Physics Commons^™

Multimessenger Search For Sources Of Gravitational Waves And High-Energy Neutrinos: Initial Results For Ligo-Virgo And Icecube, M. G. Aartsen, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010 run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of gravitational-wave emission energy of 10^-2M⊙c² at ∼150Hz with …

Route To Optimal Generation Of Soft X-Ray High Harmonics With Synthesized Two-Color Laser Pulses, Cheng Jin, Guoli Wang, Anh-Thu Le, C. D. Lin

Physics Faculty Research & Creative Works

High harmonics extending to X-rays have been generated from gases by intense lasers. To establish these coherent broadband radiations as an all-purpose tabletop light source for general applications in science and technology, new methods are needed to overcome the present low conversion efficiencies. Here we show that the conversion efficiency may be drastically increased with an optimized two-color pulse. By employing an optimally synthesized 2-µm mid-infrared laser and a small amount of its third harmonic, we show that harmonic yields from sub- to few-keV energy can be increased typically by ten-fold over the optimized single-color one. By combining with favorable …

Fully Differential Study Of Interference Effects In The Ionization Of H₂ By Proton Impact, Sachin D. Sharma, T. P. Arthanayaka, Ahmad Hasan, B. R. Lamichhane, J. Remolina, Adolph P. Smith, Michael Schulz

Physics Faculty Research & Creative Works

We have measured fully differential cross sections for ionization of H₂ by 75-keV proton impact. The coherence length of the projectile beam was varied by changing the distance between a collimating slit and the target. By comparing the cross sections measured for large and small coherence lengths pronounced interference effects could be identified in the data. A surprising result is that the phase angle in the interference term is primarily determined by the momentum transfer and only to a lesser extent by the recoil-ion momentum.

Search For Standard Model Production Of Four Top Quarks In The Lepton + Jets Channel In Pp Collisions At S√=8 Tev, The Cms Collaboration, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

A search is presented for standard model (SM) production of four top quarks (t¯tt¯t) in pp collisions in the lepton + jets channel. The data correspond to an integrated luminosity of 19.6 fb−1 recorded at a centre-of-mass energy of 8TeV with the CMS detector at the CERN LHC. The expected cross section for SM t¯tt¯t production is SM t¯tt¯t 1 fb. A combination of kinematic reconstruction and multivariate techniques is used to distinguish between the small signal and large background. The data are consistent with expectations of the SM, and an upper limit of 32 fb is set at a …

Measurement Of “Pretzelosity” Asymmetry Of Charged Pion Production In Semi-Inclusive Deep Inelastic Scattering On A Polarized 3He Target, K. Allada, C. Dutta, A. Kolarkar, Wolfgang Korsch, Y. Zhang, X. Qian, J. Huang, J. Katich, Y. Wang, K. Aniol, J. R. M. Annand, T. Averett

Physics and Astronomy Faculty Publications

An experiment to measure single-spin asymmetries of semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized ³He target was performed at Jefferson Laboratory in the kinematic region of 0.16<x<0.35 and 1.42<2.7 GeV² Pretzelosity asymmetries on ³He, which are expressed as the convolution of the h^⊥_1T transverse-momentum-dependent distribution functions and the Collins fragmentation functions in the leading order, were measured for the first time. Under the effective polarization approximation, we extracted the corresponding neutron asymmetries from the measured ³He asymmetries and cross-section ratios between the proton and ³He. Our results show that both …

Weak Measurement And Bohmian Conditional Wave Functions, Travis Norsen

Physics: Faculty Publications

It was recently pointed out (and demonstrated experimentally) by Lundeen et al. that the wave function of a particle (more precisely, the wave function possessed by each member of an ensemble of identically-prepared particles) can be "directly measured" using weak measurement. Here it is shown that if this same technique is applied, with appropriate post-selection, to one particle from a (perhaps entangled) multi-particle system, the result is precisely the so-called "conditional wave function" of Bohmian mechanics. Thus, a plausibly operationalist method for defining the wave function of a quantum mechanical sub-system corresponds to the natural definition of a sub-system wave …

Centered-Difference Applications For Schrödinger's Equation, Matthew Thomas Murachver

Physics

This project enumerates methods utilizing discretized centered-difference approximations on the second order differential equation for quantum particles known as Schrodinger’s Equation. An eigenvalue-eigenfunction scheme is developed to sieve for valid solutions to The Time Independent Schrodinger Equation. Additionally the Crank-Nicolson method is applied to the Time Dependent Schrodinger Equation to describe wavefunction (eigenfunction) time evolution. The validity of these methods is discussed with applications to several fundamental pedagogical introductory quantum mechanic systems.

