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Limits on spin-dependent wimp-nucleon interactions from the cryogenic dark matter search (open access)

Limits on spin-dependent wimp-nucleon interactions from the cryogenic dark matter search

The Cryogenic Dark Matter Search (CDMS) is an experiment to detect weakly interacting massive particles (WIMPs) based on their interactions with Ge and Si nuclei. We report the results of an analysis of data from the first two runs of CDMS at the Soudan Underground Laboratory in terms of spin-dependent WIMP-nucleon interactions on {sup 73}Ge and {sup 29}Si. These data exclude new regions of spin-dependent WIMP-nucleon interaction parameter space, including regions relevant to spin-dependent interpretations of the annual modulation signal reported by the DAMA/NaI experiment.
Date: September 1, 2005
Creator: Akerib, D. S.; Armel-Funkhouser, M. S.; Attisha, M. J.; Bailey, C. N.; Baudis, L.; Bauer, Daniel A. et al.
System: The UNT Digital Library
Limits on spin-independent wimp-nucleon interactions from the two-tower run of the cryogenic dark matter search (open access)

Limits on spin-independent wimp-nucleon interactions from the two-tower run of the cryogenic dark matter search

We report new results from the Cryogenic Dark Matter Search (CDMS II) at the Soudan Underground Laboratory. Two towers, each consisting of six detectors, were operated for 74.5 live days, giving spectrum-weighted exposures of 34 kg-d for germanium and 12 kg-d for silicon targets after cuts, averaged over recoil energies 10-100 keV for a WIMP mass of 60GeV/c{sup 2}. A blind analysis was conducted, incorporating improved techniques for rejecting surface events. No WIMP signal exceeding expected backgrounds was observed. When combined with our previous results from Soudan, the 90% C.L. upper limit on the spin-independent WIMP-nucleon cross section is 1.6 x 10{sup -43} cm{sup 2} from Ge, and 3 x 10{sup -42} cm{sup 2} from Si, for a WIMP mass of 60GeV/c{sup 2}. The combined limit from Ge (Si) is a factor of 2.5 (10) lower than our previous results, and constrains predictions of supersymmetric models.
Date: September 1, 2005
Creator: Akerib, D. S.; Attisha, M. J.; Bailey, C. N.; Baudis, L.; Bauer, Daniel A.; Brink, P. L. et al.
System: The UNT Digital Library
QCD and hard diffraction at the LHC (open access)

QCD and hard diffraction at the LHC

As an introduction to QCD at the LHC the author gives an overview of QCD at the Tevatron, emphasizing the high Q{sup 2} frontier which will be taken over by the LHC. After describing briefly the LHC detectors the author discusses high mass diffraction, in particular central exclusive production of Higgs and vector boson pairs. The author introduces the FP420 project to measure the scattered protons 420m downstream of ATLAS and CMS.
Date: September 1, 2005
Creator: Albrow, Michael G.
System: The UNT Digital Library
A spectroscopic study of the ancient milky way: f- and g-type stars in the third data release of the sloan digital sky survey (open access)

A spectroscopic study of the ancient milky way: f- and g-type stars in the third data release of the sloan digital sky survey

We perform an analysis of spectra and photometry for 22,770 stars included in the third data release (DR3) of the Sloan Digital Sky Survey (SDSS). We measure radial velocities and, based on a model-atmosphere analysis, derive estimates of the atmospheric parameters (effective temperature, surface gravity, and [Fe/H]) for each star. Stellar evolution models are then used to estimate distances. We thoroughly check our analysis procedures using three recently published spectroscopic libraries of nearby stars, and compare our results with those obtained from alternative approaches. The SDSS sample covers a range in stellar brightness of 14 < V < 22, primarily at intermediate galactic latitudes, and comprises large numbers of F- and G-type stars from the thick-disk and halo populations (up to 100 kpc from the galactic plane), therefore including some of the oldest stars in the Milky Way. In agreement with previous results from the literature, we find that halo stars exhibit a broad range of iron abundances, with a peak at [Fe/H] {approx_equal} -1.4. This population exhibits essentially no galactic rotation. Thick-disk G-dwarf stars at distances from the galactic plane in the range 1 < |z| < 3 kpc show a much more compact metallicity distribution, with a maximum …
Date: September 1, 2005
Creator: Allende Prieto, Carlos; Beers, T. C.; Wilhelm, R.; Newberg, H. J.; Rockosi, C. M.; Yanny, B. et al.
System: The UNT Digital Library
Comparative genome analysis of Bacillus cereus group genomes withBacillus subtilis (open access)

