Measurement of sigma(chi(c2)B(chi(c2) ---> J / psi gamma) / sigma(chi(c1)B(chi(c1) ---> J / psi gamma) in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Measurement of sigma(chi(c2)B(chi(c2) ---> J / psi gamma) / sigma(chi(c1)B(chi(c1) ---> J / psi gamma) in p anti-p collisions at s**(1/2) = 1.96-TeV

The authors measure the ratio of cross section times branching fraction, {sigma}{sub {chi}c2}{beta}({chi}{sub c2} {yields} J/{psi}{gamma})/{sigma}{sub {chi}c1}{beta}({chi}{sub c1} {yields} J/{psi}{gamma}), in 1.1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV. This measurement covers the kinematic range p{sub T} (J/{psi}) > 4.0 GeV/c, |{eta}(J/{psi})| < 1.0, and p{sub T}({gamma}) > 1.0 GeV/c. For events due to prompt processes, they find R{sub p} = 0.395 {+-} 0.016(stat.) {+-} 0.015(sys.). This result represents a significant improvement in precision over previous measurements of prompt {chi}{sub c1,2} hadroproduction.
Date: March 1, 2007
Creator: Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M. G.; Ambrose, D. et al.
Object Type: Article
System: The UNT Digital Library
Precise measurement of the top quark mass in the lepton+jets topology at CDF II (open access)

Precise measurement of the top quark mass in the lepton+jets topology at CDF II

The authors present a measurement of the mass of the top quark from proton-antiproton collisions recorded at the CDF experiment in Run II of the Fermilab Tevatron. They analyze events from the single lepton plus jets final state (t{bar t} {yields} W{sup +}bW{sup -}{bar b} {yields} lvbq{bar q}{bar b}). The top quark mass is extracted using a direct calculation of the probability density that each event corresponds to the t{bar t} final state. The probability is a function of both the mass of the top quark and the energy scale of the calorimeter jets, which is constrained in situ by the hadronic W boson mass. Using 167 events observed in 955 pb{sup -1} of integrated luminosity, they achieve the single most precise measurement of the top quark mass, 170.8 {+-} 2.2(stat.) {+-} 1.4(syst.) GeV/c{sup 2}.
Date: March 1, 2007
Creator: Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M. G.; Amerio, S. et al.
Object Type: Article
System: The UNT Digital Library
Radiological Survey Results for Areas A1 North, A5A, A6, and B2 at the Molycorp Washington Remediation Project, Washington, Pennsylvania (open access)

Radiological Survey Results for Areas A1 North, A5A, A6, and B2 at the Molycorp Washington Remediation Project, Washington, Pennsylvania

Perform radiological surveys of the Molycorp Washington Remediation Project (MWRP) facility in Washington, Pennsylvania
Date: March 13, 2007
Creator: Adams, W. C.
Object Type: Report
System: The UNT Digital Library
Comments on Worldsheet Theories Dual to Free Large N Gauge Theories (open access)

Comments on Worldsheet Theories Dual to Free Large N Gauge Theories

We continue to investigate properties of the worldsheet conformal field theories (CFTs) which are conjectured to be dual to free large N gauge theories, using the mapping of Feynman diagrams to the worldsheet suggested in [1]. The modular invariance of these CFTs is shown to be built into the formalism. We show that correlation functions in these CFTs which are localized on subspaces of the moduli space may be interpreted as delta-function distributions, and that this can be consistent with a local worldsheet description given some constraints on the operator product expansion coefficients. We illustrate these features by a detailed analysis of a specific four-point function diagram. To reliably compute this correlator we use a novel perturbation scheme which involves an expansion in the large dimension of some operators.
Date: March 21, 2007
Creator: Aharony, Ofer; /Weizmann Inst. /Stanford U., ITP /SLAC; David, Justin R.; Gopakumar, Rajesh; Inst., /Harish-Chandra Res.; Komargodski, Zohar et al.
Object Type: Report
System: The UNT Digital Library
The Moduli Space and M(Atrix) Theory of 9d N=1 Backgrounds of M/String Theory (open access)

