Gauge Transformations Of The Biconformal Connection, 2014 Utah State University
Gauge Transformations Of The Biconformal Connection, James Thomas Wheeler
All Physics Faculty Publications
We study the changes of the biconformal gauge fields under the local rotational and dilatational gauge transformations.
Rainich-Type Conditions For Perfect Fluid Spacetimes, 2014 Utah State University
Rainich-Type Conditions For Perfect Fluid Spacetimes, Dionisios Krongos, Charles G. Torre
Research Vignettes
In this worksheet we describe and illustrate a relatively simple set of new Rainich-type conditions on an n-dimensional spacetime which are necessary and sufficient for it to define a perfect fluid solution of the Einstein field equations. Procedures are provided which implement these Rainich-type conditions and which reconstruct the perfect fluid from the metric. These results provide an example of the idea of geometrization of matter fields in general relativity, which is a purely geometrical characterization of matter fields via the Einstein field equations.
Scattering Amplitudes In Flat Space And Anti-De Sitter Space, 2014 University of Tennessee - Knoxville
Scattering Amplitudes In Flat Space And Anti-De Sitter Space, Savan Kharel
Doctoral Dissertations
We calculate gauge theory one-loop amplitudes with the aid of the complex shift used in the Britto- Cachazo-Feng-Witten (BCFW) recursion relations of tree amplitudes. We apply the shift to the integrand and show that the contribution from the limit of infinite shift vanishes after integrating over the loop momentum, with a judicious choice of basis for polarization vectors. This enables us to write the one-loop amplitude in terms of on-shell tree and lower-point one-loop amplitudes. Some of the tree amplitudes are forward amplitudes. We show that their potential singularities do not contribute and the BCFW recursion relations can be applied …
Supergravity Backgrounds For Deformations Of Adsn×Sn Supercoset String Models, 2014 University at Albany, State University of New York
Supergravity Backgrounds For Deformations Of Adsn×Sn Supercoset String Models, Oleg Lunin, Radu Roiban, Arkady Tseytlin
Physics Faculty Scholarship
We consider type IIB supergravity backgrounds corresponding to the deformed AdS_n x S^n supercoset string models of the type constructed in arXiv:1309.5850 which depend on one deformation parameter k. In AdS_2 x S^2 case we find that the deformed metric can be extended to a full supergravity solution with non-trivial dilaton, RR scalar and RR 5-form strength. The solution depends on a free parameter (called a) that should be chosen as a particular function of k to correspond to the deformed supercoset model. In AdS_3 x S^3 case the full solution supported by the dilaton, RR scalar and RR 3-form …
Gauge Theories Of General Relativity, 2014 Utah State University
Gauge Theories Of General Relativity, James Thomas Wheeler
James Thomas Wheeler
General relativity can be seen as a gauge theory of the Lorentz, Poincaré, Weyl, de Sitter, or conformal groups. In most of these, there is little or no difference from the standard formulation in Riemannian geometry, but the higher symmetries — de Sitter and conformal — introduce new features and explain old ones. The potential presence of a cosmological constant, the spacetime metric, cosmological dust, symplectic structure, Kähler structure and even the existence of a timelike direction can all be seen to arise from the underlying group structure.
Nonlinear Dichroism In Back-To-Back Double Ionization Of He By An Intense Elliptically Polarized Few-Cycle Extreme Ultraviolet Pulse, 2014 University of Nebraska-Lincoln
Nonlinear Dichroism In Back-To-Back Double Ionization Of He By An Intense Elliptically Polarized Few-Cycle Extreme Ultraviolet Pulse, Jean Marcel Ngoko Djiokap, N. L. Manakov, A. V. Meremianin, S. X. Hu, L. B. Madsen, Anthony F. Starace
Anthony F. Starace Publications
Control of double ionization of He by means of the polarization and carrier-envelope phase (CEP) of an intense, few-cycle extreme ultraviolet (XUV) pulse is demonstrated numerically by solving the six-dimensional two-electron, time-dependent Schrödinger equation for He interacting with an elliptically polarized XUV pulse. Guided by perturbation theory (PT), we predict the existence of a nonlinear dichroic effect (∝ I3/2) that is sensitive to the CEP, ellipticity, peak intensity I, and temporal duration of the pulse. This dichroic effect (i.e., the difference of the two-electron angular distributions for opposite helicities of the ionizing XUV pulse) originates from interference of …
Physics: Rethinking The Foundations, 2014 University at Albany, State University of New York
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 …
Determination Of The Free Neutron Lifetime, 2014 Oak Ridge National Laboratory
Determination Of The Free Neutron Lifetime, J. David Bowman, Leah J. Broussard, Stephen M. Clayton, M. S. Dewey, Nadia Fomin, Keith B. Grammer, G. L. Greene, Paul R. Huffman, Anthony T. Holley, Geoffrey L. Jones, Chenyu Liu, Mark Makela, Michael P. Mendenhall, Charles L. Morris, Jonathan Mulholland, K. M. Nollett, Robert W. Pattie, Seppo Penttila, M. Ramsey-Musolf, Daniel J. Salvat, Andy Saunders, Susan J. Seestrom, William M. Snow, A. Steyerl, F. E. Wietfeldt, Albert R. Young, Andrew T. Yue
Robert W. Pattie Jr.
