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FUTURE PLANS AT BNL: RHIC-II AND eRHIC. (open access)

FUTURE PLANS AT BNL: RHIC-II AND eRHIC.

The development of future facilities relevant to the study of deep inelastic scattering at BNL is described.
Date: April 16, 2007
Creator: ARONSON,S.
Object Type: Article
System: The UNT Digital Library
Demonstration of Key Elements of a Dual Phase Argon Detection System Suitable for Measurement of Coherent Neutrino-Nucleus Scattering (open access)

Demonstration of Key Elements of a Dual Phase Argon Detection System Suitable for Measurement of Coherent Neutrino-Nucleus Scattering

This feasibility study sought to demonstrate several necessary steps in a research program whose ultimate goal is to detect coherent scattering of reactor antineutrinos in dual-phase noble liquid detectors. By constructing and operating a Argon gas-phase drift and scintillation test-bed, the study confirmed important expectations about sensitivity of these detectors, and thereby met the goals set forth in our original proposal. This work has resulted in a successful Lab-Wide LDRD for design and deployment of a coherent scatter detector at a nuclear reactor, and strong interest by DOE Office of Science. In recent years, researchers at LLNL and elsewhere have converged on a design approach for a new generation of very low noise, low background particle detectors known as two-phase noble liquid/noble gas ionization detectors. This versatile class of detector can be used to detect coherent neutrino scattering-an as yet unmeasured prediction of the Standard Model of particle physics. Using the dual phase technology, our group would be the first to verify the existence of this process. Its (non)detection would (refute)validate central tenets of the Standard Model. The existence of this process is also important in astrophysics, where coherent neutrino scattering is assumed to play an important role in energy …
Date: April 16, 2007
Creator: Adam, B.; Celeste, W.; Christian, H.; Wolfgang, S. & Norman, M.
Object Type: Report
System: The UNT Digital Library
Design and Initial Tests of the Tracker-Converter ofthe Gamma-ray Large Area Space Telescope (open access)

Design and Initial Tests of the Tracker-Converter ofthe Gamma-ray Large Area Space Telescope

The Tracker subsystem of the Large Area Telescope (LAT) science instrument of the Gamma-ray Large Area Space Telescope (GLAST) mission has been completed and tested. It is the central detector subsystem of the LAT and serves both to convert an incident gamma-ray into an electron-positron pair and to track the pair in order to measure the gamma-ray direction. It also provides the principal trigger for the LAT. The Tracker uses silicon strip detectors, read out by custom electronics, to detect charged particles. The detectors and electronics are packaged, along with tungsten converter foils, in 16 modular, high-precision carbon-composite structures. It is the largest silicon-strip detector system ever built for launch into space, and its aggressive design emphasizes very low power consumption, passive cooling, low noise, high efficiency, minimal dead area, and a structure that is highly transparent to charged particles. The test program has demonstrated that the system meets or surpasses all of its performance specifications as well as environmental requirements. It is now installed in the completed LAT, which is being prepared for launch in early 2008.
Date: April 16, 2007
Creator: Atwood, W.B.; Bagagli, R.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Belli, F. et al.
Object Type: Article
System: The UNT Digital Library
Branching Fraction and Charge Asymmetry Measurements inB to J/psi pi pi Decays (open access)

Branching Fraction and Charge Asymmetry Measurements inB to J/psi pi pi Decays

The authors study the decays B{sup 0} {yields} J/{psi} {pi}{sup +}{pi}{sup -} and B{sup +} {yields} J/{psi} {pi}{sup +}{pi}{sup 0}, including intermediate resonances, using a sample of 382 million B{bar B} pairs recorded by the BABAR detector at the PEP-II e{sup +}e{sup -} B factory. They measure the branching fractions {Beta}(B{sup 0} {yields} J/{psi} {rho}{sup 0}) = (2.7 {+-} 0.3 {+-} 0.17) x 10{sup -5} and {Beta}(B{sup +} {yields} J/{psi} {rho}{sup +}) = (5.0 {+-} 0.7 {+-} 0.31) x 10{sup -5}. The authors also set the following upper limits at the 90% confidence level: {Beta}(B{sup 0} {yields} J/{psi} {pi}{sup +}{pi}{sup -} non-resonant) < 1.2 x 10{sup -5}, {Beta}(B{sup 0} {yields} J/{psi} f{sub 2}) < 4.6 x 10{sup -6}, and {Beta}(B{sup +} {yields} J/{psi} {pi}{sup +}{pi}{sup 0} non-resonant) < 4.4 x 10{sup -6}. They measure the charge asymmetry in charged B decays to J/{psi} {rho} to be -0.11 {+-} 0.12 {+-} 0.08.
Date: April 16, 2007
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V. et al.
Object Type: Article
System: The UNT Digital Library
A Study of Emittance Measurement at the ILC (open access)