The Moduli Space and M(Atrix) Theory of 9d N=1 Backgrounds of M/String Theory

We discuss the moduli space of nine dimensional N = 1 supersymmetric compactifications of M theory/string theory with reduced rank (rank 10 or rank 2), exhibiting how all the different theories (including M theory compactified on a Klein bottle and on a Moebius strip, the Dabholkar-Park background, CHL strings and asymmetric orbifolds of type II strings on a circle) fit together, and what are the weakly coupled descriptions in different regions of the moduli space. We argue that there are two disconnected components in the moduli space of theories with rank 2. We analyze in detail the limits of the M theory compactifications on a Klein bottle and on a Moebius strip which naively give type IIA string theory with an uncharged orientifold 8-plane carrying discrete RR flux. In order to consistently describe these limits we conjecture that this orientifold non-perturbatively splits into a D8-brane and an orientifold plane of charge (-1) which sits at infinite coupling. We construct the M(atrix) theory for M theory on a Klein bottle (and the theories related to it), which is given by a 2 + 1 dimensional gauge theory with a varying gauge coupling compactified on a cylinder with specific boundary conditions. We …
Date: March 21, 2007
Creator: Aharony, Ofer; /Weizmann Inst. /Stanford U., ITP /SLAC; Komargodski, Zohar; Patir, Assaf & Inst., /Weizmann
Object Type: Report
System: The UNT Digital Library
San Francisco State University IAC 02-06 Final Report (open access)

San Francisco State University IAC 02-06 Final Report

The Industrial Assessment Center (IAC) at San Francisco State University (SFSU) has served the cause of energy efficiency as a whole, and in particular for small and medium-sized manufacturing facilities in northern and central California, within a approximately 150 miles (radial) of San Francisco since 1992. In the current reporting period (September 1, 2002 through November 31, 2006) we have had major accomplishments, which include but are not limited to: - Performing a total of 94 energy efficiency and waste minimization audit days of 87 industrial plants - Recommending and analysis of 809 energy efficiency measures - Training 22 energy engineers, most of whom have joined energy services companies in California. - Disseminating energy efficiency information among local manufacturers - Acting as an information source for energy efficiency for local manufacturers and utilizes - Cooperating with local utilities and California Energy Commission in their energy efficiency projects - Performing various assignments by DOE such as dissemination of information on SEN initiative, conducting workshops on energy efficiency issues, contacting large energy user plants - Establishing a course on “Energy: Resources, Alternatives and Conservation” as a general education course at SFSU - Bringing energy issues to the attention of students in classrooms
Date: March 5, 2007
Creator: Ahmad R. Ganji, Ph.D., P.E., IAC DIrector
Object Type: Report
System: The UNT Digital Library
Impact of astrophysical processes on the gamma-ray background from dark matter annihilations (open access)

Impact of astrophysical processes on the gamma-ray background from dark matter annihilations

We study the impact of astrophysical processes on the gamma-ray background produced by the annihilation of dark matter particles in cosmological halos, with particular attention to the consequences of the formation of supermassive black holes. In scenarios where these objects form adiabatically from the accretion of matter on small seeds, dark matter is first compressed into very dense 'spikes', then its density progressively decreases due to annihilations and scattering of stellar cusps. With respect to previous analyses, based on non-evolving halos, the predicted annihilation signal is higher and significantly distorted at low energies, reflecting the large contribution to the total flux from unevolved spikes at high redshifts. The peculiar spectral feature arising from the specific redshift distribution of the signal, would discriminate the proposed scenario from more conventional astrophysical explanations. We discuss how this affects the prospects for detection and demonstrate that the gamma-ray background from DM annihilations might be detectable even in absence of a signal from the Galactic center.
Date: March 1, 2007
Creator: Ahn, Eun-Joo; /Chicago U., Astron. Astrophys. Ctr. /KICP, Chicago /Fermilab /Bartol Research Inst.; Bertone, Gianfranco; Tech., /Rochester Inst.; Merritt, David & /Shanghai, Astron. Observ.
Object Type: Article
System: The UNT Digital Library
Development of a Novel Catalyst for NO Decomposition (open access)

