3-D Mapping Technologies for High Level Waste Tanks (open access)

3-D Mapping Technologies for High Level Waste Tanks

This research investigated four techniques that could be applicable for mapping of solids remaining in radioactive waste tanks at the Savannah River Site: stereo vision, LIDAR, flash LIDAR, and Structure from Motion (SfM). Stereo vision is the least appropriate technique for the solids mapping application. Although the equipment cost is low and repackaging would be fairly simple, the algorithms to create a 3D image from stereo vision would require significant further development and may not even be applicable since stereo vision works by finding disparity in feature point locations from the images taken by the cameras. When minimal variation in visual texture exists for an area of interest, it becomes difficult for the software to detect correspondences for that object. SfM appears to be appropriate for solids mapping in waste tanks. However, equipment development would be required for positioning and movement of the camera in the tank space to enable capturing a sequence of images of the scene. Since SfM requires the identification of distinctive features and associates those features to their corresponding instantiations in the other image frames, mockup testing would be required to determine the applicability of SfM technology for mapping of waste in tanks. There may be …
Date: August 31, 2010
Creator: Marzolf, A. & Folsom, M.
Object Type: Article
System: The UNT Digital Library
SXR Continuum Radiation Transmitted Through Metallic Filters: An Analytical Approach To Fast Electron Temperature Measurements (open access)

SXR Continuum Radiation Transmitted Through Metallic Filters: An Analytical Approach To Fast Electron Temperature Measurements

A new set of analytic formulae describes the transmission of soft X-ray (SXR) continuum radiation through a metallic foil for its application to fast electron temperature measurements in fusion plasmas. This novel approach shows good agreement with numerical calculations over a wide range of plasma temperatures in contrast with the solutions obtained when using a transmission approximated by a single-Heaviside function [S. von Goeler, Rev. Sci. Instrum., 20, 599, (1999)]. The new analytic formulae can improve the interpretation of the experimental results and thus contribute in obtaining fast teperature measurements in between intermittent Thomson Scattering data.
Date: August 26, 2010
Creator: Delgado-Aparicio, L.; Tritz, K.; Kramer, T.; Stutman, D.; Finkentha, M.; Hill, K. et al.
Object Type: Report
System: The UNT Digital Library
Coherence Properties of the LCLS (open access)

Coherence Properties of the LCLS

The LINAC Coherent Light Source (LCLS), an X-Ray free-electron laser(FEL) based on the self amplified spontaneous emission principle, has recently come on-line. For many users it is desirable to have an idea of the level of transverse coherence of the X-Ray beam produced. In this paper, we analyze the output of GENESIS simulations of electrons traveling through the FEL. We first test the validity of an approach that ignores the details of how the beam was produced, and instead, by assuming a Gaussian-Schell model of transverse coherence, predicts the level of transverse coherence simply through looking at the beam radius at several longitudinal slices. We then develop a Markov chain Monte Carlo approach to calculating the degree of transverse coherence, which offers a {approx}100-fold speedup compared to the brute-force algorithm previously in use. We find the beam highly coherent. Using a similar Markov chain Monte Carlo approach, we estimate the reasonability of assuming the beam to have a Gaussian-Schell model of transverse coherence, with inconclusive results.
Date: August 25, 2010
Creator: Ocko, Samuel
Object Type: Report
System: The UNT Digital Library
'Micromanaging de Sitter holography' (open access)

'Micromanaging de Sitter holography'

We develop tools to engineer de Sitter vacua with semi-holographic duals, using elliptic fibrations and orientifolds to uplift Freund-Rubin compactifications with CFT duals. The dual brane construction is compact and constitutes a microscopic realization of the dS/dS correspondence, realizing d-dimensional de Sitter space as a warped compactification down to (d-1)-dimensional de Sitter gravity coupled to a pair of large-N matter sectors. This provides a parametric microscopic interpretation of the Gibbons-Hawking entropy. We illustrate these ideas with an explicit class of examples in three dimensions, and describe ongoing work on four-dimensional constructions. The Gibbons-Hawking entropy of the de Sitter horizon [1] invites a microscopic interpretation and a holographic formulation of inflating spacetimes. Much progress was made in the analogous problem in black hole physics using special black holes in string theory whose microstates could be reliably counted, such as those analyzed in [2,3]; this led to the AdS/CFT correspondence [4]. In contrast, a microscopic understanding of the entropy of de Sitter space is more difficult for several reasons including its potential dynamical connections to other backgrounds (metastability), the absence of a non-fluctuating timelike boundary, and the absence of supersymmetry. In this paper, we develop a class of de Sitter constructions in …
Date: August 26, 2010
Creator: Dong, Xi; Horn, Bart; /SLAC /Stanford U., Phys. Dept. /Santa Barbara, KITP; Silverstein, Eva; /Santa Barbara, KITP /SLAC /Stanford U., Phys. Dept.; Torroba, Gonzalo et al.
Object Type: Article
System: The UNT Digital Library
Critical Currents of YBCO Tapes and Bi-2212 Wires at Different Temperatures and Magnetic Fields (open access)

