Access

Resource Type

Partner

Collection

Serial/Series Title

Degree Department

Degree Discipline

Degree Level

Country

States

Counties

Year

Month

Day

Language

2,916 Matching Results

Start Over Year 2007 Month May

Results open in a new window/tab.

Results: 1 - 24 of 2,916 next

(open access)

Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96-TeV using kinematic characteristics of lepton + jets events

We present a measurement of the top quark pair production cross section in p{bar p} collisions at {radical}s = 1.96 TeV utilizing 425 pb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair containing one high-p{sub T} electron or muon and at least four jets. We exploit specific kinematic features of t{bar t} events to extract the cross section. For a top quark mass of 175 GeV, we measure {sigma}{sub t{bar t}} = 6.4{sub -1.2}{sup +1.3}(stat) {+-} 0.7(syst) {+-} 0.4(lum)pb, in good agreement with the standard model prediction.

Date: May 1, 2007

Creator: Abazov, V.

Object Type: Article

System: The UNT Digital Library

(open access)

Observation and Properties of L = 1 B(1) and B*(2) Mesons

None

Date: May 1, 2007

Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.

Object Type: Article

System: The UNT Digital Library

(open access)

Search for stopped gluinos from p-anti-p collisions at s**(1/2) = 1.96-TeV

Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles' decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino ({tilde g}), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410 pb{sup -1} of p{bar p} collisions at sqrt(s)=1.96 TeV collected with the D0 detector during Run II of the Fermilab Tevatron collider are analyzed in search of such 'stopped gluinos' decaying into a gluon and a neutralino ({tilde {chi}}{sub 1}{sup 0}). Limits are placed on the (gluino cross section)x(probability to stop)x[BR({tilde g}{yields}g {tilde {chi}}{sub 1}{sup 0<})] as a function of the gluino and {tilde {chi}}{sub 1}{sup 0<} masses, for gluino lifetimes from 30 {micro}s-100 h.

Date: May 1, 2007

Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.

Object Type: Article

System: The UNT Digital Library

(open access)

Z gamma production and limits on anomalous Z Z gamma and Z gamma gamma couplings in panti-p collisions at s**(1/2) = 1.96- TeV

None

Date: May 1, 2007

Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.

Object Type: Article

System: The UNT Digital Library

(open access)

Abilene Philharmonic Playbill: May 5, 2007

Program for an Abilene Philharmonic concert that ran on May 5th (Pop III) during the 57th season. It includes information about the pieces performed, artists and musicians, and advertising from local companies.

Date: May 2007

Creator: Abilene Philharmonic

Object Type: Pamphlet

System: The Portal to Texas History

(open access)

First observation of K(L) ---> pi+- e-+ nu e+ e-

None

Date: May 1, 2007

Creator: Abouzaid, E.; Arenton, M.; Barker, A. R.; Bellantoni, L.; Blucher, E.; Bock, G. J. et al.

Object Type: Article

System: The UNT Digital Library

(open access)

Applying Agile Methods to Weapon/Weapon-Related Software

This white paper provides information and guidance to the Department of Energy (DOE) sites on Agile software development methods and the impact of their application on weapon/weapon-related software development. The purpose of this white paper is to provide an overview of Agile methods, examine the accepted interpretations/uses/practices of these methodologies, and discuss the applicability of Agile methods with respect to Nuclear Weapons Complex (NWC) Technical Business Practices (TBPs). It also provides recommendations on the application of Agile methods to the development of weapon/weapon-related software.

Date: May 2, 2007

Creator: Adams, Dennis; Armendariz, Maria; Blackledge, Mike; Campbell, Frank; Cloninger, Mack; Cox, Larry et al.

Object Type: Report

System: The UNT Digital Library

(open access)

MOBILE SYSTEMS FOR DILUTION OF HIGHLY ENRICHED URANIUM AND URANIUM CONTAINING COMPONENTS

A mobile melt-dilute (MMD) module for the treatment of aluminum research reactor spent fuel is being developed. The process utilizes a closed system approach to retain fission products/gases inside a sealed canister after treatment. The MMD process melts and dilutes spent fuel with depleted uranium to obtain a fissile fraction of less than 0.2. The final ingot is solidified inside the sealed canister and can be stored safely either wet or dry until final disposition or reprocessing. The MMD module can be staged at or near the research reactor fuel storage sites to facilitate the melt-dilute treatment of the spent fuel into a stable non-proliferable form.

