Material content of the universe - Introductory survey

NASA Astrophysics Data System (ADS)

Tayler, R. J.

1986-12-01

Matter in the universe can be detected either by the radiation it emits or by its gravitational influence. There is a strong suggestion that the universe contains substantial hidden matter, mass without corresponding light. There are also arguments from elementary particle physics that the universe should have closure density, which would also imply hidden mass. Observations of the chemical composition of the universe interpreted in terms of the hot Big Bang cosmological theory suggest that this hidden matter cannot all be of baryonic form but must consist of weakly interacting elementary particles. A combination of observations and theoretical ideas about the origin of large-scale structure may demand that these particles are of a type which is not yet definitely known to exist.

Understanding the masses of elementary particles: a step towards understanding the massless photon?

NASA Astrophysics Data System (ADS)

Greulich, K. O.

2011-09-01

A so far unnoticed simple explanation of elementary particle masses is given by m = N * melectron/α, where alpha (=1/137) is the fine structure constant. On the other hand photons can be described by two oppositely oscillating clouds of e / √α elementary charges. Such a model describes a number of features of the photon in a quantitatively correct manner. For example, the energy of the oscillating clouds is E = h ν, the spin is 1 and the spatial dimension is λ / 2 π. When the charge e / √α is assigned to the Planck mass mPl, the resulting charge density is e / (mPl√α) = 8,62 * 10-11 Cb / kg. This is identical to √ (G / ko) where G is the gravitational constant and ko the Coulomb constant. When one assigns this very small charge density to any matter, gravitation can be completely described as Coulomb interaction between such charges of the corresponding masses. Thus, there is a tight quantitative connection between the photon, nonzero rest masses and gravitation / Coulomb interaction.

Theory of type 3b solar radio bursts. [plasma interaction and electron beams

NASA Technical Reports Server (NTRS)

Smith, R. A.; Delanoee, J.

1975-01-01

During the initial space-time evolution of an electron beam injected into the corona, the strong beam-plasma interaction occurs at the head of the beam, leading to the amplification of a quasi-monochromatic large-amplitude plasma wave that stabilizes by trapping the beam particles. Oscillation of the trapped particles in the wave troughs amplifies sideband electrostatic waves. The sidebands and the main wave subsequently decay to observable transverse electromagnetic waves through the parametric decay instability. This process gives rise to the elementary striation bursts. Owing to velocity dispersion in the beam and the density gradient of the corona, the entire process may repeat at a finite number of discrete plasma levels, producing chains of elementary bursts. All the properties of the type IIIb bursts are accounted for in the context of the theory.

Surface charge accumulation of particles containing radionuclides in open air

DOE PAGES

Kim, Yong-ha; Yiacoumi, Sotira; Tsouris, Costas

2015-05-01

Radioactivity can induce charge accumulation on radioactive particles. But, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. Moreover, a charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify themore » particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. Our study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes.« less

Gauge Bosons--The Ties That Bind.

ERIC Educational Resources Information Center

Hill, Christopher T.

1982-01-01

Discusses four basic forces/interactions in nature (strong force, weak force, electromagnetic force and gravity), associated with elementary particles. Focuses on "gauge bosons" (for example, photons), thought to account for strong, weak, and electromagnetic forces. (Author/JN)

Surface charge accumulation of particles containing radionuclides in open air.

PubMed

Kim, Yong-Ha; Yiacoumi, Sotira; Tsouris, Costas

2015-05-01

Radioactivity can induce charge accumulation on radioactive particles. However, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. A charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify the particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. The study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Conservation Laws in Weak Interactions

DOE R&D Accomplishments Database

Lee, T. D.

1957-03-01

Notes are presented on four lectures given at Harvard University in March 1957 on elementary particle physics, the theta-tau problem, validity of parity conservation, tests for invariance under P, C, and T, and the two-component theory of the neutrino. (W.D.M.)

The Higgs mechanism and the origin of mass

NASA Astrophysics Data System (ADS)

Djouadi, Abdelhak

2012-06-01

The Higgs mechanism plays a key role in the physics of elementary particles: in the context of the Standard Model, the theory which describes in a unified framework the electromagnetic, weak and strong nuclear interactions, it allows for the generation of particle masses while preserving the fundamental symmetries of the theory. This mechanism predicts the existence of a new type of particle, the scalar Higgs boson, with unique characteristics. The detection of this particle and the study of its fundamental properties is a major goal of high-energy particle colliders, such as the CERN Large Hadron Collider or LHC.

The Higgs Mechanism and the Orogin of Mass

NASA Astrophysics Data System (ADS)

Djouadi, Abdelhak

The Higgs mechanism plays a key role in the physics of elementary particles: in the context of the Standard Model, the theory which, describes in a unified framework the electromagnetic, weak, and strong nuclear interactions, it allows for the generation of particle masses while preserving the fundamental symmetries of the theory. This mechanism predicts the existence of a new type of particle, the scalar Higgs boson, with unique characteristics. The detection of this particle and the study of its fundamental properties is a major goal of high-energy particle colliders, such as the CERN Large Hadron Collider or LHC.

Self-interacting spin-2 dark matter

NASA Astrophysics Data System (ADS)

Chu, Xiaoyong; Garcia-Cely, Camilo

2017-11-01

Recent developments in bigravity allow one to construct consistent theories of interacting spin-2 particles that are free of ghosts. In this framework, we propose an elementary spin-2 dark matter candidate with a mass well below the TeV scale. We show that, in a certain regime where the interactions induced by the spin-2 fields do not lead to large departures from the predictions of general relativity, such a light dark matter particle typically self-interacts and undergoes self-annihilations via 3-to-2 processes. We discuss its production mechanisms and also identify the regions of the parameter space where self-interactions can alleviate the discrepancies at small scales between the predictions of the collisionless dark matter paradigm and cosmological N-body simulations.

Space, Elastic And Impeding: Two Qualities Of Space Define Energy Which Defines Elementary Particles and Their Interactions

NASA Astrophysics Data System (ADS)

Salvatore, Gerard Micheal

The conceptual foundations for a deterministic quantum mechanics are presented with the Socratic method. The theory is attacked and weaknesses elucidated. These are compared against those of convention. Directions for future research are proposed.

Current status of direct dark matter detection experiments

NASA Astrophysics Data System (ADS)

Liu, Jianglai; Chen, Xun; Ji, Xiangdong

2017-03-01

Much like ordinary matter, dark matter might consist of elementary particles, and weakly interacting massive particles are one of the prime suspects. During the past decade, the sensitivity of experiments trying to directly detect them has improved by three to four orders of magnitude, but solid evidence for their existence is yet to come. We overview the recent progress in direct dark matter detection experiments and discuss future directions.

Search for the standard model Higgs boson in $$l\

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Dikai

2013-01-01

Humans have always attempted to understand the mystery of Nature, and more recently physicists have established theories to describe the observed phenomena. The most recent theory is a gauge quantum field theory framework, called Standard Model (SM), which proposes a model comprised of elementary matter particles and interaction particles which are fundamental force carriers in the most unified way. The Standard Model contains the internal symmetries of the unitary product group SU(3) c ⓍSU(2) L Ⓧ U(1) Y , describes the electromagnetic, weak and strong interactions; the model also describes how quarks interact with each other through all of thesemore » three interactions, how leptons interact with each other through electromagnetic and weak forces, and how force carriers mediate the fundamental interactions.« less

't Hooft Quantization for Interacting Systems

NASA Astrophysics Data System (ADS)

Jizba, Petr; Scardigli, Fabio; Blasone, Massimo; Vitiello, Giuseppe

2012-02-01

In the framework of 't Hooft's "deterministic quantization" proposal, we show how to obtain from a composite system of two classical Bateman's oscillators a quantum isotonic oscillator. In a specific range of parameters, such a system can be also interpreted as a particle in an effective magnetic field, interacting through a spin-orbit interaction term. In the limit of a large separation from the interaction region, the system can be described in terms of two irreducible elementary subsystems, corresponding to two independent quantum harmonic oscillators.

Particle Accelerators Test Cosmological Theory.

ERIC Educational Resources Information Center

Schramm, David N.; Steigman, Gary

1988-01-01

Discusses the symbiotic relationship of cosmology and elementary-particle physics. Presents a brief overview of particle physics. Explains how cosmological considerations set limits on the number of types of elementary particles. (RT)

An elementary singularity-free Rotational Brownian Dynamics algorithm for anisotropic particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ilie, Ioana M.; Briels, Wim J.; MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede

2015-03-21

Brownian Dynamics is the designated technique to simulate the collective dynamics of colloidal particles suspended in a solution, e.g., the self-assembly of patchy particles. Simulating the rotational dynamics of anisotropic particles by a first-order Langevin equation, however, gives rise to a number of complications, ranging from singularities when using a set of three rotational coordinates to subtle metric and drift corrections. Here, we derive and numerically validate a quaternion-based Rotational Brownian Dynamics algorithm that handles these complications in a simple and elegant way. The extension to hydrodynamic interactions is also discussed.

Let’s have a coffee with the Standard Model of particle physics!

NASA Astrophysics Data System (ADS)

Woithe, Julia; Wiener, Gerfried J.; Van der Veken, Frederik F.

2017-05-01

The Standard Model of particle physics is one of the most successful theories in physics and describes the fundamental interactions between elementary particles. It is encoded in a compact description, the so-called ‘Lagrangian’, which even fits on t-shirts and coffee mugs. This mathematical formulation, however, is complex and only rarely makes it into the physics classroom. Therefore, to support high school teachers in their challenging endeavour of introducing particle physics in the classroom, we provide a qualitative explanation of the terms of the Lagrangian and discuss their interpretation based on associated Feynman diagrams.

Electron, Muon, and Tau Heavy Lepton--Are These the Truly Elementary Particles?

ERIC Educational Resources Information Center

Perl, Martin L.

