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Composite weak bosons

Description: Dynamical mechanism of composite W and Z is studied in a 1/N field theory model with four-fermion interactions in which global weak SU(2) symmetry is broken explicitly by electromagnetic interaction. Issues involved in such a model are discussed in detail. Deviation from gauge coupling due to compositeness and higher order loop corrections are examined to show that this class of models are consistent not only theoretically but also experimentally.
Date: April 1, 1988
Creator: Suzuki, M.
Partner: UNT Libraries Government Documents Department

Composite weak bosons at supercolliders

Description: Following a brief survey of nongauge interactions of composite W and Z from a theoretical viewpoint, we point out some of conspicuous signatures of compositeness at supercolliders, in particular W..gamma.. and Z..gamma.. production through q anti q by interactions of dimension six. In these processes, a suppression factor 1/..lambda../sup 2/ due to compositeness scale ..lambda.. is largely compensated by longitudinal polarizations of W and Z, allowing us to probe up to high values of ..lambda... 10 refs., 3 figs.
Date: June 1, 1987
Creator: Suzuki, Mahiko
Partner: UNT Libraries Government Documents Department

New limit on the oscillation between nu/sub. mu. / and nu/sub e/

Description: Measurements have been made of the reactions nu/sub e/n ..-->.. e/sup -/p and nu/sub ..mu../n ..-->.. ..mu../sup -/p by wide band neutrino beam in a detector located an effective distance of 96m from a neutrino source. No evidence for the oscillation nu/sub ..mu../ ..-->.. nu/sub e/ is found.
Date: January 1, 1984
Creator: Suzuki, Y.
Partner: UNT Libraries Government Documents Department

Heavy quark jets

Description: The present understanding of heavy quark fragmentation is reviewed, and the expected behaviors of heavy quark jets is discussed. Included are short-distance versus long-distance parts of fragmentation, fragmentation dynamics at long distances, universal hadronization in rapidity plot, the heavy quark as a sizzling fireball, quantum chromodynamics ladder summation in the region of K/sub T/ < ..lambda.., and the relevance or irrelevance to super high energy experiment. 6 references. (JFP)
Date: November 12, 1979
Creator: Suzuki, M.
Partner: UNT Libraries Government Documents Department

Inelastic final-state interaction

Description: The final-state interaction in multichannel decay processes is systematically studied with application to B decay in mind. Since the final-state interaction is intrinsically interwoven with the decay interaction in this case, no simple phase theorem like&quot;Watson&#39;s theorem&quot; holds for experimentally observed final states. We first examine in detail the two-channel problem as a toy-model to clarify the issues and to remedy common mistakes made in earlier literature. Realistic multichannel problems are too challenging for quantitative analysis. To cope with mathematical complexity, we introduce a method of approximation that is applicable to the case where one prominent inelastic channel dominates over all others. We illustrate this approximation method in the amplitude of the decay B to pi K fed by the intermediate states of a charmed meson pair. Even with our approximation we need more accurate information of strong interactions than we have now. Nonetheless we are able to obtain some insight in the issue and draw useful conclusions on general features on the strong phases.
Date: October 29, 2007
Creator: Suzuki, Mahiko & Suzuki, Mahiko
Partner: UNT Libraries Government Documents Department

Approximate gauge symemtry of composite vector bosons

Description: It can be shown in a solvable field theory model that the couplings of the composite vector mesons made of a fermion pair approach the gauge couplings in the limit of strong binding. Although this phenomenon may appear accidental and special to the vector bosons made of a fermion pair, we extend it to the case of bosons being constituents and find that the same phenomenon occurs in more an intriguing way. The functional formalism not only facilitates computation but also provides us with a better insight into the generating mechanism of approximate gauge symmetry, in particular, how the strong binding and global current conservation conspire to generate such an approximate symmetry. Remarks are made on its possible relevance or irrelevance to electroweak and higher symmetries.
Date: June 1, 2010
Creator: Suzuki, Mahiko
Partner: UNT Libraries Government Documents Department

Study of reduced order model reference adaptive control systems for improved process control. Final report, May 1, 1982-January 31, 1986