Effects Of Energetic Irradiation On Materials And Devices Based On Graphene And Topological Insulators, 2014 Purdue University
Effects Of Energetic Irradiation On Materials And Devices Based On Graphene And Topological Insulators, Isaac Childres
Open Access Dissertations
This report focuses on the optical and electronic properties of graphene and topological insulators and how these Dirac fermion systems interact with energetic irradiation. We first present data exploring the effects of electron-beam and oxygen plasma induced disorder on the electronic properties and Raman spectra of graphene. These initial investigations were important for relating Raman peak intensities and weak localization features to each other and to an average disorder length in graphene, LD. ^ We then integrate gate-effect measurements into the Raman spectroscopy study to fully explore the relationships between carrier density, disorder and Raman spectrum signatures. We …
Beam-Induced Radiation Heating On The Superconducting Undulator At The Advanced Photon Source, 2014 Purdue University
Beam-Induced Radiation Heating On The Superconducting Undulator At The Advanced Photon Source, Laura Elizabeth Boon
Open Access Dissertations
In January 2013 the Advanced Photon Source (APS), a 7 GeV synchrotron X-ray source, commissioned a Superconducting Undulator (SCU). The superconducting magnet is thermally isolated from the beam vacuum chamber, which absorbs the beam-induced heating. Previous beam induced heat load studies at other laboratories had not included a robust calculation of radiation heating from the upstream dipole magnet. The mitigation of the radiation heating mechanism, and production of photoelectrons to seed an electron cloud was studied for this thesis. ^ An analytical model was developed to predict the radiation heat load on the SCU chamber. This model was benchmarked with …
Studies Of Angular Correlations Of Jets With The Atlas Detector, 2014 Louisiana Tech University
Studies Of Angular Correlations Of Jets With The Atlas Detector, Rajivalochan Subramaniam
Doctoral Dissertations
The strong force is one of the four fundamental forces and its strength is given by the coupling constant αs. The theory that describes the strong interaction is Quantum Chromodynamics (QCD) and it explains the interactions between quarks and gluons. The strong coupling constant is the only free parameter in the QCD Lagrangian if the quark masses are fixed. Determinations of αs provide direct tests of perturbative QCD calculations. The collimated sprays of particles originating from the quark and gluon interactions are called jets. The ratio of jet cross sections are sensitive to α s and are …
Direct Measurement Of The Pp Solar Neutrino Interaction Rate In Borexino, 2014 University of Massachusetts Amherst
Direct Measurement Of The Pp Solar Neutrino Interaction Rate In Borexino, Keith Otis
Doctoral Dissertations
This dissertation presents the first direct detection of pp solar neutrinos within Borexino, the underground liquid-scintilator detector located at the Gran Sasso National Labratory(LNGS) in Italy, designed to measure the interaction of neutrinos through neutrino-electron elastic scattering. The rate of scattering in Borexino from the pp solar neutrino spectrum is measured to be 155 +/- 16(stat) +/- 13(sys) counts per day per 100 tonnes. With this measurement we are able to rule out the no oscillation hypothesis at the 2-sigma C.L. and the results agree with Standard Solar Model predictions within 1.1-sigma. These neutrinos are from the keystone proton-proton fusion …
Perturbative Unitarity Constraints On A Supersymmetric Higgs Portal, 2014 SLAC National Accelerator Laboratory
Perturbative Unitarity Constraints On A Supersymmetric Higgs Portal, Kassahun Betre, Sonia Hedri, Devin Walker
Faculty Publications
We place perturbative unitarity constraints on both the dimensionful and dimensionless couplings in the Next-to-Minimal Supersymmetric Standard Model Higgs Sector. These constraints, plus the requirement that the singlino and/or Higgsino constitutes at least part of the observed dark matter relic abundance, generate upper bounds on the Higgs and neutralino/chargino mass spectrum. We obtain an upper bound of 12 TeV for the charginos and neutralinos and 20 TeV for the heavy Higgses outside defined fine-tuned regions. By using the NMSSM as a template, we describe a method which replaces naturalness arguments with more rigorous perturbative unitarity arguments to get a better …
Search For New Physical Phenomena Via Displaced Muon Signatures With The Cms Detector At The Lhc, 2014 Purdue University
Search For New Physical Phenomena Via Displaced Muon Signatures With The Cms Detector At The Lhc, Melih Solmaz
Open Access Theses
The first search at the LHC for long-lived neutral particles decaying to pairs of muons by using only the muon chambers is presented. Events were collected by the CMS detector during pp collisions at √s = 8 TeV and selected from data samples corresponding to 20.5 fb-1 of integrated luminosity. No background events are expected after the full analysis selection. Expected upper limits are derived for a model which predicts a heavy scalar decaying to two long-lived particles, each of which can decay to muon pairs. Combined expected upper limits with an analysis utilizing the CMS silicon tracker …
