2\beta + \gamma from B^0 to D^\mp K^0 \pi^\pm Decays at BaBar: aSimulation Study (open access)

2\beta + \gamma from B^0 to D^\mp K^0 \pi^\pm Decays at BaBar: aSimulation Study

The authors present the results of a simulation study to perform the extraction of 2{beta} + {gamma} from B{sup 0} {yields} D{sup {-+}}K{sup 0}{pi}{sup {+-}} decays through a time-dependent Dalitz analysis of BaBar data.
Date: April 16, 2007
Creator: Polci, Francesco; Schune, Marie-Helene; Stocchi, Achille & /Orsay, LAL
System: The UNT Digital Library
Abelian Hidden Sectors at a GeV (open access)

Abelian Hidden Sectors at a GeV

We discuss mechanisms for naturally generating GeV-scale hidden sectors in the context of weak-scale supersymmetry. Such low mass scales can arise when hidden sectors are more weakly coupled to supersymmetry breaking than the visible sector, as happens when supersymmetry breaking is communicated to the visible sector by gauge interactions under which the hidden sector is uncharged, or if the hidden sector is sequestered from gravity-mediated supersymmetry breaking. We study these mechanisms in detail in the context of gauge and gaugino mediation, and present specific models of Abelian GeV-scale hidden sectors. In particular, we discuss kinetic mixing of a U(1){sub x} gauge force with hypercharge, singlets or bi-fundamentals which couple to both sectors, and additional loop effects. Finally, we investigate the possible relevance of such sectors for dark matter phenomenology, as well as for low- and high-energy collider searches.
Date: April 16, 2009
Creator: Morrissey, David E.; Poland, David; U., /Harvard; Zurek, Kathryn & U., /Fermilab /Michigan
System: The UNT Digital Library
Applied and Environmental Microbiology Gordon Research Conference July 27 - August 1, 2003 (open access)

Applied and Environmental Microbiology Gordon Research Conference July 27 - August 1, 2003

None
Date: April 16, 2004
Creator: Wall, Judy D.
System: The UNT Digital Library
The Astro-E2 XRS/EBIT Microcalorimeter XC-ray Spectrometer (open access)

The Astro-E2 XRS/EBIT Microcalorimeter XC-ray Spectrometer

The X-ray Spectrometer (XRS) instrument is a revolutionary non-dispersive spectrometer that will form the basis for the Astro-E2 observatory to be launched in 2005. We have recently installed a flight spare XRS microcalorimeter spectrometer at the EBIT-I and SuperEBIT facility at LLNL replacing the XRS from the earlier Astro-E mission and providing twice the resolving power. The XRS microcalorimeter is an x-ray detector that senses the heat deposited by the incident photon. It achieves a high energy resolution by operating at 0.06K and by carefully engineering the heat capacity and thermal conductance. The XRS/EBIT instrument has 32 pixels in a square geometry and achieves an energy resolution of 6 eV at 6 keV, with a bandpass from 0.1 to 12 keV (or more at higher operating temperature). The instrument allows detailed studies of the x-ray line emission of laboratory plasmas. The XRS/EBIT also provides an extensive calibration 'library' for the Astro-E2 observatory.
Date: April 16, 2004
Creator: Porter, F S; Brown, G V; Boyce, K R; Kelley, R L; Kilbourne, C A; Beiersdorfer, P et al.
System: The UNT Digital Library
Asymmetric Intramolecular Alkylation of Chiral Aromatic Imines via Catalytic C-H Bond Activation (open access)

Asymmetric Intramolecular Alkylation of Chiral Aromatic Imines via Catalytic C-H Bond Activation

The asymmetric intramolecular alkylation of chiral aromatic aldimines, in which differentially substituted alkenes are tethered meta to the imine, was investigated. High enantioselectivities were obtained for imines prepared from aminoindane derivatives, which function as directing groups for the rhodium-catalyzed C-H bond activation. Initial demonstration of catalytic asymmetric intramolecular alkylation also was achieved by employing a sterically hindered achiral imine substrate and catalytic amounts of a chiral amine.
Date: April 16, 2007
Creator: Watzke, Anja; Wilson, Rebecca; O'Malley, Steven; Bergman, Robert & Ellman, Jonathan
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.
System: The UNT Digital Library
Comparative Study of Bunch Length And Arrival Time Measurements at Flash (open access)