Comparative genome analysis of Bacillus cereus group genomes withBacillus subtilis

Genome features of the Bacillus cereus group genomes (representative strains of Bacillus cereus, Bacillus anthracis and Bacillus thuringiensis sub spp israelensis) were analyzed and compared with the Bacillus subtilis genome. A core set of 1,381 protein families among the four Bacillus genomes, with an additional set of 933 families common to the B. cereus group, was identified. Differences in signal transduction pathways, membrane transporters, cell surface structures, cell wall, and S-layer proteins suggesting differences in their phenotype were identified. The B. cereus group has signal transduction systems including a tyrosine kinase related to two-component system histidine kinases from B. subtilis. A model for regulation of the stress responsive sigma factor sigmaB in the B. cereus group different from the well studied regulation in B. subtilis has been proposed. Despite a high degree of chromosomal synteny among these genomes, significant differences in cell wall and spore coat proteins that contribute to the survival and adaptation in specific hosts has been identified.
Date: September 14, 2005
Creator: Anderson, Iain; Sorokin, Alexei; Kapatral, Vinayak; Reznik, Gary; Bhattacharya, Anamitra; Mikhailova, Natalia et al.
System: The UNT Digital Library
The Integrated Waste Tracking Systems (IWTS) - A Comprehensive Waste Management Tool (open access)

The Integrated Waste Tracking Systems (IWTS) - A Comprehensive Waste Management Tool

The US Department of Energy (DOE) Idaho National Laboratory (INL) site located near Idaho Falls, ID USA, has developed a comprehensive waste management and tracking tool that integrates multiple operational activities with characterization data from waste declaration through final waste disposition. The Integrated Waste Tracking System (IWTS) provides information necessary to help facility personnel properly manage their waste and demonstrate a wide range of legal and regulatory compliance. As a client?server database system, the IWTS is a proven tracking, characterization, compliance, and reporting tool that meets the needs of both operations and management while providing a high level of flexibility. This paper describes some of the history involved with the development and current use of IWTS as a comprehensive waste management tool as well as a discussion of IWTS deployments performed by the INL for outside clients. Waste management spans a wide range of activities including: work group interactions, regulatory compliance management, reporting, procedure management, and similar activities. The IWTS documents these activities and performs tasks in a computer-automated environment. Waste characterization data, container characterization data, shipments, waste processing, disposals, reporting, and limit compliance checks are just a few of the items that IWTS documents and performs to help waste …
Date: September 1, 2005
Creator: Anderson, Robert S.
System: The UNT Digital Library
A Study of anti-p p ---> two neutral pseudoscalar mesons at the chi(c0)(1**3 P0) formation energy (open access)

A Study of anti-p p ---> two neutral pseudoscalar mesons at the chi(c0)(1**3 P0) formation energy

Fermilab experiment E835 has studied reactions {bar p}p {yields} {pi}{sup 0}{pi}{sup 0}, {pi}{sup 0}{eta}, {eta}{eta}, {pi}{sup 0}{eta}' and {eta}{eta}' in the energy region of the {chi}{sub c0}(1{sup 3} P{sub 0}) from 3340 MeV to 3470 MeV. Interference between resonant and continuum production is observed in the {pi}{sup 0}{pi}{sup 0} and {eta}{eta} channels, and the product of the input and output branching fractions is measured. Limits on resonant production are set for the {pi}{sup 0}{eta} and {pi}{sup 0}{eta}' channels. An indication of interference is observed in the {eta}{eta}' channel. The technique for extracting resonance parameters in an environment dominated by continuum production is described.
Date: September 1, 2005
Creator: Andreotti, M.; Bagnasco, S.; Baldini, W.; Bettoni, D.; Borreani, G.; Buzzo, A. et al.
System: The UNT Digital Library
Progress in Development of Kharkov X-Ray Generator Nestor (open access)

