The Complete Four-Loop Four-Point Amplitude in N (open access)

The Complete Four-Loop Four-Point Amplitude in N

We present the complete four-loop four-point amplitude in N = 4 super-Yang-Mills theory, for a general gauge group and general D-dimensional covariant kinematics, and including all non-planar contributions. We use the method of maximal cuts - an efficient application of the unitarity method - to construct the result in terms of 50 four-loop integrals. We give graphical rules, valid in D-dimensions, for obtaining various non-planar contributions from previously-determined terms. We examine the ultraviolet behavior of the amplitude near D = 11/2. The non-planar terms are as well-behaved in the ultraviolet as the planar terms. However, in the color decomposition of the three- and four-loop amplitude for an SU(N{sub c}) gauge group, the coefficients of the double-trace terms are better behaved in the ultraviolet than are the single-trace terms. The results from this paper were an important step toward obtaining the corresponding amplitude in N = 8 supergravity, which confirmed the existence of cancellations beyond those needed for ultraviolet finiteness at four loops in four dimensions. Evaluation of the loop integrals near D = 4 would permit tests of recent conjectures and results concerning the infrared behavior of four-dimensional massless gauge theory.
Date: August 25, 2010
Creator: Bern, Z.; Carrasco, J.J.M.; /UCLA; Dixon, Lance J.; /CERN, /SLAC; Johansson, H. et al.
Object Type: Article
System: The UNT Digital Library
Compliance and Verification of Standards and Labeling Programs in China: Lessons Learned (open access)

Compliance and Verification of Standards and Labeling Programs in China: Lessons Learned

After implementing several energy efficiency standards and labels (30 products covered by MEPS, 50 products covered by voluntary labels and 19 products by mandatory labels), the China National Institute of Standardization (CNIS) is now implementing verification and compliance mechanism to ensure that the energy information of labeled products comply with the requirements of their labels. CNIS is doing so by organizing check testing on a random basis for room air-conditioners, refrigerators, motors, heaters, computer displays, ovens, and self -ballasted lamps. The purpose of the check testing is to understand the implementation of the Chinese labeling scheme and help local authorities establishing effective compliance mechanisms. In addition, to ensure robustness and consistency of testing results, CNIS has coordinated a round robin testing for room air conditioners. Eight laboratories (Chinese (6), Australian (1) and Japanese (1)) have been involved in the round robin testing and tests were performed on four sets of samples selected from manufacturer's production line. This paper describes the methodology used in undertaking both check and round robin testing, provides analysis of testing results and reports on the findings. The analysis of both check and round robin testing demonstrated the benefits of a regularized verification and monitoring system for …
Date: August 1, 2010
Creator: Saheb, Yamina; Zhou, Nan; Fridley, David & Pierrot, Andre
Object Type: Report
System: The UNT Digital Library
Compton scattering sources and applications at LLNL (open access)

Compton scattering sources and applications at LLNL

None
Date: August 17, 2010
Creator: Albert, F.; Anderson, S. G.; Anderson, G.; Bayramian, A.; Betts, S. M.; Cross, R. R. et al.
Object Type: Article
System: The UNT Digital Library
Computer Aided Multi-scale Design of SiC-Si3N4 Nanoceramic Composites for High-Temperature Structural Applications (open access)

Computer Aided Multi-scale Design of SiC-Si3N4 Nanoceramic Composites for High-Temperature Structural Applications

It is estimated that by using better and improved high temperature structural materials, the power generation efficiency of the power plants can be increased by 15% resulting in significant cost savings. One such promising material system for future high-temperature structural applications in power plants is Silicon Carbide-Silicon Nitride (SiC-Si{sub 3}N{sub 4}) nanoceramic matrix composites. The described research work focuses on multiscale simulation-based design of these SiC-Si{sub 3}N{sub 4} nanoceramic matrix composites. There were two primary objectives of the research: (1) Development of a multiscale simulation tool and corresponding multiscale analyses of the high-temperature creep and fracture resistance properties of the SiC-Si{sub 3}N{sub 4} nanocomposites at nano-, meso- and continuum length- and timescales; and (2) Development of a simulation-based robust design optimization methodology for application to the multiscale simulations to predict the range of the most suitable phase morphologies for the desired high-temperature properties of the SiC-Si{sub 3}N{sub 4} nanocomposites. The multiscale simulation tool is based on a combination of molecular dynamics (MD), cohesive finite element method (CFEM), and continuum level modeling for characterizing time-dependent material deformation behavior. The material simulation tool is incorporated in a variable fidelity model management based design optimization framework. Material modeling includes development of an experimental …
Date: August 31, 2010
Creator: Tomer, Vikas & Renaud, John
Object Type: Report
System: The UNT Digital Library
Concentrating Solar Power (Fact Sheet) (open access)