1980-01-01

Discussed is the present concept of the ultimate nature of matter--the elementary particle. An explanation is given for why the lepton family of particles--the electron, muon, and tau--may be truly elementary. The tau lepton is described in more detail. (Author/DS)

Action of Penetrating Radiation on Radio Parts,

DTIC Science & Technology

1984-05-24

the formation of the pair of particles the electron - positron . This process is called the effect of the formation of electron- positron pairs. Pair...formation can occur during the absorption 7-quantum with the energy, greater than total rest energy of electron and positron (more than the doubled...rest energy of electron, equal to 2mc 2=!.02 MeV). Positron (unstable elementary DOC - 83167601 PAGE 9 particle) in turn interacts with the electron of

Mesure de la section efficace de production de paires de quarks top dans le canal lepton+tau+jets+MET dans l'experience D0 et interpretation en termes de boson de Higgs charge (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lacroix, Florent

The standard model of particle physics describes the matter as elementary particles interacting via strong and electroweak interactions. The top quark is the heaviest quark described by this model and has been discovered in 1995 by CDF and D collaborations in proton-antiproton collisions at the Tevatron. This thesis is devoted to the measurement of the top pair production cross-section via the strong interaction, in a final state composed of one lepton, one hadronic tau, two b-jets and missing transverse energy. This analysis uses the 1,2 fb

Nineteenth International Cosmic Ray Conference. Conference Papers: Invited Rapporteur, Highlight, Miscellaneous, Volume 9

NASA Technical Reports Server (NTRS)

Jones, F. C. (Compiler)

1986-01-01

Invited talks, rapporteur talks, and highlight talks are included. Topics of the invited and highlight talks include astrophysical jets, gamma-ray line astronomy, cosmic rays and gamma rays in astrophysics, the early universe, elementary particle physics, solar flares and acceleration of energetic particles, cosmogenic nuclei, extragalactic astronomy, composition of solar flare particles, very high energy gamma ray sources, gamma-ray bursts, shock acceleration in the solar wind, cosmic rays in deep underground detectors, spectrum of cosmic rays at 10 to the 19th power eV, and nucleus-nucleus interactions.

Elementary Particle Physics and High Energy Phenomena: Final Report for FY2010-13

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cumalat, John P.; de Alwis, Senarath P.; DeGrand, Thomas A.

2013-06-27

The work under this grant consists of experimental, theoretical, and phenomenological research on the fundamental properties of high energy subnuclear particles. The work is conducted at the University of Colorado, the European Organization for Nuclear Research (CERN), the Japan Proton Accelerator Research Complex (J-PARC), Fermi National Accelerator Laboratory (FNAL), SLAC National Accelerator Laboratory (SLAC), Los Alamos National Laboratory (LANL), and other facilities, employing neutrino-beam experiments, test beams of various particles, and proton-proton collider experiments. It emphasizes mass generation and symmetry-breaking, neutrino oscillations, bottom particle production and decay, detector development, supergravity, supersymmetry, superstrings, quantum chromodynamics, nonequilibrium statistical mechanics, cosmology, phase transitions,more » lattice gauge theory, and anomaly-free theories. The goals are to improve our understanding of the basic building blocks of matter and their interactions. Data from the Large Hadron Collider at CERN have revealed new interactions responsible for particle mass, and perhaps will lead to a more unified picture of the forces among elementary material constituents. To this end our research includes searches for manifestations of theories such as supersymmetry and new gauge bosons, as well as the production and decay of heavy-flavored quarks. Our current work at J-PARC, and future work at new facilities currently under conceptual design, investigate the specifics of how the neutrinos change flavor. The research is integrated with the training of students at all university levels, benefiting both the manpower and intellectual base for future technologies.« less

Dissipation and quantization for composite systems

NASA Astrophysics Data System (ADS)

Blasone, Massimo; Jizba, Petr; Scardigli, Fabio; Vitiello, Giuseppe

2009-11-01

In the framework of 't Hooft's quantization proposal, we show how to obtain from the composite system of two classical Bateman's oscillators a quantum isotonic oscillator. In a specific range of parameters, such a system can be interpreted as a particle in an effective magnetic field, interacting through a spin-orbit interaction term. In the limit of a large separation from the interaction region one can describe the system in terms of two irreducible elementary subsystems which correspond to two independent quantum harmonic oscillators.

Extended micro objects as dark matter particles

NASA Astrophysics Data System (ADS)

Belotsky, K.; Rubin, S.; Svadkovsky, I.

2017-05-01

Models of various forms of composite dark matter (DM) predicted by particle theory and the DM constituents formed by gravity that are not reduced to new elementary particle candidates are discussed. Main attention is paid to a gravitational origin of the DM. The influence of extended mass spectrum of primordial black holes on observational limits is considered. It is shown that non-uniformly deformed extra space can be considered as point-like masses which possess only gravitational interaction with each other and with the ordinary particles. The recently discussed six-dimensional stable wormholes could contribute to the DM. The contribution of dark atoms is also considered.

TOPICAL REVIEW: TeV mini black hole decay at future colliders

NASA Astrophysics Data System (ADS)

Casanova, Alex; Spallucci, Euro

2006-02-01

It is generally believed that mini black holes decay by emitting elementary particles with a black body energy spectrum. The original calculation leads to the conclusion that about the 90% of the black hole mass is radiated away in the form of photons, neutrinos and light leptons, mainly electrons and muons. With the advent of string theory, such a scenario must be updated by including new effects coming from the stringy nature of particles and interactions. The main modifications with respect to the original picture of black hole evaporation come from recent developments in non-perturbative string theory globally referred to as TeV-scale gravity. By taking for granted that black holes can be produced in hadronic collisions, then their decay must take into account that: (i) we live in a D3 brane embedded into a higher dimensional bulk spacetime; (ii) fundamental interactions, including gravity, are unified at the TeV energy scale. Thus, the formal description of the Hawking radiation mechanism has to be extended to the case of more than four spacetime dimensions and includes the presence of D-branes. This kind of topological defect in the bulk spacetime fabric acts as a sort of 'cosmic fly-paper' trapping electro-weak standard model elementary particles in our (3 + 1)-dimensional universe. Furthermore, unification of fundamental interactions at an energy scale many orders of magnitude lower than the Planck energy implies that any kind of fundamental particle, not only leptons, is expected to be emitted. A detailed understanding of the new scenario is instrumental for optimal tuning of detectors at future colliders, where, hopefully, this exciting new physics will be tested. In this review, we study higher dimensional black hole decay, considering not only the emission of particles according to the Hawking mechanism, but also their near-horizon QED/QCD interactions. The ultimate motivation is to build up a phenomenologically reliable scenario, allowing a clear experimental signature of the event.

Bosonization of free Weyl fermions

NASA Astrophysics Data System (ADS)

Marino, E. C.

2017-03-01

We generalize the method of bosonization, in its complete form, to a spacetime with 3  +  1 dimensions, and apply it to free Weyl fermion fields, which thereby, can be expressed in terms of a boson field, namely the Kalb-Ramond anti-symmetric tensor gauge field. The result may have interesting consequences both in condensed matter and in particle physics. In the former, the bosonized form of the Weyl chiral currents provides a simple explanation for the angle-dependent magneto-conductance recently observed in materials known as Weyl semimetals. In the latter, conversely, since electrons can be thought of as a combination of left and right Weyl fermions, our result suggests the possibility of a unified description of the elementary particles, which undergo the fundamental interactions, with the mediators of such interactions, namely, the gauge fields. This would fulfill the pioneering attempt of Skyrme, to unify the particles with their interaction mediators (Skyrme 1962 Nucl. Phys. 31 556).

The Richtmyer Memorial Lecture--When is a Particle?

ERIC Educational Resources Information Center

Drell, Sidney D.

1978-01-01

Discusses the concept of elementary particles. Reviews the history of the neutrino, and explains why the quarks, although they themselves are not "observed" in isolation, are to be considered elementary particles. (GA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tannenbaum, Michael J.

The search for the left-handed W± bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven elementary-particle physics research from the time that I entered college to the present and has led to many unexpected and exciting discoveries which revolutionized our view of subnuclear physics over that period. In this article I describe how these searches and discoveries have intertwined with my own career.

BOOK REVIEW: Modern Supersymmetry

NASA Astrophysics Data System (ADS)

Kulish, Petr P.

2006-12-01

We have spent more than twenty years applying supersymmetry (SUSY) to elementary particle physics and attempting to find an experimental manifestation of this symmetry. Terning's monograph demonstrates the strong influence of SUSY on theoretical elaborations in the field of elementary particles. It gives both an overview of modern supersymmetry in elementary particle physics and calculation techniques. The author, trying to be closer to applications of SUSY in the real world of elementary particles, is also anticipating the importance of supersymmetry for rigorous study of nonperturbative phenomena in quantum field theory. In particular, he presents the `exact' SUSY β function using instanton methods, phenomena of anomalies and dualities. Supersymmetry algebra is introduced by adding two anticommuting spinor generators to Poincaré algebra and by presenting massive and massless supermultiplets of its representations. The author prefers to use mostly the component description of field contents of the theories in question rather than the superfield formalism. Such a style makes the account closer to physical chartacteristics. Relations required by SUSY among β functions of the gauge, Yukawa and quartic interactions are checked by direct calculations as well as to all orders in perturbation theory, thus demonstrating that SUSY survives quantization. A discussion is included of the hierarchy problem of different scales of weak and strong interactions and its possible solution by the minimal supersymmetric standard model. Different SUSY breaking mechanisms are presented corresponding to a realistic phenomenology. The monograph can also be considered as a guide to `duality' relations connecting different SUSY gauge theories, supergravities and superstrings. This is demonstrated referring to the particular properties and characteristics of these theories (field contents, scaling dimensions of appropriate operators etc). In particular, the last chapter deals with the AdS/CFT correspondence. The author explains clearly most of the arguments in discussions and refers for further details to original papers (with corresponding arXiv numbers), selected lists of which appear at the end of each chapter (there are more than 300 references in the book). Considered as a whole the book covers primers on quantum fields, Feynman diagrams, renormalization procedure and renormalization groups, as well as the representation theory of classical linear Lie algebras. Some necessary information on irreducible representations of su(N), so(N) and sp(2N) is given in an appendix. There are in the text short historical and biographical notes concerning those scientists who made important contributions to the subject of the monograph: S Coleman, Yu Golfand, E Witten and others. Most of the seventeen chapters contain a few exercises to check the reader's understanding of the corresponding material. This monograph will be useful for graduate students and researchers in the field of elementary particles.