Progress in Development of Kharkov X-Ray Generator Nestor

The sources of the X-rays based on Compton scattering of intense Nd:YAG laser beam on electron beam circulating in a storage ring with beam energy 43-225 MeV is under construction in NSC KIPT. In the paper the progress in development and construction of Kharkov X-ray generator NESTOR is presented. The current status of the main facility system design and development are described. New scheme and main parameters of injection system are presented. The status of power supply system and control system is described. The facility is going to be in operation in the middle of 2007 and generated X-rays flux is expected to be of about 10{sup 13} phot/s.
Date: September 14, 2005
Creator: Androsov, V.; Bulyak, V.; Dovbnya, A.; Drebot, I.; Gladkikh, P.; Grevtsev, V. et al.
System: The UNT Digital Library
South Asian Summer Monsoon and Its Relationship with ENSO in the IPCC AR4 Simulations (open access)

South Asian Summer Monsoon and Its Relationship with ENSO in the IPCC AR4 Simulations

In this paper we use the extensive integrations produced for the IPCC Fourth Assessment Report (AR4) to examine the relationship between ENSO and the monsoon at interannual and decadal timescales. We begin with an analysis of the monsoon simulation in the 20th century integrations. Six of the 18 models were found to have a reasonably realistic representation of monsoon precipitation climatology. For each of these six models SST and anomalous precipitation evolution along the equatorial Pacific during El Nino events display considerable differences when compared to observations. Out of these six models only four (GFDL{_}CM{_}2.0, GFDL{_}CM{_}2.1, MRI, and MPI{_}ECHAM5) exhibit a robust ENSO-monsoon contemporaneous teleconnection, including the known inverse relationship between ENSO and rainfall variations over India. Lagged correlations between the all-India rainfall (AIR) index and Nino3.4 SST reveal that three models represent the timing of the teleconnection, including the spring predictability barrier which is manifested as the transition from positive to negative correlations prior to the monsoon onset. Furthermore, only one of these three models (GFDL{_}CM{_}2.1) captures the observed phase lag with the strongest anticorrelation of SST peaking 2-3 months after the summer monsoon, which is partially attributable to the intensity of simulated El Nino itself. We find that …
Date: September 7, 2005
Creator: Annamalai, H.; Hamilton, K. & Sperber, K. R.
System: The UNT Digital Library
Future hadron physics at Fermilab (open access)

Future hadron physics at Fermilab

Today, hadron physics research occurs at Fermilab as parts of broader experimental programs. This is very likely to be the case in the future. Thus, much of this presentation focuses on our vision of that future--a future aimed at making Fermilab the host laboratory for the International Linear Collider (ILC). Given the uncertainties associated with the ILC--the level of needed R&D, the ILC costs, and the timing--Fermilab is also preparing for other program choices. I will describe these latter efforts, efforts focused on a Proton Driver to increase the numbers of protons available for experiments. As examples of the hadron physics which will be coming from Fermilab, I summarize three experiments: MIPP/E907 which is running currently, and MINERvA and Drell-Yan/E906 which are scheduled for future running periods. Hadron physics coming from the Tevatron Collider program will be summarized by Arthur Maciel in another talk at Hadron05.
Date: September 1, 2005
Creator: Appel, Jeffrey A.
System: The UNT Digital Library
Flow Through PCR Module of BioBriefcase (open access)

