Ttbar Production Cross Section Measurement In The Muon Plus Jets Channel Using Soft Electron Tagging In Pp Collisions At √(S) = 8 Tev,
2013
University of Nebraska-Lincoln
Ttbar Production Cross Section Measurement In The Muon Plus Jets Channel Using Soft Electron Tagging In Pp Collisions At √(S) = 8 Tev, Jason Keller
Department of Physics and Astronomy: Dissertations, Theses, and Student Research
A measurement is made of the top quark pair production cross section through the decay channel ttbar -> mu nu + jets, carried out using the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC), located at CERN in Geneva, Switzerland. The top quark pair events were produced in proton-proton collisions at a center-of-mass energy of 8 TeV. To facilitate the detection of ttbar events, jets produced from bottom quarks, which are decay products of the top quarks, are identified using electrons with low transverse momentum with respect to the beam axis (soft electrons). The dominant background, W …
The Spacetime Geometry Of A Null Electromagnetic Field,
2013
Department of Physics, Utah State University
The Spacetime Geometry Of A Null Electromagnetic Field, Charles G. Torre
Presentations and Publications
We give a set of local geometric conditions on a spacetime metric which are necessary and sufficient for it to be a null electrovacuum, that is, the metric is part of a solution to the Einstein-Maxwell equations with a null electromagnetic field. These conditions are restrictions on a null congruence canonically constructed from the spacetime metric, and can involve up to five derivatives of the metric. The null electrovacuum conditions are counterparts of the Rainich conditions, which geometrically characterize non-null electrovacua. Given a spacetime satisfying the conditions for a null electrovacuum, a straightforward procedure builds the null electromagnetic field from …
Contributions To The Cuore Collaboration,
2013
California Polytechnic State University - San Luis Obispo
Contributions To The Cuore Collaboration, Samuel Joseph Meijer
Physics
This paper describes work done between 2010 and 2013 to contribute to the CUORE collaboration, a physics collaboration searching for neutrinoless double-beta decay in tellurium. Measurement of this decay would indicate fundamental information about the nature of the neutrino. The implementation of a parylene-coated detector frame is described. Also, a temperature stabilization system for an automated gluing system was constructed. An image recognition algorithm is described for locating spots of glue and evaluating their acceptability.
Asymmetries In Production Of He+(N = 2) With An Intense Few-Cycle Attosecond Pulse,
2013
University of Nebraska-Lincoln
Asymmetries In Production Of He+(N = 2) With An Intense Few-Cycle Attosecond Pulse, Jean Marcel Ngoko Djiokap, S. X. Hu, Wei-Chao Jiang, Liang-You Peng, Anthony F. Starace
Anthony F. Starace Publications
By solving the two-electron time-dependent Schrödinger equation, we study carrier-envelope-phase (CEP) effects on ionization plus excitation of He to He+(n = 2) states by a few-cycle attosecond pulse with a carrier frequency of 51 eV. For most CEPs the asymmetries in the photoelectron angular distributions with excitation of He+(2s) or He+(2p) have opposite signs and are two orders of magnitude larger than for ionization without excitation. These results indicate that attosecond pulse CEP effects may be significantly amplified in correlated two-electron ionization processes.
Third Harmonic Flow Of Charged Particles In Au + Au Collisions At √ S Nn = 200 Gev,
2013
Old Dominion University
Third Harmonic Flow Of Charged Particles In Au + Au Collisions At √ S Nn = 200 Gev, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, Av. V. Alakhverdyants, I. Alekseev, S. Bültmann, I. Koraly, Star Collaboration
Physics Faculty Publications
We report measurements of the third harmonic coefficient of the azimuthal anisotropy, v3, known as triangular flow. The analysis is for charged particles in Au+Au collisions at √sNN=200 GeV, based on data from the STAR experiment at the BNL Relativistic Heavy Ion Collider. Two-particle correlations as a function of their pseudorapidity separation are fit with narrow and wide Gaussians. Measurements of triangular flow are extracted from the wide Gaussian, from two-particle cumulants with a pseudorapidity gap, and also from event plane analysis methods with a large pseudorapidity gap between the particles and the event plane. These results are …
Field Emission Studies Toward Improving The Performance Of Dc High Voltage Photoelectron Guns,
2013
Old Dominion University
Field Emission Studies Toward Improving The Performance Of Dc High Voltage Photoelectron Guns, Mahzad Bastaninejad
Mechanical & Aerospace Engineering Theses & Dissertations
Field emission is the main mechanism that prevents DC high voltage photoemission electron guns from operating at the very high bias voltages required to produce low emittance beams. Gas conditioning is shown to eliminate field emission from cathode electrodes used inside DC high voltage photoelectron guns. Measurements and simulation results indicate that gas conditioning eliminates field emission from cathode electrodes via two mechanisms: sputtering and implantation, with the benefits of implantation reversed by heating the electrode. The field emission characteristics of 5 stainless steel electrodes varied significantly upon the initial application of voltage but improved to nearly the same level …
Contributions To Background Reduction And Computer Simulations For Cuore & Cuore-0,
2013
California Polytechnic State University - San Luis Obispo
Contributions To Background Reduction And Computer Simulations For Cuore & Cuore-0, Ivo J. Plamenac
Physics
CUORE and CUORE-0 aim to observe neutrinoless double beta decay in 130Te; observing such this particular decay would substantiate the Majorana model for the neutrino and expand our current understanding of particle physics. This report will provide an overview of the Standard Model, our current framework for particle interactions, as well as the technical details of the CUORE experiment. Over the summers of 2010 and 2011, I contributed to the efforts of the CUORE collaboration by assisting in aspects such as background reduction, and explored detector behavior using computer simulations.