Symmetry properties of the configuration interaction space in relation to one- and two-particle operators: The splitting theorem

NASA Astrophysics Data System (ADS)

Živković, Tomislav P.

1984-09-01

The configuration interaction (CI) space Xn built upon n electrons moving over 2n orthonormalized orbitals χi is considered. It is shown that the space Xn splits into two complementary subspaces X+n and X-n having special properties: each state Ψ+∈X+n and Ψ-∈X-n is ``alternantlike'' in the sense that it has a uniform charge density distribution over all orbitals χi and vanishing bond-orders between all orbitals of the same parity. In addition, matrix elements Γ(ij;kl) of a two-particle density matrix vanish whenever four distinct orbitals are involved and there is an odd number of orbitals of the same parity. Further, Γ(ij;lj)=γ(il)/4 ( j≠i,l), whenever (i) and (l) are of different parity. This last relation shows the connection between a two-particle (Γ) and a one-particle (γ) density matrix. ``Elementary'' alternant and antialternant operators are identified. These operators connect either only the states in the same subspace, or only the states in different subspaces, and each one- and two-particle symmetric operator can be represented by their linear combination. Alternant Hamiltonians, which can be represented as linear combinations of elementary alternant operators, have alternantlike eigenstates. It is also shown that each symmetric Hamiltonian possessing alternantlike eigenstates can be represented as such a linear combination. In particular, the PPP Hamiltonian describing an alternant hydrocarbon system is such a case. Complementary subspaces X+n and X-n can be explicitly constructed using the so-called regular resonance structures (RRS's) which are normalized determinants containing mutually disjunct bond orbitals. Expressions for the derivation of matrix elements of one- and two-particle operators between different RRS's are also derived.

The Trigonometry of Twistors and Elementary Particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustafson, Karl

2009-03-10

A new trigonometry for twistors is presented. The operator-theoretic maximum twistor turning angle is shown to be related to the space-time geometric angle within the light cone. The corresponding maximally turned twistor antieigenvectors are calculated and interpretted. The two weak interaction CP eigenvectors of neutral kaons are shown to be exactly the two strong interaction strangeness antieigenvectors. Quark mixing is seen trigonometrically. 't Hooft's microcosmos model is connected to the theories of normal degree and complex dynamics.

The notions of mass in gravitational and particle physics

NASA Astrophysics Data System (ADS)

Castellani, Gianluca

It is presently thought that the mass of all of the elementary particles is determined by the Higgs field. This scalar field couples directly into the trace of the energy momentum tensor of the elementary particles. The attraction between two or more masses arises from the exchange of gravitational quantum particles of spin 2, called gravitons. The gravitational field couples directly into the energy momentum tensor. Then there is a close connection between the Higgs field, that originates the mass, and the gravitational field that dictates how the masses interact. Our purpose in this thesis is to discuss this close connection in terms of fundamental definitions of inertial and gravitational masses. On a practical level we explore two properties of mass from the viewpoint of coupling into the Higgs field: (i) The coupling of the both the Higgs and gravity to the energy-pressure tensor allows for the decay of the Higgs particle into two gravitons. We use the self energy part of the Higgs propagator to calculate the electromagnetic, weak, fermionic and gravitational decay rate of the Higgs particle. We show that the former process appears to dominate the other decay modes. Since the gravitons are detectable with virtually zero probability, the number of Higgs particles with observable decay products will be much less than previously expected. (ii) Some new experimental results seem to indicate that the mass of the heavy elementary particles like the Z,W+,W- and especially the top quark, depends on the particle environment in which these particles are produced. The presence of a Higgs field due to neighboring particles could be responsible for induced mass shifts. Further measurements of mass shift effects might give an indirect proof of the Higgs particle. Such can be in principle done by re-analyzing some of the production data e +e- → ZZ (or W+W-) already collected at the LEP experiment. About the physical property of the top quark, it is too early to arrive at any conclusion. In the foreseeable future, there will be more extended top quark production statistics from the Tevatron accelerator so that the mass shift hypothesis can be experimentally probed.

Can There Be Massive Photons? A Pedagogical Glance at the Origin of Mass

ERIC Educational Resources Information Center

Robles, P.; Claro, F.

2012-01-01

Among the most startling experiences a student encounters is learning that, unlike electrons and other elementary particles, photons have no mass. Under certain circumstances, however, the light quantum behaves as if it did have a finite mass. Starting from Maxwell's equations, we discuss how this arises when light interacts with a charged plasma,…

Goldstone mode and pair-breaking excitations in atomic Fermi superfluids

NASA Astrophysics Data System (ADS)

Hoinka, Sascha; Dyke, Paul; Lingham, Marcus G.; Kinnunen, Jami J.; Bruun, Georg M.; Vale, Chris J.

2017-10-01

Spontaneous symmetry breaking is a central paradigm of elementary particle physics, magnetism, superfluidity and superconductivity. According to Goldstone's theorem, phase transitions that break continuous symmetries lead to the existence of gapless excitations in the long-wavelength limit. These Goldstone modes can become the dominant low-energy excitation, showing that symmetry breaking has a profound impact on the physical properties of matter. Here, we present a comprehensive study of the elementary excitations in a homogeneous strongly interacting Fermi gas through the crossover from a Bardeen-Cooper-Schrieffer (BCS) superfluid to a Bose-Einstein condensate (BEC) of molecules using two-photon Bragg spectroscopy. The spectra exhibit a discrete Goldstone mode, associated with the broken-symmetry superfluid phase, as well as pair-breaking single-particle excitations. Our techniques yield a direct determination of the superfluid pairing gap and speed of sound in close agreement with strong-coupling theories.

When is a Particle?

ERIC Educational Resources Information Center

Drell, Sidney D.

1978-01-01

Gives a new definition for the concept of the elementary particle in nuclear physics. Explains why the existance of the quark as an elementary particle could be an accepted fact even though it lacks what traditionally identifies a particle. Compares this with the development which took place during the discovery of the neutrino in the early…

Waiting for the W and the Higgs

DOE PAGES

Tannenbaum, Michael J.

2016-10-06

The search for the left-handed W± bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven elementary-particle physics research from the time that I entered college to the present and has led to many unexpected and exciting discoveries which revolutionized our view of subnuclear physics over that period. In this article I describe how these searches and discoveries have intertwined with my own career.

Waiting for the W. and the Higgs

NASA Astrophysics Data System (ADS)

Tannenbaum, M. J.

2016-12-01

The search for the left-handed W± bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven elementary-particle physics research from the time that I entered college to the present and has led to many unexpected and exciting discoveries which revolutionized our view of subnuclear physics over that period. In this article I describe how these searches and discoveries have intertwined with my own career.

The early universe history from contraction-deformation of the Standard Model

NASA Astrophysics Data System (ADS)

Gromov, N. A.

2017-03-01

The elementary particles evolution in the early Universe from Plank time up to several milliseconds is presented. The developed theory is based on the high-temperature (high-energy) limit of the Standard Model which is generated by the contractions of its gauge groups. At the infinite temperature all particles lose masses. Only massless neutral -bosons, massless Z-quarks, neutrinos and photons are survived in this limit. The weak interactions become long-range and are mediated by neutral currents, quarks have only one color degree of freedom.

Latest AMS Results on elementary particles in cosmic rays

NASA Astrophysics Data System (ADS)

Kounine, Andrei; AMS Collaboration

2017-01-01

AMS-02 is a particle physics detector collecting data on the International Space Station since May 2011. Precision measurements of all elementary charged cosmic ray particles have been performed by AMS using a data sample of 85 billion cosmic ray events collected during the first five years of operations on the Station. The latest AMS results on the fluxes and flux ratios of the elementary cosmic ray particles are presented. They show unique features that require accurate theoretical interpretation as to their origin, be it from dark matter collisions or new astrophysical sources. On behalf of the AMS Collaboration.

Engineering of frustration in colloidal artificial ice (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ortiz-Ambriz, Antonio; Tierno, Pietro

2016-09-01

Artificial spin-ice systems have been used to date as microscopic models of frustration induced by lattice topology, as they allow for the direct visualization of spin arrangements and textures. However, the engineering of frustrated ice states in which individual spins can be manipulated in situ and the real-time observation of their collective dynamics remain both challenging tasks. Recently, an analogue system has been proposed theoretically, where an optical landscape confined colloidal particles that interacted electrostatically. Here we realize experimentally another version of a colloidal artificial ice system using interacting magnetically polarizable particles confined to lattices of bistable gravitational traps. We show quantitatively that ice-selection rules emerge in this frustrated soft matter system by tuning the strength of the pair-interactions between the microscopic units. By using optical tweezers, we can control particle positioning and dipolar coupling, we introduce monopole-like defects and strings and use loops with defined chirality as an elementary unit to store binary information.

Teaching Elementary Particle Physics: Part I

ERIC Educational Resources Information Center

Hobson, Art

2011-01-01

I'll outline suggestions for teaching elementary particle physics, often called "high energy physics," in high school or introductory college courses for non-scientists or scientists. Some presentations of this topic simply list the various particles along with their properties, with little overarching structure. Such a laundry list approach is a…

100 years of elementary particles [Beam Line, vol. 27, issue 1, Spring 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pais, Abraham; Weinberg, Steven; Quigg, Chris

1997-04-01

This issue of Beam Line commemorates the 100th anniversary of the April 30, 1897 report of the discovery of the electron by J.J. Thomson and the ensuing discovery of other subatomic particles. In the first three articles, theorists Abraham Pais, Steven Weinberg, and Chris Quigg provide their perspectives on the discoveries of elementary particles as well as the implications and future directions resulting from these discoveries. In the following three articles, Michael Riordan, Wolfgang Panofsky, and Virginia Trimble apply our knowledge about elementary particles to high-energy research, electronics technology, and understanding the origin and evolution of our Universe.

