17th Annual ALS Users' Association Meeting (open access)

17th Annual ALS Users' Association Meeting

It's not exactly Russian roulette, but scheduling October events outdoors is not risk-free, even in usually sunny California. An overflow crowd of more than 400 registered users, ALS staff, and vendors enjoyed a full indoor program featuring science highlights and workshops spread over two and a half days from October 18 to October 20. However, a major storm, heralding the onset of the San Francisco Bay Area rainy season, posed a few weather challenges for the events on the ALS patio.
Date: November 29, 2004
Creator: Robinson, Art & Tamura, Lori
System: The UNT Digital Library
Accurate Position Sensing of Defocused Beams Using Simulated Beam Templates (open access)

Accurate Position Sensing of Defocused Beams Using Simulated Beam Templates

In position detection using matched filtering one is faced with the challenge of determining the best position in the presence of distortions such as defocus and diffraction noise. This work evaluates the performance of simulated defocused images as the template against the real defocused beam. It was found that an amplitude modulated phase-only filter is better equipped to deal with real defocused images that suffer from diffraction noise effects resulting in a textured spot intensity pattern. It is shown that the there is a tradeoff of performance dependent upon the type and size of the defocused image. A novel automated system was developed that can automatically select the right template type and size. Results of this automation for real defocused images are presented.
Date: September 29, 2004
Creator: Awwal, A.; Candy, J.; Haynam, C.; Widmayer, C.; Bliss, E. & Burkhart, S.
System: The UNT Digital Library
ADMP Mixing of Tank 18F: History, Modeling, Testing, and Results (open access)

ADMP Mixing of Tank 18F: History, Modeling, Testing, and Results

Residual radioactive waste was removed from Tank 18F in the F-Area Tank Farm at Savannah River Site (SRS), using the advanced design mixer pump (ADMP). Known as a slurry pump, the ADMP is a 55 foot long pump with an upper motor mounted to a steel super structure, which spans the top of the waste tank. The motor is connected by a long vertical drive shaft to a centrifugal pump, which is submerged in waste near the tank bottom. The pump mixes, or slurries, the waste within the tank so that it may be transferred out of the tank. Tank 18F is a 1.3 million gallon, 85 foot diameter underground waste storage tank, which has no internal components such as cooling coils or structural supports. The tank contained a residual 47,000 gallons of nuclear waste, consisting of a gelatinous radioactive waste known as sludge and particulate zeolite. The prediction of the ADMP success was based on nearly twenty five years of research and the application of that research to slurry pump technology. Many personnel at SRS and Pacific Northwest National Laboratories (PNNL) have significantly contributed to these efforts. This report summarizes that research which is pertinent to the ADMP performance …
Date: March 29, 2004
Creator: LEISHEAR, ROBERTA
System: The UNT Digital Library
Automatic Identification of the Templates in Matched Filtering (open access)

Automatic Identification of the Templates in Matched Filtering

In laser beam position determination, various shapes of markers may be used to identify different beams. When matched filtering is used for identifying the markers, one is faced with the challenge of determining the appropriate filter to use in the presence of distortions and marker size variability. If the incorrect filter is used, it will result in significant position uncertainty. Thus in the very first step of position detection one has to come up with an automated process to select the right template to use. The automated template identification method proposed here is based on a two-step approach. In the first step an approximate type of the object is determined. Then the filter is chosen based on the best size of the specific type. After the appropriate filter is chosen, the correlation peak position is used to identify the beam position. Real world examples of the application of this technique from the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory are presented.
Date: September 29, 2004
Creator: Awwal, A. S.
System: The UNT Digital Library
Azimuthal anisotropy in Au+Au collisions at {radical}s{sub NN} = 200 GeV (open access)

Azimuthal anisotropy in Au+Au collisions at {radical}s{sub NN} = 200 GeV

The results from the STAR Collaboration on directed flow (v{sub 1}), elliptic flow (v{sub 2}), and the fourth harmonic (v{sub 4}) in the anisotropic azimuthal distribution of particles from Au+Au collisions at {radical}s{sub NN} = 200 GeV are summarized and compared with results from other experiments and theoretical models. Results for identified particles are presented and fit with a Blast Wave model. For v{sub 2}, scaling with the number of constituent quarks and parton coalescence is discussed. For v{sub 4}, scaling with v{sub 22} and quark coalescence predictions for higher harmonic flow is discussed. The different anisotropic flow analysis methods are compared and nonflow effects are extracted from the data. For v{sub 2}, scaling with the number of constituent quarks and parton coalescence are discussed. For v{sub 2}{sup 2} and quark coalescence are discussed.
Date: September 29, 2004
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Akhipkin, D. et al.
System: The UNT Digital Library
BuildingPI: A future tool for building life cycle analysis (open access)