Comparative Study of Bunch Length And Arrival Time Measurements at Flash

Diagnostic devices to precisely measure the longitudinal electron beam profile and the bunch arrival time require elaborate new instrumentation techniques. At FLASH, two entirely different methods are used. The bunch profile can be determined with high precision by a transverse deflecting RF structure, but the method is disruptive and does not allow to monitor multiple bunches in a macro-pulse train. It is therefore complemented by two non-disruptive electrooptical devices, called EO and TEO. The EO setup uses a dedicated diagnostic laser synchronized to the machine RF. The longitudinal electron beam profile is encoded in the intensity profile of a chirped laser pulse and analyzed by looking at the spectral composition of the pulse. The second setup, TEO, utilizes the TiSa-based laser system used for pump-probe experiments. Here, the temporal electron shape is encoded into the spatial dimension of the laser pulse by an intersection angle between the laser and the electron beam at the EO-crystal. In this paper, we present a comparative study of bunch length and arrival time measurements performed simultaneously with all three experimental techniques.
Date: April 16, 2007
Creator: Schlarb, H.; Azima, A.; Dusterer, S.; Huning, M.; Knabbe, E.A.; Roehrs, M. et al.
System: The UNT Digital Library
Convergent evolution in primates and an insectivore (open access)

Convergent evolution in primates and an insectivore

The cardiovascular risk factor apolipoprotein(a) (apo(a)) has a puzzling distribution among mammals, its presence being limited to a subset of primates and a member of the insectivore lineage, the hedgehog. To explore the evolutionary history of apo(a), we performed extensive genomic sequence comparisons of multiple species with and without an apo(a) gene product, such as human, baboon, hedgehog, lemurand mouse. This analysis indicated that apo(a) arose independently in a subset of primates, including baboon and human, and an insectivore, the hedgehog, and was not simply lost by species lacking it. The similar structural domains shared by the hedgehog and primate apo(a) indicate that they were formed by a unique molecular mechanism involving the convergent evolution of paralogous genes in these distantspecies.
Date: April 16, 2003
Creator: Boffelli, Dario; Cheng, Jan-Fang & Rubin, Edward M.
System: The UNT Digital Library
Correlation between Strand Stability and Magnet Performance (open access)

Correlation between Strand Stability and Magnet Performance

Magnet programs at BNL, LBNL and FNAL have observed instabilities in high J{sub c} Nb{sub 3}Sn strands and magnets made from these strands. This paper correlates the strand stability determined from a short sample-strand test to the observed magnet performance. It has been observed that strands that carry high currents at high fields (greater than 10T) cannot sustain these same currents at low fields (1-3T) when the sample current is fixed and the magnetic field is ramped. This suggests that the present generation of strand is susceptible to flux jumps (FJ). To prevent flux jumps from limiting stand performance, one must accommodate the energy released during a flux jump. To better understand FJ this work has focused on wire with a given sub-element diameter and shows that one can significantly improve stability by increasing the copper conductivity (higher residual resistivity ratio, RRR, of the Cu). This increased stability significantly improves the conductor performance and permits it to carry more current.
Date: April 16, 2005
Creator: Dietderich, Daniel R.; Bartlett, Scott E.; Caspi, Shlomo; Ferracin, Paolo; G ourlay, Stephen A.; Higley, Hugh C. et al.
System: The UNT Digital Library
CP violation at CDF (open access)

CP violation at CDF

A major goal of experimental particle physics over the next decade is to measure the sides and angles of the Unitarity triangle redundantly, and as precisely as possible. Overconstraining the triangle will test the Cabbibo-Kobayashi-Maskawa model of quark mixing. The CDF collaboration, due to begin a second run in March 2001 with major upgrades to both the accelerator and the detector, will study the angle {beta} using B{sup 0} decays, the angle {gamma} using B{sup 0} and B{sub s}{sup 0} decays, and a side of the triangle through the observation of B{sub s}{sup 0}--{bar B}{sub s}{sup 0} mixing. Projected sensitivities are driven mostly by previous measurements using data from the first run. One highlight of the Run I B physics program is a measurement of the CP violating parameter sin 2{beta} = 0.79{sub {minus}0.44}{sup +0.41}, based on a tagged sample of 400 B{sup 0} decays in the mode B{sub 0}/{bar B}{sup 0} {r_arrow} J/{psi}K{sub s}{sup 0}. The technology of flavor tagging, used here as well as in numerous B{sup 0}-{bar B}{sup 0} mixing analyses in run I, is crucial and will be augmented in Run II with better particle identification capabilities. Exclusive all-hadronic final states will enter the data sample …
Date: April 16, 2001
Creator: Boudreau, J.
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.
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.
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
System: The UNT Digital Library
DOWN-STREAM SPATIAL DISTRIBUTION OF ANTIBIOTIC RESISTANCE TRAITS ALONG METAL CONTAMINATED STREAM REACHES (open access)