100 years of Elementary Particles [Beam Line, vol. 27, issue 1, Spring 1997

DOE R&D Accomplishments Database

Pais, Abraham; Weinberg, Steven; Quigg, Chris; Riordan, Michael; Panofsky, Wolfgang K. H.; Trimble, Virginia

1997-04-01

This issue of Beam Line commemorates the 100th anniversary of the April 30, 1897 report of the discovery of the electron by J.J. Thomson and the ensuing discovery of other subatomic particles. In the first three articles, theorists Abraham Pais, Steven Weinberg, and Chris Quigg provide their perspectives on the discoveries of elementary particles as well as the implications and future directions resulting from these discoveries. In the following three articles, Michael Riordan, Wolfgang Panofsky, and Virginia Trimble apply our knowledge about elementary particles to high-energy research, electronics technology, and understanding the origin and evolution of our Universe.

Cosmology and particle physics

NASA Technical Reports Server (NTRS)

Turner, Michael S.

1988-01-01

The interplay between cosmology and elementary particle physics is discussed. The standard cosmology is reviewed, concentrating on primordial nucleosynthesis and discussing how the standard cosmology has been used to place constraints on the properties of various particles. Baryogenesis is discussed, showing how a scenario in which the B-, C-, and CP-violating interactions in GUTs provide a dynamical explanation for the predominance of matter over antimatter and for the present baryon-to-photon ratio. It is shown how the very early dynamical evolution of a very weakly coupled scalar field which is initially displaced from the minimum of its potential may explain a handful of very fundamental cosmological facts which are not explained by the standard cosmology.

Plato's Ideas and the Theories of Modern Particle Physics: Amazing Parallels

NASA Astrophysics Data System (ADS)

Machleidt, Ruprecht

2006-05-01

It is generally known that the question, ``What are the most elementary particles that all matter is made from?'', was already posed in the antiquity. The Greek natural philosophers Leucippus and Democritus were the first to suggest that all matter was made from atoms. Therefore, most people perceive them as the ancient fathers of elementary particle physics. However, this perception is wrong. Modern particle physics is not just a simple atomism. The characteristic point of modern particle theory is that it is concerned with the symmetries underlying the particles we discover in experiment. More than 2000 years ago, a similar idea was already advanced by the Greek philosopher Plato in his dialogue Timaeus: Geometric symmetries generate the atoms from just a few even more elementary items. Plato's vision is amazingly close to the ideas of modern particle theory. This fact, which is unfortunately little known, has been pointed out repeatedly by Werner Heisenberg.

Electrostatic interaction energy and factor 1.23

NASA Astrophysics Data System (ADS)

Rubčić, A.; Arp, H.; Rubčić, J.

The factor F≫1.23 has originally been found in the redshift of quasars. Recently, it has been found in very different physical phenomena: the life-time of muonium, the masses of elementary particles (leptons, quarks,...), the correlation of atomic weight (A) and atomic number (Z) and the correlation of the sum of masses of all orbiting bodies with the mass of the central body in gravitational systems.

Chemical Potential for the Interacting Classical Gas and the Ideal Quantum Gas Obeying a Generalized Exclusion Principle

ERIC Educational Resources Information Center

Sevilla, F. J.; Olivares-Quiroz, L.

2012-01-01

In this work, we address the concept of the chemical potential [mu] in classical and quantum gases towards the calculation of the equation of state [mu] = [mu](n, T) where n is the particle density and "T" the absolute temperature using the methods of equilibrium statistical mechanics. Two cases seldom discussed in elementary textbooks are…

40 years of neutrino physics

NASA Astrophysics Data System (ADS)

Reines, Frederick

Wolfgang Pauli and Enrico Fermi pioneered the hypothesis and characteristics of the weak interaction and the elementary particle called the neutrino. Since its discovery some forty years ago the neutrino has been shown to be a fundamental constituent of matter with a surprisingly rich, and in very many ways unexpected, set of characteristics ranging from basic roles in the generation of energy in the sun to supernovæ.

Report of NRL Progress. Fifty Years of Science for the Navy and the Nation, 1923-1973

DTIC Science & Technology

1973-07-01

on High Energy Physics in September, 1960. In the decade of the sixties we were gradually to disengage from elementary particle physicsf in ...Progress, July 1973 IQI M. M. SHAPIRO Figure 2 - A high - energy interaction of a nitrogen nucleus in photographic emul- sion. The nitrogen ion from ...particularly as induced by a radiation environment. In the

Planck's constant and the three waves (TWs) of Einstein's covariant ether

NASA Astrophysics Data System (ADS)

Kostro, L.

1985-11-01

The implications of a three-wave model for elementary particles, satisfying the principles of both quantum mechanics and General Relativity (GR), are discussed. In GR, the ether is the fundamental source of all activity, where particles (waves) arise at singularities. Inertia and gravity are field properties of the ether. In flat regions of the space-time geodesic, wave excitations correspond to the presence of particles. A momentum-carrying excitation which occurs in the ether is a superluminal radiation (phase- or B-waves) which transports neither energy nor mass. Superposition of the B-waves produces soliton-like excitations on the ether to form C-waves, i.e., particles. The particle-waves travel through space-time on D-waves, and experience reflection, refraction and interference only where B-waves have interacted with the ether. The original particles, photons-maximons, existed at the Big Bang and had physical properties which are describable in terms of Planck's quantities.

Abdus Salam

NASA Astrophysics Data System (ADS)

Ziman, John

Mr. Vice-Chancellor Only connect! That is the theme that runs through the life and work of Abdus Salam. He has followed the teaching of Islam and has dedicated his life to the principle of unity — the unity of Nature and the unity of Mankind. As a natural philosopher he has seen that the various interactions of the elementary particles must be no more than diverse aspects of a single primary force. As a political and moral leader he has demonstrated that the various interactions of nations and cultures are no obstacle to the brotherhood of Man in science…

Engineering of frustration in colloidal artificial ices realized on microfeatured grooved lattices

PubMed Central

Ortiz-Ambriz, Antonio; Tierno, Pietro

2016-01-01

Artificial spin ice systems, namely lattices of interacting single domain ferromagnetic islands, have been used to date as microscopic models of frustration induced by lattice topology, allowing for the direct visualization of spin arrangements and textures. However, the engineering of frustrated ice states in which individual spins can be manipulated in situ and the real-time observation of their collective dynamics remain both challenging tasks. Inspired by recent theoretical advances, here we realize a colloidal version of an artificial spin ice system using interacting polarizable particles confined to lattices of bistable gravitational traps. We show quantitatively that ice-selection rules emerge in this frustrated soft matter system by tuning the strength of the pair interactions between the microscopic units. Via independent control of particle positioning and dipolar coupling, we introduce monopole-like defects and strings and use loops with defined chirality as an elementary unit to store binary information. PMID:26830629

Engineering of frustration in colloidal artificial ices realized on microfeatured grooved lattices.

PubMed

Ortiz-Ambriz, Antonio; Tierno, Pietro

2016-02-01

Artificial spin ice systems, namely lattices of interacting single domain ferromagnetic islands, have been used to date as microscopic models of frustration induced by lattice topology, allowing for the direct visualization of spin arrangements and textures. However, the engineering of frustrated ice states in which individual spins can be manipulated in situ and the real-time observation of their collective dynamics remain both challenging tasks. Inspired by recent theoretical advances, here we realize a colloidal version of an artificial spin ice system using interacting polarizable particles confined to lattices of bistable gravitational traps. We show quantitatively that ice-selection rules emerge in this frustrated soft matter system by tuning the strength of the pair interactions between the microscopic units. Via independent control of particle positioning and dipolar coupling, we introduce monopole-like defects and strings and use loops with defined chirality as an elementary unit to store binary information.

Engineering of frustration in colloidal artificial ices realized on microfeatured grooved lattices

NASA Astrophysics Data System (ADS)

Tierno, Pietro

Artificial spin-ice systems, namely lattices of interacting single domain ferromagnetic islands, have been used to date as microscopic models of frustration induced by lattice topology, allowing for the direct visualization of spin arrangements and textures. However, the engineering of frustrated ice states in which individual spins can be manipulated in situ and the real-time observation of their collective dynamics remain both challenging tasks. Inspired by recent theoretical advances, we realize a colloidal version of an artificial spin ice system using interacting polarizable particles confined to lattices of bistable gravitational traps. We show quantitatively that ice-selection rules emerge in this frustrated soft matter system by tuning the strength of the pair-interactions between the microscopic units. Via independent control of particle positioning and dipolar coupling, we introduce monopole-like defects and strings and use loops with defined chirality as an elementary unit to store binary information.

Engineering of frustration in colloidal artificial ices realized on microfeatured grooved lattices

NASA Astrophysics Data System (ADS)

Ortiz-Ambriz, Antonio; Tierno, Pietro

2016-02-01

Artificial spin ice systems, namely lattices of interacting single domain ferromagnetic islands, have been used to date as microscopic models of frustration induced by lattice topology, allowing for the direct visualization of spin arrangements and textures. However, the engineering of frustrated ice states in which individual spins can be manipulated in situ and the real-time observation of their collective dynamics remain both challenging tasks. Inspired by recent theoretical advances, here we realize a colloidal version of an artificial spin ice system using interacting polarizable particles confined to lattices of bistable gravitational traps. We show quantitatively that ice-selection rules emerge in this frustrated soft matter system by tuning the strength of the pair interactions between the microscopic units. Via independent control of particle positioning and dipolar coupling, we introduce monopole-like defects and strings and use loops with defined chirality as an elementary unit to store binary information.

Nuclear and particle physics in the early universe

NASA Technical Reports Server (NTRS)

Schramm, D. N.

1981-01-01

Basic principles and implications of Big Bang cosmology are reviewed, noting the physical evidence of a previous universe temperature of 10,000 K and theoretical arguments such as grand unification decoupling indicating a primal temperature of 10 to the 15th eV. The Planck time of 10 to the -43rd sec after the Big Bang is set as the limit before which gravity was quantized and nothing is known. Gauge theories of elementary particle physics are reviewed for successful predictions of similarity in weak and electromagnetic interactions and quantum chromodynamic predictions for strong interactions. The large number of photons in the universe relative to the baryons is considered and the grand unified theories are cited as showing the existence of baryon nonconservation as an explanation. Further attention is given to quark-hadron phase transition, the decoupling for the weak interaction and relic neutrinos, and Big Bang nucleosynthesis.