BuildingPI: A future tool for building life cycle analysis

Traditionally building simulation models are used at the design phase of a building project. These models are used to optimize various design alternatives, reduce energy consumption and cost. Building performance assessment for the operational phase of a buildings life cycle is sporadic, typically working from historical metered data and focusing on bulk energy assessment. Building Management Systems (BMS) do not explicitly incorporate feedback to the design phase or account for any changes, which have been made to building layout or fabric during construction. This paper discusses a proposal to develop an Industry Foundation Classes (IFC) compliant data visualization tool Building Performance Indicator (BuildingPI) for performance metric and performance effectiveness ratio evaluation.
Date: March 29, 2004
Creator: O'Donnell, James; Morrissey, Elmer; Keane, Marcus & Bazjanac,Vladimir
System: The UNT Digital Library
Characterization of Uranium Solids Precipitated with Aluminosilicates (open access)

Characterization of Uranium Solids Precipitated with Aluminosilicates

At the Savannah River Site (SRS), the High-Level Waste (HLW) Tank Farms store and process high-level liquid radioactive wastes from the Canyons and recycle water from the Defense Waste Processing Facility. The waste is concentrated using evaporators to minimize the volume of space required for HLW storage. Recently, the 2H Evaporator was shutdown due to the crystallization of sodium aluminosilicate (NAS) solids (such as cancrinite and sodalite) that contained close to 10 weight percent of elementally-enriched uranium (U). Prior to extensive cleaning,the evaporator deposits resided on the evaporator walls and other exposed internal surfaces within the evaporator pot. Our goal is to support the basis for the continued safe operation of SRS evaporators and to gain more information that could be used to help mitigate U accumulation during evaporator operation.
Date: April 29, 2004
Creator: Duff, M. C.
System: The UNT Digital Library
Chemical Origins of Permanent Set in a Peroxide Cured Filled Silicone Elastomer - Tensile and 1H NMR Analysis (open access)

Chemical Origins of Permanent Set in a Peroxide Cured Filled Silicone Elastomer - Tensile and 1H NMR Analysis

The aging of a commercial filled siloxane polymeric composite in states of high stress and Co-60 {gamma}-radiation exposure has been studied. DC-745 is a commercially available silicone elastomer consisting of dimethyl, methyl-phenyl, and vinyl-methyl siloxane monomers crosslinked with a peroxide vinyl specific curing agent. It is filled with {approx}30 wt.% mixture of high and low surface area silicas. This filled material is shown to be subject to permanent set if exposed to radiation while under tensile stress. Tensile modulus measurements show that the material gets marginally softer with combined radiation exposure and tensile strain as compared to material exposed to radiation without tensile strain. In addition, the segmental dynamics as measured by both uniaxial NMR relaxometry and Multiple Quantum NMR methods indicate that the material is undergoes radiatively-induced crosslinking in the absence of tensile strain and a combination of crosslinking and strain dependent increase in dynamic order parameter for the network chains. The MQ-NMR also suggests a small change in the number of polymer chains associated with the silica filler surface. Comparison of the prediction of the relative change in crosslink density from the NMR data as well as solvent swelling data and from that predicted from the Tobolsky model …
Date: October 29, 2004
Creator: Chinn, S.; Deteresa, S.; Shields, A.; Sawvel, A.; Balazs, B. & Maxwell, R. S.
System: The UNT Digital Library
CIRCE, the Coherent Infrared Center at the ALS (open access)

CIRCE, the Coherent Infrared Center at the ALS

CIRCE (Coherent InfraRed CEnter) is a proposal for a new electron storage ring to be built at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL). The ring design is optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range. Among others, CIRCE operation includes three interesting CSR modes: ultra stable, femtosecond laser slicing and broadband bursting. CSR allows CIRCE to generate an extremely high flux in the terahertz frequency region. The many orders of magnitude increase in the intensity over that presently achievable by conventional sources, has the potential to enable new science experiments. The characteristics of CIRCE and of the different modes of operation are described in this paper.
Date: June 29, 2004
Creator: Byrd, John M.; De Santis, Stefano; Jung, Jin-Young; Li, Derun; Martin, Michael C.; McKinney, W. et al.
System: The UNT Digital Library
Cluster Form Factor Calculation in the Ab Initio No-Core Shell Model (open access)