A Study of Emittance Measurement at the ILC

The measurement of the International Linear Collider (ILC) emittance in the ILC beam delivery system (BDS) is simulated. Estimates of statistical and machine-related errors are discussed and the implications for related diagnostics R&D are inferred. A simulation of the extraction of the laser-wire Compton signal is also presented.
Date: April 16, 2007
Creator: Blair, G. A.; Agapov, I. V.; Carter, J.; Deacon, L.; Angal-Kalinin, D. A. K.; Jenner, L. J. et al.
Object Type: Article
System: The UNT Digital Library
Design of the ILC Prototype FONT4 Digital Intra-Train Beam-Based Feedback System (open access)

Design of the ILC Prototype FONT4 Digital Intra-Train Beam-Based Feedback System

We present the design of the FONT4 digital intra-train beam position feedback system prototype and preliminary results of initial beam tests at the Accelerator Test Facility (ATF) at KEK. The feedback system incorporates a fast analogue beam position monitor (BPM) front-end signal processor, a digital feedback board, and a kicker driver amplifier. The short bunchtrain, comprising 3 electron bunches separated by c. 150ns, in the ATF extraction line was used to test components of the prototype feedback system.
Date: April 16, 2007
Creator: Burrows, P.; /Queen Mary, U. of London; Christian, G. B.; Hartin, A. F.; Dabiri Khah, H.; White, G. R. et al.
Object Type: Article
System: The UNT Digital Library
Performance of the FONT3 Fast Analogue Intra-Train Beam-Based Feedback System at ATF (open access)

Performance of the FONT3 Fast Analogue Intra-Train Beam-Based Feedback System at ATF

We report results of beam tests of the FONT3 intra-train position feedback system prototype at the Accelerator Test Facility (ATF) at KEK. The feedback system incorporates a novel beam position monitor (BPM) processor with latency below 5 nanoseconds, and a kicker driver amplifier with similar low latency. The 56 nanosecond-long bunchtrain in the ATF extraction line was used to test the prototype feedback system. The achieved latency of 23ns provides a demonstration of intra-train feedback on very short timescales relevant even for the CLIC Linear Collider design.
Date: April 16, 2007
Creator: Burrows, P.; /Queen Mary, U. of London; Christian, G. B.; Hartin, A. F.; Dabiri Khah, H.; White, G. R. et al.
Object Type: Article
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Monday, April 16, 2007 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Monday, April 16, 2007

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: April 16, 2007
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Altus Times (Altus, Okla.), Vol. 108, No. 327, Ed. 1 Monday, April 16, 2007 (open access)

The Altus Times (Altus, Okla.), Vol. 108, No. 327, Ed. 1 Monday, April 16, 2007

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: April 16, 2007
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
WEATHER RELATED VARIABILITY OF CALORIMETERY PERFORMANCE IN A POORLY CONTROLLED ENVIRONMENT (open access)

WEATHER RELATED VARIABILITY OF CALORIMETERY PERFORMANCE IN A POORLY CONTROLLED ENVIRONMENT

Four Antech airbath calorimeters at the Hanford site were studied for three summers and two winters in a location not well-shielded from outside temperature changes. All calorimeters showed significant increases in variability of standard measurements during hot weather. The increased variability is postulated to be due to a low setting of the Peltier cold face temperature, which doesn't allow the instrument to drain heat fast enough in a hot environment. A higher setting of the Peltier cold face might lead to better performance in environments subjected to a broad range of temperatures.
Date: April 16, 2007
Creator: Cameron, M. A. & Spellman, J. D.
Object Type: Article
System: The UNT Digital Library
WEATHER RELATED VARIABILITY OF CALORIMETERY PERFORMANCE IN A POORLY CONTROLLED ENVIRONMENT (open access)