Plato's TIMAIOσ (TIMAEUS) and Modern Particle Physics

NASA Astrophysics Data System (ADS)

Machleidt, Ruprecht

2005-04-01

It is generally known that the question, ``What are the smallest particles (elementary particles) that all matter is made from?'', was posed already in the antiquity. The Greek natural philosophers Leucippus and Democritus were the first to suggest that all matter was made from atoms. Therefore, most people perceive them as the ancient fathers of elementary particle physics. It will be the purpose of my contribution to point out that this perception is wrong. Modern particle physics is not just a primitive atomism. More important than the materialistic particles are the underlying symmetries (e. g., SU(3) and SU(6)). A similar idea was first advanced by Plato in his dialog TIMAIOσ (Latin translation: TIMAEUS): Geometric symmetries generate the materialistic particles from a few even more elementary items. Plato's vision is amazingly close to the ideas of modern particle physics. This fact, which is unfortunately little known, has been pointed out repeatedly by Heisenberg (see, e. g., Werner Heisenberg, Across the Frontiers, Harper & Row, New York, 1974).

Higgs Particle: The Origin of Mass

NASA Astrophysics Data System (ADS)

Okada, Yasuhiro

2007-11-01

The Higgs particle is a new elementary particle predicted in the Standard Model of the elementary particle physics. It plays a special role in the theory of mass generation of quarks, leptons, and gauge bosons. In this article, theoretical issues on the Higgs mechanism are first discussed, and then experimental prospects on the Higgs particle study at the future collider experiments, LHC and ILC, are reviewed. The Higgs coupling determination is an essential step to establish the mass generation mechanism, which could lead to a deeper understanding of particle physics.

Neutrino Oscillation Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kayser, Boris

2012-06-01

To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures. Neutrinos and photons are by far themore » most abundant elementary particles in the universe. Thus, if we would like to comprehend the universe, we must understand the neutrinos. Of course, studying the neutrinos is challenging, since the only known forces through which these electrically-neutral leptons interact are the weak force and gravity. Consequently, interactions of neutrinos in a detector are very rare events, so that very large detectors and intense neutrino sources are needed to make experiments feasible. Nevertheless, we have confirmed that the weak interactions of neutrinos are correctly described by the Standard Model (SM) of elementary particle physics. Moreover, in the last 14 years, we have discovered that neutrinos have nonzero masses, and that leptons mix. These discoveries have been based on the observation that neutrinos can change from one 'flavor' to another - the phenomenon known as neutrino oscillation. We shall explain the physics of neutrino oscillation, deriving the probability of oscillation in a new way. We shall also provide a very brief guide to references that can be used to study some major neutrino-physics topics other than neutrino oscillation.« less

Matter in the form of toroidal electromagnetic vortices

NASA Astrophysics Data System (ADS)

Hagen, Wilhelm F.

2015-09-01

The creation of charged elementary particles from neutral photons is explained as a conversion process of electromagnetic (EM) energy from linear to circular motion at the speed of light into two localized, toroidal shaped vortices of trapped EM energy that resist change of motion, perceptible as particles with inertia and hence mass. The photon can be represented as a superposition of left and right circular polarized transverse electric fields of opposite polarity originating from a common zero potential axis, the optical axis of the photon. If these components are separated by interaction with a strong field (nucleon) they would curl up into two electromagnetic vortices (EMV) due to longitudinal magnetic field components forming toroids. These vortices are perceptible as opposite charged elementary particles e+/- . These spinning toroids generate extended oscillating fields that interact with stationary field oscillations. The velocity-dependent frequency differences cause beat signals equivalent to matter waves, leading to interference. The extended fields entangled with every particle explain wave particle duality issues. Spin and magnetic moment are the natural outcome of these gyrating particles. As the energy and hence mass of the electron increases with acceleration so does its size shrink proportional to its reduced wavelength. The artificial weak and strong nuclear forces can be easily explained as different manifestations of the intermediate EM forces. The unstable neutron consists of a proton surrounded by a contracted and captured electron. The associated radial EM forces represent the weak nuclear force. The deuteron consists of two axially separated protons held together by a centrally captured electron. The axial EM forces represent the strong nuclear force, providing stability for "neutrons" only within nucleons. The same principles were applied to determine the geometries of force-balanced nuclei. The alpha-particle emerges as a very compact symmetric cuboid that provides a unique building block to assemble the isotopic chart. Exotic neutron- 4 appears viable which may explain dark matter. The recognition that all heavy particles, including the protons, are related to electrons via muons and pions explains the identity of all charges to within 10-36. Greater deviations would overpower gravitation. Gravitation can be traced to EM vacuum fluctuations generated by standing EM waves between interacting particles. On that basis, gravity can be correlated via microscopic quantities to the age of the universe of 13.5 billion years. All forces and particles and potentially dark matter and dark energy are different manifestations of EM energy.

Instrumentation for Applied Physics and Industrial Applications

NASA Astrophysics Data System (ADS)

Hillemanns, H.; Le Goff, J.-M.

This document is part of Part 2 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '7.3 Instrumentation for Applied Physics and Industrial Applications' of Chapter '7 Applications of Detectors in Technology; Medicine and Other Fields' with the content:

Research of fundamental interactions with use of ultracold neutrons

NASA Astrophysics Data System (ADS)

Serebrov, A. P.

2017-01-01

Use of ultracold neutrons (UCN) gives unique opportunities of a research of fundamental interactions in physics of elementary particles. Search of the electric dipole moment of a neutron (EDM) aims to test models of CP violation. Precise measurement of neutron lifetime is extremely important for cosmology and astrophysics. Considerable progress in these questions can be reached due to supersource of ultracold neutrons on the basis of superfluid helium which is under construction now in PNPI NRC KI. This source will allow us to increase density of ultracold neutrons approximately by 100 times in respect to the best UCN source at high flux reactor of Institute Laue-Langevin (Grenoble, France). Now the project and basic elements of the source are prepared, full-scale model of the source is tested, the scientific program is developed. Increase in accuracy of neutron EDM measurements by order of magnitude, down to level 10-27 -10-28 e cm is planned. It is highly important for physics of elementary particles. Accuracy of measurement of neutron lifetime can be increased by order of magnitude also. At last, at achievement of UCN density ˜ 103 - 104 cm-3, the experiment search for a neutron-antineutron oscillations using UCN will be possible. The present status of the project and its scientific program will be discussed.

Quantum Optics, Diffraction Theory, and Elementary Particle Physics

ScienceCinema

Glauber, Roy

2018-05-22

Physical optics has expanded greatly in recent years. Though it remains part of the ancestry of elementary particle physics, there are once again lessons to be learned from it. I shall discuss several of these, including some that have emerged at CERN and Brookhaven.

11.2 Solar Neutrinos

NASA Astrophysics Data System (ADS)

Nakahata, Masayuki

This document is part of Subvolume A `Theory and Experiments' of Volume 21 `Elementary Particles' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It contains of the Chapter `11 Experimental Results on Neutrino Masses and Mixings' the Section `11.2 Solar Neutrinos' with the content:

The Origin of Inertia and Matter as a Superradiant Phase Transition of Quantum Vacuum

NASA Astrophysics Data System (ADS)

Maxmilian Caligiuri, Luigi

Mass is one of the most important concepts in physics and its real understanding represents the key for the formulation of any consistent physical theory. During the past years, a very interesting model of inertial and gravitational mass as the result of the reaction interaction between the charged particles (electrons and quarks) contained in a given body and a suitable "fraction" of QED Zero Point Fields confined within an ideal resonant cavity, associated to the same body, has been proposed by Haish, Rueda and Puthoff. More recently, the author showed that this interpretation is consistent with a picture of mass (both inertial and gravitational) as the seat of ZPF standing waves whose presence reduces quantum vacuum energy density inside the resonant cavity ideally associated to the body volume. Nevertheless so far, the ultimate physical origin of such resonant cavity as well as the mechanism able to "select" the fraction of ZPF electromagnetic modes interacting within it, remained unrevealed. In this paper, basing on the framework of QED coherence in condensed matter, we'll show mass can be viewed as the result of a spontaneous superradiant phase transition of quantum vacuum giving rise to a more stable, energetically favored, oscopic quantum state characterized by an ensemble of coherence domains, "trapping" the coherent ZPF fluctuations inside a given volume just acting as a resonant cavity. Our model is then able to explain the "natural" emergence of the ideal resonant cavity speculated by Haish, Rueda and Puthoff and its defining parameters as well as the physical mechanism selecting the fraction of ZPF interacting with the body particles. Finally, a generalization of the model to explain the origin of mass of elementary particles is proposed also suggesting a new understanding of Compton's frequency and De Broglie's wavelength. Our results indicates both inertia and matter could truly originate from coherent interaction between quantum matter-wave and radiation fields condensed from quantum vacuum and also give novel and interesting insights into fundamental physical questions as, for example, the structure of elementary particles and matter stability.

Teaching Elementary Particle Physics, Part II

NASA Astrophysics Data System (ADS)

Hobson, Art

2011-03-01

In order to explain certain features of radioactive beta decay, Wolfgang Pauli suggested in 1930 that the nucleus emitted, in addition to a beta particle, another particle of an entirely new type. The hypothesized particle, dubbed the neutrino, would not be discovered experimentally for another 25 years. It's not easy to detect neutrinos, because they respond to neither the EM force nor the strong force. For example, the mean free path (average penetration distance before it interacts) of a typical beta-decay neutrino moving through solid lead is about 1.5 light years! Enrico Fermi argued that neutrinos indicated a new force was at work. During the 1930s, he quickly adapted ideas from the developing new theory of QED to this new force, dubbed the weak force. Fermi's theory was able to predict the half-lives of beta-emitting nuclei and the range of energies of the emitted beta particles.

Emergent Weyl excitations in systems of polar particles.