Description: The objective of this research is to provide a method for design of control systems when the plant involved is highly variable in both structure and parameter values. This typifies many manufacturing processes, which in general are highly sensitive to intrinsic properties of the infeed material, have poorly understood or controlled boundary conditions, and often have highly non-linear characteristics. In addition, the disturbances most frequent in a manufacturing process are best characterized as parameter changes rather than state variable changes. The choice of a parameter adaptive control paradigm is obvious since it has the property of optimizing system response characteristics in the face of wide plant parameter variations. Model Reference Adaptive Systems (MRAS) enjoy an ease of performance specification, and again seem applicable; however, there is a restriction within current theory that the plant be characterized in its structure well enough to have a reference model of identical order. This restriction implies a static plant structure and more a priori information than is often present. During this contract the basic design characteristics of certain MRAS have been studied and problems with reduced order models identified, such as noise and input magnitude sensitivity and instability caused by high frequency learning signals. This has lead to certain solutions and resulting guidelines for design. This is then followed by design studies for a position servomechanism (which serves as the foundation of many automated manufacturing processes). This study expanded the domain from MRAS to self-tuning controllers (STC) and found that both can deal with reduced order models if the initial parameter values are not too distant from the actual values. However, the STC appears to be the more robust. 12 refs., 56 figs.
Date: February 1, 1986
Creator: Hardt, D.E.; Papadpoulos, E. & Suzuki, A.
Partner: UNT Libraries Government Documents Department

Long-term research in Japan: amorphous metals, metal oxide varistors, high-power semiconductors and superconducting generators

Description: The review revealed that significant activity is under way in the research of amorphous metals, but that little fundamental work is being pursued on metal oxide varistors and high-power semiconductors. Also, the investigation of long-term research program plans for superconducting generators reveals that activity is at a low level, pending the recommendations of a study currently being conducted through Japan's Central Electric Power Council.
Date: April 1, 1985
Creator: Hane, G.J.; Yorozu, M.; Sogabe, T. & Suzuki, S.
Partner: UNT Libraries Government Documents Department

The X(3872) boson: Molecule or charmonium

Description: It has been argued that the mystery boson X(3872) is a molecular state consisting of primarily D{sup 0}{bar D}*{sup 0} + {bar D}{sup 0}D*{sup 0}. In contrast, apparent puzzles and potential difficulties have been pointed out for the charmonium assignment of X(3872). They examine several aspects of these alternatives by semi-quantitative methods since quantitatively accurate results are often hard to reach on them. they point out that some of the observed properties of X(3872), in particular, the binding and the production rates are incompatible with the molecule interpretation. Despite puzzles and obstacles, X(3872) may fit more likely to the excited {sup 3}P{sub 1} charmonium than to the molecule after the mixing of c{bar c} with D{bar D}* + {bar D}D* is taken into account.
Date: August 1, 2005
Creator: Suzuki, Mahiko
Partner: UNT Libraries Government Documents Department

A Magnetic Diagnostic Code for 3D Fusion Equilibria

Description: A synthetic magnetic diagnostics code for fusion equilibria is presented. This code calculates the response of various magnetic diagnostics to the equilibria produced by the VMEC and PIES codes. This allows for treatment of equilibria with both good nested flux surfaces and those with stochastic regions. DIAGNO v2.0 builds upon previous codes through the implementation of a virtual casing principle. The code is validated against a vacuum shot on the Large Helical Device (LHD) where the vertical field was ramped. As an exercise of the code, the diagnostic response for various equilibria are calculated on the LHD.
Date: March 12, 2013
Creator: Lazerson, Samuel A.; Sakakibara, S. & Suzuki, Y.
Partner: UNT Libraries Government Documents Department

Elastic properties of Pu metal and Pu-Ga alloys

Description: We present elastic properties, theoretical and experimental, of Pu metal and Pu-Ga ({delta}) alloys together with ab initio equilibrium equation-of-state for these systems. For the theoretical treatment we employ density-functional theory in conjunction with spin-orbit coupling and orbital polarization for the metal and coherent-potential approximation for the alloys. Pu and Pu-Ga alloys are also investigated experimentally using resonant ultrasound spectroscopy. We show that orbital correlations become more important proceeding from {alpha} {yields} {beta} {yields} {gamma} plutonium, thus suggesting increasing f-electron correlation (localization). For the {delta}-Pu-Ga alloys we find a softening with larger Ga content, i.e., atomic volume, bulk modulus, and elastic constants, suggest a weakened chemical bonding with addition of Ga. Our measurements confirm qualitatively the theory but uncertainties remain when comparing the model with experiments.
Date: January 5, 2010
Creator: Soderlind, P; Landa, A; Klepeis, J E; Suzuki, Y & Migliori, A
Partner: UNT Libraries Government Documents Department