Development of a Novel Catalyst for NO Decomposition

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NOx emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N2 will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation leads one …
Date: March 14, 2007
Creator: Akyurtlu, Ates & Akyurtlu, Jale F.
Object Type: Report
System: The UNT Digital Library
Improved Biomass Utilization Through Remote Flow Sensing (open access)

Improved Biomass Utilization Through Remote Flow Sensing

The growth of the livestock industry provides a valuable source of affordable, sustainable, and renewable bioenergy, while also requiring the safe disposal of the large quantities of animal wastes (manure) generated at dairy, swine, and poultry farms. If these biomass resources are mishandled and underutilized, major environmental problems will be created, such as surface and ground water contamination, odors, dust, ammonia leaching, and methane emission. Anaerobic digestion of animal wastes, in which microorganisms break down organic materials in the absence of oxygen, is one of the most promising waste treatment technologies. This process produces biogas typically containing {approx}65% methane and {approx}35% carbon dioxide. The production of biogas through anaerobic digestion from animal wastes, landfills, and municipal waste water treatment plants represents a large source of renewable and sustainable bio-fuel. Such bio-fuel can be combusted directly, used in internal combustion engines, converted into methanol, or partially oxidized to produce synthesis gas (a mixture of hydrogen and carbon monoxide) that can be converted to clean liquid fuels and chemicals via Fischer-Tropsch synthesis. Different design and mixing configurations of anaerobic digesters for treating cow manure have been utilized commercially and/or tested on a laboratory scale. These digesters include mechanically mixed, gas recirculation mixed, …
Date: March 26, 2007
Creator: Al-Dahhan, Muthanna; Varma, Rajneesh; Karim, Khursheed; Vesvikar, Mehul; Hoffman, Rebecca; Depaoli, David et al.
Object Type: Report
System: The UNT Digital Library
Achieve Continuous Injection of Solid Fuels into Advanced Combustion System Pressures (open access)

Achieve Continuous Injection of Solid Fuels into Advanced Combustion System Pressures

The overall objective of this project is the development of a mechanical rotary-disk feeder, known as the Stamet Posimetric High Pressure Solids Feeder System, to demonstrate feeding of dry granular coal continuously and controllably into pressurized environments of up to 70 kg/cm2 (1,000 psi). This is the Phase III of the ongoing program. Earlier Phases 1 and II successfully demonstrated feeding into pressures up to 35 kg/cm{sup 2} (500 psi). The final report for those phases was submitted in April 2005. Based on the previous work done in Phases I & II using Powder River Basin coal provided by the PSDF facility in Wilsonville, AL, a Phase III feeder system was designed and built to accomplish the target of feeding the coal into a pressure of 70 kg/cm2 (1,000 psi) and to be capable of feed rates of up to 550 kilograms (1,200lbs) per hour. The drive motor system from Phase II was retained for use on Phase III since projected performance calculations indicated it should be capable of driving the Phase III pump to the target levels. The pump & motor system was installed in a custom built test rig comprising an inlet vessel containing an active live-wall hopper …
Date: March 31, 2007
Creator: Aldred, Derek L. & Saunders, Timothy
Object Type: Report
System: The UNT Digital Library
The Wild and Scenic Rivers Act and Federal Water Rights (open access)

The Wild and Scenic Rivers Act and Federal Water Rights

This report discusses federal authority over water, and federal "reserved" and non-reserved water rights. Based on the language of the act and its legislative history, it appears that the act creates federal water rights. The act does not specify the quantity of the right. The amount of the federal right is likely to vary from river to river depending on the river's flows, the unappropriated flows in the river at the time of designation, and the values for which the river is being protected.
Date: March 5, 2007
Creator: Alexander, Kristina
Object Type: Report
System: The UNT Digital Library
Evaluation of ITER MSE Viewing Optics (open access)

