Nuclear physics with a medium-energy Electron-Ion Collider (open access)

Nuclear physics with a medium-energy Electron-Ion Collider

A polarized ep/eA collider (Electron-Ion Collider, or EIC) with variable center-of-mass energy {radical}s {approx} 20-70 GeV and a luminosity {approx}10{sup 34} cm{sup -2} s{sup -1} would be uniquely suited to address several outstanding questions of Quantum Chromodynamics (QCD) and the microscopic structure of hadrons and nuclei: (i) the three-dimensional structure of the nucleon in QCD (sea quark and gluon spatial distributions, orbital motion, polarization, correlations); (ii) the fundamental color fields in nuclei (nuclear parton densities, shadowing, coherence effects, color transparency); (iii) the conversion of color charge to hadrons (fragmentation, parton propagation through matter, in-medium jets). We briefly review the conceptual aspects of these questions and the measurements that would address them, emphasizing the qualitatively new information that could be obtained with the collider. Such a medium-energy EIC could be realized at Jefferson Lab after the 12 GeV Upgrade (MEIC), or at Brookhaven National Lab as the low-energy stage of eRHIC.
Date: June 1, 2012
Creator: A. Accardi, V. Guzey, A. Prokudin, C. Weiss
System: The UNT Digital Library
Extending Performance and Evaluating Risks of PV Systems Failure Using a Fault Tree and Event Tree Approach: Analysis of the Possible Application (open access)

Extending Performance and Evaluating Risks of PV Systems Failure Using a Fault Tree and Event Tree Approach: Analysis of the Possible Application

Performance and reliability of photovoltaic (PV) systems are important issues in the overall evaluation of a PV plant and its components. While performance is connected to the amount of energy produced by the PV installation in the working environmental conditions, reliability impacts the availability of the system to produce the expected amount of energy. In both cases, the evaluation should be done considering information and data coming from indoor as well as outdoor tests. In this paper a way of re-thinking performance, giving it a probabilistic connotation, and connecting the two concepts of performance and reliability is proposed. The paper follows a theoretical approach and discusses the way to obtaining such information, facing benefits and problems. The proposed probabilistic performance accounts for the probability of the system to function correctly, thus passing through the complementary evaluation of the probability of system malfunctions and consequences. Scenarios have to be identified where the system is not functioning properly or at all. They are expected to be combined in a probabilistic safety analysis (PSA) based approach, providing not only the required probability, but also being capable of giving a prioritization of the risks and the most dominant scenario associated to a specific situation. …
Date: June 3, 2012
Creator: A., Colli
System: The UNT Digital Library
Search for High-Mass States with One Lepton Plus Missing Transverse Momentum in Proton-Proton Collisions at $\sqrt{s} with the ATLAS Detector (open access)

Search for High-Mass States with One Lepton Plus Missing Transverse Momentum in Proton-Proton Collisions at $\sqrt{s} with the ATLAS Detector

The ATLAS detector is used to search for high-mass states, such as heavy charged gauge bosons (W{prime},W*), decaying to a charged lepton (electron or muon) and a neutrino. Results are presented based on the analysis of ppcollisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 36 pb{sup -1}. No excess beyond standard model expectations is observed. A W{prime} with sequential standard model couplings is excluded at 95% confidence level for masses below 1.49 TeV, and a W* (charged chiral boson) for masses below 1.35 TeV.
Date: June 20, 2012
Creator: Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat et al.
System: The UNT Digital Library
Diffractive Dijet Production in $\bar{p}p$ Collisions at $\sqrt{s}=1.96$ TeV (open access)