Concentrating Solar Power (Fact Sheet)

Fact sheet describing the overall capabilities of the NREL CSP Program: collector/receiver characterization, advanced reflector and absorber materials, thermal storage and advanced heat transfer fluids, and CSP modeling and analysis.
Date: August 1, 2010
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Concepts for the PEP-X Light Source (open access)

Concepts for the PEP-X Light Source

SSRL and SLAC groups are developing a long-range plan to transfer its evolving scientific programs from the SPEAR3 light source to a much higher performing photon source that would be housed in the 2.2-km PEP-II tunnel. While various concepts for the PEP-X light source are under consideration, including ultimate storage ring and ERL configurations, the present baseline design is a very low-emittance storage ring. A hybrid lattice has double bend achromat (DBA) cells in two of the six arcs that provide a total 30 straight sections for insertion device (ID) beam lines extending into two new experimental halls. The remaining arcs contain TME cells. Using 90 m of damping wigglers the horizontal emittance at 4.5 GeV would be 100 pm-rad with 1.5-A stored beam. PEP-X will produce photon beams having brightnesses near 10{sup 22} (ph/s/mm{sup 2}/mrad{sup 2}/0.1% BW) at 10 keV. Studies indicate that a 90-m undulator could have FEL gain and brightness enhancement at soft x-ray wavelengths with the stored beam. Crab cavities or other beam manipulation systems could be used to reduce bunch length or otherwise enhance photon emission properties. The present status of the design of PEP-X as a storage ring is presented.
Date: August 26, 2010
Creator: Hettel, Robert; Bane, Karl; Bertsche, Kirk; Cai, Yunhai; Chao, Alex; Dolgashev, Valery et al.
Object Type: Article
System: The UNT Digital Library
Conformality or Confinement (II): One-flavor CFTs and Mixed-Representation QCD (open access)

Conformality or Confinement (II): One-flavor CFTs and Mixed-Representation QCD

We study QCD-like four dimensional theories in the theoretically controlled framework of deformation theory and/or twisted partition function on S{sup 1} x R{sup 3}. By using duality, we show that a class of one-flavor theories exhibit new physical phenomena: discrete chiral symmetry breaking ({chi}SB) induced by the condensation of topological disorder operators, and confinement and the generation of mass gap due to new non-selfdual topological excitations. In the R{sup 4} limit, we argue that the mass gap disappears, the {chi}SB vacua are of runaway type, and the theory flows to a CFT. We also study mixed representation theories and find abelian {chi}SB by topological operators charged under abelian chiral symmetries. These are reminiscent to, but distinct, from Seiberg-Witten theory with matter, where 4d monopoles have non-abelian chiral charge. This examination also helps us refine our recent bounds on the conformal window. In an Addendum, we also discuss mixed vectorlike/chiral representation theories, obtain bounds on their conformal windows, and compare with the all-order beta function results of arXiv:0911.0931.
Date: August 26, 2010
Creator: Poppitz, Erich; U., /Toronto; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
Conformality or confinement: (IR)relevance of topological excitations (open access)