Critical Currents of YBCO Tapes and Bi-2212 Wires at Different Temperatures and Magnetic Fields

Design studies for the cooling channel of a Muon Collider call for straight and helical solenoids generating field well in excess of the critical fields of state of the art Low Temperature Superconductors (LTS) such as Nb{sub 3}Sn or NbTi. Therefore, High Temperature Superconductors (HTS) will need to be used for the manufacturing of all or certain sections of such magnets to be able to generate and withstand the field levels at the cryogenic temperatures required by the new machine. In this work, two major High Temperature Superconductors - Bi2212 round wires and YBCO coated conductor tapes - are investigated to understand how critical current density of such conductors scales as a function of external field and operating temperature. This is vital information to make conductor choices depending on the application and to proceed with the design of such magnets.
Date: August 1, 2010
Creator: Lombardo, V.; Barzi, E.; Turrioni, D. & Zlobin, A. V.
Object Type: Article
System: The UNT Digital Library
Vector Boson Jets with BlackHat and Sherpa (open access)

Vector Boson Jets with BlackHat and Sherpa

We review recent NLO QCD results for W, Z + 3-jet production at hadron colliders, computing using BlackHat and SHERPA, and including also some new results for Z + 3-jet production for the LHC at 7 TeV. We report new progress towards the NLO cross section for W + 4-jet production. In particular, we show that the virtual matrix elements produced by BlackHat are numerically stable. We also show that with an improved integrator and tree-level matrix elements from BlackHat, SHERPA produces well-behaved real-emission contributions. As an illustration, we present the real-emission contributions - including dipole-subtraction terms - to the p{sub T} distribution of the fourth jet, for a single subprocess with the maximum number of gluons.
Date: August 25, 2010
Creator: Berger, C.F.; /MIT, LNS; Bern, Z.; /UCLA; Dixon, Lance J.; /SLAC et al.
Object Type: Article
System: The UNT Digital Library
Enumerating a Diverse Set of Building Designs Using Discrete Optimization: Preprint (open access)

Enumerating a Diverse Set of Building Designs Using Discrete Optimization: Preprint

Numerical optimization is a powerful method for identifying energy-efficient building designs. Automating the search process facilitates the evaluation of many more options than is possible with one-off parametric simulation runs. However, input data uncertainties and qualitative aspects of building design work against standard optimization formulations that return a single, so-called optimal design. This paper presents a method for harnessing a discrete optimization algorithm to obtain significantly different, economically viable building designs that satisfy an energy efficiency goal. The method is demonstrated using NREL's first-generation building analysis platform, Opt- E-Plus, and two example problems. We discuss the information content of the results, and the computational effort required by the algorithm.
Date: August 1, 2010
Creator: Hale, E. & Long, N.
Object Type: Article
System: The UNT Digital Library
PAGOSA physics manual (open access)

PAGOSA physics manual

PAGOSA is a computational fluid dynamics computer program developed at Los Alamos National Laboratory (LANL) for the study of high-speed compressible flow and high-rate material deformation. PAGOSA is a three-dimensional Eulerian finite difference code, solving problems with a wide variety of equations of state (EOSs), material strength, and explosive modeling options.
Date: August 1, 2010
Creator: Weseloh, Wayne N.; Clancy, Sean P. & Painter, James W.
Object Type: Report
System: The UNT Digital Library
Final Work Plan : Phase II Investigation of Potential Contamination at the Former CCC/USDA Grain Storage Facility in Savannah, Missouri. (open access)

Final Work Plan : Phase II Investigation of Potential Contamination at the Former CCC/USDA Grain Storage Facility in Savannah, Missouri.

