August 15, 2011
Creator: Hikita, Y.
Object Type: Article
System: The UNT Digital Library
Unitarity Constraints on Asymmetric Freeze-In (open access)

Unitarity Constraints on Asymmetric Freeze-In

This paper considers unitarity and CPT constraints on asymmetric freeze-in, the use of freeze-in to store baryon number in a dark sector. In this scenario, Sakharov's out of equilibrium condition is satisfied by placing the visible and hidden sectors at different temperatures while a net visible baryon number is produced by storing negative baryon number in a dark sector. It is shown that unitarity and CPT lead to unexpected cancellations. In particular, the transfer of baryon number cancels completely at leading order. This note has shown that if two sectors are in thermal equilibrium with themselves, but not with each other, then the leading effect transferring conserved quantities between the two sectors is of order the the weak coupling connecting them to the third power. When freeze-in is used to produce a net baryon number density, the leading order effect comes from {Omicron}({lambda}{sup 3}) diagrams where the intermediate state that goes on-shell has a different visible baryon number than the final state visible baryon number. Models in which the correct baryon number is generated with freeze-in as the dominant source of abundance, typically require {lambda} {approx}> 10{sup -6} and m{sub bath} {approx}> TeV. m{sub bath} is the mass of the …
Date: August 15, 2011
Creator: Hook, Anson
Object Type: Article
System: The UNT Digital Library
Building Toxic Metal Characterization and Decontamination Report: Area 6, Building 914 (open access)

Building Toxic Metal Characterization and Decontamination Report: Area 6, Building 914

The purpose of this report is to outline the toxic metal characterization and decontamination efforts in Area 6, Building 914. This includes the initial building inspection, the hotspot sampling, results/findings, building cleanup, and the verification sampling. Building 914 is a steel light frame building that was constructed in 1992. It is about 16,454 square feet, and five employees are assigned to this building. According to the building's floor plan blueprints, it could be inferred that this building was once a Wiremen/Lineman shop. In 2002-2004, the National Nuclear Security Administration Nevada Site Office embarked on a broad characterization of beryllium (Be) surface concentrations throughout the North Las Vegas Facility, the Nevada National Security Site (NNSS), and ancillary facilities like the Special Technologies Laboratory, Remote Sensing Laboratory, etc. Building 914 was part of this characterization. The results of the 2002 study illustrated that the metal housekeeping limits were within acceptable limits and from a Be standpoint, the building was determined to be fit for occupancy. On March 2, 2011, based on a request from Building 914 users, National Security Technologies, LLC (NSTec) Industrial Hygiene (IH) collected bulk samples from the southwest corner of Building 914 at heights above 6 feet where black …
Date: August 15, 2011
Creator: Hygiene, NSTec Industrial
Object Type: Report
System: The UNT Digital Library
Evaluation of the Impact of the Defense Waste Processing Facility (DWPF) Laboratory Germanium Oxide Use on Recycle Transfers to the H-Tank Farm (open access)

Evaluation of the Impact of the Defense Waste Processing Facility (DWPF) Laboratory Germanium Oxide Use on Recycle Transfers to the H-Tank Farm

When processing High Level Waste (HLW) glass, the Defense Waste Processing Facility (DWPF) cannot wait until the melt or waste glass has been made to assess its acceptability, since by then no further changes to the glass composition and acceptability are possible. Therefore, the acceptability decision is made on the upstream feed stream, rather than on the downstream melt or glass product. This strategy is known as 'feed forward statistical process control.' The DWPF depends on chemical analysis of the feed streams from the Sludge Receipt and Adjustment Tank (SRAT) and the Slurry Mix Evaporator (SME) where the frit plus adjusted sludge from the SRAT are mixed. The SME is the last vessel in which any chemical adjustments or frit additions can be made. Once the analyses of the SME product are deemed acceptable, the SME product is transferred to the Melter Feed Tank (MFT) and onto the melter. The SRAT and SME analyses have been analyzed by the DWPF laboratory using a 'Cold Chemical' method but this dissolution did not adequately dissolve all the elemental components. A new dissolution method which fuses the SRAT or SME product with cesium nitrate (CsNO{sub 3}), germanium (IV) oxide (GeO{sub 2}) and cesium …
Date: August 15, 2011
Creator: Jantzen, Carol M. & Laurinat, J. E.
Object Type: Report
System: The UNT Digital Library
Towards a Holographic Marginal Fermi Liquid (open access)

Towards a Holographic Marginal Fermi Liquid

We present an infinite class of 2+1 dimensional field theories which, after coupling to semi-holographic fermions, exhibit strange metallic behavior in a suitable large N limit. These theories describe lattices of hypermultiplet defects interacting with parity-preserving supersymmetric Chern-Simons theories with U(N) x U(N) gauge groups at levels {+-}k. They have dual gravitational descriptions in terms of lattices of probe M2 branes in AdS{sub 4} x S{sup 7}/Z{sub k} (for N >> 1,N >> k{sup 5}) or probe D2 branes in AdS{sub 4} x CP{sup 3} (for N >> k >> 1,N << k{sup 5}). We discuss several challenges one faces in maintaining the success of these models at finite N, including backreaction of the probes in the gravity solutions and radiative corrections in the weakly coupled field theory limit.
Date: August 15, 2011
Creator: Jensen, Kristan; Kachru, Shamit; Karch, Andreas; Polchinski, Joseph & Silverstein, Eva
Object Type: Article
System: The UNT Digital Library