Evaluation of ITER MSE Viewing Optics

The Motional Stark Effect (MSE) diagnostic on ITER determines the local plasma current density by measuring the polarization angle of light resulting from the interaction of a high energy neutral heating beam and the tokamak plasma. This light signal has to be transmitted from the edge and core of the plasma to a polarization analyzer located in the port plug. The optical system should either preserve the polarization information, or it should be possible to reliably calibrate any changes induced by the optics. This LLNL Work for Others project for the US ITER Project Office (USIPO) is focused on the design of the viewing optics for both the edge and core MSE systems. Several design constraints were considered, including: image quality, lack of polarization aberrations, ease of construction and cost of mirrors, neutron shielding, and geometric layout in the equatorial port plugs. The edge MSE optics are located in ITER equatorial port 3 and view Heating Beam 5, and the core system is located in equatorial port 1 viewing heating beam 4. The current work is an extension of previous preliminary design work completed by the ITER central team (ITER resources were not available to complete a detailed optimization of …
Date: March 26, 2007
Creator: Allen, S.; Lerner, S.; Morris, K.; Jayakumar, J.; Holcomb, C.; Makowski, M. et al.
Object Type: Report
System: The UNT Digital Library
Groundwater Level Status Report for Fiscal Year 2006 Los Alamos National Laboratory (open access)

Groundwater Level Status Report for Fiscal Year 2006 Los Alamos National Laboratory

The status of groundwater level monitoring at Los Alamos National Laboratory in Fiscal Year 2006 is provided in this report. The Groundwater Level Monitoring Project was instituted in 2005 for providing a framework for the collection and processing of quality controlled groundwater level data. This report summarizes groundwater level data for 158 monitoring wells, including 43 regional aquifer wells, 23 intermediate wells, and 92 alluvial wells. Pressure transducers were installed in 132 monitoring wells for continuous monitoring of groundwater levels. Time-series hydrographs of groundwater level data are presented along with pertinent construction and location information for each well.
Date: March 30, 2007
Creator: Allen, Shannon P. & Koch, Richard J.
Object Type: Report
System: The UNT Digital Library
Development of a National Center for Hydrogen Technology (open access)

Development of a National Center for Hydrogen Technology

In November 2005, the Energy & Environmental Research Center (EERC), ePowerSynergies, Inc. (ePSI), and Resurfice Corporation teamed to develop, produce, and demonstrate the world's first and only fuel cell-powered ice resurfacer. The goals of this project were: {sm_bullet} To educate the public on the readiness, practicality, and safety of fuel cells powered by hydrogen fuel and {sm_bullet} To establish a commercialization pathway in an early-adopter, niche market. The vehicle was developed and produced in a short 3-month span. The vehicle made its world debut at U.S. Senator Byron Dorgan's (D-ND) 2005 Hydrogen Energy Action Summit. Subsequently, the vehicle toured North America appearing at numerous public events and conferences, receiving much attention from international media outlets.
Date: March 1, 2007
Creator: Almlie, Jay C.; Wood, Bruce & Schlupp, Rich
Object Type: Report
System: The UNT Digital Library
Quasar H II Regions During Cosmic Reionization (open access)

Quasar H II Regions During Cosmic Reionization

Cosmic reionization progresses as HII regions form around sources of ionizing radiation. Their average size grows continuously until they percolate and complete reionization. We demonstrate how this typical growth can be calculated around the largest, biased sources of UV emission such as quasars by further developing an analytical model based on the excursion set formalism. This approach allows us to calculate the sizes and growth of the HII regions created by the progenitors of any dark matter halo of given mass and redshift with a minimum of free parameters. Statistical variations in the size of these pre-existing HII regions are an additional source of uncertainty in the determination of very high redshift quasar properties from their observed HII region sizes. We use this model to demonstrate that the transmission gaps seen in very high redshift quasars can be understood from the radiation of only their progenitors and associated clustered small galaxies. The fit requires the epoch of overlap to be at z = 5.8 {+-} 0.1. This interpretation makes the transmission gaps independent of the age of the quasars observed. If this interpretation were correct it would raise the prospects of using radio interferometers currently under construction to detect the …
Date: March 30, 2007
Creator: Alvarez, Marcelo A.; Abel, Tom & /KIPAC, Menlo Park
Object Type: Article
System: The UNT Digital Library
LER-LHC injector workshop summary and super-ferric fast cycling injector in the SPS tunnel (open access)