From approximately 1949 until 1970, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility on federally owned property approximately 0.25 mi northwest of Savannah, Missouri (Figure 1.1). During this time, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the private grain storage industry to preserve grain in their facilities. In November 1998, carbon tetrachloride was detected in a private well (Morgan) roughly 50 ft south of the former CCC/USDA facility, as a result of statewide screening of private wells near former CCC/USDA facilities, conducted in Missouri by the U.S. Environmental Protection Agency (EPA 1999). The 1998 and subsequent investigations by the EPA and the Missouri Department of Natural Resources (MoDNR) confirmed the presence of carbon tetrachloride in the Morgan well, as well as in a second well (on property currently occupied by the Missouri Department of Transportation [MoDOT]) described as being approximately 400 ft east of the former CCC/USDA facility. The identified concentrations in these two wells were above the EPA maximum contaminant level (MCL) and the Missouri risk-based corrective action default target level (MRBCA DTL) values of 5.0 {micro}g/L for carbon tetrachloride in water used for domestic …
Date: August 16, 2010
Creator: LaFreniere, L. M. & Division, Environmental Science
Object Type: Report
System: The UNT Digital Library
beam loss scenarios for MuCool Test Area (open access)

beam loss scenarios for MuCool Test Area

The MuCool Test Area (MTA) is an intense primary beam facility derived directly from the Fermilab Linac to test heat deposition and other technical concerns associated with the liquid hydrogen targets, gas-filled RF cavities, and other apparatus being developed to cool intense, large-emittance muon beams. In this study the results of Monte Carlo modeling of several beam loss scenarios are presented. The MTA facility was designed to test targets and other muon cooling apparatus using the intense Fermilab Linac beam. The requested intensity of the proton beam for the MTA is essentially full Linac capability, or 1.6 x 10{sup 13} protons per pulse and an energy of 400 MeV. Two modes of operation will be supported in the MuCOOL beamline: one mode for emittance measurements (and beamline studies) and a second mode for MTA experiments. Maximum beam intensity for these two modes is: 9.6 x 10{sup 15} protons/hr - 600 beam pulses/hour of full Linac beam pulse intensity (1.6 x 10{sup 13} protons/pulse) to the emittance beam absorber and 9.6 x 10{sup 14} protons/hour - 60 beam pulses/hour of full Linac beam pulse intensity to experiments in the MTA experimental hall. This extremely high intensity implies careful investigation into and …
Date: August 1, 2010
Creator: Rakhno, Igor & Johnstone, Carol
Object Type: Report
System: The UNT Digital Library
Developing an Instrumentation Package for in-Water Testing of Marine Hydrokinetic Energy Devices: Preprint (open access)

Developing an Instrumentation Package for in-Water Testing of Marine Hydrokinetic Energy Devices: Preprint

The ocean-energy industry is still in its infancy and device developers have provided their own equipment and procedures for testing. Currently, no testing standards exist for ocean energy devices in the United States. Furthermore, as prototype devices move from the test tank to in-water testing, the logistical challenges and costs grow exponentially. Development of a common instrumentation package that can be moved from device to device is one means of reducing testing costs and providing normalized data to the industry as a whole. As a first step, the U.S. National Renewable Energy Laboratory (NREL) has initiated an effort to develop an instrumentation package to provide a tool to allow common measurements across various ocean energy devices. The effort is summarized in this paper. First, we present the current status of ocean energy devices. We then review the experiences of the wind industry in its development of the instrumentation package and discuss how they can be applied in the ocean environment. Next, the challenges that will be addressed in the development of the ocean instrumentation package are discussed. For example, the instrument package must be highly adaptable to fit a large array of devices but still conduct common measurements. Finally, some …
Date: August 1, 2010
Creator: Nelson, E.
Object Type: Article
System: The UNT Digital Library
Opportunities for Open Automated Demand Response in Wastewater Treatment Facilities in California - Phase II Report. San Luis Rey Wastewater Treatment Plant Case Study (open access)

Opportunities for Open Automated Demand Response in Wastewater Treatment Facilities in California - Phase II Report. San Luis Rey Wastewater Treatment Plant Case Study