Two Strategies to Speed up Connected Component LabelingAlgorithms

Description: This paper presents two new strategies to speed up connectedcomponent labeling algorithms. The first strategy employs a decisiontreeto minimize the work performed in the scanning phase of connectedcomponent labeling algorithms. The second strategy uses a simplifiedunion-find data structure to represent the equivalence information amongthe labels. For 8-connected components in atwo-dimensional (2D) image,the first strategy reduces the number of neighboring pixels visited from4 to7/3 on average. In various tests, using a decision tree decreases thescanning time by a factor of about 2. The second strategy uses a compactrepresentation of the union-find data structure. This strategysignificantly speeds up the labeling algorithms. We prove analyticallythat a labeling algorithm with our simplified union-find structure hasthe same optimal theoretical time complexity as do the best labelingalgorithms. By extensive experimental measurements, we confirm theexpected performance characteristics of the new labeling algorithms anddemonstrate that they are faster than other optimal labelingalgorithms.
Date: November 13, 2005
Creator: Wu, Kesheng; Otoo, Ekow & Suzuki, Kenji
Partner: UNT Libraries Government Documents Department

Redox behavior below 1000K of Pt-impregnated CeO{sub 2}-ZrO{sub 2} solid solutions : an in-situ neutron diffraction study.

Description: The Ce{sup 3+} {leftrightarrow} Ce{sup 4+} redox process in automotive three-way catalysts such as Ce-ZrO{sub 2}/Pt provides an essential mechanism to oxygen storage/release under dynamic air-to-fuel ratio cycling. Such a function requires a metal-support interaction which is not completely understood. We have carried out an in-situ neutron powder diffraction study to monitor the crystal structures (a mixture of a major tetragonal and a minor monoclinic phase) of 10mol% Ce-doped ZrO{sub 2} with and without Pt (1wt%) impregnation under oxidizing and reducing conditions over the temperature range of 25--7000 C. The samples were heated first in flowing 2%O{sub 2}/Ar from room temperature to 400 C and then in 1%CO/Ar to about 700 C. A discontinued increase of the tetragonal unit-cell volume, a decrease of tetragonality (c/a), and a change of color from light yellow to gray when changing from oxidizing to reducing atmosphere were observed only in the sample containing Pt. This result supports the model which assumes the formation of oxygen vacancies initially near the Pt atoms. As more Ce ions are reduced from 4+ to 3+ oxidation states at high temperatures, oxygen vacancies migrate to the bulk of the oxide particles.
Date: January 12, 1998
Creator: Loong, C.-K.; Short, S. M.; Ozawa, M. & Suzuki, S.
Partner: UNT Libraries Government Documents Department

Dynamic response of physisorbed hydrogen molecules on lanthanide-modified zirconia nanoparticles

Description: Ultrafine lanthanide (Ln = Ce and Nd)-modified zirconia powders synthesized by a coprecipitation method exhibit high surface areas and adsorption sites that are essential for catalytic applications. We report a study of the surface chemistry of Ce{sub 0.1}Zr{sub 0.9}O{sub 2} and Nd{sub 0.1}Zr{sub 0.9}O{sub 1.95} powders. First, the specific surface area and porosity are characterized by nitrogen isotherm-adsorption measurements. Second, the motion of hydrogen molecules physisorbed on Ce- and Nd-doped zirconias is studied by inelastic neutron scattering. Nitrogen adsorption-desorption isotherm measurements yield a BET surface area (26.1 m{sup 2}/g) and mesopore size ({approximately}5 nm radius) in Ce{sub 0.1}Zr{sub 0.9}O{sub 2} as compared to those (72.3 m{sup 2}/g and {approximately}3 nm) in Nd{sub 0.1}Zr{sub 0.9} O{sub 1.95}. The vibrational densities of states of H{sub 2} on Ce{sub 0.1}Zr{sub 0.9}O{sub 2} and Nd{sub 0.1}Zr{sub 0.9}O{sub 1.95} were measured at 20 K over the 0-200 meV energy range for three hydrogen coverage. The spectra for both samples consist of two parts: a sharp peak at {approximately}14.5 meV and a broad component extending beyond 200 meV. The sharp peak corresponds to transitions from the J=0 to J=1 rotational states of bulk hydrogen molecules, and its intensity decreases with decreasing H{sub 2} coverage. The broad component corresponds to overdamped motion of surface adsorbed hydrogen molecules. The major difference in the latter component between the Ce- and Nd-doped samples is an excess of intensities in the 5-14 meV region in Nd{sub 0.1}Zr{sub 0.9}O{sub 1.95}. The confined motion of adsorbed H{sub 2} on the different micropore and mesopore surfaces of Ce{sub 0.1}Zr{sub 0.9}O{sub 2} and Nd{sub 0.1}Zr{sub 0.9}O{sub 1.95} is discussed.
Date: October 1, 1997
Creator: Loong, C.K.; Trouw, F.; Ozawa, Masakuni & Suzuki, Suguru
Partner: UNT Libraries Government Documents Department

