The Sloan Digital Sky Survey-II: Photometry and Supernova Ia Light Curves from the 2005 Data (open access)

The Sloan Digital Sky Survey-II: Photometry and Supernova Ia Light Curves from the 2005 Data

We present ugriz light curves for 146 spectroscopically confirmed or spectroscopically probable Type Ia supernovae from the 2005 season of the SDSS-II Supernova survey. The light curves have been constructed using a photometric technique that we call scene modeling, which is described in detail here; the major feature is that supernova brightnesses are extracted from a stack of images without spatial resampling or convolution of the image data. This procedure produces accurate photometry along with accurate estimates of the statistical uncertainty, and can be used to derive photometry taken with multiple telescopes. We discuss various tests of this technique that demonstrate its capabilities. We also describe the methodology used for the calibration of the photometry, and present calibrated magnitudes and fluxes for all of the spectroscopic SNe Ia from the 2005 season.
Date: August 26, 2010
Creator: Holtzman, Jon A.; Marriner, John; Kessler, Richard; Sako, Masao; Dilday, Ben; Frieman, Joshua A. et al.
Object Type: Article
System: The UNT Digital Library
A Distance Measure Comparison to Improve Crowding in Multi-Modal Problems. (open access)

A Distance Measure Comparison to Improve Crowding in Multi-Modal Problems.

Solving multi-modal optimization problems are of interest to researchers solving real world problems in areas such as control systems and power engineering tasks. Extensions of simple Genetic Algorithms, particularly types of crowding, have been developed to help solve these types of problems. This paper examines the performance of two distance measures, Mahalanobis and Euclidean, exercised in the processing of two different crowding type implementations against five minimization functions. Within the context of the experiments, empirical evidence shows that the statistical based Mahalanobis distance measure when used in Deterministic Crowding produces equivalent results to a Euclidean measure. In the case of Restricted Tournament selection, use of Mahalanobis found on average 40% more of the global optimum, maintained a 35% higher peak count and produced an average final best fitness value that is 3 times better.
Date: August 1, 2010
Creator: Vollmer, D. Todd; Soule, Terence & Manic, Milos
Object Type: Article
System: The UNT Digital Library
Microwave Processing of Simulated Advanced Nuclear Fuel Pellets (open access)

Microwave Processing of Simulated Advanced Nuclear Fuel Pellets

Throughout the three-year project funded by the Department of Energy (DOE) and lead by Virginia Tech (VT), project tasks were modified by consensus to fit the changing needs of the DOE with respect to developing new inert matrix fuel processing techniques. The focus throughout the project was on the use of microwave energy to sinter fully stabilized zirconia pellets using microwave energy and to evaluate the effectiveness of techniques that were developed. Additionally, the research team was to propose fundamental concepts as to processing radioactive fuels based on the effectiveness of the microwave process in sintering the simulated matrix material.
Date: August 29, 2010
Creator: Clark, D. E. & Folz, D. C.
Object Type: Report
System: The UNT Digital Library
Fission prompt gamma-ray multiplicity distribution measurements and simulations at DANCE (open access)

Fission prompt gamma-ray multiplicity distribution measurements and simulations at DANCE

The nearly energy independence of the DANCE efficiency and multiplicity response to {gamma} rays makes it possible to measure the prompt {gamma}-ray multiplicity distribution in fission. We demonstrate this unique capability of DANCE through the comparison of {gamma}-ray energy and multiplicity distribution between the measurement and numerical simulation for three radioactive sources {sup 22}Na, {sup 60}Co, and {sup 88}Y. The prospect for measuring the {gamma}-ray multiplicity distribution for both spontaneous and neutron-induced fission is discussed.
Date: August 24, 2010
Creator: Chyzh, A.; Wu, C. Y.; Ullmann, J.; Jandel, M.; Bredeweg, T.; Couture, A. et al.
Object Type: Report
System: The UNT Digital Library
Experimental Study of Current-Driven Turbulence During Magnetic Reconnection (open access)