Cluster Form Factor Calculation in the Ab Initio No-Core Shell Model

None
Date: July 29, 2004
Creator: Navratil, P
System: The UNT Digital Library
Commissioning of BL 7.2, the new diagnostic beam line at the ALS (open access)

Commissioning of BL 7.2, the new diagnostic beam line at the ALS

BL 7.2 is a new beamline at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL) dedicated to electron beam diagnostics. The system, which is basically a hard x-ray pinhole camera, was installed in the storage ring in August 2003 and commissioning with the ALS electron beam followed immediately after. In this paper the commissioning results are presented together with the description of the relevant measurements performed for the beamline characterization.
Date: June 29, 2004
Creator: Sannibale, Fernando; Baum, Dennis; Biocca, Alan; Kelez, Nicholas; Nishimura, Toshiro; Scarvie, Tom et al.
System: The UNT Digital Library
Comparison of Varve and 14C Chronologies from Steel Lake, Minnesota, USA (open access)

Comparison of Varve and 14C Chronologies from Steel Lake, Minnesota, USA

Annually laminated sediments (varves) offer an effective means of acquiring high-quality paleoenvironmental records. However, the strength of a varve chronology can be compromised by a number of factors, such as missing varves, ambiguous laminations, and human counting error. We assess the quality of a varve chronology for the last three millennia from Steel Lake, Minnesota, through comparisons with nine AMS {sup 14}C dates on terrestrial plant macrofossils from the same core. These comparisons revealed an overall 8.4% discrepancy, primarily because of missing/uncountable varves within two stratigraphic intervals characterized by low carbonate concentrations and obscure laminations. Application of appropriate correction factors to these two intervals results in excellent agreement between the varve and {sup 14}C chronologies. These results, together with other varve studies, demonstrate that an independent age-determination method, such as {sup 14}C dating, is usually necessary to verify, and potentially correct, varve chronologies.
Date: December 29, 2004
Creator: Tian, J; Brown, T A & Hu, F S
System: The UNT Digital Library
Computational Needs for Muon Accelerators. (open access)

Computational Needs for Muon Accelerators.

Muon accelerators contain beam lines and components which are unlike any found in existing accelerators. Production of the muons requires targets for beams with powers which are at or beyond what has currently been achieved. Many subsystems use solenoid focusing systems where at any given point, several magnets have a significant influence. The beams that are transported can have energy spreads of {+-}30% or more. The required emittances necessitate accurate tracking of particles with angles of tenths of a radian and which are positioned almost at the edge of the beam pipe. Tracking must be done not only in vacuum, but also in materials; therefore, statistical fluctuations must also be included. Design and simulation of muon accelerators requires software which can: accurately simulate the dynamics of solid and liquid targets under proton bombardment; predict the production of particles from these targets; accurately compute magnetic fields based on either a real magnet design or a model which includes end fields; and accurately design and simulate a beam line where the transported beam satisfies the above specifications and the beam line contains non-standard, overlapping elements. The requirements for computational tools will be discussed, the capabilities of existing tools will be described and …
Date: June 29, 2004
Creator: Berg, J. S.
System: The UNT Digital Library
Considerations for Efficient Airflow Design in Cleanrooms (open access)