WEATHER RELATED VARIABILITY OF CALORIMETERY PERFORMANCE IN A POORLY CONTROLLED ENVIRONMENT

Four Antech airbath calorimeters at the Hanford site were studied for three summers and two winters in a location not well-shielded from outside temperature changes. Calorimeters showed significant increases in variability of standard measurements during hot weather. The increased variability is postulated to be due to a low setting of the Peltier cold face temperature, which doesn't allow the instrument to drain heat fast enough in a hot environment. A higher setting of the Peltier cold face might lead to better performance in environments subjected to a broad range of temperatures.
Date: April 16, 2007
Creator: Cameron, M. A. & Spellman, J. D.
Object Type: Article
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 86, No. 140, Ed. 1 Monday, April 16, 2007 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 86, No. 140, Ed. 1 Monday, April 16, 2007

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: April 16, 2007
Creator: Clements, Clifford E.
Object Type: Newspaper
System: The Portal to Texas History
Effect of pre-equilibrium spin distribution on neutron induced 150Sm cross sections (open access)

Effect of pre-equilibrium spin distribution on neutron induced 150Sm cross sections

Prompt {gamma}-ray production cross section measurements were made as a function of incident neutron energy (En = 1 to 35 MeV) on an enriched (95.6%) {sup 150}Sm sample. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the Los Alamos Neutron Science Center (LANSCE) facility. The prompt-reaction {gamma} rays were detected with the large-scale Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Above E{sub n} {approx} 8 MeV the pre-equilibrium reaction process dominates the inelastic reaction. The spin distribution transferred in pre-equilibrium neutron-induced reactions was calculated using the quantum mechanical theory of Feshbach, Kerman, and Koonin (FKK). These preequilibrium spin distributions were incorporated into the Hauser-Feshbach statistical reaction code GNASH and the {gamma}-ray production cross sections were calculated and compared with experimental data. Neutron inelastic scattering populates 150Sm excited states either by (1) forming the compound nucleus {sup 151}Sm* and decaying by neutron emission, or (2) by the incoming neutron transferring energy to create a particle-hole pair, and thus initiating the pre-equilibrium process. These two processes produce rather different spin distributions: the momentum transfer via the pre-equilibrium process tends to be smaller than in the compound reaction. This difference in the spin population has …
Date: April 16, 2007
Creator: Dashdorj, D.; Kawano, T.; Mitchell, G. E.; Becker, J. A.; Agvaanluvsan, U.; Chadwick, M. et al.
Object Type: Article
System: The UNT Digital Library
The Federal Networking and Information Technology Research and Development Program: Funding Issues and Activities (open access)

The Federal Networking and Information Technology Research and Development Program: Funding Issues and Activities

This report discusses the federal government's role in the country's information technology (IT) research and development (R&D) activities. The government's support of IT R&D began because it had an important interest in creating computers and software that would be capable of addressing the problems and issues the government needed to solve and study.
Date: April 16, 2007
Creator: Figliola, Patricia Moloney
Object Type: Report
System: The UNT Digital Library
Direct Extraction of One-loop Integral Coefficients (open access)

Direct Extraction of One-loop Integral Coefficients

We present a general procedure for obtaining the coefficients of the scalar bubble and triangle integral functions of one-loop amplitudes. Coefficients are extracted by considering two-particle and triple unitarity cuts of the corresponding bubble and triangle integral functions. After choosing a specific parameterization of the cut loop momentum we can uniquely identify the coefficients of the desired integral functions simply by examining the behavior of the cut integrand as the unconstrained parameters of the cut loop momentum approach infinity. In this way we can produce compact forms for scalar integral coefficients. Applications of this method are presented for both QCD and electroweak processes, including an alternative form for the recently computed three-mass triangle coefficient in the six-photon amplitude A{sub 6}(1{sup -}, 2{sup +}, 3{sup -}, 4{sup +}, 5{sup -}, 6{sup +}). The direct nature of this extraction procedure allows for a very straightforward automation of the procedure.
Date: April 16, 2007
Creator: Forde, Darren
Object Type: Article
System: The UNT Digital Library
In situ Investigation of the Silver-CTAB system (open access)