LER-LHC injector workshop summary and super-ferric fast cycling injector in the SPS tunnel

A Workshop on Low Energy Ring (LER) in the LHC tunnel as main injector was convened at CERN on October 11-12, 2006. We present the outline of the LER based on the presentations, and respond to the raised questions and discussions including the post-workshop studies. We also outline the possibility of using the LER accelerator technologies for the fast cycling injector accelerator in the SPS tunnel (SF-SPS). A primary goal for the LER (Low Energy Ring) injector accelerator is to inject 1.5 TeV proton beams into the LHC, instead of the current injection scheme with 0.45 TeV beams from the SPS. At this new energy, the field harmonics [1] of the LHC magnets are sufficiently satisfactory to prevent the luminosity losses expected to appear when applying the transfer of the 0.45 TeV SPS beams. In addition, a feasibility study of batch slip stacking in the LER has been undertaken with a goal of increasing in this way the LHC luminosity by up to a factor of 4. A combined luminosity increase may, therefore, be in the range of an order of magnitude. In the long term, the LER injector accelerator would greatly facilitate the implementation of a machine, which doubles …
Date: March 1, 2007
Creator: Ambrosio, Giorgio; Hays, Steven; Huang, Yuenian; Johnstone, John; Kashikhin, Vadim; MacLachlan, James et al.
Object Type: Article
System: The UNT Digital Library
Kootenai River White Sturgeon Recovery Implementation Plan and Schedule; 2005-2010, Technical Report 2004-2005. (open access)

Kootenai River White Sturgeon Recovery Implementation Plan and Schedule; 2005-2010, Technical Report 2004-2005.

Kootenai River white sturgeon have been declining for at least 50 years and extinction of the wild population is now imminent (Paragamian et al. 2005). Only 630 adults were estimated to remain in 2002 from a population ten times that size just 20 years ago. Significant recruitment of young sturgeon has not been observed since the early 1970s and consistent annual recruitment has not been seen since the 1950s. The remaining wild population consists of a cohort of large, old fish that is declining by about 9% per year as fish die naturally and are not replaced. At this rate, the wild population will disappear around the year 2040. Numbers have already reached critical low levels where genetic and demographic risks are acute. The Kootenai River White Sturgeon Recovery Team was convened in 1994, provided a draft Recovery Plan in 1996 and the first complete Recovery Plan for Kootenai River white sturgeon in 1999 (USFWS 1996, 1999). The Plan outlined a four part strategy for recovery, including: (1) measures to restore natural recruitment, (2) use of conservation aquaculture to prevent extinction, (3) monitoring survival and recovery, and (4) updating and revising recovery plan criteria and objectives as new information becomes …
Date: March 1, 2007
Creator: Anders, Paul
Object Type: Report
System: The UNT Digital Library
Ecological Monitoring and Compliance Program 2006 Report (open access)

Ecological Monitoring and Compliance Program 2006 Report

The Ecological Monitoring and Compliance program (EMAC), funded through the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO), monitors the ecosystem of the Nevada Test Site (NTS) and ensures compliance with laws and regulations pertaining to NTS biota. This report summarizes the program's activities conducted by National Security Technologies LLC (NSTec) during the Calendar Year 2006. Program activities included: (a) biological surveys at proposed construction sites, (b) desert tortoise compliance, (c) ecosystem mapping and data management, (d) sensitive plant species monitoring, (e) sensitive and protected/regulated animal monitoring, (f) habitat monitoring, (g) habitat restoration monitoring, and (h) monitoring of the Nonproliferation Test and Evaluation Complex (NPTEC). Sensitive and protected/regulated species of the NTS include 44 plants, 1 mollusk, 2 reptiles, over 250 birds, and 26 mammals protected, managed, or considered sensitive as per state or federal regulations and natural resource agencies and organizations. The threatened desert tortoise (Gopherus agassizii) is the only species on the NTS protected under the Endangered Species Act. Biological surveys for the presence of sensitive and protected/regulated species and important biological resources on which they depend were conducted for 34 projects. A total of 342.1 hectares (ha) (845.37 acres [ac]) was surveyed for …
Date: March 1, 2007
Creator: Anderson, David C.; Greger, Paul D.; Hall, Derek B.; Hansen, Dennis J. & Ostler, William K.
Object Type: Report
System: The UNT Digital Library
Ecological Monitoring and Compliance Program 2006 Report (open access)