Considerations for Efficient Airflow Design in Cleanrooms

A high-performance cleanroom should provide efficient energy performance in addition to effective contamination control. Energy-efficient designs can yield capital and operational cost savings, and can be part of a strategy to improve productivity in the cleanroom industry. Based upon in-situ measurement data from ISO Class 5 clean rooms, this article discusses key factors affecting cleanroom air system performance and benefits of efficient airflow design in clean rooms. Cleanroom HVAC systems used in the semiconductor, pharmaceutical, and healthcare industries are very energy intensive, requiring large volumes of cleaned air to remove or dilute contaminants for satisfactory operations. There is a tendency, however, to design excessive airflow rates into cleanroom HVAC systems, due to factors such as design conservatism, lack of thorough understanding of airflow requirements, concerns about cleanliness reliability, and potential design and operational liabilities. Energy use of cleanroom environmental systems varies with system type and design, cleanroom functions, and the control of critical parameters such as temperature and humidity. In particular, cleanroom cleanliness requirements specified by cleanliness class have an impact on overall energy use. A previous study covering Europe and the US reveals annual cleanroom electricity usage for cooling and fan energy varies significantly depending on cleanliness class, and …
Date: July 29, 2004
Creator: Xu, Tengfang
System: The UNT Digital Library
Coupled Vadose Zone and Atmospheric Surface-Layer Transport of CO2 from Geologic Carbon Sequestration Sites (open access)

Coupled Vadose Zone and Atmospheric Surface-Layer Transport of CO2 from Geologic Carbon Sequestration Sites

Geologic carbon dioxide (CO{sub 2}) sequestration is being considered as a way to offset fossil-fuel-related CO{sub 2} emissions to reduce the rate of increase of atmospheric CO{sub 2} concentrations. The accumulation of vast quantities of injected carbon dioxide (CO{sub 2}) in geologic sequestration sites may entail health and environmental risks from potential leakage and seepage of CO{sub 2} into the near-surface environment. We are developing and applying a coupled subsurface and atmospheric surface-layer modeling capability built within the framework of the integral finite difference reservoir simulator TOUGH2. The overall purpose of modeling studies is to predict CO{sub 2} concentration distributions under a variety of seepage scenarios and geologic, hydrologic, and atmospheric conditions. These concentration distributions will provide the basis for determining above-ground and near-surface instrumentation needs for carbon sequestration monitoring and verification, as well as for assessing health, safety, and environmental risks. A key feature of CO{sub 2} is its large density ({rho} = 1.8 kg m{sup -3}) relative to air ({rho} = 1.2 kg m{sup -3}), a property that may allow small leaks to cause concentrations in air above the occupational exposure limit of 4 percent in low-lying and enclosed areas such as valleys and basements where dilution rates …
Date: March 29, 2004
Creator: Oldenburg, Curtis M. & Unger, Andre J. A.
System: The UNT Digital Library
Design and Implementation of the Control System for a 2 kHz Rotary Fast Tool Servo (open access)

Design and Implementation of the Control System for a 2 kHz Rotary Fast Tool Servo

This paper presents a summary of the performance of our 2 kHz rotary fast tool servo and an overview of its control systems. We also discuss the loop shaping techniques used to design the power amplifier current control loop and the implementation of that controller in an op-amp circuit. The design and development of the control system involved a long list of items including: current compensation; tool position compensation; notch filter design and phase stabilizing with an additional pole for a plant with an undamped resonance; adding viscous damping to the fast tool servo; voltage budget for driving real and reactive loads; dealing with unwanted oscillators; ground loops; digital-to-analog converter glitches; electrical noise from the spindle motor switching power supply; and filtering the spindle encoder signal to generate smooth tool tip trajectories. Eventually, all of these topics will be discussed in detail in a Ph.D. thesis that will include this work. For the purposes of this paper, rather than present a diluted discussion that attempts to touch on all of these topics, we will focus on the first item with sufficient detail for providing insight into the design process.
Date: March 29, 2004
Creator: Montesanti, R C & Trumper, D L
System: The UNT Digital Library
Design of a Multi-Channel Ultra-High Resolution Superconducting Gamma-Ray Spectrometer (open access)

Design of a Multi-Channel Ultra-High Resolution Superconducting Gamma-Ray Spectrometer

Superconducting Gamma-ray microcalorimeters operated at temperatures around {approx}0.1 K offer an order of magnitude improvement in energy resolution over conventional high-purity Germanium spectrometers. The calorimeters consist of a {approx}1 mm{sup 3} superconducting or insulating absorber and a sensitive thermistor, which are weakly coupled to a cold bath. Gamma-ray capture increases the absorber temperature in proportion to the Gamma-ray energy, this is measured by the thermistor, and both subsequently cool back down to the base temperature through the weak link. We are developing ultra-high-resolution Gamma-ray spectrometers based on Sn absorbers and superconducting Mo/Cu multilayer thermistors for nuclear non-proliferation applications. They have achieved an energy resolution between 60 and 90 eV for Gamma-rays up to 100 keV. We also build two-stage adiabatic demagnetization refrigerators for user-friendly detector operation at 0.1 K. We present recent results on the performance of single pixel Gamma-ray spectrometers, and discuss the design of a large detector array for increased sensitivity.
Date: November 29, 2004
Creator: Friedrich, S.; Terracol, S. F.; Miyazaki, T.; Drury, O. B.; Ali, Z. A.; Cunningham, M. F. et al.
System: The UNT Digital Library
Determining flow, recharge, and vadose zonedrainage in anunconfined aquifer from groundwater strontium isotope measurements, PascoBasin, WA (open access)