In situ Investigation of the Silver-CTAB system

Recent research has shown that biologically inspired approaches to materials synthesis and self-assembly, hold promise of unprecedented atomic level control of structure and interfaces. In particular, the use of organic molecules to control the production of inorganic technological materials has the potential for controlling grain structure to enhance material strength; controlling facet expression for enhanced catalytic activity; and controlling the shape of nanostructured materials to optimize optical, electrical and magnetic properties. In this work, we use organic molecules to modify silver crystal shapes towards understanding the metal-organic interactions that lead to nanoparticle shape control. Using in situ electrochemical AFM (EC-AFM) as an in situ probe, we study the influence of a cationic surfactant cetyltrimethylamminobromide (CTAB) on Ag growth during electrochemical deposition on Ag(100). The results show that the organic surfactant promotes the growth of steps on the (100) surface and changes the surface evolution from island nucleation to step flow growth. Overall, this leads to a smoother, faster growing (100) surface, which may promote plate-formation.
Date: April 16, 2007
Creator: Gray, J J; Orme, C A; Du, D & Srolovitz, D
Object Type: Article
System: The UNT Digital Library
Strings on AdS2 and the high-energy limit of noncritical M-theory (open access)

Strings on AdS2 and the high-energy limit of noncritical M-theory

Abstract. Noncritical M-theory in 2+1 dimensions has been defined as a double-scaling limit of a nonrelativistic Fermi liquid on a flat two-dimensional plane. Here we study this noncritical M-theory in the limit of high energies, analogous to the alpha' --> infinity limit of string theory. In the related case of two-dimensional Type 0A strings, it has been argued that the conformal alpha' --> infinity limit leads to AdS_2 with a propagating fermion whose mass is set by the value of the RR flux. Here we provide evidence that in the high-energy limit, the natural ground state of noncritical M-theory similarly describes the AdS_2 x S1 spacetime, with a massless propagating fermion. We argue that the spacetime effective theory in this background is captured by a topological higher-spin extension of conformal Chern-Simons gravity in 2+1 dimensions, consistently coupled to a massless Dirac field. Intriguingly, the two-dimensional plane populated by the original nonrelativistic fermions is essentially the twistor space associated with the symmetry group of the AdS_2 x S1 spacetime; thus, at least in the high-energy limit, noncritical M-theory can be nonperturbatively described as a"Fermi liquid on twistor space.''
Date: April 16, 2007
Creator: Horava, Petr; Horava, Petr & Keeler, Cynthia A.
Object Type: Article
System: The UNT Digital Library
GRBs from the First Stars (open access)

GRBs from the First Stars

We present an estimate of the Gamma Ray Bursts which should be expected from metal-free, elusive first generation of stars known as PopulationIII (PopIII). We derive the GRB rate from these stars from the Stellar Formation Rate obtained in several Reionization scenarios available in the literature. In all of the analyzed models we find that GRBs from PopIII are subdominant with respect to the ''standard'' (PopII) ones up to z {approx} 10.
Date: April 16, 2007
Creator: Iocco, Fabio & /Naples U. /KIPAC, Menlo Park
Object Type: Article
System: The UNT Digital Library
Mitigation of Emittance Dilution Due to Transverse Mode Coupling in the L-Band Linacs of the ILC (open access)

Mitigation of Emittance Dilution Due to Transverse Mode Coupling in the L-Band Linacs of the ILC

The main L-band linacs of the ILC accelerate 2820 bunches from a center of mass of 10 GeV to 500 GeV (and in the proposed later upgrade, to 1 TeV). The emittance of the vertical plane is approximately 400 times less than that of the horizontal plane. Provided the vertical and horizontal mode dipole frequencies are degenerate then the motion in each plane is not coupled. However, in reality the frequency degeneracy is split and the eigenmodes are shifted due to inevitable manufacturing errors introduced in fabricating 20,000 cavities. This gives rise to a transverse coupling in the horizontal-vertical motion and can readily lead to a dilution in the emittance in the vertical plane. We investigate means to ameliorate this effect dilution by splitting the horizontal-vertical tune of the lattice.
Date: April 16, 2007
Creator: Jones, R. M. & Miller, R. H.
Object Type: Article
System: The UNT Digital Library
Single Spin Asymmetries of Identified Hadrons in P +P at Square Root S = 62.4 and 200 Gev. (open access)

Single Spin Asymmetries of Identified Hadrons in P +P at Square Root S = 62.4 and 200 Gev.