Semi-Inclusive Charged-Current Neutrino-Nucleus Reactions, 2014 Old Dominion University
Semi-Inclusive Charged-Current Neutrino-Nucleus Reactions, O. Moreno, T. W. Donnelly, J. W. Van Orden, W. P. Ford
Physics Faculty Publications
The general, universal formalism for semi-inclusive charged-current (anti) neutrino-nucleus reactions is given for studies of any hadronic system, namely, either nuclei or the nucleon itself. The detailed developments are presented with the former in mind and are further specialized to cases where the final-state charged lepton and an ejected nucleon are presumed to be detected. General kinematics for such processes are summarized, and then explicit expressions are developed for the leptonic and hadronic tensors involved and for the corresponding responses according to the usual charge, longitudinal and transverse projections, keeping finite the masses of all particles involved. In the case …
Investigation And Optimization Of A New Compact Superconducting Cavity For Deflecting And Crabbing Applications, 2014 Old Dominion University
Investigation And Optimization Of A New Compact Superconducting Cavity For Deflecting And Crabbing Applications, Subashini Uddika De Silva
Physics Theses & Dissertations
Deflecting and crabbing structures have many applications in current accelerator systems. The primary use of a deflecting cavity is to separate a single beam into multiple beams. A crabbing cavity enables the head-on collision at the interaction point in particle colliders in order to increase the luminosity. The early uses of the deflecting structures have been in the early 1960s: these structures were disk loaded structures operating at room temperature. The crabbing structure which was installed at the NEK electron-positron collider was the first and only operational superconducting cavity of that kind. The most common design of superconducting deflecting and …
Analytic Evolution Of Singular Distribution Amplitudes In Qcd, 2014 Old Dominion University
Analytic Evolution Of Singular Distribution Amplitudes In Qcd, Asli Tandogan
Physics Theses & Dissertations
Distribution amplitudes (DAs) are the basic functions that contain information about the quark momentum. DAs are necessary to describe hard exclusive processes in quantum chromodynamics. We describe a method of analytic evolution of DAs that have singularities such as nonzero values at the end points of the support region, jumps at some points inside the support region and cusps. We illustrate the method by applying it to the evolution of a flat (constant) DA, antisymmetric flat DA, and then use the method for evolution of the two-photon generalized distribution amplitude. Our approach to DA evolution has advantages over the standard …
Initial Conditions In High-Energy Collisions, 2014 Graduate Center, City University of New York
Initial Conditions In High-Energy Collisions, Elena Petreska
Dissertations, Theses, and Capstone Projects
This thesis is focused on the initial stages of high-energy collisions in the saturation regime. We start by extending the McLerran-Venugopalan distribution of color sources in the initial wave-function of nuclei in heavy-ion collisions. We derive a fourth-order operator in the action and discuss its relevance for the description of color charge distributions in protons in high-energy experiments. We calculate the dipole scattering amplitude in proton-proton collisions with the quartic action and find an agreement with experimental data. We also obtain a modification to the fluctuation parameter of the negative binomial distribution of particle multiplicities in proton-proton experiments. The result …
Yang-Mills Theories As Deformations Of Massive Integrable Models, 2014 Graduate Center, City University of New York
Yang-Mills Theories As Deformations Of Massive Integrable Models, Axel Cortes Cubero
Dissertations, Theses, and Capstone Projects
Yang Mills theory in 2+1 dimensions can be expressed as an array of coupled (1+1)-dimensional principal chiral sigma models. The SU(N) principal chiral sigma model in 1+1 dimensions is integrable, asymptotically free and has massive excitations. We calculate all the form factors and two- point correlation functions of the Noether current and energy-momentum tensor, in
't Hooft's large-N limit (some form factors can be found even at finite N). We use these new form factors to calculate physical quantities in (2+1)-dimensional Yang-Mills theory, generalizing previous SU(2) by P. Orland to SU(N). The anisotropic gauge theory is related to standard isotropic …
Perihelion Precession In General Relativity, 2014 Department of Physics, Utah State University
Perihelion Precession In General Relativity, Charles G. Torre
Charles G. Torre
This is a Maple worksheet providing a relatively quick and informal sketch of a demonstration that general relativistic corrections to the bound Kepler orbits introduce a perihelion precession. Any decent textbook will derive this result. My analysis aligns with that found in the old text "Introduction to General Relativity", by Adler, Bazin and Schiffer. The plan of the analysis is as follows. * Model the planetary orbits as geodesics in the (exterior) Schwarzschild spacetime. * Compute the geodesic equations. * Simplify them using symmetries and first integrals. * Isolate the differential equation expressing the radial coordinate as a function of …