Ecological Monitoring and Compliance Program 2006 Report

The Ecological Monitoring and Compliance program (EMAC), funded through the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO), monitors the ecosystem of the Nevada Test Site (NTS) and ensures compliance with laws and regulations pertaining to NTS biota. This report summarizes the program's activities conducted by National Security Technologies LLC (NSTec) during the Calendar Year 2006. Program activities included: (a) biological surveys at proposed construction sites, (b) desert tortoise compliance, (c) ecosystem mapping and data management, (d) sensitive plant species monitoring, (e) sensitive and protected/regulated animal monitoring, (f) habitat monitoring, (g) habitat restoration monitoring, and (h) monitoring of the Nonproliferation Test and Evaluation Complex (NPTEC). Sensitive and protected/regulated species of the NTS include 44 plants, 1 mollusk, 2 reptiles, over 250 birds, and 26 mammals protected, managed, or considered sensitive as per state or federal regulations and natural resource agencies and organizations. The threatened desert tortoise (Gopherus agassizii) is the only species on the NTS protected under the Endangered Species Act. Biological surveys for the presence of sensitive and protected/regulated species and important biological resources on which they depend were conducted for 34 projects. A total of 342.1 hectares (ha) (845.37 acres [ac]) was surveyed for …
Date: March 1, 2007
Creator: Anderson, David C.; Greger, Paul D.; Hall, Derek B.; Hansen, Dennis J. & Ostler, William K.
Object Type: Report
System: The UNT Digital Library
Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods (open access)

Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods

Studies conducted at the Pacific Northwest National Laboratory in Richland, Washington, have focused on assessing the effectiveness and reliability of novel approaches to nondestructive examination (NDE) for inspecting coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the U.S. Nuclear Regulatory Commission on the effectiveness and reliability of advanced NDE methods as related to the inservice inspection of safety-related components in pressurized water reactors (PWRs). This report provides progress, recent developments, and results from an assessment of low frequency ultrasonic testing (UT) for detection of inside surface-breaking cracks in cast stainless steel reactor piping weldments as applied from the outside surface of the components. Vintage centrifugally cast stainless steel piping segments were examined to assess the capability of low-frequency UT to adequately penetrate challenging microstructures and determine acoustic propagation limitations or conditions that may interfere with reliable flaw detection. In addition, welded specimens containing mechanical and thermal fatigue cracks were examined. The specimens were fabricated using vintage centrifugally cast and statically cast stainless steel materials, which are typical of configurations installed in PWR primary coolant circuits. Ultrasonic studies on the vintage centrifugally cast stainless steel piping segments were conducted with a 400-kHz …
Date: March 1, 2007
Creator: Anderson, Michael T.; Crawford, Susan L.; Cumblidge, Stephen E.; Denslow, Kayte M.; Diaz, Aaron A. & Doctor, Steven R.
Object Type: Report
System: The UNT Digital Library
Precision measurements of the total and partial widths of the psi(2S) charmonium meson with a new complementary-scan technique in anti-p p annihilations (open access)

Precision measurements of the total and partial widths of the psi(2S) charmonium meson with a new complementary-scan technique in anti-p p annihilations

We present new precision measurements of the {Psi}(2S) total and partial widths from excitation curves obtained in antiproton-proton annihilations by Fermilab experiment E835 at the Antiproton Accumulator in the year 2000. A new technique of complementary scans was developed to study narrow resonances with stochastically cooled antiproton beams. It relies on precise revolution-frequency and orbit-length measurements, while making the analysis of the excitation curve almost independent of machine lattice parameters. For the {Psi}(2S) meson, by studying the processes {bar p}p {yields} e{sup +}e{sup -} and {bar p}p {yields} J/{Psi} + X {yields} e{sup +}e{sup -} + X, we measure the width {Gamma} = 290 {+-} 25(sta) {+-} 4(sys) keV and the combination of partial widths {Gamma}{sub e{sup +}e{sup -}}{Gamma}{sub {bar p}p}/{Gamma} = 579 {+-} 38(sta) {+-} 36(sys) meV, which represent the most precise measurements to date.
Date: March 1, 2007
Creator: Andreotti, M.; Bagnasco, S.; Baldini, W.; Bettoni, D.; Borreani, G.; Buzzo, A. et al.
Object Type: Article
System: The UNT Digital Library
Proposed RF Breakdown Studies at the AWA (open access)