Particle Moment Canting In Cofe2O4 Nanoparticles, K. Hasz, Yumi Ijiri, Kathryn L. Krycka, Julie A. Borchers, R.A. Booth, S. Oberdick, S.A. Majetich

Faculty & Staff Scholarship

Polarization-analyzed small-angle neutron scattering methods are used to determine the spin morphology in high crystalline anisotropy, 11 nm diameter CoFe2O4 nanoparticle assemblies with randomly oriented easy axes. In moderate to high magnetic fields, the nanoparticles adopt a uniformly canted structure, rather than forming domains, shells, or other arrangements. The observed canting angles agree quantitatively with those predicted from an energy model dominated by Zeeman and anisotropy competition, with implications for the technological use of such nanoparticles.

Incoherent Scatter Radar Observations Of Dynamic Ion Composition Changes At High Latitudes During Geomagnetic Storms, Bryan C. Wright

Doctoral Dissertations and Master's Theses

Two new methods are developed for estimating F region ion composition from field-aligned incoherent scatter radar (ISR) measurements. These methods address incoherent scatter spectra temperature-mass ambiguities by self-consistently modeling ion temperature profiles as a function of electric fields and plasma interactions with the neutral atmosphere. These two new methods improve on previous, similar work developed in Zettergren et al. [2010,2011] by incorporating more accurate physical models and improving the estimation procedures. These techniques enable studies of ionospheric composition during highly disturbed conditions and are suitable for data collected with short integration times (2-10 minutes). The improved models incorporate the effects …

Cross-Disciplinary Sciences At Gettysburg College: Second Annual Poster Presentation, X-Sig

Student Publications

This booklet includes Biology student presentations by: Taylor Bury, Abigail Dworkin-Brodsky, Mary Pearce, Jasper Leavitt, Morgan Panzer, Ellen Petley, Kalli Qutub, Taylor Randell, Samantha Eck, Lana McDowell, Jenn Soroka, Celina Harris, Natalie Tanke, Alexandra Turano, and Caroline Garliss.

This booklet includes Biochemistry & Molecular Biology student presentations by: Matthew Dunworth, Andrew Sydenstricker, Brianne Tomko, Albert Vill, Warren Campbell, David Van Doren, Kevin Mrugalski, Stacey Heaver, Alecia Achimovich, and Katherine Boas.

This booklet includes Chemistry student presentations by: Kristen Baker, Laura Lee, Kathryn Fodale, Daniel Ruff, Michael Counihan, Ida DiMucci, Joshua Sgroi, Celina Harris, and Natalie Tanke.

This booklet include Health …

Timed/Saber Satellite Investigations Of Mesospheric Gravity Wave Variances Over The Andes, Jonathan Pugmire, Michael J. Taylor, Yucheng Zhao, Dominique Pautet, James Russell

Graduate Student Presentations

Focusing on data from the SABER instrument aboard the TIMED satellite temperature variances are determined as a function of altitude to quantify small scale gravity waves. This was done using IDL software to extract all the temperature profile measurements that were measured by SABER within a limited geographical area, centered on our ground-based optical imager at Cerro Pachon, Chile (30.3°S, 70.7°S). Then large-scale tidal waves, with wavenumbers 0-6, were removed from each profile revealing the gravity wave perturbations. The temperature variance were computed and recorded at several altitudes. Temperature variances reveal possible increased activity due to mountain waves. Mountain waves …

Detecting Corrosion Utilizing A Passive Rfid Tag, Emily Layden

Von Braun Symposium Student Posters

No abstract provided.