A laser spectroscopic study of Nd-doped Zirconia

Description: High-surface-area rare-earth (RE) modified zirconia powders prepared by solution methods can be used as catalytic support of noble metals and as electrolyte oxygen sensors in automobile exhaust-emission- control systems. Previous neutron-scattering study showed that substituting Zr with trivalent RE ions not only stabilizes the cubic and tetrgonal phases over a wide range of temperatures but also creates oxygen vacancies in the RE-Zr oxide solid solution. This work focuses on Nd fluorescence in Nd{sub 0.1}Zr{sub 0.9}O{sub 1.95} powders under laser excitation of the Nd{sup 3+} ground state to the {sup 4}G{sub 7.2} states. Distinct features were found at 8K in the {sup 4}I{sub 9/2}{r_arrow}{sup 4}G{sub 7/2} excitation and {sup 4}F{sub 3.2}{r_arrow}{sup 4}I{sub 9/2} emission spectra using two sets of incident and emission frequencies, respectively. Results are discussed in terms of site-sensitive local structures surrounding the Nd ions in the two-phased oxide structure.
Date: June 1, 1996
Creator: Loong, C.-K.; Liu, G.K.; Ozawa, M. & Suzuki, S.
Partner: UNT Libraries Government Documents Department

Crystal phases and lattice dynamics of slip-cast {beta}{prime}-sialons

Description: The crystal structures and phonon densities of states (DOS) of {beta}{prime}-Sialon ceramics, Si{sub 6-z}Al{sub z}O{sub z}N{sub 8-z} (O {le} z {le} 6), prepared by a novel slip-cast method were studied by neutron scattering techniques. A Rietveld analysis of the diffraction patterns shows that samples of z < 4 form a single-phase solid solution of Si-Al-O-N isostructural to {beta}-Si{sub 3}N{sub 4} (space group P6{sub 3}/m). Within this structure there is a consistent preferred occupation of O on the 2c sites and N on the 6h sites. For z > 4 the materials exhibit multiple-phase structure. The observed phonon DOS of the O {le} z {le} 4 ceramics displays phonon bands at about 50 and 115 meV. These features are considerably broader than the corresponding ones in {beta}-Si{sub 3}N{sub 4} powder. As z increases, effects due to atomic disorder lead to an overlap of the two phonon bands and a complete fill up of the phonon gap at {approximately} 100 meV observed in Si{sub 3}N{sub 4}.
Date: December 31, 1995
Creator: Loong, C.K.; Richardson, J.W. Jr.; Suzuki, S. & Ozawa, M.
Partner: UNT Libraries Government Documents Department

Enhanced seed production under prolonged heat stress conditions in Arabidopsis thaliana plants deficient in cytosolic ascorbate peroxidase 2

Description: Article discussing enhanced seed production under prolonged heat stress conditions in Arabidopsis thaliana plants deficient in cytosolic ascorbate peroxidase 2.
Date: November 26, 2012
Creator: Suzuki, Nobuhiro; Miller, Gad; Sejima, Hiroe; Harper, Jeffrey F. & Mittler, Ron
Partner: UNT College of Arts and Sciences

Gender differences in college choice, aspirations, and self-concept among community college students in science, mathematics, and engineering.

Description: Educational researchers, practitioners, and policy makers have long expressed their concern that gender disparity of academic performance and participation in science and mathematics education continues to increase with educational progress of students through the pipeline. Educational and occupational aspirations, high school experience, external support from family members and significant others appear to be influential factors that develop strong self-concept among female students who aspire to study science and mathematics. Using a national sample of aspirants in science, mathematics, and engineering majors in public community colleges, that participated in the 1996 Cooperative Institutional Research Program American Freshman Survey, this study investigated the influences of students' pre-college experiences on their college choice, aspirations, and self-concept by examining three theoretical structural models. In addition, gender differences were tested by using multiple group analysis. The findings from the multiple group analysis revealed that there was no statistically significant gender difference in predicting college choice, aspirations, and self-concept. The results from the descriptive analysis indicated that the female students were already underrepresented in science, mathematics, and engineering majors. Taken together, the findings challenge researchers, practitioners, and policy makers to examine why the persistent fall off, and how can community colleges support and retain these students who already enrolled. The results from the model fit analysis revealed that the encouragement from family and others played as a contributing factor in predicting students' college choice, aspirations, and self-concept. This study confirmed that the development of self-concept among community college students in science, mathematics, and engineering is complex and unique. Several recommendations that are pertaining to policy implications, improvement of practice, and future research to increase the representations of female students in science, mathematics, and engineering in the post-secondary education were developed from the findings of this study. The results of this study contribute to the research literature ...
Access: This item is restricted to the UNT Community Members at a UNT Libraries Location.
Date: August 2004
Creator: Starobin, Soko Suzuki
Partner: UNT Libraries