Date: May 2, 2007

Creator: Adams, T

Object Type: Article

System: The UNT Digital Library

(open access)

Searches for new phenomena with lepton final states at the Tevatron

Numerous searches for new phenomena have been carried out using data from proton-antiproton collisions at Fermilab's Tevatron. Final states with leptons give signatures which are relatively unique and generally have small backgrounds. We present many of the latest results from the CDF and D0 collaborations from 0.4-1.2 fb{sup -1} of data. Topics include supersymmetry, extra gauge bosons, Randall-Sundrum gravitons, excited electrons and neutral, long-lived particles.

Date: May 1, 2007

Creator: Adams, T.

Object Type: Article

System: The UNT Digital Library

(open access)

Verification Survey of the Building 315 Zero Power Reactor-6 Facility, Argonne National Laboratory-East, Argonne, Illinois

Oak Ridge Institute for Science and Education (ORISE) conducted independent verification radiological survey activities at Argonne National Laboratory’s Building 315, Zero Power Reactor-6 facility in Argonne, Illinois. Independent verification survey activities included document and data reviews, alpha plus beta and gamma surface scans, alpha and beta surface activity measurements, and instrumentation comparisons. An interim letter report and a draft report, documenting the verification survey findings, were submitted to the DOE on November 8, 2006 and February 22, 2007, respectively (ORISE 2006b and 2007).

Date: May 25, 2007

Creator: Adams, W. C.

Object Type: Report

System: The UNT Digital Library

(open access)

Measurement of the atmospheric muon charge ratio at TeV energies with MINOS

The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 m.w.e. in the Soudan Underground Laboratory, Minnesota, USA. The data with both forward and reversed magnetic field running configurations were combined to minimize systematic errors in the determination of the underground muon charge ratio. When averaged, two independent analyses find the charge ratio underground to be N{sub {mu}}+/N{sub {mu}}-=1.374{+-}0.004(stat)-0.010{sup +0.012}(sys). Using the map of the Soudan rock overburden, the muon momenta as measured underground were projected to the corresponding values at the surface in the energy range 1-7 TeV. Within this range of energies at the surface, the MINOS data are consistent with the charge ratio being energy independent at the 2 standard deviation level. When the MINOS results are compared with measurements at lower energies, a clear rise in the charge ratio in the energy range 0.3-1.0 TeV is apparent. A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio.

Date: May 1, 2007

Creator: Adamson, P.; Andreopoulos, C.; Arms, K.E.; Armstrong, R.; Auty, D.J.; Avvakumov, S. et al.

Object Type: Article

System: The UNT Digital Library

Biomass and Biofuels: Technology and Economic Overview

Presentation on biomass and biofuels technology and economics presented at Pacific Northwest National Laboratory, May 23, 2007.

Date: May 23, 2007

Creator: Aden, Andy

Object Type: Presentation

System: The UNT Digital Library

(open access)

Topological Strings And (Almost) Modular Forms

The B-model topological string theory on a Calabi-Yau threefold X has a symmetry group {Lambda}, generated by monodromies of the periods of X. This acts on the topological string wave function in a natural way, governed by the quantum mechanics of the phase space H{sup 3}(X). We show that, depending on the choice of polarization, the genus g topological string amplitude is either a holomorphic quasi-modular form or an almost holomorphic modular form of weight 0 under {Lambda}. Moreover, at each genus, certain combinations of genus g amplitudes are both modular and holomorphic. We illustrate this for the local Calabi-Yau manifolds giving rise to Seiberg-Witten gauge theories in four dimensions and local IP{sub 2} and IP{sub 1} x IP{sub 1}. As a byproduct, we also obtain a simple way of relating the topological string amplitudes near different points in the moduli space, which we use to give predictions for Gromov-Witten invariants of the orbifold C{sub 3}/ZZ{sub 3}.

Date: May 4, 2007

Creator: Aganagic, Mina; Bouchard, Vincent & Klemm, Albrecht

Object Type: Article

System: The UNT Digital Library

(open access)

U.S.-European Union Relations and the 2007 Summit

This report evaluates the results of the annual U.S.-EU summit on April 30, 2007, in Washington, DC.

Date: May 14, 2007

Creator: Ahearn, Raymond; Archick, Kristin & Belkin, Paul

Object Type: Report

System: The UNT Digital Library

(open access)

Structural and Magnetothermal Properties of Compounds: Yb5SixGe4-x,Sm5SixGe4-x, EuO, and Eu3O4