Digital Optical Correlator X-Ray Telescope Alignment Tracking System, Tomasz Marek Lis

Von Braun Symposium Student Posters

No abstract provided.

Development Of An Optically-Actuated Carbon Nanotube (Cnt) Laminated Composite, John Alcorn

Von Braun Symposium Student Posters

No abstract provided.

Dead-Box Helicase Proteins Disrupt Rna Tertiary Structure Through Helix Capture, Cynthia Pan, Jeffrey P. Potratz, Brian Cannon, Zachary B. Simpson, Jessica L. Ziehr, Pilar Tijerina, Rick Russell

Physics: Faculty Publications and Other Works

DEAD-box helicase proteins accelerate folding and rearrangements of highly structured RNAs and RNA–protein complexes (RNPs) in many essential cellular processes. Although DEAD-box proteins have been shown to use ATP to unwind short RNA helices, it is not known how they disrupt RNA tertiary structure. Here, we use single molecule fluorescence to show that the DEAD-box protein CYT-19 disrupts tertiary structure in a group I intron using a helix capture mechanism. CYT-19 binds to a helix within the structured RNA only after the helix spontaneously loses its tertiary contacts, and then CYT-19 uses ATP to unwind the helix, liberating the product …

The Immersion Mode Ice Nucleation Behavior Of Mineral Dusts: A Comparison Of Different Pure And Surface Modified Dusts, S. Augustin-Bauditz, H. Wex, S. Kanter, M. Ebert, D. Niedermeier, F. Stolz, A. Prager, F. Stratmann

Michigan Tech Publications, Part 1

In this study we present results from immersion freezing experiments with size-segregated mineral dust particles. Besides two already existing data sets for Arizona Test Dust (ATD), and Fluka kaolinite, we show two new data sets for illite-NX, which consists mainly of illite, a clay mineral, and feldspar, a common crustal material. The experiments were carried out with the Leipzig Aerosol Cloud Interaction Simulator. After comparing the different dust samples, it became obvious that the freezing ability was positively correlated with the K-feldspar content. Furthermore, a comparison of the composition of the ATD, illite-NX, and feldspar samples suggests that within the …

Fate Of The Bose Insulator In The Limit Of Strong Localization And Low Cooper-Pair Density In Ultrathin Films, Shawna M. Hollen, G. E. Fernandes, J. M. Xu, J M. Valles Jr.

Physics & Astronomy

A Bose insulator composed of a low density of strongly localized Cooper pairs develops at the two-dimensional superconductor to insulator transition (SIT) in a number of thin film systems. Investigations of ultrathin amorphous PbBi films far from the SIT described here provide evidence that the Bose insulator gives way to a second insulating phase with decreasing film thickness. At a critical film thickness dc the magnetoresistance changes sign from positive, as expected for boson transport, to negative, as expected for fermion transport, signs of local Cooper-pair phase coherence effects on transport vanish, and the transport activation energy exhibits a kink. …

Physics: Rethinking The Foundations, Kevin H. Knuth

Physics Faculty Scholarship

Physics is traditionally conceived of as a set of laws that universally governs the behavior of physical systems. These laws, however they are decreed, are believed to govern the behavior of not only everything in the universe, but the form of the universe itself. However, this traditional concept of physics as a universal governance is at odds with our modern theories of quantum mechanics and relativity, which place the observer and information in a central role. In this talk, I aim to rethink the foundations and attempt to build physics from the bottom up based on a very simple foundational …

An Analysis Of The Gravitational Waves Null Memory, Maria Babiuc-Hamilton

Physics Faculty Research

Gravitational wave astronomy sees (hears) gravitational waves by observing the phenomena of gravitational and electromagnetic memory, and the formation of trapped surfaces and horizons.

Higgs Boson Mass In The Standard Model At Two-Loop Order And Beyond, Steve P. Martin, David G. Robertson

Physics Faculty Scholarship

We calculate the mass of the Higgs boson in the standard model in terms of the underlying Lagrangian parameters at complete 2-loop order with leading 3-loop corrections. A computer program implementing the results is provided. The program also computes and minimizes the standard model effective potential in Landau gauge at 2-loop order with leading 3-loop corrections.