Proposed RF Breakdown Studies at the AWA

A study of breakdown mechanism has been initiated at the Argonne Wakefield Accelerator (AWA). Breakdown may include several factors such as local field enhancement, explosive electron emission, Ohmic heating, tensile stress produced by electric field, and others. The AWA is building a dedicated facility to test various models for breakdown mechanisms and to determine the roles of different factors in the breakdown. We plan to trigger breakdown events with a high-powered laser at various wavelengths (IR to UV) to determine the role of explosive electron emission in the breakdown process. Another experimental idea follows from the recent work on a Schottky-enabled photoemission in an RF photoinjector [1] that allows us to determine in situ the field enhancement factor on a cathode surface. Monitoring the field enhancement factor before and after the breakdown can shed some light on a number of observations such as the crater formation process.
Date: March 21, 2007
Creator: Antipov, S.; Conde, M.; Gai, W.; Power, J. G.; Spentzouris, L.; Yusof, Z. et al.
Object Type: Article
System: The UNT Digital Library
Allinea DDT as a Parallel Debugging Alternative to Totalview (open access)

Allinea DDT as a Parallel Debugging Alternative to Totalview

Totalview, from the Etnus Corporation, is a sophisticated and feature rich software debugger for parallel applications. As Totalview has gained in popularity and market share its pricing model has increased to the point where it is often prohibitively expensive for massively parallel supercomputers. Additionally, many of Totalview's advanced features are not used by members of the scientific computing community. For these reasons, supercomputing centers have begun to search for a basic parallel debugging tool which can be used as an alternative to Totalview. As the cost and complexity of Totalview has increased over the years, scientific computing centers have started searching for a viable parallel debugging alternative. DDT (Distributed Debugging Tool) from Allinea Software is a relatively new parallel debugging tool which aims to provide much of the same functionality as Totalview. This review outlines the basic features and limitations of DDT to determine if it can be a reasonable substitute for Totalview. DDT was tested on the NERSC platforms Bassi, Seaborg, Jacquard and Davinci with Fortran90, C, and C++ codes using MPI and OpenMP for parallelism.
Date: March 5, 2007
Creator: Antypas, K.B.
Object Type: Report
System: The UNT Digital Library
MARMOSET: The Path from LHC Data to the New Standard Model via On-Shell Effective Theories (open access)

MARMOSET: The Path from LHC Data to the New Standard Model via On-Shell Effective Theories

We describe a coherent strategy and set of tools for reconstructing the fundamental theory of the TeV scale from LHC data. We show that On-Shell Effective Theories (OSETs) effectively characterize hadron collider data in terms of masses, production cross sections, and decay modes of candidate new particles. An OSET description of the data strongly constrains the underlying new physics, and sharply motivates the construction of its Lagrangian. Simulating OSETs allows efficient analysis of new-physics signals, especially when they arise from complicated production and decay topologies. To this end, we present MARMOSET, a Monte Carlo tool for simulating the OSET version of essentially any new-physics model. MARMOSET enables rapid testing of theoretical hypotheses suggested by both data and model-building intuition, which together chart a path to the underlying theory. We illustrate this process by working through a number of data challenges, where the most important features of TeV-scale physics are reconstructed with as little as 5 fb{sup -1} of simulated LHC signals.
Date: March 1, 2007
Creator: Arkani-Hamed, Nima; Schuster, Philip; Toro, Natalia; Thaler, Jesse; Wang, Lian-Tao; Knuteson, Bruce et al.
Object Type: Report
System: The UNT Digital Library