The family of R{sub 5}Si{sub x}Ge{sub 4-x} alloys demonstrates a variety of unique physical phenomena related to magneto-structural transitions associated with reversible breaking and reforming of specific bonds that can be controlled by numerous external parameters such as chemical composition, magnetic field, temperature, and pressure. Therefore, R{sub 5}Si{sub x}Ge{sub 4-x} systems have been extensively studied to uncover the mechanism of the extraordinary magneto-responsive properties including the giant magnetoresistance (GMR) and colossal magnetostriction, as well as giant magnetocaloric effect (GMCE). Until now, more than a half of possible R{sub 5}Si{sub x}Ge{sub 4-x} pseudobinary systems have been completely or partially investigated with respect to their crystallography and phase relationships (R = La, Pr, Nd, Gd, Tb, Dy, Er, Lu, Y). Still, there are other R{sub 5}Si{sub x}Ge{sub 4-x} systems (R = Ce, Sm, Ho, Tm, and Yb) that are not studied yet. Here, we report on phase relationships and structural, magnetic, and thermodynamic properties in the Yb{sub 5}Si{sub x}Ge{sub 4-x} and Sm{sub 5}Si{sub x}Ge{sub 4-x} pseudobinary systems, which may exhibit mixed valence states. The crystallography, phase relationships, and physical properties of Yb{sub 5}Si{sub x}Ge{sub 4-x} alloys with 0 {le} x {le} 4 have been examined by using single crystal and powder x-ray …

Date: May 9, 2007

Creator: Ahn, Kyunghan

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

An Analysis of the Characteristics of Female Juvenile Offenders as Predictors of Resocialization or Recidivism.

Because there has been a paucity of research on the educational needs of females with academic, behavioral, and emotional problems involved with the juvenile justice system, this study has been an attempt to classify and compare specific characteristics of this population. In particular, it examined their demographics, disability prevalence rates, along with academic, behavioral, and emotional functioning levels, in order to further understand their relationship to the resocialization or recidivism of the different groups of female juveniles incarcerated in the state of Texas, and contribute to the research for further developing successful prevention and intervention programs. Various demographic factors of the female juveniles in this study were examined: (a) offender type, (b) county of commitment, (c) race/ethnicity, (d) age at first referral, and (e) English language proficiency. Prevalence rates of special education disabilities were determined. Academic functioning was measured by (a) IQ; (b) last school grade completed; (c) Test of Adult Basic Education (TABE) reading gain score; and (d) TABE math gain score. Behavioral functioning was indicated through (a) offense history, (b) documented behavior incidents, and (c) total risk score. Emotional functioning included DSM-IV diagnoses and treatment needs. Due to the design of the research being a descriptive exploration, the …

Date: May 2007

Creator: Aiello, Jan Elizabeth

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Supersymmetry in Particle Physics - An Elementary Introduction

None

Date: May 11, 2007

Creator: Aitchison, I.J.R. & /Oxford U., Theor. Phys. /SLAC

Object Type: Report

System: The UNT Digital Library

(open access)

Global Cooling: Effect of Urban Albedo on Global Temperature

In many urban areas, pavements and roofs constitute over 60% of urban surfaces (roof 20-25%, pavements about 40%). The roof and the pavement albedo can be increased by about 0.25 and 0.10, respectively, resulting in a net albedo increase for urban areas of about 0.1. Many studies have demonstrated building cooling-energy savings in excess of 20% upon raising roof reflectivity from an existing 10-20% to about 60%. We estimate U.S. potential savings in excess of $1 billion (B) per year in net annual energy bills. Increasing albedo of urban surfaces can reduce the summertime urban temperature and improve the urban air quality. Increasing the urban albedo has the added benefit of reflecting more of the incoming global solar radiation and countering the effect of global warming. We estimate that increasing albedo of urban areas by 0.1 results in an increase of 3 x 10{sup -4} in Earth albedo. Using a simple global model, the change in air temperature in lowest 1.8 km of the atmosphere is estimated at 0.01K. Modelers predict a warming of about 3K in the next 60 years (0.05K/year). Change of 0.1 in urban albedo will result in 0.01K global cooling, a delay of {approx}0.2 years in …

Date: May 22, 2007

Creator: Akbari, Hashem; Menon, Surabi & Rosenfeld, Arthur

Object Type: Article

System: The UNT Digital Library

(open access)

Laser heating of solid matter by light pressure-driven shocks

Heating by irradiation of a solid surface in vacuum with 5 x 10{sup 20} W cm{sup -2}, 0.8 ps, 1.05 {micro}m wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo and V. A surface layer is heated to {approx} 5 keV with an axial temperature gradient of 0.6 {micro}m scale length. Images of Ni Ly{sub {alpha}} show the hot region has a {approx} 25 {micro}m diameter, much smaller than {approx} 70 {micro}m region of K{sub {alpha}} emission. 2D particle-in-cell (PIC) simulations suggest that the surface heating is due to a light pressure driven shock.

Date: May 4, 2007

Creator: Akli, K.; Hansen, S. B.; Kemp, A. J.; Freeman, R. R.; Beg, F. N.; Clark, D. et al.

Object Type: Article

System: The UNT Digital Library