PubMed

Syzranov, Sergey V; Wall, Michael L; Zhu, Bihui; Gurarie, Victor; Rey, Ana Maria

2016-12-12

Weyl fermions are massless chiral particles first predicted in 1929 and once thought to describe neutrinos. Although never observed as elementary particles, quasiparticles with Weyl dispersion have recently been experimentally discovered in solid-state systems causing a furore in the research community. Systems with Weyl excitations can display a plethora of fascinating phenomena and offer great potential for improved quantum technologies. Here, we show that Weyl excitations generically exist in three-dimensional systems of dipolar particles with weakly broken time-reversal symmetry (by for example a magnetic field). They emerge as a result of dipolar-interaction-induced transfer of angular momentum between the J=0 and J=1 internal particle levels. We also discuss momentum-resolved Ramsey spectroscopy methods for observing Weyl quasiparticles in cold alkaline-earth-atom systems. Our results provide a pathway for a feasible experimental realization of Weyl quasiparticles and related phenomena in clean and controllable atomic systems.

Development of Concepts in the History of Quantum Theory

ERIC Educational Resources Information Center

Heisenberg, Werner

1975-01-01

Traces the development of quantum theory from the concept of the discrete stationary states, to the generalized concept of state, to the search for the elementary particle. States that the concept of the elementary particle should be replaced by the concept of a fundamental symmetry. (MLH)

The Latest IceCube Results and the Implications

NASA Astrophysics Data System (ADS)

Mase, Keiichi

IceCube was built at the South Pole and aims to detect high energy neutrinos from the universe mainly above 100 GeV. The transparent ice media allows us to build a 1 km3 large detection volume to detect the rarely interacting particles. Neutrinos are thought to be generated at astrophysical sources such as active galactic nuclei and gamma-ray bursts. Nature of the rare interaction with matters and little deflection by a magnetic field makes it possible to explore such sources located at the deep universe. Since the neutrinos are produced through collisions of hadronic particles, the observation can elucidate the origin of cosmic rays, which is still mystery after the discovery 100 years ago. The detector was completed at the end of 2010 and is running smoothly. Recently, IceCube has found the first evidence of extraterrestrial neutrinos with energies above approximately 60 TeV. IceCube also contributes to elementary particle physics by searching for neutrinos produced in self-annihilation of SUSY particles such as neutralinos and by investigating atmospheric neutrino oscillations. The latest IceCube results and the corresponding implications are presented.

Mutual interactions of phonons, rotons, and gravity

NASA Astrophysics Data System (ADS)

Nicolis, Alberto; Penco, Riccardo

2018-04-01

We introduce an effective point-particle action for generic particles living in a zero-temperature superfluid. This action describes the motion of the particles in the medium at equilibrium as well as their couplings to sound waves and generic fluid flows. While we place the emphasis on elementary excitations such as phonons and rotons, our formalism applies also to macroscopic objects such as vortex rings and rigid bodies interacting with long-wavelength fluid modes. Within our approach, we reproduce phonon decay and phonon-phonon scattering as predicted using a purely field-theoretic description of phonons. We also correct classic results by Landau and Khalatnikov on roton-phonon scattering. Finally, we discuss how phonons and rotons couple to gravity, and show that the former tend to float while the latter tend to sink but with rather peculiar trajectories. Our formalism can be easily extended to include (general) relativistic effects and couplings to additional matter fields. As such, it can be relevant in contexts as diverse as neutron star physics and light dark matter detection.

Microswimmers - From Single Particle Motion to Collective Behavior

NASA Astrophysics Data System (ADS)

Gompper, Gerhard; Bechinger, Clemens; Herminghaus, Stephan; Isele-Holder, Rolf; Kaupp, U. Benjamin; Löwen, Hartmut; Stark, Holger; Winkler, Roland G.

2016-11-01

Locomotion of autonomous microswimmers is a fascinating field at the cutting edge of science. It combines the biophysics of self-propulsion via motor proteins, artificial propulsion mechanisms, swimming strategies at low Reynolds numbers, the hydrodynamic interaction of swimmers, and the collective motion and synchronisation of large numbers of agents. The articles of this Special Issue are based on the lecture notes of an international summer school, which was organized by the DFG Priority Programme 1726 "Microswimmers - From Single Particle Motion to Collective Behaviour" in the fall of 2015. The minireviews provide a broad overview of the field, covering both elementary and advanced material, as well as selected areas from current research.

The decay of the proton

NASA Astrophysics Data System (ADS)

Weinberg, S.

1981-06-01

The principal decay modes of subatomic particles are governed by fundamental conservation laws, and it is recounted how traditional views of conservation laws have been altered by the development of modern theories of elementary particle interactions. Proton decay experiments have gradually increased the empirical lower boundary on the lifetime of the proton. It is now known to have a lifetime at least 10 to the 30th times the age of the universe, but recent theoretical work is cited as an indication that this fundamental constituent of matter is not immortal. The conclusion is that all matter will eventually disintegrate if the proton indeed does not live forever.

PEAS AND PARTICLES, TEACHER'S GUIDE.

ERIC Educational Resources Information Center

1966

THIS TEACHER'S GUIDE IS DESIGNED FOR USE WITH AN ELEMENTARY SCIENCE STUDY UNIT ON "PEAS AND PARTICLES" WHICH DEALS WITH LARGE NUMBERS AND ESTIMATIONS. ITS PURPOSE IS TO GIVE ELEMENTARY SCHOOL CHILDREN AN UNDERSTANDING OF WHAT LARGE NUMBERS MEAN THROUGH INFORMAL ACTIVITIES INVOLVING FAMILIAR OBJECTS. THE MATERIAL HAS BEEN FOUND SUITABLE…

Search for free fractional electric charge elementary particles using an automated millikan oil drop technique

PubMed

Halyo; Kim; Lee; Lee; Loomba; Perl

2000-03-20

We have carried out a direct search in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied-about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0. 16e ( e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71x10(-22) particles per nucleon with 95% confidence.

Final Report May 1, 2012 to May 31, 2015: "Theoretical Studies in Elementary Particle Physics"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collins, John C.; Roiban, Radu

2015-08-19

This final report summarizes work at Penn State University from May 1, 2012 to May 31, 2015. The work was in theoretical elementary particle physics. Many new results in perturbative QCD, in string theory, and in related areas were obtained, with a substantial impact on the experimental program.

Can the Hypothesis 'Photon Interferes only with Itself' be Reconciled with Superposition of Light from Multiple Beams or Sources?

NASA Technical Reports Server (NTRS)

Roychoudhuri, Chandrasekhar; Prasad, Narasimha S.; Peng, Qing

2007-01-01

Any superposition effect as measured (SEM) by us is the summation of simultaneous stimulations experienced by a detector due to the presence of multiple copies of a detectee each carrying different values of the same parameter. We discus the cases with light beams carrying same frequency for both diffraction and multiple beam Fabry-Perot interferometer and also a case where the two superposed light beams carry different frequencies. Our key argument is that if light really consists of indivisible elementary particle, photon, then it cannot by itself create superposition effect since the state vector of an elementary particle cannot carry more than one values of any parameter at the same time. Fortunately, semiclassical model explains all light induced interactions using quantized atoms and classical EM wave packet. Classical physics, with its deeper commitment to Reality Ontology, was better prepared to nurture the emergence of Quantum Mechanics and still can provide guidance to explore nature deeper if we pay careful attention to successful classical formulations like Huygens-Fresnel diffraction integral.

Self-assembled structures of Gaussian nematic particles.

PubMed

Nikoubashman, Arash; Likos, Christos N

2010-03-17

We investigate the stable crystalline configurations of a nematic liquid crystal made of soft parallel ellipsoidal particles interacting via a repulsive, anisotropic Gaussian potential. For this purpose, we use genetic algorithms (GA) in order to predict all relevant and possible solid phase candidates into which this fluid can freeze. Subsequently we present and discuss the emerging novel structures and the resulting zero-temperature phase diagram of this system. The latter features a variety of crystalline arrangements, in which the elongated Gaussian particles in general do not align with any one of the high-symmetry crystallographic directions, a compromise arising from the interplay and competition between anisotropic repulsions and crystal ordering. Only at very strong degrees of elongation does a tendency of the Gaussian nematics to align with the longest axis of the elementary unit cell emerge.

Spreadsheet analysis of stability and meta-stability of low-dimensional magnetic particles using the Ising approach

NASA Astrophysics Data System (ADS)

Ehrmann, Andrea; Blachowicz, Tomasz; Zghidi, Hafed

2015-05-01

Modelling hysteresis behaviour, as it can be found in a broad variety of dynamical systems, can be performed in different ways. An elementary approach, applied for a set of elementary cells, which uses only two possible states per cell, is the Ising model. While such Ising models allow for a simulation of many systems with sufficient accuracy, they nevertheless depict some typical features which must be taken into account with proper care, such as meta-stability or the externally applied field sweeping speed. This paper gives a general overview of recent results from Ising models from the perspective of a didactic model, based on a 2D spreadsheet analysis, which can be used also for solving general scientific problems where direct next-neighbour interactions take place.

Collisional Lifetimes of Elementary Excitations in Two-Dimensional Systems in the Field of a Strong Electromagnetic Wave

NASA Astrophysics Data System (ADS)

Kovalev, V. M.

2018-04-01

A two-dimensional system with two nonequivalent valleys in the field of a strong circularly polarized electromagnetic wave is considered. It is assumed that the optical selection rules for a given polarization of light allow band-to-band transitions only in valleys of one, optically active, type (two-dimensional layer based on transition metal dichalcogenides, gapped graphene, etc.). This leads to the formation of photon-coupled electron-hole pairs, or an "optical insulator" state. It is assumed that the valleys of the second type (optically inactive) are populated with an equilibrium electron gas. The relaxation of elementary excitations in this hybrid system consisting of an electron gas and a gas of electron-hole pairs caused by the Coulomb interaction between the particles is investigated.

Atomic Mass and Nuclear Binding Energy for I-131 (Iodine)

NASA Astrophysics Data System (ADS)

Sukhoruchkin, S. I.; Soroko, Z. N.

This document is part of the Supplement containing the complete sets of data of Subvolume A `Nuclei with Z = 1 - 54' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope I-131 (Iodine, atomic number Z = 53, mass number A = 131).