Conformality or confinement: (IR)relevance of topological excitations

What distinguishes two asymptotically-free non-abelian gauge theories on R{sup 4}, one of which is just below the conformal window boundary and confines, while the other is slightly above the boundary and flows to an infrared conformal field theory? In this work, we aim to answer this question for non-supersymmetric Yang-Mills theories with fermions in arbitrary chiral or vectorlike representations. We use the presence or absence of mass gap for gauge fluctuations as an identifier of the infrared behavior. With the present-day understanding of such gauge theories, the mass gap for gauge fluctuations cannot be computed on R{sup 4}. However, recent progress allows its non-perturbative computation on R{sup 3} x S{sup 1} by using either the twisted partition function or deformation theory, for a range of sizes of S{sup 1} depending on the theory. For small number of fermions, N{sub f}, we show that the mass gap increases with increasing radius, due to the non-dilution of monopoles and bions - the topological excitations relevant for confinement on R{sup 3} x S{sup 1}. For sufficiently large N{sub f}, we show that the mass gap decreases with increasing radius. In a class of theories, we claim that the decompactification limit can be taken …
Date: August 26, 2010
Creator: Poppitz, Erich; U., /Toronto; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
CONSIDERATIONS FOR GROUT FORMULATIONS FOR FACILITY CLOSURES USING IN SITU STRATEGIES (open access)

CONSIDERATIONS FOR GROUT FORMULATIONS FOR FACILITY CLOSURES USING IN SITU STRATEGIES

The U.S. Department of Energy (DOE) is conducting in situ closures (entombment) at a large number of facilities throughout the complex. Among the largest closure actions currently underway are the closures of the P and R Reactors at the Savannah River Site (SRS), near Aiken, South Carolina. In these facilities, subgrade open spaces are being stabilized with grout; this ensures the long term structural integrity of the facilities and permanently immobilizes and isolates residual contamination. The large size and structural complexity of these facilities present a wide variety of challenges for the identification and selection of appropriate fill materials. Considerations for grout formulations must account for flowability, long term stability, set times, heat generation and interactions with materials within the structure. The large size and configuration of the facility necessitates that grout must be pumped from the exterior to the spaces to be filled, which requires that the material must retain a high degree of flowability to move through piping without clogging while achieving the required leveling properties at the pour site. Set times and curing properties must be controlled to meet operations schedules, while not generating sufficient heat to compromise the properties of the fill material. The properties of …
Date: August 25, 2010
Creator: Gladden, J.; Serrato, M.; Langton, C.; Long, T.; Blankenship, J.; Hannah, G. et al.
Object Type: Article
System: The UNT Digital Library
Construction and Bench Testing of a Rotatable Collimator for the LHC Collimation Upgrade (open access)

Construction and Bench Testing of a Rotatable Collimator for the LHC Collimation Upgrade

The Phase II upgrade to the LHC collimation system calls for complementing the 30 high robust Phase I graphite secondary collimators with 30 high Z Phase II collimators. The Phase II collimators must be robust in various operating conditions and accident scenarios. This paper reports on the final construction and testing of the prototype collimator to be installed in the SPS (Super Proton Synchrotron) at CERN. Bench-top measurements will demonstrate that the device is fully operational and has the mechanical and vacuum characteristics acceptable for installation in the SPS.
Date: August 26, 2010
Creator: Smith, Jeffrey Claiborne; Keller, Lewis; Lundgren, Steven; Markiewicz, Thomas & /SLAC
Object Type: Article
System: The UNT Digital Library
Construction Method Study for Installation of a Large Riser in a Single-Shell Tank (open access)

Construction Method Study for Installation of a Large Riser in a Single-Shell Tank

This study evaluates and identifies a construction method for cutting a hole in a single-shell tank dome. This study also identifies and evaluates vendors for performing the cut.
Date: August 4, 2010
Creator: Adkisson, D. A.
Object Type: Report
System: The UNT Digital Library
Construction of a Novel Tabletop X-Ray Generator (open access)

Construction of a Novel Tabletop X-Ray Generator

None
Date: August 25, 2010
Creator: Hostetter, James & /SLAC, /Louisiana State U.
Object Type: Report
System: The UNT Digital Library
Control system devices : architectures and supply channels overview. (open access)

Control system devices : architectures and supply channels overview.