Diffractive Dijet Production in $\bar{p}p$ Collisions at $\sqrt{s}=1.96$ TeV

We report on a study of diffractive dijet production in {bar p}p collisions at {radical}s = 1.96 TeV using the CDF II detector at the Fermilab Tevatron {bar p}p collider. A data sample from 310 pb{sup -1} of integrated luminosity collected by triggering on a high transverse energy jet, E{sub T}{sup jet}, in coincidence with a recoil antiproton detected in a Roman pot spectrometer is used to measure the ratio of single-diffractive to inclusive-dijet event rates as a function of x{sup {bar p}} of the interacting parton in the antiproton, the Bjorken-x, x{sub Bj}{sup {bar p}}, and a Q{sup 2} {approx} (E{sub T}{sup jet}){sup 2} in the ranges 10{sup -3} < x{sub Bj}{sup {bar p}} < 10{sup -1} and 10{sup 2} < Q{sup 2} < 10{sup 4} GeV{sup 2}, respectively. Results are presented for the region of {bar p}-momentum-loss fraction 0.03 < {zeta}{sub {bar p}} < 0.09 and a four-momentum transfer squared t{sub {bar p}} > -4 GeV{sup 2}. The t{sub {bar p}} dependence is measured as a function of Q{sup 2} and x{sub Bj}{sup {bar p}} and compared with that of inclusive single diffraction dissociation. We find weak x{sub Bj}{sup bar p}} and Q{sup 2} dependencies in the ratio …
Date: June 1, 2012
Creator: Aaltonen, T.; Albrow, M.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A. et al.
System: The UNT Digital Library
Measurement of the differential cross section $d\sigma/dt$ in elastic $p\bar{p}$ scattering at $\sqrt{s}=1.96$ TeV (open access)

Measurement of the differential cross section $d\sigma/dt$ in elastic $p\bar{p}$ scattering at $\sqrt{s}=1.96$ TeV

We present a measurement of the elastic differential cross section differential cross section d{sigma}(p{bar p}{yields}p{bar p})/dt as a function of the four-momentum-transfer squared t. The data sample corresponds to an integrated luminosity of {approx}31 nb{sup -1} collected with the D0 detector using dedicated Tevatron p{bar p} Collider operating conditions at {radical}s = 1.96 TeV and covers the range 0.26 < |t| < 1.2 GeV{sup 2}. For |t| < 0.6 GeV{sup 2}, d{sigma}/dt is described by an exponential function of the form Ae{sup -b|t|} with a slope parameter b = 16.86 {+-} 0.10 (stat) {+-} 0.20 (syst) GeV{sup -2}. A change in slope is observed at |t| {approx} 0.6 GeV{sup 2}, followed by a more gradual |t| dependence with increasing values of |t|.
Date: June 1, 2012
Creator: Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D. et al.
System: The UNT Digital Library
Boosted Objects: A Probe of Beyond the Standard Model Physics (open access)

Boosted Objects: A Probe of Beyond the Standard Model Physics

We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools developed to meet the challenge of reconstructing and isolating these topologies. In the second part, we present new results comparing the performance of jet grooming techniques and top tagging algorithms on a common set of benchmark channels. We also study the sensitivity of jet substructure observables to the uncertainties in Monte Carlo predictions.
Date: June 12, 2012
Creator: Abdesselam, A.; U., /Oxford; Kuutmann, E.Bergeaas; /DESY; Bitenc, U.; U., /Freiburg et al.
System: The UNT Digital Library
Insights Into the High-Energy Gamma-Ray Emission of Markarian 501 From Extensive Multifrequency Observations in the Fermi Era (open access)

Insights Into the High-Energy Gamma-Ray Emission of Markarian 501 From Extensive Multifrequency Observations in the Fermi Era

None
Date: June 14, 2012
Creator: Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J. et al.
System: The UNT Digital Library
PRECEDENTS FOR AUTHORIZATION OF CONTENTS USING DOSE RATE MEASUREMENTS (open access)

PRECEDENTS FOR AUTHORIZATION OF CONTENTS USING DOSE RATE MEASUREMENTS

For the transportation of Radioactive Material (RAM) packages, the requirements for the maximum allowed dose rate at the package surface and in its vicinity are given in Title 10 of the Code of Federal Regulations, Section 71.47. The regulations are based on the acceptable dose rates to which the public, workers, and the environment may be exposed. As such, the regulations specify dose rates, rather than quantity of radioactive isotopes and require monitoring to confirm the requirements are met. 10CFR71.47 requires that each package of radioactive materials offered for transportation must be designed and prepared for shipment so that under conditions normally incident to transportation the radiation level does not exceed 2 mSv/h (200 mrem/h) at any point on the external Surface of the package, and the transport index does not exceed 10. Before shipment, the dose rate of the package is determined by measurement, ensuring that it conforms to the regulatory limits, regardless of any analyses. This is the requirement for all certified packagings. This paper discusses the requirements for establishing the dose rates when shipping RAM packages and the precedents for meeting these requirements by measurement.
Date: June 5, 2012
Creator: Abramczyk, G.; Bellamy, S.; Nathan, S. & Loftin, B.
System: The UNT Digital Library
Detection of a Spectral Break in the Extra Hard Component of GRB 090926A (open access)