This case study enhances the understanding of open automated demand response opportunities in municipal wastewater treatment facilities. The report summarizes the findings of a 100 day submetering project at the San Luis Rey Wastewater Treatment Plant, a municipal wastewater treatment facility in Oceanside, California. The report reveals that key energy-intensive equipment such as pumps and centrifuges can be targeted for large load reductions. Demand response tests on the effluent pumps resulted a 300 kW load reduction and tests on centrifuges resulted in a 40 kW load reduction. Although tests on the facility?s blowers resulted in peak period load reductions of 78 kW sharp, short-lived increases in the turbidity of the wastewater effluent were experienced within 24 hours of the test. The results of these tests, which were conducted on blowers without variable speed drive capability, would not be acceptable and warrant further study. This study finds that wastewater treatment facilities have significant open automated demand response potential. However, limiting factors to implementing demand response are the reaction of effluent turbidity to reduced aeration load, along with the cogeneration capabilities of municipal facilities, including existing power purchase agreements and utility receptiveness to purchasing electricity from cogeneration facilities.
Date: August 20, 2010
Creator: Thompson, Lisa; Lekov, Alex; McKane, Aimee & Piette, Mary Ann
Object Type: Report
System: The UNT Digital Library
Walmart Experimental Store Performance Stories: Preprint (open access)

Walmart Experimental Store Performance Stories: Preprint

Walmart opened two experimental stores--one in Colorado and one in Texas--in 2005 to serve as test beds for several advanced building systems. Each embodied more than 50 experiments covering materials, water systems, energy systems, and renewable energy production. Walmart worked for three years with the National Renewable Energy Laboratory for the Colorado Store and Oak Ridge National Laboratory for the Texas store to monitor, analyze, and report on their performance. HVAC experiments included waste oil boilers, a microturbine/absorption chiller combined heat and power system, evaporative cooling, and a transpired solar collector. The refrigeration systems integrated a medium-temperature secondary loop, evaporatively cooled condenser, doors on medium-temperature cases, and light-emitting diodes on cases. Experiments in the lighting systems included a redesigned roof for clerestory daylighting and T-5 fluorescent lamps. Three photovoltaic systems for a total of 135 kW and a 50-kW wind turbine are also included. The energy system performance was compared to the measured performance of a prototypical Walmart store and to other benchmarks.
Date: August 1, 2010
Creator: Deru, M.; Kozubal, E. & Norton, P.
Object Type: Article
System: The UNT Digital Library
2009 Wind Technologies Market Report (open access)

2009 Wind Technologies Market Report

The U.S. wind power industry experienced yet another record year in 2009, once again surpassing even optimistic growth projections from years past. At the same time, 2009 was a year of upheaval, with the global financial crisis impacting the wind power industry and with federal policy changes enacted to push the industry toward continued aggressive expansion. The year 2010, meanwhile, is anticipated to be one of some retrenchment, with expectations for fewer wind power capacity additions than seen in 2009. The rapid pace of development and change within the industry has made it difficult to keep up with trends in the marketplace, yet the need for timely, objective information on the industry and its progress has never been greater. This report - the fourth in an ongoing annual series - attempts to meet this need by providing a detailed overview of developments and trends in the United States wind power market, with a particular focus on 2009.
Date: August 1, 2010
Creator: Wiser, R. & Bolinger, M.
Object Type: Report
System: The UNT Digital Library
Practical Integration Approach and Whole Building Energy Simulation of Three Energy Efficient Building Technologies: Preprint (open access)

Practical Integration Approach and Whole Building Energy Simulation of Three Energy Efficient Building Technologies: Preprint

Three technologies that have potential to save energy and improve sustainability of buildings are dedicated outdoor air systems, radiant heating and cooling systems and tighter building envelopes. To investigate the energy savings potential of these three technologies, whole building energy simulations were performed for a barracks facility and an administration facility in 15 U.S. climate zones and 16 international locations.
Date: August 1, 2010
Creator: Miller, J. P.; Zhivov, A.; Heron, D.; Deru, M. & Benne, K.
Object Type: Article
System: The UNT Digital Library
Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS) (open access)

Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)