Determining flow, recharge, and vadose zonedrainage in anunconfined aquifer from groundwater strontium isotope measurements, PascoBasin, WA

Strontium isotope compositions (87Sr/86Sr) measured in groundwater samples from 273 wells in the Pasco Basin unconfined aquifer below the Hanford Site show large and systematic variations that provide constraints on groundwater recharge, weathering rates of the aquifer host rocks, communication between unconfined and deeper confined aquifers, and vadose zone-groundwater interaction. The impact of millions of cubic meters of wastewater discharged to the vadose zone (103-105 times higher than ambient drainage) shows up strikingly on maps of groundwater 87Sr/86Sr. Extensive access through the many groundwater monitoring wells at the site allows for an unprecedented opportunity to evaluate the strontium geochemistry of a major aquifer, hosted primarily in unconsolidated sediments, and relate it to both long term properties and recent disturbances. Groundwater 87Sr/86Sr increases systematically from 0.707 to 0.712 from west to east across the Hanford Site, in the general direction of groundwater flow, as a result of addition of Sr from the weathering of aquifer sediments and from diffuse drainage through the vadose zone. The lower 87Sr/86Sr groundwater reflects recharge waters that have acquired Sr from Columbia River Basalts. Based on a steady-state model of Sr reactive transport and drainage, there is an average natural drainage flux of 0-1.4 mm/yr near …
Date: June 29, 2004
Creator: Singleton, Michael J.; Maher, Katharine; DePaulo, Donald J.; Conrad, Mark E. & Dresel, P. Evan
System: The UNT Digital Library
Direct Experimental Evidence of Back-Surface Acceleration from Laser-Irradiated Foils (open access)

Direct Experimental Evidence of Back-Surface Acceleration from Laser-Irradiated Foils

Au foils were irradiated with a 100-TW, 100-fs laser at intensities greater than 10{sup 20} W/cm{sup 2} producing proton beams with a total yield of {approx} 10{sup 11} and maximum proton energy of > 9 MeV. Removing contamination from the back surface of Au foils with an Ar-ion sputter gun reduced the total yield of accelerated protons to less than 1% of the yield observed without removing contamination. Removing contamination the front surface (laser-interaction side) of the target had no observable effect on the proton beam. We present a one-dimensional particle-in-cell simulation that models the experiment. Both experimental and simulation results are consistent with the back-surface acceleration mechanism described in the text.
Date: March 29, 2004
Creator: Allen, Matthew; Patel, Pravesh K.; Mackinnon, Andrew; Price, Dwight; Wilks, Scott & Morse, Edward
System: The UNT Digital Library
Draft versus finished sequence data for DNA and protein diagnostic signature development (open access)

Draft versus finished sequence data for DNA and protein diagnostic signature development

Sequencing pathogen genomes is costly, demanding careful allocation of limited sequencing resources. We built a computational Sequencing Analysis Pipeline (SAP) to guide decisions regarding the amount of genomic sequencing necessary to develop high-quality diagnostic DNA and protein signatures. SAP uses simulations to estimate the number of target genomes and close phylogenetic relatives (near neighbors, or NNs) to sequence. We use SAP to assess whether draft data is sufficient or finished sequencing is required using Marburg and variola virus sequences. Simulations indicate that intermediate to high quality draft with error rates of 10{sup -3}-10{sup -5} ({approx} 8x coverage) of target organisms is suitable for DNA signature prediction. Low quality draft with error rates of {approx} 1% (3x to 6x coverage) of target isolates is inadequate for DNA signature prediction, although low quality draft of NNs is sufficient, as long as the target genomes are of high quality. For protein signature prediction, sequencing errors in target genomes substantially reduce the detection of amino acid sequence conservation, even if the draft is of high quality. In summary, high quality draft of target and low quality draft of NNs appears to be a cost-effective investment for DNA signature prediction, but may lead to underestimation …
Date: October 29, 2004
Creator: Gardner, S N; Lam, M W; Smith, J R; Torres, C L & Slezak, T R
System: The UNT Digital Library
Elastic Face, An Anatomy-Based Biometrics Beyond Visible Cue (open access)