Detection of a Spectral Break in the Extra Hard Component of GRB 090926A

None
Date: June 12, 2012
Creator: Ackermann, M.; Ajello, M.; Asano, K.; Axelsson, M.; Baldini, L.; Ballet, J. et al.
System: The UNT Digital Library
Fermi-LAT Search for Pulsar Wind Nebulae Around Gamma-Ray Pulsars (open access)

Fermi-LAT Search for Pulsar Wind Nebulae Around Gamma-Ray Pulsars

None
Date: June 15, 2012
Creator: Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D. et al.
System: The UNT Digital Library
A Terrestrial Search for Dark Contents of the Vacuum, Such as Dark Energy, Using Atom Interferometry (open access)

A Terrestrial Search for Dark Contents of the Vacuum, Such as Dark Energy, Using Atom Interferometry

We describe the theory and first experimental work on our concept for searching on earth for the presence of dark contents of the vacuum (DCV) using atom interferometry. Specifically, we have in mind any DCV that has not yet been detected on a laboratory scale, but which might manifest itself as dark energy on the cosmological scale. The experimental method uses two atom interferometers to cancel the effect of earth's gravity and diverse noise sources. It depends upon two assumptions: first, that the DCV possesses some space inhomogeneity in density, and second that it exerts a sufficiently strong nongravitational force on matter. The motion of the apparatus through the DCV should then lead to an irregular variation in the detected matter-wave phase shift. We discuss the nature of this signal and note the problem of distinguishing it from instrumental noise. We also discuss the relation of our experiment to what might be learned by studying the noise in gravitational wave detectors such as LIGO. The paper concludes with a projection that a future search of this nature might be carried out using an atom interferometer in an orbiting satellite. The laboratory apparatus is now being constructed.
Date: June 11, 2012
Creator: Adler, Ronald J.; /Stanford U., HEPL /San Francisco State U.; Muller, Holger; /UC, Berkeley; Perl, Martin L. & /KIPAC, Menlo Park /SLAC
System: The UNT Digital Library
Combined Limits on WIMPs from the CDMS and EDELWEISS Experiments (open access)

Combined Limits on WIMPs from the CDMS and EDELWEISS Experiments

this is a report on WIMPs and CDMS and EDELWEISS Experiments
Date: June 1, 2012
Creator: Ahmed, Z.; Akerib, D. S.; Armengaud, E.; Arrenberg, S.; Augier, C.; Bailey, C. N. et al.
System: The UNT Digital Library
Results from a Low-Energy Analysis of the CDMS II Germanium Data (open access)

Results from a Low-Energy Analysis of the CDMS II Germanium Data

None
Date: June 4, 2012
Creator: Ahmed, Z.; Akerib, D. S.; Arrenberg, S.; Bailey, C. N.; Balakishiyeva, D.; Baudis, L. et al.
System: The UNT Digital Library
Search for Inelastic Dark Matter with the CDMS II Experiment (open access)

Search for Inelastic Dark Matter with the CDMS II Experiment

None
Date: June 4, 2012
Creator: Ahmed, Z.; Akerib, D. S.; Arrenberg, S.; Bailey, C. N.; Balakishiyeva, D.; Baudis, L. et al.
System: The UNT Digital Library
Process Optimization for High Efficiency Heterojunction c-Si Solar Cells Fabrication Using Hot-Wire Chemical Vapor Deposition: Preprint (open access)

Process Optimization for High Efficiency Heterojunction c-Si Solar Cells Fabrication Using Hot-Wire Chemical Vapor Deposition: Preprint