Atomic Mass and Nuclear Binding Energy for F-22 (Fluorine)

NASA Astrophysics Data System (ADS)

Sukhoruchkin, S. I.; Soroko, Z. N.

This document is part of the Supplement containing the complete sets of data of Subvolume A `Nuclei with Z = 1 - 54' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope F-22 (Fluorine, atomic number Z = 9, mass number A = 22).

The Mathematical Structure of Elementary Particles. II.

DTIC Science & Technology

1985-05-01

apparently related to the Higgs fields of electroweak interactions. 6.11 UNITARY SYM’ILTRY OF THE STABLE QUANTA We still need to analyze the implications of...Remark this A has nothing to do with the cosmological constant in Chapter V.) From now on we agree to represent any complex number A in...bring in the axial symmetry effects, but this would be useless because in our case new phe- nomena arise (exchange forces, metric averaging, Higgs

Self-Consistency of the Theory of Elementary Stage Rates of Reversible Processes and the Equilibrium Distribution of Reaction Mixture Components

NASA Astrophysics Data System (ADS)

Tovbin, Yu. K.

2018-06-01

An analysis is presented of one of the key concepts of physical chemistry of condensed phases: the theory self-consistency in describing the rates of elementary stages of reversible processes and the equilibrium distribution of components in a reaction mixture. It posits that by equating the rates of forward and backward reactions, we must obtain the same equation for the equilibrium distribution of reaction mixture components, which follows directly from deducing the equation in equilibrium theory. Ideal reaction systems always have this property, since the theory is of a one-particle character. Problems arise in considering interparticle interactions responsible for the nonideal behavior of real systems. The Eyring and Temkin approaches to describing nonideal reaction systems are compared. Conditions for the self-consistency of the theory for mono- and bimolecular processes in different types of interparticle potentials, the degree of deviation from the equilibrium state, allowing for the internal motions of molecules in condensed phases, and the electronic polarization of the reagent environment are considered within the lattice gas model. The inapplicability of the concept of an activated complex coefficient for reaching self-consistency is demonstrated. It is also shown that one-particle approximations for considering intermolecular interactions do not provide a theory of self-consistency for condensed phases. We must at a minimum consider short-range order correlations.

Quantum phases for point-like charged particles and for electrically neutral dipoles in an electromagnetic field

NASA Astrophysics Data System (ADS)

Kholmetskii, A. L.; Missevitch, O. V.; Yarman, T.

2018-05-01

We point out that the known quantum phases for an electric/magnetic dipole moving in an electromagnetic (EM) field must be presented as the superposition of more fundamental quantum phases emerging for elementary charges. Using this idea, we find two new fundamental quantum phases for point-like charges, next to the known electric and magnetic Aharonov-Bohm (A-B) phases, named by us as the complementary electric and magnetic phases, correspondingly. We further demonstrate that these new phases can indeed be derived via the Schrödinger equation for a particle in an EM field, where however the operator of momentum is re-defined via the replacement of the canonical momentum of particle by the sum of its mechanical momentum and interactional field momentum for a system "charged particle and a macroscopic source of EM field". The implications of the obtained results are discussed.

Teaching the Conceptual Scheme "The Particle Nature of Matter" in the Elementary School.

ERIC Educational Resources Information Center

Pella, Milton O.; And Others

Conclusions of an extensive project aimed to prepare lessons and associated materials related to teaching concepts included in the scheme "The Particle Nature of Matter" for grades two through six are presented. The hypothesis formulated for the project was that children in elementary schools can learn theoretical concepts related to the particle…

Solutions for correlations along the coexistence curve and at the critical point of a kagomé lattice gas with three-particle interactions

NASA Astrophysics Data System (ADS)

Barry, J. H.; Muttalib, K. A.; Tanaka, T.

2008-01-01

We consider a two-dimensional (d=2) kagomé lattice gas model with attractive three-particle interactions around each triangular face of the kagomé lattice. Exact solutions are obtained for multiparticle correlations along the liquid and vapor branches of the coexistence curve and at criticality. The correlation solutions are also determined along the continuation of the curvilinear diameter of the coexistence region into the disordered fluid region. The method generates a linear algebraic system of correlation identities with coefficients dependent only upon the interaction parameter. Using a priori knowledge of pertinent solutions for the density and elementary triplet correlation, one finds a closed and linearly independent set of correlation identities defined upon a spatially compact nine-site cluster of the kagomé lattice. Resulting exact solution curves of the correlations are plotted and discussed as functions of the temperature and are compared with corresponding results in a traditional kagomé lattice gas having nearest-neighbor pair interactions. An example of application for the multiparticle correlations is demonstrated in cavitation theory.

Particles and forces. At the heart of matter. Readings from Scientific American magazine.

NASA Astrophysics Data System (ADS)

Carrigan, R. A., Jr.; Trower, W. P.

In this volume a selection of Scientific American articles chronicles the most recent developments in particle physics. In these twelve articles, distinguished physicists look at the tools, ideas, and experiments that shed light on events at the early moments of the universe, as well as the increasingly sophisticated instruments that will make further developments possible in the years to come. For the companion volume Particle physics in the cosmos see 49.003.059. Contents: Introduction. I. Ideas. 1. Elementary particles and forces (C. Quigg). 2. Quarks with color and flavor (S. L. Glashow). 3. The lattice theory of quark confinement (C. Rebbi). Postscript to Ideas (C. Quigg). II. Tools. 4. The next generation of particle accelerators (R. R. Wilson). 5. The Superconducting Super Collider (J. D. Jackson, M. Tigner, S. Wojcicki). Postscript to Tools (R. A. Carrigan Jr.). III. Weak interactions. 6. Heavy leptons (M. L. Perl, W. T. Kirk). 7. The search for intermediate vector bosons (D. B. Cline, C. Rubbia, S. van der Meer). IV. Strong interactions. 8. The Upsilon particle (L. M. Lederman). 9. Quarkonium (E. D. Bloom, G. J. Feldman). 10. Particles with naked beauty (N. B. Mistry, R. A. Poling, E. H. Thorndike). V. Now and beyond. 11. Superstrings (M. B. Green). 12. The structure of quarks and leptons (H. Harari). Postscript to Now and beyond (R. A. Carrigan Jr., W. P. Trower).

Big Bang Day: 5 Particles - 3. The Anti-particle

ScienceCinema

None

2017-12-09

Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.

Big Bang Day: 5 Particles - 3. The Anti-particle

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2009-10-07

Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existencemore » be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.« less

Elementary particles, dark matter candidate and new extended standard model

NASA Astrophysics Data System (ADS)

Hwang, Jaekwang

2017-01-01

Elementary particle decays and reactions are discussed in terms of the three-dimensional quantized space model beyond the standard model. Three generations of the leptons and quarks correspond to the lepton charges. Three heavy leptons and three heavy quarks are introduced. And the bastons (new particles) are proposed as the possible candidate of the dark matters. Dark matter force, weak force and strong force are explained consistently. Possible rest masses of the new particles are, tentatively, proposed for the experimental searches. For more details, see the conference paper at https://www.researchgate.net/publication/308723916.

REVIEWS OF TOPICAL PROBLEMS: Elementary particles and cosmology (Metagalaxy and Universe)

NASA Astrophysics Data System (ADS)

Rozental', I. L.

1997-08-01

The close relation between cosmology and the theory of elementary particles is analyzed in the light of prospects of a unified field theory. The unity of their respective problems and solution methodologies is indicated. The difference between the concepts of 'Metagalaxy' and 'Universe' is emphasized and some possible schemes for estimating the size of the Universe are pointed out.

The Joint Institute for Nuclear Research in Experimental Physics of Elementary Particles

NASA Astrophysics Data System (ADS)

Bednyakov, V. A.; Russakovich, N. A.

2018-05-01

The year 2016 marks the 60th anniversary of the Joint Institute for Nuclear Research (JINR) in Dubna, an international intergovernmental organization for basic research in the fields of elementary particles, atomic nuclei, and condensed matter. Highly productive advances over this long road clearly show that the international basis and diversity of research guarantees successful development (and maintenance) of fundamental science. This is especially important for experimental research. In this review, the most significant achievements are briefly described with an attempt to look into the future (seven to ten years ahead) and show the role of JINR in solution of highly important problems in elementary particle physics, which is a fundamental field of modern natural sciences. This glimpse of the future is full of justified optimism.

Indirect detection of dark matter with γ rays.

PubMed

Funk, Stefan

2015-10-06

The details of what constitutes the majority of the mass that makes up dark matter in the Universe remains one of the prime puzzles of cosmology and particle physics today-80 y after the first observational indications. Today, it is widely accepted that dark matter exists and that it is very likely composed of elementary particles, which are weakly interacting and massive [weakly interacting massive particles (WIMPs)]. As important as dark matter is in our understanding of cosmology, the detection of these particles has thus far been elusive. Their primary properties such as mass and interaction cross sections are still unknown. Indirect detection searches for the products of WIMP annihilation or decay. This is generally done through observations of γ-ray photons or cosmic rays. Instruments such as the Fermi large-area telescope, high-energy stereoscopic system, major atmospheric gamma-ray imaging Cherenkov, and very energetic radiation imaging telescope array, combined with the future Cherenkov telescope array, will provide important complementarity to other search techniques. Given the expected sensitivities of all search techniques, we are at a stage where the WIMP scenario is facing stringent tests, and it can be expected that WIMPs will be either be detected or the scenario will be so severely constrained that it will have to be rethought. In this sense, we are on the threshold of discovery. In this article, I will give a general overview of the current status and future expectations for indirect searches of dark matter (WIMP) particles.