Flow Through PCR Module of BioBriefcase

The BioBriefcase is an integrated briefcase-sized aerosol collection and analysis system for autonomous monitoring of the environment, which is currently being jointly developed by Lawrence Livermore and Sandia National Laboratories. This poster presents results from the polymerase chain reaction (PCR) module of the system. The DNA must be purified after exiting the aerosol collector to prevent inhibition of the enzymatic reaction. Traditional solid-phase extraction results in a large loss of sample. In this flow-through system, we perform sample purification, concentration and amplification in one reactor, which minimizes the loss of material. The sample from the aerosol collector is mixed with a denaturation solution prior to flowing through a capillary packed with silica beads. The DNA adheres to the silica beads allowing the environmental contaminants to be flushed to waste while effectively concentrating the DNA on the silica matrix. The adhered DNA is amplified while on the surface of the silica beads, resulting in a lower limit of detection than an equivalent eluted sample. Thus, this system is beneficial since more DNA is available for amplification, less reagents are utilized, and contamination risks are reduced.
Date: September 19, 2005
Creator: Arroyo, E. S.; Wheeler, E. K.; Hindson, B.; Nasarabadi, S.; Vrankovich, G.; Bell, P. et al.
System: The UNT Digital Library
Improved Measurements of Branching Fractions for B0 -> pi+pi-, K+pi-, and Search for B0 -> K+K- (open access)

Improved Measurements of Branching Fractions for B0 -> pi+pi-, K+pi-, and Search for B0 -> K+K-

We present preliminary measurements of branching fractions for the charmless two-body decays B{sup 0} {yields} {pi}{sup +}{pi}{sup -} and K{sup +}{pi}{sup -}, and a search for B{sup 0} {yields} K{sup +}K{sup -} using a data sample of approximately 227 million B{bar B} decays. Signal yields are extracted with a multi-dimensional maximum likelihood fit, and the efficiency is corrected for the effects of final-state radiation. We find the charge-averaged branching fractions (in units of 10{sup -6}): {Beta}(B{sup 0} {yields} {pi}{sup +}{pi}{sup -}) = 5.5 {+-} 0.4 {+-} 0.3; {Beta}(B{sup 0} {yields} K{sup +}{pi}{sup -}) = 19.2 {+-} 0.6 {+-} 0.6; and {Beta}(B{sup 0} {yields} K{sup +}K{sup -}) = < 0.40. The errors are statistical followed by systematic, and the upper limit on K{sup +}K{sup -} represents a confidence level of 90%.
Date: September 28, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
System: The UNT Digital Library
Measurement of Branching Fractions and Resonance Contributions for B0 -> D0bar K+ pi- and Search for B0 -> D0 K+ pi- Decays (open access)

Measurement of Branching Fractions and Resonance Contributions for B0 -> D0bar K+ pi- and Search for B0 -> D0 K+ pi- Decays

Using 226 million {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEp-II e{sup +}e{sup -} storage ring at the Stanford Linear Accelerator Center, they measure the branching fraction for B{sup 0} {yields} {bar D}{sup 0}K{sup +}{pi}{sup -}, excluding B{sup 0} {yields} D*{sup -}K{sup +}, to be {Beta}(B{sup 0} {yields} {bar D}{sup 0}K{sup +}{pi}{sup -}) = 88 {+-} 15 {+-} 9 x 10{sup -6}. They observe B{sup 0} {yields} {bar D}{sup 0}K*(892){sup 0} and B{sup 0} {yields} D*{sub 2}(2460){sup -}K{sup +} contributions. The ratio of branching fractions {Beta}(B{sup 0} {yields} D*{sup -} K{sup +})/{Beta}(B{sup 0} {yields} D*{sup -}{pi}{sup +}) = (7.76 {+-} 0.34 {+-} 0.29)% is measured separately. The branching fraction for the suppressed mode B{sup 0} {yields} D{sup 0}K{sup +}{pi}{sup -} is {Beta}(B{sup 0} {yields} D{sup 0}K{sup +}{pi}{sup -}) < 19 x 10{sup -6} at the 90% confidence level.
Date: September 30, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
System: The UNT Digital Library
Measurement of the Inclusive Electron Spectrum in Charmless Semileptonic B Decays Near the Kinematic Endpoint and Determination of |Vub| (open access)