This report describes a research project to examine the hardware used in automated control systems like those that control the electric grid. This report provides an overview of the vendors, architectures, and supply channels for a number of control system devices. The research itself represents an attempt to probe more deeply into the area of programmable logic controllers (PLCs) - the specialized digital computers that control individual processes within supervisory control and data acquisition (SCADA) systems. The report (1) provides an overview of control system networks and PLC architecture, (2) furnishes profiles for the top eight vendors in the PLC industry, (3) discusses the communications protocols used in different industries, and (4) analyzes the hardware used in several PLC devices. As part of the project, several PLCs were disassembled to identify constituent components. That information will direct the next step of the research, which will greatly increase our understanding of PLC security in both the hardware and software areas. Such an understanding is vital for discerning the potential national security impact of security flaws in these devices, as well as for developing proactive countermeasures.
Date: August 1, 2010
Creator: Trent, Jason; Atkins, William Dee; Schwartz, Moses Daniel & Mulder, John C.
Object Type: Report
System: The UNT Digital Library
Controlling X-rays With Light (open access)

Controlling X-rays With Light

Ultrafast x-ray science is an exciting frontier that promises the visualization of electronic, atomic and molecular dynamics on atomic time and length scales. A largelyunexplored area of ultrafast x-ray science is the use of light to control how x-rays interact with matter. In order to extend control concepts established for long wavelengthprobes to the x-ray regime, the optical control field must drive a coherent electronic response on a timescale comparable to femtosecond core-hole lifetimes. An intense field is required to achieve this rapid response. Here an intense optical control pulse isobserved to efficiently modulate photoelectric absorption for x-rays and to create an ultrafast transparency window. We demonstrate an application of x-ray transparencyrelevant to ultrafast x-ray sources: an all-photonic temporal cross-correlation measurement of a femtosecond x-ray pulse. The ability to control x-ray/matterinteractions with light will create new opportunities at current and next-generation x-ray light sources.
Date: August 2, 2010
Creator: Glover, Ernie; Hertlein, Marcus; Southworth, Steve; Allison, Tom; van Tilborg, Jeroen; Kanter, Elliot et al.
Object Type: Article
System: The UNT Digital Library
Cooling Coil Effects on Blending in a Pilot Scale Tank (open access)

Cooling Coil Effects on Blending in a Pilot Scale Tank

Blending, or mixing, processes in 1.3 million gallon nuclear waste tanks are complicated by the fact that miles of serpentine, vertical, cooling coils are installed in the tanks. As a step toward investigating blending interference due to coils in this type of tank, a 1/10.85 scale tank and pump model were constructed for pilot scale testing. A series of tests were performed in this scaled tank by adding blue dye to visualize blending, and by adding acid or base tracers to solution to quantify the time required to effectively blend the tank contents. The acid and base tests were monitored with pH probes, which were located in the pilot scale tank to ensure that representative samples were obtained. Using the probes, the hydronium ion concentration [H{sup +}] was measured to ensure that a uniform concentration was obtained throughout the tank. As a result of pilot scale testing, a significantly improved understanding of mixing, or blending, in nuclear waste tanks has been achieved. Evaluation of test data showed that cooling coils in the waste tank model increased pilot scale blending times by 200% in the recommended operating range, compared to previous theoretical estimates of a 10-50% increase. Below the planned operating …
Date: August 26, 2010
Creator: Leishear, R.; Poirier, M.; Fowley, M. & Steeper, T.
Object Type: Article
System: The UNT Digital Library
Corrective Action Decision Document for Corrective Action Unit 562: Waste Systems Nevada Test Site, Nevada, Revision 0 (open access)

Corrective Action Decision Document for Corrective Action Unit 562: Waste Systems Nevada Test Site, Nevada, Revision 0

This Corrective Action Decision Document (CADD) presents information supporting the selection of corrective action alternatives (CAAs) leading to the closure of Corrective Action Unit (CAU) 562, Waste Systems, in Areas 2, 23, and 25 of the Nevada Test Site, Nevada. This complies with the requirements of the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. Corrective Action Unit 562 comprises the following corrective action sites (CASs): • 02-26-11, Lead Shot • 02-44-02, Paint Spills and French Drain • 02-59-01, Septic System • 02-60-01, Concrete Drain • 02-60-02, French Drain • 02-60-03, Steam Cleaning Drain • 02-60-04, French Drain • 02-60-05, French Drain • 02-60-06, French Drain • 02-60-07, French Drain • 23-60-01, Mud Trap Drain and Outfall • 23-99-06, Grease Trap • 25-60-04, Building 3123 Outfalls The purpose of this CADD is to identify and provide the rationale for the recommendation of CAAs for the 13 CASs within CAU 562. Corrective action investigation (CAI) activities were performed from July 27, 2009, through May 12, 2010, as set forth in the CAU 562 Corrective Action Investigation Plan. The …
Date: August 1, 2010
Creator: Krause, Mark
Object Type: Report
System: The UNT Digital Library
Coupling effect on the proton optics from the electron lenses (open access)