Keck-I Mosfire Spectroscopy Of Compact Star-Forming Galaxies At Z ≳ 2: High Velocity Dispersions In Progenitors Of Compact Quiescent Galaxies, Guillermo Barro, Jonathan R. Trump, David C. Koo, Avishai Dekel, Susan A. Kassin, Dale D. Kocevski, Sandra M. Faber, Arjen Van Der Wel, Yicheng Guo, Pablo G. Pérez-González, Elisa Toloba, Jerome J. Fang, Camilla Pacifici, Raymond Simons, Randy D. Campbell, Daniel Ceverino, Steven L. Finkelstein, Bob Goodrich, Marc Kassis, Anton M. Koekemoer, Nicholas P. Konidaris, Rachel C. Livermore, James E. Lyke, Bahram Mobasher, Hooshang Nayyeri, Michael Peth, Joel R. Primack, Luca Rizzi, Rachel S. Somerville, Gregory D. Wirth, Adi Zolotov

Physics and Astronomy Faculty Publications

We present Keck-I MOSFIRE near-infrared spectroscopy for a sample of 13 compact star-forming galaxies (SFGs) at redshift 2 ≤ z ≤ 2.5 with star formation rates of SFR ~ 100 M _☉ yr^–1 and masses of log(M/M _☉) ~10.8. . . .

For the remainder of the abstract, please visit:

http://dx.doi.org/10.1088/0004-637X/795/2/145

Pre-Breakdown Arcing And Electrostatic Discharge In Dielectrics Under High Dc Electric Field Stress, Allen Andersen, Jr Dennison

Journal Articles

Highly disordered insulating materials exposed to high electric fields will, over time, degrade and fail, potentially causing catastrophic damage to devices. Step-up to electrostatic discharge (ESD) tests were performed for two common polymer dielectrics, low density polyethylene and polyimide. Pre-breakdown transient current spikes or arcs were observed, using both slow and high speed detection. These pre-ESD discharge phenomena are explained in terms of breakdown modes and defect generation on a microscopic scale. The field at which pre-breakdown arcing begins was compared to the onset field for electrostatic discharge at which complete breakdown occurs for each material studied. We present evidence …

Photophysical And Electronic Properties Of Low-Bandgap Semiconducting Polymers, Evan Lafalce

USF Tampa Graduate Theses and Dissertations

In this Ph.D. work, we investigate the optoelectronic properties of low-bandgap semiconducting polymers and project the potential for employing these materials in electronic and photonics devices, with a particular emphasis on use in organic solar cells. The field of organic solar cells is well developed and many of the fundamental aspects of device operation and material requirements have been established. However, there is still more work to be done in order for these devices to ultimately reach their full potential and achieve commercialization. Of immediate concern is the low power conversion efficiency demonstrated in these devices so far. In order …

Measurement Of Quasiparticle Transport In Aluminum Films Using Tungsten Transition-Edge Sensors, Jeffrey Yen, Benjamin Shank, Betty Young, Blas Cabrera, Paul Brink, Matthew Cherry, John Mark Kreikebaum, Robert Moffatt, Peter Redl, Astrid Tomada, Ted Tortorici

Faculty Publications

We report on experimental studies of phonon sensors which utilize quasiparticle diusion in thin aluminum films connected to tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al lms in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al lms using a simple diusion equation approach. These studies allow the design of phonon sensors with improved performance.

The Decomposed Bulge And Disc Size–Mass Relations Of Massive Galaxies At 1 < Z < 3 In Candels, V. A. Bruce, J. S. Dunlop, R. J. Mclure, M. Cirasuolo, F. Buitrago, R. A. A. Bowler, T. A. Targett, E. F. Bell, D. H. Mcintosh, A. Dekel, S. M. Faber, H. C. Ferguson, N. A. Grogin, W. Hartley, Dale D. Kocevski, A. M. Koekemoer, D. C. Koo, E. J. Mcgrath