The researchers extensively studied the effects of annealing or thermal history of cell process on the minority carrier lifetimes of FZ n-type c-Si wafers with various i-layer thicknesses from 5 to 60 nm, substrate temperatures from 100 to 350 degrees C, doped layers both p- and n-types, and transparent conducting oxide (TCO).
Date: June 1, 2012
Creator: Ai, Y.; Yuan, H. C.; Page, M.; Nemeth, W.; Roybal, L. & Wang, Q.
System: The UNT Digital Library
A Low-threshold Analysis of CDMS Shallow-site Data (open access)

A Low-threshold Analysis of CDMS Shallow-site Data

Data taken during the final shallow-site run of the first tower of the Cryogenic Dark Matter Search (CDMS II) detectors have been reanalyzed with improved sensitivity to small energy depositions. Four {approx}224 g germanium and two {approx}105 g silicon detectors were operated at the Stanford Underground Facility (SUF) between December 2001 and June 2002, yielding 118 live days of raw exposure. Three of the germanium and both silicon detectors were analyzed with a new low-threshold technique, making it possible to lower the germanium and silicon analysis thresholds down to the actual trigger thresholds of {approx}1 and {approx}2 keV, respectively. Limits on the spin-independent cross section for weakly interacting massive particles (WIMPs) to elastically scatter from nuclei based on these data exclude interesting parameter space for WIMPs with masses below 9 GeV/c{sup 2}. Under standard halo assumptions, these data partially exclude parameter space favored by interpretations of the DAMA/LIBRA and CoGeNT experiments data as WIMP signals, and exclude new parameter space for WIMP masses between 3 and 4 GeV/c{sup 2}.
Date: June 4, 2012
Creator: Akerib, D. S.; Attisha, M. J.; Baudis, L.; Bauer, D. A.; Bolozdynya, A. I.; Brink, P. L. et al.
System: The UNT Digital Library
SELECTION OF SURPLUS PLUTONIUM MATERIALS FOR DISPOSITION TO WIPP (open access)

SELECTION OF SURPLUS PLUTONIUM MATERIALS FOR DISPOSITION TO WIPP

The U.S. Department of Energy (DOE) is preparing a Surplus Plutonium Disposition (SPD) Supplemental Environmental Impact Statement (SEIS). Included in the evaluation are up to 6 metric tons (MT) of plutonium in the form of impure oxides and metals for which a disposition plan has not been decided, among options that include preparation as feed for the Mixed Oxide Fuel Fabrication Facility; disposing to high-level waste through the Savannah River Site (SRS) HB Line and H Canyon; can-in-canister disposal using the SRS Defense Waste Processing Facility; and preparation for disposal at the Waste Isolation Pilot Plant (WIPP). DOE and SRS have identified at least 0.5 MT of plutonium that, because of high levels of chemical and isotopic impurities, is impractical for disposition by methods other than the WIPP pathway. Characteristics of these items and the disposition strategy are discussed.
Date: June 8, 2012
Creator: Allender, J.; Mcclard, J. & Christopher, J.
System: The UNT Digital Library
Enhancing the Sensitivity to New Physics in the top-antitop Invariant Mass Distribution (open access)

Enhancing the Sensitivity to New Physics in the top-antitop Invariant Mass Distribution

We propose selection cuts on the LHC t{bar t} production sample which should enhance the sensitivity to New Physics signals in the study of the t{bar t} invariant mass distribution. We show that selecting events in which the t{bar t} object has little transverse and large longitudinal momentum enlarges the quark-fusion fraction of the sample and therefore increases its sensitivity to New Physics which couples to quarks and not to gluons. We find that systematic error bars play a fundamental role and assume a simple model for them. We check how a non-visible new particle would become visible after the selection cuts enhance its resonance bump. A final realistic analysis should be done by the experimental groups with a correct evaluation of the systematic error bars.
Date: June 14, 2012
Creator: Alvarez, Ezequiel & /SLAC, /Univ. Nacional San Luis
System: The UNT Digital Library
Simplified Models for LHC New Physics Searches (open access)

Simplified Models for LHC New Physics Searches

This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the 'Topologies for Early LHC Searches' workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first {approx} 50-500 pb{sup -1} of data and those motivated by supersymmetric models. This note largely summarizes material posted …
Date: June 1, 2012
Creator: Alves, Daniele; Arkani-Hamed, Nima; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua et al.
System: The UNT Digital Library
The Electromagnetic Self-Energy Contribution to M_p - M_n and the Isovector Nucleon Magnetic Polarizability (open access)