Measurement of the Inclusive Electron Spectrum in Charmless Semileptonic B Decays Near the Kinematic Endpoint and Determination of |Vub|

We present a measurement of the inclusive electron spectrum in B {yields} X{sub u}e{nu} decays near the kinematic limit for B {yields} X{sub c}e{nu} transitions, using a sample of 88 million B{bar B} pairs recorded by the BABAR detector at the {Upsilon}(4S) resonance. Partial branching fraction measurements are performed in five overlapping intervals of the electron momentum; for the interval of 2.0-2.6 GeV/c we obtain {Delta}{Beta}(B {yields} X{sub u}e{nu}) = (0.572 {+-} 0.041{sub stat} {+-} 0.065{sub syst}) x 10{sup -3}. Combining this result with shape function parameters extracted from BABAR measurements of moments of the inclusive photon spectrum in B {yields} X{sub s}{gamma} decays and moments of the hadron mass and lepton energy spectra in B {yields} X{sub c}l{nu} decays we determine |V{sub ub}| = 4.44 {+-} 0.25{sub exp{sub -0.38}{sup +0.42}SF} {+-} 0.22{sub theory} x 10{sup -3}. Here the first error represents the combined statistical and systematic experimental uncertainties of the partial branching fraction measurement, the second error refers to the uncertainty of the determination of the shape function parameters, and the third error is due to theoretical uncertainties in the QCD calculations.
Date: September 30, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
System: The UNT Digital Library
Measurement of Time-dependent CP-Violating Asymmetries in B0 -> K+K-K0L Decays (open access)

Measurement of Time-dependent CP-Violating Asymmetries in B0 -> K+K-K0L Decays

The authors present preliminary measurements of the Cp asymmetry parameters and CP content in B{sup 0} {yields} K{sup +}K{sup -}K{sub L}{sup 0} decays, with B{sup 0} {yields} {phi}K{sub L}{sup 0} events excluded. In a sample of 227 M B{bar B} pairs collected by the BABAR detector at the PEP-II B Factory at SLAC, they find the CP parameters to be S = 0.07 {+-} 0.28(stat){sub -0.12}{sup +0.11}(syst); C = 0.54 {+-} 0.22(stat){sub -0.09}{sup +0.08}(syst) where the first error is statistical and the second is systematic. Estimating the fraction of CP-odd final states from angular moments analysis in the K{sup +}K{sup -}K{sub S}{sup 0} CP-conjugate final state, f{sub odd}(K{sup +}K{sup -}K{sub L}{sup 0}) = 0.92 {+-} 0.07(stat) {+-} 0.06(syst), they determine sin2{beta}{sub eff} = 0.09 {+-} 0.33(stat){sub -0.14}{sup +0.13}(syst) {+-} 0.10(syst CP-cont) where the last error is due to uncertainty on the CP content.
Date: September 20, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
System: The UNT Digital Library
Results from the BABAR Fully Inclusive Measurement of B? Xs? (open access)

Results from the BABAR Fully Inclusive Measurement of B? Xs?

We present preliminary results from a lepton-tagged fully-inclusive measurement of B {yields} X{sub s}{gamma} decays, where X{sub s} is any strange hadronic state. Results are based on a BABAR data set of 88.5 million B{bar B} pairs at the {Upsilon}(4S) resonance. We present a reconstructed photon energy spectrum in the {Upsilon}(4S) frame, and partial branching fractions above minimum reconstructed photon energies of 1.9, 2.0, 2.1 and 2.2 GeV. We then convert these to measurements of partial branching fractions and truncated first and second moments of the true photon energy distribution in the B rest frame, above the same minimum photon energy values. The full correlation matrices between the first and second moments are included to allow fitting to any parameterized theoretical calculation. We also measure the direct CP asymmetry {Alpha}{sub CP}(B {yields} X{sub s+d{gamma}}) (based on the charge of the tagging lepton) above a reconstructed photon energy of 2.2 GeV.
Date: September 20, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
System: The UNT Digital Library
A Study of Production and Decay of Omega_c^0 Baryons in BABAR (open access)