Experimental Study of Current-Driven Turbulence During Magnetic Reconnection

CMPD Final Report Experimental Study of Current-Driven Turbulence During Magnetic Reconnection Miklos Porkolab, PI, Jan Egedal, co-PI, William Fox, graduate student. This is the final report for Grant DE-FC02-04ER54786, “MIT Participation in the Center for Multiscale Plasma Dynamics,” which was active from 8/1/2004 to 7/31/2010. This Grant supported the thesis work of one MIT graduate student, William Fox, The thesis research consisted of an experimental study of the fluctuations arising during magnetic reconnection in plasmas on the Versatile Toroidal Facility (VTF) at MIT Plasma Science and Fusion Center (PSFC). The thesis was submitted and accepted by the MIT physics Department, “W. Fox, Experimental Study of Current-Driven Turbulence During Magnetic Reconnection, Ph.D. Thesis, MIT (2009)”. In the VTF experiment reconnection and current-sheet formation is driven by quickly changing currents in a specially arranged set of internal conductors. Previous work on this device [Egedal, et al, PRL 98, 015003, (2007)] identified a “spontaneous” reconnection regime. In this work fluctuations were studied using impedance-matched, high-bandwidth Langmuir probes. Strong, broadband fluctuations, with frequencies extending from near the lower-hybrid frequency [fLH = (fcefci)1/2] to the electron cyclotron frequency fce were found to arise during the reconnection events. Based on frequency and wavelength measurements, lower-hybrid waves …
Date: August 31, 2010
Creator: Porkolab, Miklos; Egedal-Pedersen, Jan & Fox, William
Object Type: Report
System: The UNT Digital Library
From Tragedy to Triumph: Rebuilding Greensburg, Kansas To Be a 100% Renewable Energy City; Preprint (open access)

From Tragedy to Triumph: Rebuilding Greensburg, Kansas To Be a 100% Renewable Energy City; Preprint

On May 4, 2007, Greensburg, Kansas, was hit by a 1.7-mile wide tornado with 200 mph-plus wind speeds. This tornado destroyed or severely damaged 90% of Greensburg?s structures. We discuss the progress made in rebuilding Greensburg, with a focus on the built environment and on meeting Greensburg?s goal of 100% renewable energy, 100% of the time. We also discuss key disaster recovery efforts that enabled Greensburg to reach this goal. Key strategies included a Sustainable Comprehensive Master Plan, an ordinance resolving that city-owned buildings achieve LEED Platinum and 42% energy savings, a strong focus on rebuilding 'right' with an integrated design process, attracting significant and sustained technical experts and national media attention, and linking renewable and energy efficiency technologies to business development. After three years, more than half the homes that have been rebuilt are rated at an average of 40% energy savings. All significant commercial buildings, including the school, hospital, banks, courthouse, and retail buildings, have been rebuilt to LEED Gold and Platinum standards and exceed 40% savings, with many exceeding 50% savings. Greensburg recently constructed a 12.5-MW community wind farm to provide all the remaining energy needed for its energy-efficient buildings and homes.
Date: August 1, 2010
Creator: Pless, S.; Billman, L. & Wallach, D.
Object Type: Article
System: The UNT Digital Library
Hydrogen Safety Training for Researchers (open access)

Hydrogen Safety Training for Researchers

None
Date: August 3, 2010
Creator: Aceves, S.; Petitpas, G.; Ross, T. & Switzer, V.
Object Type: Report
System: The UNT Digital Library
Measurement of CP observables in B__ ->D_CPK__ decays and constraints on the CKM angle gamma (open access)

Measurement of CP observables in B__ ->D_CPK__ decays and constraints on the CKM angle gamma

Using the entire sample of 467 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, we perform a 'GLW' analysis of B{sup {+-}} {yields} D{sup {+-}} decays, using decay modes in which the neutral D meson decays to either CP-eigenstates or non-CP-eigenstates. We measure the partial decay rate charge asymmetries for CP-even and CP-odd D final states to be A{sub CP+} = 0.25 {+-} 0.06 {+-} 0.02 and A{sub CP-} = -0.09 {+-} 0.07 {+-} 0.02, respectively, where the first error is the statistical and the second is the systematic uncertainty. The parameter A{sub CP+} is different from zero with a significance of 3.6 standard deviations, constituting evidence for direct CP violation. We also measure the ratios of the charged-averaged B partial decay rates in CP and non-CP decays, R{sub CP+} = 1.18 {+-} 0.09 {+-} 0.05 and R{sub CP-} = 1.07 {+-} 0.08 {+-} 0.04. We infer frequentist confidence intervals for the angle {gamma} of the (db) unitarity triangle, for the strong phase difference {delta}{sub B}, and for the amplitude ratio r{sub B}, which are related to the B{sup -} {yields} D{sup -} decay amplitude by r{sub B}e{sup i({delta}{sub …
Date: August 25, 2010
Creator: del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J. et al.
Object Type: Article
System: The UNT Digital Library
Single-Sector Supersymmetry Breaking in Supersymmetric QCD (open access)