Double Spin Asymmetry In D →(E→E'P)N,
2013
Old Dominion University
Double Spin Asymmetry In D →(E→E'P)N, Michael Mayer
Physics Theses & Dissertations
Using the CLAS detector at Jefferson Lab, double spin asymmetries (A ∥) for quasi-elastic electron scattering off the deuteron have been measured at several beam energies. The data were collected during the EG1 experiment, which scattered longitudinally polarized electrons with energies from 1.6 to 5.8 GeV off a longitudinally polarized cryogenic ND3 target. The double spin asymmetries were measured as a function of photon virtuality Q2 (0.13-3.17 (GeV/c)2), missing momentum (0.0-0.5 GeV/c), and the angle between the (inferred) "spectator" neutron and the momentum transfer direction (θng). The results from EG1b are compared with a recent model …
Information-Based Physics: An Intelligent Embedded Agent's Guide To The Universe,
2013
University at Albany, State University of New York
Information-Based Physics: An Intelligent Embedded Agent's Guide To The Universe, Kevin H. Knuth
Physics Faculty Scholarship
In this talk, I propose an approach to understanding the foundations of physics by considering the optimal inferences an intelligent agent can make about the universe in which he or she is embedded. Information acts to constrain an agent’s beliefs. However, at a fundamental level, any information is obtained from interactions where something influences something else. Given this, the laws of physics must be constrained by both the nature of such influences and the rules by which we can make inferences based on information about these influences. I will review the recent progress we have made in this direction. This …
Session E-4: What's Up With The Higgs Boson? Teaching Particle Physics In High School,
2013
Illinois Mathematics and Science Academy
Session E-4: What's Up With The Higgs Boson? Teaching Particle Physics In High School, Peter Dong
Professional Learning Day
Best-selling books, popular PBS specials, and multi-billion-dollar machines all attest to the fascination with particle physics - including many teenagers. Physics and physical science classes can capitalize on this interest by talking about high-profile results, such as last summer's Higgs Boson Discovery. This session will answer some basic questions about contemporary particle physics and suggest some ideas for lessons and projects in particle physics.
How To Find Killing Vectors,
2013
Utah State University
How To Find Killing Vectors, Charles G. Torre
How to... in 10 minutes or less
We show how to compute the Lie algebra of Killing vector fields of a metric in Maple using the commands KillingVectors and LieAlgebraData. A Maple worksheet and a PDF version can be found below.
The Higgs Boson In The Periodic System Of Elementary Particles,
2013
Southern Adventist University
The Higgs Boson In The Periodic System Of Elementary Particles, Ding-Yu Chung, Ray Hefferlin
Faculty Works
It is proposed that the observed Higgs Boson at the LHC is the Standard Model Higgs boson that adopts the existence of the hidden lepton condensate. The hidden lepton is in the forbidden lepton family, outside of the three lepton families of the Standard Model. Being forbidden, a single hidden lepton cannot exist alone; so it must exist in the lepton condensate as a composite of μ’ and μ’± hidden leptons and their corresponding antileptons. The calculated average mass of the hidden lep-ton condensate is 128.8 GeV in good agreements with the observed 125 or 126 GeV. …
Using Heavy Flavors To Study New Physics,
2013
Wayne State University
Using Heavy Flavors To Study New Physics, Kristopher Jason Healey
Wayne State University Dissertations
In this doctoral dissertation I discuss the possible standard model contributions to select leptonic heavy meson decay modes. Included are calculations of soft photon contributions to a di-lepton decay of B-mesons as well as two-particle hadronic unitary contributions to the rare di-leptonic decay of the neutral D meson. Additionally, constraints are calculated for two super-WIMP dark matter models from rare heavy flavor decays.