A Study of Production and Decay of Omega_c^0 Baryons in BABAR

Production and decay of {Omega}{sub c}{sup 0} baryons is studied with {approx} 230 fb{sup -1} of data recorded with the BABAR detector at the PEP-II e{sup +}e{sup -} asymmetric-energy storage ring at SLAC. The {Omega}{sub c}{sup 0} is reconstructed through its decays into {Omega}{sup -}{pi}{sup +}, {Omega}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}, {Xi}{sup -}K{sup -}{pi}{sup +}{pi}{sup +} final states. The invariant mass spectra are presented and the signal yields are extracted. Ratios of branching fractions are measured relative to the {Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +} mode {Beta}({Omega}{sub c}{sup 0} {yields} {Xi}{sup -} K{sup -}{pi}{sup +}{pi}{sup +})/{Beta}({Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +}) = 0.31 {+-} 0.15(stat.) {+-} 0.04(syst.), {Beta}({Omega}{sub c}{sup 0} {yields} {Omega}{sup -} {pi}{sup +}{pi}{sup -}{pi}{sup +})/{Beta}({Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +}) < 0.30 (90%CL). The momentum spectrum (not corrected for efficiency) of {Omega}{sub c}{sup 0} baryons is extracted from decays into {Omega}{sup -}{pi}{sup +}, establishing the first observation of {Omega}{sub c}{sup 0} production from B decays.
Date: September 28, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
System: The UNT Digital Library
Graph-based Methods for Orbit Classification (open access)

Graph-based Methods for Orbit Classification

An important step in the quest for low-cost fusion power is the ability to perform and analyze experiments in prototype fusion reactors. One of the tasks in the analysis of experimental data is the classification of orbits in Poincare plots. These plots are generated by the particles in a fusion reactor as they move within the toroidal device. In this paper, we describe the use of graph-based methods to extract features from orbits. These features are then used to classify the orbits into several categories. Our results show that existing machine learning algorithms are successful in classifying orbits with few points, a situation which can arise in data from experiments.
Date: September 29, 2005
Creator: Bagherjeiran, A. & Kamath, C.
System: The UNT Digital Library
An assumed partition algorithm for determining processor inter-communication (open access)

An assumed partition algorithm for determining processor inter-communication

The recent advent of parallel machines with tens of thousands of processors is presenting new challenges for obtaining scalability. A particular challenge for large-scale scientific software is determining the inter-processor communications required by the computation when a global description of the data is unavailable or too costly to store. We present a type of rendezvous algorithm that determines communication partners in a scalable manner by assuming the global distribution of the data. We demonstrate the scaling properties of the algorithm on up to 32,000 processors in the context of determining communication patterns for a matrix-vector multiply in the hypre software library. Our algorithm is very general and is applicable to a variety of situations in parallel computing.
Date: September 23, 2005
Creator: Baker, A H; Falgout, R D & Yang, U M
System: The UNT Digital Library
Tomographic reconstruction of high energy density plasmas with picosecond temporal resolution (open access)

Tomographic reconstruction of high energy density plasmas with picosecond temporal resolution

Three-dimensional reconstruction of the electron density in a plasma can be obtained by passing multiple beams at different field angles simultaneously through a plasma and performing a tomographic reconstruction of the measured field-dependent phase profiles. In this letter, a relatively simple experimental setup is proposed and simulations are carried out to verify the technique. The plasma distribution is modeled as a discreet number of phase screens and a Zernike polynomial representation of the phase screens is used to reconstruct the plasma profile. Using a subpicosecond laser, the complete three-dimensional electron density of the plasma can be obtained with a time resolution limited only by the transit time of the probe through the plasma.
Date: September 20, 2005
Creator: Baker, K L
System: The UNT Digital Library
Randall-Sundrum membrane model with 7D anti-de Sitter space (open access)