DOWN-STREAM SPATIAL DISTRIBUTION OF ANTIBIOTIC RESISTANCE TRAITS ALONG METAL CONTAMINATED STREAM REACHES

Sediment bacteria samples were collected from three streams in South Carolina, two contaminated with multiple metals (Four Mile Creek and Castor Creek), one uncontaminated (Meyers Branch), and another metal contaminated stream (Lampert Creek) in northern Washington State. Growth plates inoculated with Four Mile Creek sample extracts show bacteria colony growth after incubation on plates containing either one of two aminoglycosides (kanamycin or streptomycin), tetracycline or chloramphenocol. This study analyzes the spatial pattern of antibiotic resistance in culturable sediment bacteria in all four streams that may be due to metal contamination. We summarize the two aminoglycoside resistance measures and the 10 metals concentrations by Principal Components Analysis. Respectively, 63% and 58% of the variability was explained in the 1st principal component of each variable set. We used the respective multivariate summary metrics (i.e. 1st principal component scores) as input measures for exploring the spatial correlation between antibiotic resistance and metal concentration for each stream reach sampled. Results show a significant and negative correlation between metals scores versus aminoglycoside resistance scores and suggest that selection for metal tolerance among sediment bacteria may influence selection for antibiotic resistance differently than previously supposed.. In addition, we borrow a method from geostatistics (variography) wherein a …
Date: April 16, 2007
Creator: Tuckfield, C & J V Mcarthur (NOEMAIL), J
System: The UNT Digital Library
Effect of flow fluctuations and nonflow on elliptic flow methods (open access)

Effect of flow fluctuations and nonflow on elliptic flow methods

We discuss how the different estimates of elliptic flow are influenced by flow fluctuations and nonflow effects. It is explained why the event-plane method yields estimates between the two-particle correlation methods and the multiparticle correlation methods. It is argued that nonflow effects and fluctuations cannot be disentangled without other assumptions. However, we provide equations where, with reasonable assumptions about fluctuations and nonflow, all measured values of elliptic flow converge to a unique mean v_2,PP elliptic flow in the participant plane and, with a Gaussian assumption on eccentricity fluctuations, can be converted to the mean v_2,RP in the reaction plane. Thus, the 20percent spread in observed elliptic flow measurements from different analysis methods is no longer mysterious.
Date: April 16, 2009
Creator: Ollitrault, Jean-Yves; Poskanzer, Arthur M. & Voloshin, Sergei A.
System: The UNT Digital Library
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.
System: The UNT Digital Library
Effusive-Flow of Pure Elemental Species in Tubular Transport Systems: Radioactive Ion Beam Applications (open access)

Effusive-Flow of Pure Elemental Species in Tubular Transport Systems: Radioactive Ion Beam Applications

Maximum practically achievable intensities are required for research with accelerated radioactive ion beams (RIBs). Time delays due to diffusion of radioactive species from solid or liquid target materials and their effusive-flow transport to the ion source can severely limit intensities of short-lived radioactive beams, and therefore, such delays must be minimized. An analytical formula has been developed that can be used to calculate characteristic effusive-flow times through tubular transport systems, independent of species, tube material, and operational temperature for ideal cases. Thus, the equation permits choice of materials of construction on a relative basis that minimize transport times of atoms or molecules moving through the system, independent of transport system geometry and size. In this report, we describe the formula and compare results derived by its use with those determined by use of Monte-Carlo techniques.
Date: April 16, 2001
Creator: Bilheux, J.C.
System: The UNT Digital Library
Enhanced Sensitivity of Micro Mechanical Chemical Sensors Through Structural Variation (open access)

Enhanced Sensitivity of Micro Mechanical Chemical Sensors Through Structural Variation