Geological repositories for disposal of high-level nuclear wastes generally rely on a multi-barrier system to isolate radioactive wastes from the biosphere. The multi-barrier system typically consists of a natural barrier system, including repository host rock and its surrounding subsurface environment, and an engineering barrier system (EBS). EBS represents the man-made, engineered materials placed within a repository, including the waste form, waste canisters, buffer materials, backfill and seals (OECD, 2003). EBS plays a significant role in the containment and long-term retardation of radionuclide release. EBS is involved in complex thermal, hydrogeological, mechanical, chemical and biological processes, such as heat release due to radionuclide decay, multiphase flow (including gas release due to canister corrosion), swelling of buffer materials, radionuclide diffusive transport, waste dissolution and chemical reactions. All these processes are related to each other. An in-depth understanding of these coupled processes is critical for the performance assessment (PA) for EBS and the entire repository. Within the EBS group of Used Fuel Disposition (UFD) Campaign, LBNL is currently focused on (1) thermal-hydraulic-mechanical-chemical (THMC) processes in buffer materials (bentonite) and (2) diffusive transport in EBS associated with clay host rock, with a long-term goal to develop a full understanding of (and needed modeling capabilities …
Date: August 31, 2010
Creator: Steefel, Carl; Rutqvist, Jonny; Tsang, Chin-Fu; Liu, Hui-Hai; Sonnenthal, Eric; Houseworth, Jim et al.
Object Type: Report
System: The UNT Digital Library
Building Energy Simulation Test for Existing Homes (BESTEST-EX); Phase 1 Test Procedure: Building Thermal Fabric Cases (open access)

Building Energy Simulation Test for Existing Homes (BESTEST-EX); Phase 1 Test Procedure: Building Thermal Fabric Cases

The U.S. Department of Energy tasked NREL to develop a process for testing the reliability of models that predict retrofit energy savings, including their associated calibration methods. DOE asked NREL to conduct the work in phases so that a test procedure would be ready should DOE need it to meet legislative requirements related to residential retrofits in FY 2010. This report documents the initial 'Phase 1' test procedure.
Date: August 1, 2010
Creator: Judkoff, R.; Polly, B.; Bianchi, M. & Neymark, J.
Object Type: Report
System: The UNT Digital Library
Optimization of the LCLS Single Pulse Shutter (open access)

Optimization of the LCLS Single Pulse Shutter

A mechanical shutter which operates on demand is used to isolate a single pulse from a 120 Hz X-ray source. This is accomplished with a mechanical shutter which is triggered on demand with frequencies ranging from 0 to 10 Hz. The single pulse shutter is an iron blade that oscillates on a pivot in response to a force generated by a pair of pulsed electromagnets (current driven teeter-totter). To isolate an individual pulse from the X-ray beam, the motion of the mechanical shutter should be synchronized in such a way that it allows a single pulse to pass through the aperture and blocks the other incoming pulses. Two consecutive pulses are only {approx} 8 ms apart and the shutter is required to complete one full cycle such that no two pulses pass through the opening. Also the opening of the shutter blade needs to be at least 4 mm so that a 1 mm diameter rms Gaussian beam can pass through without modulation. However, the 4 mm opening is difficult to obtain due to blade rebound and oscillation of the blade after colliding with the electromagnet. The purpose of this project is to minimize and/or totally eliminate the rebound of …
Date: August 25, 2010
Creator: Adera, Solomon & /Georgia Tech., Atlanta /SLAC
Object Type: Report
System: The UNT Digital Library
Fuel Efficient Diesel Particulate Filter (DPF) Modeling and Development (open access)

Fuel Efficient Diesel Particulate Filter (DPF) Modeling and Development

The project described in this report seeks to promote effective diesel particulate filter technology with minimum fuel penalty by enhancing fundamental understanding of filtration mechanisms through targeted experiments and computer simulations. The overall backpressure of a filtration system depends upon complex interactions of particulate matter and ash with the microscopic pores in filter media. Better characterization of these phenomena is essential for exhaust system optimization. The acicular mullite (ACM) diesel particulate filter substrate is under continuing development by Dow Automotive. ACM is made up of long mullite crystals which intersect to form filter wall framework and protrude from the wall surface into the DPF channels. ACM filters have been demonstrated to effectively remove diesel exhaust particles while maintaining relatively low backpressure. Modeling approaches developed for more conventional ceramic filter materials, such as silicon carbide and cordierite, have been difficult to apply to ACM because of properties arising from its unique microstructure. Penetration of soot into the high-porosity region of projecting crystal structures leads to a somewhat extended depth filtration mode, but with less dramatic increases in pressure drop than are normally observed during depth filtration in cordierite or silicon carbide filters. Another consequence is greater contact between the soot and …
Date: August 1, 2010
Creator: Stewart, Mark L.; Gallant, Thomas R.; Kim, Do Heui; Maupin, Gary D. & Zelenyuk, Alla
Object Type: Report
System: The UNT Digital Library
Beam dynamics simulations of the NML photoinjector at Fermilab (open access)