The Electromagnetic Self-Energy Contribution to M_p - M_n and the Isovector Nucleon Magnetic Polarizability

We update the determination of the isovector nucleon electromagnetic self-energy, valid to leading order in QED. A technical oversight in the literature concerning the elastic contribution to Cottingham's formula is corrected and modern knowledge of the structure functions is used to precisely determine the inelastic contribution. We find {delta}M{sub p-n}{sup {gamma}} = 1.30(03)(47) MeV. The largest uncertainty arises from a subtraction term required in the dispersive analysis, which can be related to the isovector magnetic polarizability. With plausible model assumptions, we can combine our calculation with additional input from lattice QCD to constrain this polarizability as: {beta}{sub p-n} = -0.87(85) x 10{sup -4} fm{sup 3}.
Date: June 1, 2012
Creator: Andre Walker-Loud, Carl E. Carlson, Gerald A. Miller
System: The UNT Digital Library
Direct Hadron Production in Hadronic Collisions (open access)

Direct Hadron Production in Hadronic Collisions

None
Date: June 7, 2012
Creator: Arleo, Francois; Brodsky, Stanley J.; Hwang, Dae Sung & Sickles, Anne M.
System: The UNT Digital Library
Assessment of the Geothermal System Near Stanley, Idaho (open access)

Assessment of the Geothermal System Near Stanley, Idaho

The City of Stanley, Idaho (population 63) is situated in the Salmon River valley of the central Idaho highlands. Due to its location and elevation (6270 feet amsl) it is one of the coldest locales in the continental U.S., on average experiencing frost 290 days of the year as well as 60 days of below zero (oF) temperatures. Because of high snowfall (76 inches on average) and the fact that it is at the terminus of its rural grid, the city also frequently endures extended power outages during the winter. To evaluate its options for reducing heating costs and possible local power generation, the city obtained a rural development grant from the USDA and commissioned a feasibility study through author Roy Mink to determine whether a comprehensive site characterization and/or test drilling program was warranted. Geoscience students and faculty at Idaho State University (ISU), together with scientists from the Idaho Geological Survey (IGS) and Idaho National Laboratory (INL) conducted three field data collection campaigns between June, 2011 and November, 2012 with the assistance of author Beckwith who arranged for food, lodging and local property access throughout the field campaigns. Some of the information collected by ISU and the IGS were …
Date: June 1, 2012
Creator: Armstrong, Trent; Welhan, John & McCurry, Mike
System: The UNT Digital Library
Tunable Plasmonic Nanogap Resonator (open access)

Tunable Plasmonic Nanogap Resonator

None
Date: June 19, 2012
Creator: BOnd, T.; Bora, M.; Chang, A. & Miles, R.
System: The UNT Digital Library
Hardware Architecture for Measurements for 50-V Battery Modules (open access)

Hardware Architecture for Measurements for 50-V Battery Modules

Energy storage devices, especially batteries, have become critical for several industries including automotive, electric utilities, military and consumer electronics. With the increasing demand for electric and hybrid electric vehicles and the explosion in popularity of mobile and portable electronic devices such as laptops, cell phones, e-readers, tablet computers and the like, reliance on portable energy storage devices such as batteries has likewise increased. Because many of the systems these batteries integrated into are critical, there is an increased need for an accurate in-situ method of monitoring battery state-of-health. Over the past decade the Idaho National Laboratory (INL), Montana Tech of the University of Montana (Tech), and Qualtech Systems, Inc. (QSI) have been developing the Smart Battery Status Monitor (SBSM), an integrated battery management system designed to monitor battery health, performance and degradation and use this knowledge for effective battery management and increased battery life. Key to the success of the SBSM is an in-situ impedance measurement system called the Impedance Measurement Box (IMB). One of the challenges encountered has been development of a compact IMB system that will perform rapid accurate measurements of a battery impedance spectrum working with higher voltage batteries of up to 300 volts. This paper discusses …
Date: June 1, 2012
Creator: Bald, Patrick; Juras, Evan; Christophersen, Jon P. & Morrison, William
System: The UNT Digital Library