Randall-Sundrum membrane model with 7D anti-de Sitter space

In the same sense that AdS{sub 5} warped geometries arise naturally from Type IIB string theory with stacks of D3 branes, AdS{sub 7} warped geometries arise naturally from M theory with stacks of M5 branes. We compactify two spatial dimensions of AdS{sub 7} to get AdS{sub 5} x {Sigma}{sup 2}, where {Sigma}{sup 2} is e.g. a torus T{sup 2} or a sphere S{sup 2}. The metric for {Sigma} inherits the same warp factor as appears in the AdS{sub 5}. Bulk fields generically have both Kaluza-Klein and winding modes associated with {Sigma}. In the effective 5d action these will contribute exotic new excitations. We analyze the 5d spectrum in detail for the case of a bulk scalar or a graviton in AdS{sub 5} x T{sup 2}, in a setup which mimics the first Randall-Sundrum model. The results display several novel features, some of which might be observed in experiments at the LHC. For example, we obtain TeV scale string winding states without lowering the string scale. This is due to the double warping which is a generic feature of winding states along compactified AdS directions. Experimental verification of these signatures of AdS{sub 7} could be interpreted as direct evidence for M …
Date: September 1, 2005
Creator: Bao, Ruoyu; /Chicago U., EFI /Chicago U.; Lykken, Joseph D. & /Chicago U., EFI /Chicago U. /Fermilab
System: The UNT Digital Library
Lateral width of shower image in the auger fluorescence detector (open access)

Lateral width of shower image in the auger fluorescence detector

The impact of the lateral distribution of light in extensive air showers on the detection and reconstruction of shower profiles is investigated for the Auger fluorescence telescopes. Based on three-dimensional simulations, the capability of the Auger telescopes to measure the lateral distribution of light is evaluated. The ability to infer the actual lateral distribution is confirmed by the comparison of detailed simulations with real data. The contribution of pixels located far from the axis of the shower image is calculated and the accepted signal is rescaled in order to reconstruct a correct shower profile. The analysis presented here shows that: (a) the Auger telescopes are able to observe the lateral distribution of showers and (b) the energy corrections to account for the signal in outlying pixels can exceed 10%, depending on shower geometry.
Date: September 1, 2005
Creator: Barbosa, H.; de Souza, V.; Dobrigkeit, C.; Engel, R.; Gora, D.; Heck, D. et al.
System: The UNT Digital Library
LEAP Phase II, Net Energy Gain From Laser Fields in Vacuum (open access)

LEAP Phase II, Net Energy Gain From Laser Fields in Vacuum

The current Laser Electron Acceleration Program (LEAP) seeks to modulate the energy of an electron bunch by interaction of the electrons with a copropagating pair of crossed laser beams at 800 nm. We present an optical injector design for a LEAP cell so that it can be used to give net energy gain to an electron bunch. Unique features of the design are discussed which will allow this net energy gain and which will also provide a robust signature for the LEAP interaction.
Date: September 27, 2005
Creator: Barnes, C.D.; Colby, E.R.; Plettner, T. & /SLAC /Stanford U., Appl. Mech. Dept.
System: The UNT Digital Library
Effective Interactions and Operators in Nuclei within the No-Core Shell Model (open access)

Effective Interactions and Operators in Nuclei within the No-Core Shell Model

We review the application of effective operator formalism to the ab initio no core shell model (NCSM). For short-range operators, such as the nucleon-nucleon potential, the unitary-transformation method works extremely well at the two-body cluster approximation and good results are obtained for the binding energies and excitation spectra of light nuclei (A {<=} 16). However, for long-range operators, such as the radius or the quadrupole moment, performing this unitary transformation at the two-body cluster level, does not include the higher-order correlations needed to renormalize these long-range operators adequately. Usually, such correlations can be obtained either by increasing the order of the cluster approximation, or by increasing the model space. We will discuss the difficulties of these approaches as well as alternate possible solutions for including higher-order correlations in small model spaces.
Date: September 14, 2005
Creator: Barrett, B; Navratil, P; Stetcu, I & Vary, J
System: The UNT Digital Library