Single-Sector Supersymmetry Breaking in Supersymmetric QCD

We construct examples of single-sector supersymmetry breaking based on simple deformations of supersymmetric QCD with (weakly) gauged flavor group. These theories are calculable in a weakly coupled Seiberg dual description. In these models, some of the particles in the first two generations of quarks and leptons are composites of the same strong dynamics which leads to dynamical supersymmetry breaking. Such models can explain the hierarchies of Yukawa couplings in the Standard Model, in a way that predictively correlates with the spectrum of SUSY-breaking soft terms.
Date: August 26, 2010
Creator: Franco, Sebastian & Kachru, Shamit
Object Type: Article
System: The UNT Digital Library
Dual Purpose Landscaping Tools: Small Extra Dimensions in AdS/CFT (open access)

Dual Purpose Landscaping Tools: Small Extra Dimensions in AdS/CFT

We propose a class of AdS/CFT dual pairs which have small internal dimensions on the gravity side. Starting from known Freund-Rubin AdS/CFT dual pairs, we use 7-branes to nearly cancel the curvature energy of the internal dimensions while maintaining their stabilization. This leads to a new corner of the landscape - a class of AdS solutions with a hierarchically large AdS radius - with a dual field theory given (implicitly) by the infrared limit of a concrete brane construction involving D3-branes, 7-branes, and curvature. We first construct a class of hierarchical AdS5/CFT4 dual pairs with a simple formula for the number of degrees of freedom which we interpret in the dual QFT. We then generalize these to AdS4/CFT3 duals, and suggest extensions of the method to obtain de Sitter solutions.
Date: August 26, 2010
Creator: Polchinski, Joseph & Silverstein, Eva
Object Type: Report
System: The UNT Digital Library
'Dynamical Supersymmetry Breaking, with Flavor' (open access)

'Dynamical Supersymmetry Breaking, with Flavor'

We explore calculable models with low-energy supersymmetry where the flavor hierarchy is generated by quark and lepton compositeness, and where the composites emerge from the same sector that dynamically breaks supersymmetry. The observed pattern of Standard Model fermion masses and mixings is obtained by identifying the various generations with composites of different dimension in the ultraviolet. These 'single-sector' supersymmetry breaking models give rise to various spectra of soft masses which are, in many cases, quite distinct from what is commonly found in models of gauge or gravity mediation. In typical models which satisfy all flavor-changing neutral current constraints, both the first and second generation sparticles have masses of order 20 TeV, while the stop mass is a few TeV. In other cases, all sparticles obtain masses of order a few TeV predominantly from gauge mediation, even though the first two generations are composite.
Date: August 26, 2010
Creator: Craig, Nathaniel; Essig, Rouven; Franco, Sebastian; Kachru, Shamit & Torroba, Gonzalo
Object Type: Article
System: The UNT Digital Library
Measurement of CP violation observables and parameters for the decays $B^{\pm}\to DK^{*\pm}$ (open access)

Measurement of CP violation observables and parameters for the decays $B^{\pm}\to DK^{*\pm}$