Physics and Astronomy Faculty Publications

We have constructed a mass-selected sample of M_* > 10¹¹ M_⊙ galaxies at 1 < z < 3 in the CANDELS UKIDSS UDS and COSMOS fields and have decomposed these systems into their separate bulge and disc components according to their H₁₆₀-band morphologies. By extending this analysis to multiple bands, we have been able to conduct individual bulge and disc component SED fitting which has provided us with stellar-mass and star formation rate estimates for the separate bulge and disc components. Having utilized the new decomposed stellar-mass estimates, we confirm that the bulge components display a stronger size evolution than the discs. The median sizes of the bulge components is 3.09 ± 0.20 times smaller than similarly massive local galaxies over the …

The Bulge–Disc Decomposed Evolution Of Massive Galaxies At 1 < Z < 3 In Candels, V. A. Bruce, J. S. Dunlop, R. J. Mclure, M. Cirasuolo, F. Buitrago, R. A. A. Bowler, T. A. Targett, E. F. Bell, D. H. Mcintosh, A. Dekel, S. M. Faber, H. C. Ferguson, N. A. Grogin, W. Hartley, Dale D. Kocevski, A. M. Koekemoer, D. C. Zoo, E. J. Mcgrath

Physics and Astronomy Faculty Publications

We present the results of a new and improved study of the morphological and spectral evolution of massive galaxies over the redshift range 1 < z < 3. Our analysis is based on a bulge–disc decomposition of 396 galaxies with M_* > 10¹¹ M_⊙ uncovered from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) Wide Field Camera 3 (WFC3)/IR imaging within the Cosmological Evolution Survey (COSMOS) and UKIRT Infrared Deep Sky Survey (UKIDSS) UDS survey fields. We find that, by modelling the H₁₆₀ image of each galaxy with a combination of a de Vaucouleurs bulge (Sérsic index n = 4) and an exponential disc (n = 1), we can then …

Casimir Energies In Spherically Symmetric Background Potentials Revisited, Matthew Beauregard, Michael Bordag, Klaus Kirsten

Faculty Publications

In this paper we reconsider the formulation for the computation of the Casimir energy in spherically symmetric background potentials. Compared to the previous analysis, the technicalities are much easier to handle and final answers are surprisingly simple.

Measurement Of Quasiparticle Transport In Aluminum Films Using Tungsten Transition-Edge Sensors, J. J. Yen, B. Shank, Betty A. Young, Blas Cabrera, P. L. Brink, M. Cherry, J. M. Kreikebaum, R. Moffatt, P. Redl, A. Tomada, E. C. Tortorici

Physics

We report on experimental studies of phonon sensors which utilize quasiparticle diffusion in thin aluminum films connected to tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al films in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al films using a simple diffusion equation approach. These studies allow the design of phonon sensors with improved performance.

Optimization Of Nanograv's Time Allocation For Maximum Sensitivity To Single Sources, Brian Christy, Ryan Anella, Andrea N. Lommen, Lee Samuel Finn, Richard S. Camuccio, Emma Handzo

Physics & Astronomy Faculty Publications

Pulsar timing arrays (PTAs) are a collection of precisely timed millisecond pulsars (MSPs) that can search for gravitational waves (GWs) in the nanohertz frequency range by observing characteristic signatures in the timing residuals. The sensitivity of a PTA depends on the direction of the propagating GW source, the timing accuracy of the pulsars, and the allocation of the available observing time. The goal of this paper is to determine the optimal time allocation strategy among the MSPs in the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) for a single source of GW under a particular set of assumptions. We …

Near Horizon Geometry Of Strings Ending On Intersecting D8/D4-Branes, J. Estes, D. Krym, B. Van Pol

Publications and Research

We consider solutions of massive IIA supergravity corresponding to the half- BPS intersection of D8/D4-branes with fundamental strings. The 1 + 1-dimensional intersection preserves the symmetry D(2, 1; ; 1) × SO(4). We give a reduction and partial integration of the BPS equations for this symmetry group. We then specialize to the cases of enhanced supersymmetry corresponding to = −1/2,−2 or = 1. In the first case, we show that the only solution with enhanced symmetry is given by the AdS6 geometry describing the near horizon geometry of D8/D4-branes in the presence of an O8-plane. In the second case, we …