Coupling effect on the proton optics from the electron lenses

In this note we calculate the effect of the electron lense solenoids on the proton optics. Electron lenses (e-lenses) are to be used for head-on beam-beam compensation in the Relativistic Heavy Ion Collider (RHIC). Electron lenses are to be used for head-on beam-beam compensation in the polarized proton (pp) runs to compensate the large tune spread generated by the head-on proton-proton beam-beam interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC). The main part of an electron lens is a superconducting solenoid with a longitudinal magnetic field up to 6 T. In this report, we will estimate the e-elenses effects on the {beta} and dispersion functions with 100 GeV and 250 GeV pp run lattices. Table 1 lists some lattice and beam parameters to be used in the following study.
Date: August 1, 2010
Creator: Luo, Y.; Gu, X. & Fischer, W.
Object Type: Report
System: The UNT Digital Library
Creep-Fatigue of Advanced Austenitic Alloys (open access)

Creep-Fatigue of Advanced Austenitic Alloys

This report addresses the creep-fatigue of advanced austenitic alloys.
Date: August 1, 2010
Creator: Carroll, Laura; Benz, Julian & Wright, Richard
Object Type: Report
System: The UNT Digital Library
Critical Currents of YBCO Tapes and Bi-2212 Wires at Different Temperatures and Magnetic Fields (open access)

Critical Currents of YBCO Tapes and Bi-2212 Wires at Different Temperatures and Magnetic Fields

Design studies for the cooling channel of a Muon Collider call for straight and helical solenoids generating field well in excess of the critical fields of state of the art Low Temperature Superconductors (LTS) such as Nb{sub 3}Sn or NbTi. Therefore, High Temperature Superconductors (HTS) will need to be used for the manufacturing of all or certain sections of such magnets to be able to generate and withstand the field levels at the cryogenic temperatures required by the new machine. In this work, two major High Temperature Superconductors - Bi2212 round wires and YBCO coated conductor tapes - are investigated to understand how critical current density of such conductors scales as a function of external field and operating temperature. This is vital information to make conductor choices depending on the application and to proceed with the design of such magnets.
Date: August 1, 2010
Creator: Lombardo, V.; Barzi, E.; Turrioni, D. & Zlobin, A. V.
Object Type: Article
System: The UNT Digital Library
Cryptographic Trust Management System Design Document (open access)

Cryptographic Trust Management System Design Document

Deliverable for DOE NSTB Cryptographic Trust Management project. Design document to follow the Requirements document submitted in Sept 2009.
Date: August 4, 2010
Creator: Edgar, Thomas W.; Clements, Samuel L.; Hadley, Mark D.; Maiden, Wendy M.; Manz, David O. & Zabriskie, Sean J.
Object Type: Report
System: The UNT Digital Library
Cultural Resource Investigations for a Multipurpose Haul Road on the Idaho National Laboratory (open access)

Cultural Resource Investigations for a Multipurpose Haul Road on the Idaho National Laboratory