Elastic Face, An Anatomy-Based Biometrics Beyond Visible Cue

This paper describes a face recognition method that is designed based on the consideration of anatomical and biomechanical characteristics of facial tissues. Elastic strain pattern inferred from face expression can reveal an individual's biometric signature associated with the underlying anatomical structure, and thus has the potential for face recognition. A method based on the continuum mechanics in finite element formulation is employed to compute the strain pattern. Experiments show very promising results. The proposed method is quite different from other face recognition methods and both its advantages and limitations, as well as future research for improvement are discussed.
Date: March 29, 2004
Creator: Tsap, L V; Zhang, Y; Kundu, S J; Goldgof, D B & Sarkar, S
System: The UNT Digital Library
Experimental Demonstration of Wavelength Tuning in High-Gain Harmonic Generation Free Electron Laser. (open access)

Experimental Demonstration of Wavelength Tuning in High-Gain Harmonic Generation Free Electron Laser.

Tunability is one of the key aspects of any laser system. In High-Gain Harmonic Generation Free Electron Laser (HGHG FEL) the seed laser determines the output wavelength. Conventional scheme of tunable HGHG FEL requires tunable seed laser. The alternative scheme [1] is based on compression of the electron bunch with energy-time correlation (chirped bunch) in the FEL dispersive section. The chirped energy modulation, induced by the seed laser with constant wavelength, compressed as the whole bunch undergoes compression. In this paper we discuss experimental verification of the proposed approach at the DUV FEL [2,3] and compare experimental results with analytical estimates.
Date: August 29, 2004
Creator: Shaftan, T.; Johnson, E.; Krinsky, S.; Loos, H.; Murphy, J. B.; Rakowsky, G. et al.
System: The UNT Digital Library
Field-Scale Migration of 99Tc and 129I at the Nevada Test Site (open access)

Field-Scale Migration of 99Tc and 129I at the Nevada Test Site

The groundwater at the Nevada Test Site (NTS) contains many long-lived radionuclides, including {sup 99}Tc (technetium) and {sup 129}I (iodine), as a result of 828 underground nuclear weapons tests conducted between 1951 and 1992. We synthesized a body of data collected on the distribution of {sup 99}Tc and {sup 129}I in groundwater to assess their migration at NTS, at field scales over distances of hundreds of meters and for durations up to forty years and under hydrogeologic conditions very similar to the proposed geological repository at Yucca Mountain. The results of our study show that Tc does not necessarily exist as a mobile and conservative species TcO{sub 4}{sup -}, as has been commonly assumed. This conclusion is corroborated by recent in situ redox potential measurements, which show that groundwaters at multiple locations of the NTS are not oxidizing, and mobility of reduced Tc species (TcO{sub 2} {center_dot} nH{sub 2}O) is greatly decreased. Speciation of iodine and its associated reactivity is also complex in the groundwater at the NTS, and its effect on the mobility of iodine should be the subject of future studies.
Date: March 29, 2004
Creator: Hu, Q & Smith, D K
System: The UNT Digital Library
Flavor violation in warped extra dimensions and CP Asymmetries in B decays (open access)

Flavor violation in warped extra dimensions and CP Asymmetries in B decays

We show that CP asymmetries in b {yields} s hadronic decays are potentially affected by the presence of massive color-octet particles strongly coupled to the third generation quarks. Theories with warped extra dimensions provide natural candidates in the Kaluza-Klein excitations of gluons in scenarios where flavor-breaking by bulk fermion masses results in the localization of fermion wave-functions. Topcolor models, in which a new gauge interaction leads to top-condensation and a large top mass, also result in the presence of these color-octet states with TeV masses. We find that large effects are possible in modes such as B {yields} {phi}K{sub s}, B {yields} {eta}{prime}K{sub s} and B {yields} {pi}{sup 0}K{sub s} among others.
Date: April 29, 2004
Creator: Burdman, Gustavo
System: The UNT Digital Library