Semiclassical Partition Functions For Gravity With Cosmic Strings,
2013
Merrimack
Semiclassical Partition Functions For Gravity With Cosmic Strings, Christopher L. Duston
Physics Faculty Publications
In this paper we describe an approach to construct semiclassical partition functions in gravity which are complete in the sense that they contain a complete description of the differentiable structures of the underlying 4-manifold. In addition, we find our construction naturally includes cosmic strings. We prove that the mass density of these strings uniquely specifies the topology of the leaves of a dimension 2 foliation, and conjecture that spacetime topology emerges as a result of the symmetry breaking of the fundamental fields. We discuss some possible applications of the partition functions in the fields of both quantum gravity and topological …
Massive Gravity Theories,
2013
Colby College
Massive Gravity Theories, Greg Seyfarth
Honors Theses
We examine Fierz and Pauli's work in 1939 of adding a mass term to the Lagrangian for linearized gravity with the form ?? where h is a small perturbation away from flat spacetime and showing that the only value for ? which gives a ghost-free theory with the correct five degrees of freedom expected for a massive spin- 2 particle such as the graviton is ? [1]. We start by rederiving the Lagrangian formulation for classical electrodynamics and giving examples of a ghost. Then we solve the linearized massless gravity equations to show their two degrees of freedom. We perform …
Analytic Description Of Elastic Electron-Atom Scattering In An Elliptically Polarized Laser Field,
2013
University of Nebraska-Lincoln
Analytic Description Of Elastic Electron-Atom Scattering In An Elliptically Polarized Laser Field, A. V. Flegel, M. V. Frolov, N. L. Manakov, Anthony F. Starace, A. N. Zheltukhin
Anthony F. Starace Publications
An analytic description of laser-assisted electron-atom scattering (LAES) in an elliptically polarized field is presented using time-dependent effective range (TDER) theory to treat both electron-laser and electron-atom interactions nonperturbatively. Closed-form formulas describing plateau features in LAES spectra are derived quantum mechanically in the low-frequency limit. These formulas provide an analytic explanation for key features of the LAES differential cross section. For the low-energy region of the LAES spectrum, our result generalizes the Kroll-Watson formula to the case of elliptic polarization. For the high-energy (rescattering) plateau in the LAES spectrum, our result generalizes prior results for a linearly polarized field valid …
Photon Impact Factor And 𝑘T Factorization For Dis In The Next-To-Leading Order,
2013
Old Dominion University
Photon Impact Factor And 𝑘T Factorization For Dis In The Next-To-Leading Order, Ian Balitsky, Giovanni A. Chirilli
Physics Faculty Publications
The photon impact factor for the Balitsky-Fadin-Kuraev-Lipatov pomeron is calculated in the next-to-leading order approximation using the operator expansion in Wilson lines. The result is represented as a next-to-leading order 𝑘T-factorization formula for the structure functions of small-𝓍 deep inelastic scattering.
Single Spin Asymmetry An In Polarized Proton–Proton Elastic Scattering At √S = 200 Gev,
2013
Old Dominion University
Single Spin Asymmetry An In Polarized Proton–Proton Elastic Scattering At √S = 200 Gev, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, C. D. Anson, D. Arkhipkin, E. Aschenauer, S. Bültmann, I. Koralt, D. Plyku
Physics Faculty Publications
We report a high precision measurement of the transverse single spin asymmetry AN at the center of mass energy √s = 200 GeV in elastic proton–proton scattering by the STAR experiment at RHIC. The AN was measured in the four-momentum transfer squared t range 0.003 ⩽ | t | ⩽ 0.035 ( GeV / c ) 2 , the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of AN and its t-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the …
Design Evolution And Properties Of Superconducting Parallel-Bar Rf-Dipole Detecting And Crabbing Cavities,
2013
Old Dominion University
Design Evolution And Properties Of Superconducting Parallel-Bar Rf-Dipole Detecting And Crabbing Cavities, S. U. De Silva, J. R. Delayen
Physics Faculty Publications
Deflecting/crabbing cavities serve a variety of purposes in different accelerator applications, primarily in separating a single beam into multiple beams and in rotating bunches for head-on collisions at the interaction point in particle colliders. Deflecting/crabbing cavities are also used for transverse and longitudinal emittance exchange in beams, x-ray pulse compression, and for beam diagnostics. Compact superconducting deflecting/crabbing cavities are under development due to strict dimensional constraints and requirements for higher field gradients with low surface losses. The TEM-like superconducting parallel-bar cavity supports low operating frequencies, thus making the design favorable for many of the deflecting/crabbing cavity applications. The design of …
Transverse Polarization Of Σ+ (1189) In Photoproduction On A Hydrogen Target In Clas,
2013
Old Dominion University
Transverse Polarization Of Σ+ (1189) In Photoproduction On A Hydrogen Target In Clas, Clas Collaboration, C. S. Nepali, M. Amaryan, K. P. Adhikari, H. Baghdasaryan, S. Bültmann, N. Guler, C. E. Hyde, A. Klein, S. E. Kuhn, M. Mayer, H. Seraydaryan, B. Torayev, L. B. Weinstein
Physics Faculty Publications
Experimental results on the Σ+(1189) hyperon transverse polarization in photoproduction on a hydrogen target using the CLAS detector at Jefferson Laboratory are presented. The Σ+(1189) was reconstructed in the exclusive reaction γ+p→K0S+Σ+(1189) via the Σ+→pπ0 decay mode. The K0S was reconstructed in the invariant mass of two oppositely charged pions with the π0 identified in the missing mass of the detected pπ+π− final state. Experimental data were collected in the photon energy range Eγ=1.0 –3.5 GeV (√s range 1.66–2.73 GeV). We observe a large negative polarization …