The U. S. Department of Energy, Idaho Operations Office is considering options for construction of a multipurpose haul road to transport materials and wastes between the Materials and Fuels Complex (MFC) and other Idaho National Laboratory (INL) Site facilities. The proposed road will be closed to the public and designed for limited year-round use. Two primary options are under consideration: a new route south of the existing T-25 power line road and an upgrade to road T-24. In the Spring of 2010, archaeological field surveys and initial coordination and field reconnaissance with representatives from the Shoshone-Bannock Tribes were completed to identify any resources that may be adversely affected by the proposed road construction and to develop recommendations to protect any listed or eligible for listing on the National Register of Historic Places. The investigations showed that 24 archaeological resources and one historic marker are located in the area of potential effects for road construction and operation south of the T-25 powerline road and 27archaeological resources are located in the area of potential effects for road construction and operation along road T-24. Generalized tribal concerns regarding protection of natural resources were also documented in both road corridors. This report outlines recommendations …
Date: August 1, 2010
Creator: Pace, Brenda R.; Brizzee, Cameron; Gilbert, Hollie; Marler, Clayton & Williams, Julie Braun
Object Type: Report
System: The UNT Digital Library
D0 Evidence for CP Violation and Implication for CPT Violation in B-Meson Mixing (open access)

D0 Evidence for CP Violation and Implication for CPT Violation in B-Meson Mixing

A D0 analysis measuring the charge asymmetry A{sub sl}{sup b} of like-sign dimuon events due to semileptonic b-hadron decays at the Fermilab Tevatron Collider is described. It differs by 3.2 standard deviations from the Standard Model prediction to provide first evidence of CPT-invariant anomalous CP violation in the mixing of neutral B mesons, and is compared to the CP-violating phase obtained from a D0 analysis of the time-dependent decay angles in B{sub s}{sup 0} {yields} J/{psi}{phi}. If CPT violation is allowed, the dimuon asymmetry also yields the first sensitivity to CPT violation in the B{sub s}{sup 0} system.
Date: August 1, 2010
Creator: Kooten, R.Van
Object Type: Article
System: The UNT Digital Library
The DAFT/FADA survey. I.Photometric redshifts along lines of sight to clusters in the z=[0.4,0.9] interval (open access)

The DAFT/FADA survey. I.Photometric redshifts along lines of sight to clusters in the z=[0.4,0.9] interval

As a contribution to the understanding of the dark energy concept, the Dark energy American French Team (DAFT, in French FADA) has started a large project to characterize statistically high redshift galaxy clusters, infer cosmological constraints from Weak Lensing Tomography, and understand biases relevant for constraining dark energy and cluster physics in future cluster and cosmological experiments. Aims. The purpose of this paper is to establish the basis of reference for the photo-z determination used in all our subsequent papers, including weak lensing tomography studies. This project is based on a sample of 91 high redshift (z {ge} 0.4), massive ({approx}> 3 x 10{sup 14} M{sub {circle_dot}}) clusters with existing HST imaging, for which we are presently performing complementary multi-wavelength imaging. This allows us in particular to estimate spectral types and determine accurate photometric redshifts for galaxies along the lines of sight to the first ten clusters for which all the required data are available down to a limit of I{sub AB} = 24./24.5 with the LePhare software. The accuracy in redshift is of the order of 0.05 for the range 0.2 {le} z {le} 1.5. We verified that the technique applied to obtain photometric redshifts works well by comparing …
Date: August 1, 2010
Creator: Guennou, L.; /Northwestern U. /Marseille, Lab. Astrophys.; Adami, C.; /Marseille, Lab. Astrophys.; Ulmer, M.P.; /Northwestern U. /Marseille, Lab. Astrophys. et al.
Object Type: Article
System: The UNT Digital Library
Dalitz-plot Analysis of B0 -> anti-D0 pi pi- (open access)

Dalitz-plot Analysis of B0 -> anti-D0 pi pi-

The authors report preliminary results from a study of the decay B{sup 0} {yields} {bar D}{sup 0}{pi}{sup +}{pi}{sup -} using a data sample of 470.9 {+-} 2.8 million B{bar B} events collected with the BABAR detector at the {Upsilon}(4S) resonance. Using the Dalitz-plot analysis technique, they find contributions from the intermediate resonances D*{sub 2}(2460){sup -}, D*{sub 0}(2400){sup -}, {rho}(770){sup 0} and f{sub 2}(1270) as well as a {pi}{sup +}{pi}{sup -} S-wave term, a {bar D}{sup 0}{pi}{sup -} nonresonant S-wave term and a virtual D*(2010) amplitude. They measure the branching fractions of the contributing decays.
Date: August 25, 2010
Creator: del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP et al.
Object Type: Article
System: The UNT Digital Library