Chemical detection devices are very effective; however, their bulkiness makes them undesirable for portable applications. The next generation of chemical detectors is microscopic mechanical devices capable of measuring trace amounts of chemical vapor within the environment. The chemicals do not react directly with the detector, instead intermolecular forces cause chemicals to adhere to the surface. This surface adhesion of the chemical creates surface stress on the detectors leading to measurable movement. Modifications to the structural design of these microstructures have resulted in signal enhancement to over seven hundred percent.
Date: April 16, 2001
Creator: Harris, J.C.
System: The UNT Digital Library
EVALUATION OF RADIONUCLIDE ACCUMULATION IN SOIL DUE TO LONG-TERM IRRIGATION (open access)

EVALUATION OF RADIONUCLIDE ACCUMULATION IN SOIL DUE TO LONG-TERM IRRIGATION

Radionuclide accumulation in soil due to long-term irrigation is an important part of the model for predicting radiation dose in a long period of time. The model usually assumes an equilibrium condition in soil with a constant irrigation rate, so that radionuclide concentration in soil does not change with time and can be analytically solved. This method is currently being used for the dose assessment in the Yucca Mountain project, which requires evaluating radiation dose for a period of 10,000 years. There are several issues associated with the method: (1) time required for the equilibrium condition, (2) validity of constant irrigation rate, (3) agricultural land use for a long period of time, and (4) variation of a radionuclide concentration in water. These issues are evaluated using a numerical method with a simple model built in the GoldSim software. Some key radionuclides, Tc-99, Np-237, Pu-239, and Am-241 are selected as representative radionuclides. The results indicate that the equilibrium model is acceptable except for a radionuclide that requires long time to accumulate in soil and that its concentration in water changes dramatically with time (i.e. a sharp peak). Then the calculated dose for that radionuclide could be overestimated using the current equilibrium …
Date: April 16, 2006
Creator: Wu, De Wesley
System: The UNT Digital Library
The Evolution of a Hierarchical Partitioning Algorithm for Large-Scale Scientific Data: Three Steps of Increasing Complexity (open access)

The Evolution of a Hierarchical Partitioning Algorithm for Large-Scale Scientific Data: Three Steps of Increasing Complexity

As scientific data sets grow exponentially in size, the need for scalable algorithms that heuristically partition the data increases. In this paper, we describe the three-step evolution of a hierarchical partitioning algorithm for large-scale spatio-temporal scientific data sets generated by massive simulations. The first version of our algorithm uses a simple top-down partitioning technique, which divides the data by using a four-way bisection of the spatio-temporal space. The shortcomings of this algorithm lead to the second version of our partitioning algorithm, which uses a bottom-up approach. In this version, a partition hierarchy is constructed by systematically agglomerating the underlying Cartesian grid that is placed on the data. Finally, the third version of our algorithm utilizes the intrinsic topology of the data given in the original scientific problem to build the partition hierarchy in a bottom-up fashion. Specifically, the topology is used to heuristically agglomerate the data at each level of the partition hierarchy. Despite the growing complexity in our algorithms, the third version of our algorithm builds partition hierarchies in less time and is able to build trees for larger size data sets as compared to the previous two versions.
Date: April 16, 2003
Creator: Baldwin, C.; Eliassi-Rad, T.; Abdulla, G. & Critchlow, T.
System: The UNT Digital Library
Four Federal Grid-Connected Photovoltaic Systems: Powering Our Nation's Capital with Solar (open access)

Four Federal Grid-Connected Photovoltaic Systems: Powering Our Nation's Capital with Solar

One of the fastest growing markets for photovoltaics (PV) is the urban sector. Municipal planners have discovered that PV systems operate favorably in their urban areas, and can be aesthetically integrated into the urban landscape. The federal government has a long history of using PV in a variety of applications, but until recently few applications have been in urban environments. During the last five years, four grid-connected PV systems have been installed on federally owned or federally leased facilities in the Washington, D.C. area: (1) Earth Day Park, (2) U.S. Department of Energy Headquarters, (3) the Pentagon, and (4) Federal Energy Regulatory Commission Headquarters. This paper reviews these four urban, grid-connected systems-particularly the issues of siting, permitting, and grid interconnection.
Date: April 16, 2001
Creator: Plympton, P.; Kappaz, P.; Kroposki, B.; Stafford, B. & Thornton, J.
System: The UNT Digital Library
Future Accelerator Magnet Needs (open access)

Future Accelerator Magnet Needs

None
Date: April 16, 2005
Creator: Devred, Arnaud; Gourlay, Stephen A. & Yamamoto, Akira
System: The UNT Digital Library
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.
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
System: The UNT Digital Library