We study the decay B{sup -} {yields} DK*{sup -} using a sample of 379 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEP-II B-factory. We perform a 'GLW' analysis where the D meson decays into either a CP-even (CP+) eigenstate (K{sup +}K{sup -}, {pi}{sup +}{pi}{sup -}), CP-odd (CP-) eigenstate (K{sub S}{sup 0}{pi}{sup 0}, K{sub S}{sup 0}{phi}, K{sub S}{sup 0}{omega}) or a non-CP state (K{sup -}{pi}{sup +}). We also analyze D meson decays into K{sup +}{pi}{sup -} from a Cabibbo-favored {bar D}{sup 0} decay or doubly suppressed D{sup 0} decay ('ADS' analysis). We measure observables that are sensitive to the CKM angle {gamma}: the partial-rate charge asymmetries A{sub CP{+-}}, the ratios R{sub CP{+-}} of the B-decay branching fractions in CP{+-} and non-CP decay, the ratio R{sub ADS} of the charge-averaged branching fractions, and the charge asymmetry A{sub ADS} of the ADS decays: A{sub CP+} = 0.09 {+-} 0.13 {+-} 0.06, A{sub CP-} = -0.23 {+-} 0.21 {+-} 0.07, R{sub CP+} = 2.17 {+-} 0.35 {+-} 0.09, R{sub CP-} = 1.03 {+-} 0.27 {+-} 0.13, R{sub ADS} = 0.066 {+-} 0.031 {+-} 0.010, and A{sub ADS} = -0.34 {+-} 0.43 {+-} 0.16, where the first …
Date: August 26, 2010
Creator: Aubert, Bernard; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X. et al.
Object Type: Article
System: The UNT Digital Library
Flavor Physics in the Quark Sector (open access)

Flavor Physics in the Quark Sector

In the past decade, one of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor. In this time frame, measurements and the theoretical interpretation of their results have advanced tremendously. A much broader understanding of flavor particles has been achieved, apart from their masses and quantum numbers, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. In the past, observations of CP violation were confined to neutral K mesons, but since the early 1990s, a large number of CP-violating processes have been studied in detail in neutral B mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of K,D, and B mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model. In the near future, there will be a transition from the current to a new generation of experiments, thus a review of …
Date: August 26, 2010
Creator: Antonelli, Mario; Asner, David Mark; Bauer, Daniel Adams; Becher, Thomas G.; Beneke, M.; Bevan, Adrian John et al.
Object Type: Article
System: The UNT Digital Library
B-meson decays to eta' rho, eta' f0, and eta' K* (open access)

B-meson decays to eta' rho, eta' f0, and eta' K*

We present measurements of B-meson decays to the final states {eta}{prime} {rho}, {eta}{prime} f{sub 0}, and {eta}{prime} K*, where K* stands for a vector, scalar, or tensor strange meson. We observe a significant signal or evidence for {eta}{prime} {rho}{sup +} and all the {eta}{prime}K* channels. We also measure, where applicable, the charge asymmetries, finding results consistent with no direct CP violation in all cases. The measurements are performed on a data sample consisting of 467 x 10{sup 6} B{bar B} pairs, collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. Our results favor the theoretical predictions from perturbative QCD and QCD Factorization and we observe an enhancement of the tensor K*{sub 2} (1430) with respect to the vector K*(892) component.
Date: August 25, 2010
Creator: del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J. et al.
Object Type: Article
System: The UNT Digital Library
RELAP5 Model of the Divertor Primary Heat Transfer System (open access)

RELAP5 Model of the Divertor Primary Heat Transfer System

This report describes the RELAP5 model that has been developed for the divertor primary heat transfer system (PHTS). The model is intended to be used to examine the transient performance of the divertor PHTS and evaluate control schemes necessary to maintain parameters within acceptable limits during transients. Some preliminary results are presented to show the maturity of the model and examine general divertor PHTS transient behavior. The model can be used as a starting point for developing transient modeling capability, including control system modeling, safety evaluations, etc., and is not intended to represent the final divertor PHTS design. Preliminary calculations using the models indicate that during normal pulsed operation, present pressurizer controls may not be sufficient to keep system pressures within their desired range. Additional divertor PHTS and control system design efforts may be required to ensure system pressure fluctuation during normal operation remains within specified limits.
Date: August 1, 2010
Creator: Popov, Emilian L.; Yoder, Graydon L., Jr. & Kim, Seokho H.
Object Type: Report
System: The UNT Digital Library
Pu2O3 and the plutonium hydriding process (open access)

Pu2O3 and the plutonium hydriding process

None
Date: August 4, 2010
Creator: Dinh, L. N.; Haschke, J. M.; Saw, C. K.; Allen, P. G. & McLean, W., II
Object Type: Article
System: The UNT Digital Library