Beam dynamics simulations of the NML photoinjector at Fermilab

Fermilab is currently constructing a superconducting RF (SRF) test linear accelerator at the New Muon Lab (NML). Besides testing SRF accelerating modules for ILC and Project-X, NML will also eventually support a variety of advanced accelerator R&D experiments. The NML incorporates a 40 MeV photoinjector capable of providing electron bunches with variable parameters. The photoinjector is based on the 1+1/2 cell DESY-type gun followed by two superconducting cavities. It also includes a magnetic bunch compressor, a round-to-flat beam transformer and a low-energy experimental area for beam physics experiments and beam diagnostics R&D. In this paper, we explore, via beam dynamics simulations, the performance of the photoinjector for different operating scenarios.
Date: August 1, 2010
Creator: Piot, P.; U., /Fermilab /Northern Illinois; Sun, Y. E.; Church, M. & /Fermilab
Object Type: Article
System: The UNT Digital Library
Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet) (open access)

Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet)

Fact sheet describing NREL CSP Program capabilities in the area of thermal storage and advanced heat transfer fluids: measuring thermophysical properties, measuring fluid flow and heat transfer, and simulating flow of thermal energy and fluid.
Date: August 1, 2010
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Lessons Learned From Developing Reactor Pressure Vessel Steel Embrittlement Database (open access)

Lessons Learned From Developing Reactor Pressure Vessel Steel Embrittlement Database

Materials behaviors caused by neutron irradiation under fission and/or fusion environments can be little understood without practical examination. Easily accessible material information system with large material database using effective computers is necessary for design of nuclear materials and analyses or simulations of the phenomena. The developed Embrittlement Data Base (EDB) at ORNL is this comprehensive collection of data. EDB database contains power reactor pressure vessel surveillance data, the material test reactor data, foreign reactor data (through bilateral agreements authorized by NRC), and the fracture toughness data. The lessons learned from building EDB program and the associated database management activity regarding Material Database Design Methodology, Architecture and the Embedded QA Protocol are described in this report. The development of IAEA International Database on Reactor Pressure Vessel Materials (IDRPVM) and the comparison of EDB database and IAEA IDRPVM database are provided in the report. The recommended database QA protocol and database infrastructure are also stated in the report.
Date: August 1, 2010
Creator: Wang, Jy-An John
Object Type: Report
System: The UNT Digital Library
High precision tune and coupling measurements and tune/coupling feedback in RHIC (open access)

High precision tune and coupling measurements and tune/coupling feedback in RHIC

Precision measurement and control of the betatron tunes and betatron coupling in RHIC are required for establishing and maintaining both good operating conditions and, particularly during the ramp to high beam energies, high proton beam polarization. While the proof-of-principle for simultaneous tune and coupling feedback was successfully demonstrated earlier, routine application of these systems has only become possible recently. Following numerous modifications for improved measurement resolution and feedback control, the time required to establish full-energy beams with the betatron tunes and coupling regulated by feedback was reduced from several weeks to a few hours. A summary of these improvements, select measurements benefitting from the improved resolution and a review of system performance are the subject of this report.
Date: August 1, 2010
Creator: Minty, M.; Curcio, A.; Dawson, C.; Degen, C.; Luo, Y.; Marr, G. et al.
Object Type: Report
System: The UNT Digital Library
Present Limits on the Precision of SM Predictions for Jet Energies (open access)

Present Limits on the Precision of SM Predictions for Jet Energies

We investigate the impact of theoretical uncertainties on the accuracy of measurements involving hadronic jets. The analysis is performed using events with a Z boson and a single jet observed in p{bar p} collisions at {radical}s = 1.96 TeV in 4.6 fb{sup -1} of data from the Collider Detector at Fermilab (CDF). The transverse momenta (p{sub T}) of the jet and the boson should balance each other due to momentum conservation in the plane transverse to the direction of the p and {bar p} beams. We evaluate the dependence of the measured p{sub T}-balance on theoretical uncertainties associated with initial and final state radiation, choice of renormalization and factorization scales, parton distribution functions, jet-parton matching, calculations of matrix elements, and parton showering. We find that the uncertainty caused by parton showering at large angles is the largest amongst the listed uncertainties. The proposed method can be re-applied at the LHC experiments to investigate and evaluate the uncertainties on the predicted jet energies. The distributions produced at the CDF environment are intended for comparison to those from modern event generators and new tunes of parton showering.
Date: August 1, 2010
Creator: Paramonov, A. A.; Canelli, F.; D'Onofrio, M.; Frisch, H. J. & Mrenna, S.
Object Type: Article
System: The UNT Digital Library