Measurements of x{sub F}-dependent single spin asymmetries of identified charged hadrons, {pi}{sup {+-}}, K{sup {+-}}, p, and {bar p}, from transversely polarized proton collisions at {radical}s = 200 and 62.4 GeV at RHIC are presented. The energy and flavor dependent asymmetry measurements bring new insight into the fundamental mechanisms of transverse spin asymmetries and Quantum Chromodynamical description of hadronic structure.
Date: April 16, 2007
Creator: Lee, J. H.; Videbaek, F. & Collaboration), (for the Brahms
Object Type: Article
System: The UNT Digital Library
Initial Search for 9-keV XTR from a 28-GeV Beam at SPPS (open access)

Initial Search for 9-keV XTR from a 28-GeV Beam at SPPS

The potential to use x-ray transition radiation (XTR) as a beam diagnostic and coherent XTR (CXTR) as a gain diagnostic in an x-ray FEL was proposed previously. At that time we noted that the unique configuration of the SLAC Sub-picosecond Photon Source (SPPS) with its known x-ray wiggler source, a special three-element x-ray monochromator, x-ray transport line, and experimental end station with x-ray detectors made it an ideal location for an XTR feasibility experiment. Estimates of the XTR compared to the SPPS source strength were done, and initial experiments were performed in September 2005. Complementary measurements on optical transition radiation (OTR) far-field images from a 7-GeV beam are also discussed.
Date: April 16, 2007
Creator: Lumpkin, A. H.; Hastings, J. B. & Rule, D.W.
Object Type: Article
System: The UNT Digital Library
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 92, No. 134, Ed. 1 Monday, April 16, 2007 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 92, No. 134, Ed. 1 Monday, April 16, 2007

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: April 16, 2007
Creator: Mattox, Jami
Object Type: Newspaper
System: The Gateway to Oklahoma History
Legal Issues Raised by Provision in House Energy Bill (H.R. 6) Creating Incentives for Certain OCS Leaseholders to Accept Price Thresholds (open access)

Legal Issues Raised by Provision in House Energy Bill (H.R. 6) Creating Incentives for Certain OCS Leaseholders to Accept Price Thresholds

This report looks at several of the legal issues arguably raised by one such proposal, which on January 18, 2007, passed the House of Representatives as section 204 of H.R.6, the House energy bill.
Date: April 16, 2007
Creator: Meltz, Robert & Vann, Adam
Object Type: Report
System: The UNT Digital Library
Identifying Dark Matter Burners in the Galactic Center (open access)

Identifying Dark Matter Burners in the Galactic Center

If the supermassive black hole (SMBH) at the center of our Galaxy grew adiabatically, then a dense ''spike'' of dark matter is expected to have formed around it. Assuming that dark matter is composed primarily of weakly interacting massive particles (WIMPs), a star orbiting close enough to the SMBH can capture WIMPs at an extremely high rate. The stellar luminosity due to annihilation of captured WIMPs in the stellar core may be comparable to or even exceed the luminosity of the star due to thermonuclear burning. The model thus predicts the existence of unusual stars, i.e. ''WIMP burners'', in the vicinity of an adiabatically grown SMBH. We find that the most efficient WIMP burners are stars with degenerate electron cores, e.g. white dwarfs (WD) or degenerate cores with envelopes. If found, such stars would provide evidence for the existence of particle dark matter and could possibly be used to establish its density profile. In our previous paper we computed the luminosity from WIMP burning for a range of dark matter spike density profiles, degenerate core masses, and distances from the SMBH. Here we compare our results with the observed stars closest to the Galactic center and find that they could …
Date: April 16, 2007
Creator: Moskalenko, Igor V. & Wai, Lawrence L.
Object Type: Report
System: The UNT Digital Library