Indirect detection of dark matter with γ rays

PubMed Central

Funk, Stefan

2015-01-01

The details of what constitutes the majority of the mass that makes up dark matter in the Universe remains one of the prime puzzles of cosmology and particle physics today—80 y after the first observational indications. Today, it is widely accepted that dark matter exists and that it is very likely composed of elementary particles, which are weakly interacting and massive [weakly interacting massive particles (WIMPs)]. As important as dark matter is in our understanding of cosmology, the detection of these particles has thus far been elusive. Their primary properties such as mass and interaction cross sections are still unknown. Indirect detection searches for the products of WIMP annihilation or decay. This is generally done through observations of γ-ray photons or cosmic rays. Instruments such as the Fermi large-area telescope, high-energy stereoscopic system, major atmospheric gamma-ray imaging Cherenkov, and very energetic radiation imaging telescope array, combined with the future Cherenkov telescope array, will provide important complementarity to other search techniques. Given the expected sensitivities of all search techniques, we are at a stage where the WIMP scenario is facing stringent tests, and it can be expected that WIMPs will be either be detected or the scenario will be so severely constrained that it will have to be rethought. In this sense, we are on the threshold of discovery. In this article, I will give a general overview of the current status and future expectations for indirect searches of dark matter (WIMP) particles. PMID:24821791

Casimir interaction of rodlike particles in a two-dimensional critical system.

PubMed

Eisenriegler, E; Burkhardt, T W

2016-09-01

We consider the fluctuation-induced interaction of two thin, rodlike particles, or "needles," immersed in a two-dimensional critical fluid of Ising symmetry right at the critical point. Conformally mapping the plane containing the needles onto a simpler geometry in which the stress tensor is known, we analyze the force and torque between needles of arbitrary length, separation, and orientation. For infinite and semi-infinite needles we utilize the mapping of the plane bounded by the needles onto the half plane, and for two needles of finite length we use the mapping onto an annulus. For semi-infinite and infinite needles the force is expressed in terms of elementary functions, and we also obtain analytical results for the force and torque between needles of finite length with separation much greater than their length. Evaluating formulas in our approach numerically for several needle geometries and surface universality classes, we study the full crossover from small to large values of the separation to length ratio. In these two limits the numerical results agree with results for infinitely long needles and with predictions of the small-particle operator expansion, respectively.

Personal Reflections on the Interaction of Science and Government and Possible Lessons for the Present Crisis (450th Brookhaven Lecture)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samios, Nicholas

2009-05-06

The 450th Brookhaven Lecture, to be held today, Wednesday, May 6, will be given by BNL Distinguished Senior Physicist Nicholas Samios, director of the RIKEN BNL Research Center and former Lab Director. Samios will discuss "Personal Reflections on the Interaction of Science and Government and Possible Lessons for the Present Crisis" at 4 p.m. in Berkner Hall. As many members of his prospective audience know, Samios's distinguished achievements in science and administration qualify him more than most to take on this topic. Having received his B.A. and Ph.D. degrees in physics from Columbia University in 1953 and 1957, respectively, hemore » joined the Lab in 1959. In addition to his work in experimental physics, he served as Physics Department Chair from 1975 to 81 and Deputy Director for High-Energy & Nuclear Physics from 1981 to 82. As a researcher, Samios made many of the particle discoveries that have helped define and lead to the acceptance of the "Standard Model" of particle physics, the accepted theory that explains known particle interactions. In particular, he is noted for the discovery of the phi meson and the omega minus hyperon, crucial elements delineating the symmetry of hadrons, which ultimately led to the quark model of elementary particles, a pillar of the Standard Model.« less

Certain problems in the current theory of gravitation

NASA Astrophysics Data System (ADS)

Markov, M. A.

1984-04-01

A number of problems (considered by the author to be the most significant) connected with the possible role of gravitation in the elementary-particle physics and cosmology are examined. Particular attention is given to the problems of self-energy, the limit mass of elementary particles, maximons and the evolution of the universe, the origin of the universe, and the physical meaning of Planck's length.

The Relative Effectiveness of the Use of Static and Dynamic Mechanical Models in Teaching Elementary School Children the Theoretical Concept--The Particle Nature of Matter.

ERIC Educational Resources Information Center

Ziegler, Robert Edward

This study is concerned with determining the relative effectiveness of a static and dynamic theoretical model in teaching elementary school students to use the particle idea of matter when explaining certain physical phenomena. A clinical method of personal individual interview-testing, teaching, and retesting of a random sample population from…

Teaching Elementary Particle Physics: Part I1

NASA Astrophysics Data System (ADS)

Hobson, Art

2011-01-01

I'll outline suggestions for teaching elementary particle physics, often called high energy physics, in high school or introductory college courses for non-scientists or scientists. Some presentations of this topic simply list the various particles along with their properties, with little overarching structure. Such a laundry list approach is a great way to make a fascinating topic meaningless. Students need a conceptual framework from which to view the elementary particles. That conceptual framework is quantum field theory (QFT). Teachers and students alike tend to quake at this topic, but bear with me. We're talking here about concepts, not technicalities. My approach will be conceptual and suitable for non-scientists and scientists; if mathematical details are added in courses for future scientists, they should be simple and sparse. Introductory students should not be expected to do QFT, but only to understand its concepts. Those concepts take some getting used to, but they are simple and can be understood by any literate person, be she plumber, attorney, musician, or physicist.

Research in Lattice Gauge Theory and in the Phenomenology of Neutrinos and Dark Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meurice, Yannick L; Reno, Mary Hall

Research in theoretical elementary particle physics was performed by the PI Yannick Meurice and co-PI Mary Hall Reno. New techniques designed for precision calculations of strong interaction physics were developed using the tensor renormalization group method. Large-scale Monte Carlo simulations with dynamical quarks were performed for candidate models for Higgs compositeness. Ab-initio lattice gauge theory calculations of semileptonic decays of B-mesons observed in collider experiments and relevant to test the validity of the standard model were performed with the Fermilab/MILC collaboration. The phenomenology of strong interaction physics was applied to new predictions for physics processes in accelerator physics experiments andmore » to cosmic ray production and interactions. A research focus has been on heavy quark production and their decays to neutrinos. The heavy quark contributions to atmospheric neutrino and muon fluxes have been evaluated, as have the neutrino fluxes from accelerator beams incident on heavy targets. Results are applicable to current and future particle physics experiments and to astrophysical neutrino detectors such as the IceCube Neutrino Observatory.« less

Observation of chiral phonons

NASA Astrophysics Data System (ADS)

Zhu, Hanyu; Yi, Jun; Li, Ming-Yang; Xiao, Jun; Zhang, Lifa; Yang, Chih-Wen; Kaindl, Robert A.; Li, Lain-Jong; Wang, Yuan; Zhang, Xiang

2018-02-01

Chirality reveals symmetry breaking of the fundamental interaction of elementary particles. In condensed matter, for example, the chirality of electrons governs many unconventional transport phenomena such as the quantum Hall effect. Here we show that phonons can exhibit intrinsic chirality in monolayer tungsten diselenide. The broken inversion symmetry of the lattice lifts the degeneracy of clockwise and counterclockwise phonon modes at the corners of the Brillouin zone. We identified the phonons by the intervalley transfer of holes through hole-phonon interactions during the indirect infrared absorption, and we confirmed their chirality by the infrared circular dichroism arising from pseudoangular momentum conservation. The chiral phonons are important for electron-phonon coupling in solids, phonon-driven topological states, and energy-efficient information processing.

Statistics of excitations in the electron glass model

NASA Astrophysics Data System (ADS)

Palassini, Matteo

2011-03-01

We study the statistics of elementary excitations in the classical electron glass model of localized electrons interacting via the unscreened Coulomb interaction in the presence of disorder. We reconsider the long-standing puzzle of the exponential suppression of the single-particle density of states near the Fermi level, by measuring accurately the density of states of charged and electron-hole pair excitations via finite temperature Monte Carlo simulation and zero-temperature relaxation. We also investigate the statistics of large charge rearrangements after a perturbation of the system, which may shed some light on the slow relaxation and glassy phenomena recently observed in a variety of Anderson insulators. In collaboration with Martin Goethe.

Princeton University High Energy Physics Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marlow, Daniel R.

This is the Final Report on research conducted by the Princeton Elementary Particles group over the approximately three-year period from May 1, 2012 to April 30, 2015. The goal of our research is to investigate the fundamental constituents of matter, their fields, and their interactions; to understand the properties of space and time; and to study the profound relationships between cosmology and particle physics. During the funding period covered by this report, the group has been organized into a subgroup concentrating on the theory of particles, strings, and cosmology; and four subgroups performing major experiments at laboratories around the world: CERN, Daya Bay, Gran Sasso as well as detector R\\&D on the Princeton campus. Highlights in of this research include the discovery of the Higgs Boson at CERN and the measurement ofmore » $$\\sin^22\\theta_{13}$$ by the Daya Bay experiment. In both cases, Princeton researchers supported by this grant played key roles.« less

Neutrino astrophysics: a new tool for exploring the universe.

PubMed

Waxman, Eli

2007-01-05

In the past four decades a new type of astronomy has emerged, where instead of looking up into the sky, "telescopes" are buried miles underground or deep under water or ice and search not for photons (that is, light), but rather for particles called neutrinos. Neutrinos are nearly massless particles that interact very weakly with matter. The detection of neutrinos emitted by the Sun and by a nearby supernova provided direct tests of the theory of stellar evolution and led to modifications of the standard model describing the properties of elementary particles. At present, several very large neutrino detectors are being constructed, aiming at the detection of the most powerful sources of energy and particles in the universe. The hope is that the detection of neutrinos from these sources, which are extra-Galactic and are most likely powered by mass accretion onto black holes, will not only allow study of the sources, but, much like solar neutrinos, will also provide new information about fundamental properties of matter.

Magnetic trapping of neutrons

PubMed

Huffman; Brome; Butterworth; Coakley; Dewey; Dzhosyuk; Golub; Greene; Habicht; Lamoreaux; Mattoni; McKinsey; Wietfeldt; Doyle

2000-01-06

Accurate measurement of the lifetime of the neutron (which is unstable to beta decay) is important for understanding the weak nuclear force and the creation of matter during the Big Bang. Previous measurements of the neutron lifetime have mainly been limited by certain systematic errors; however, these could in principle be avoided by performing measurements on neutrons stored in a magnetic trap. Neutral-particle and charged-particle traps are widely used for studying both composite and elementary particles, because they allow long interaction times and isolation of particles from perturbing environments. Here we report the magnetic trapping of neutrons. The trapping region is filled with superfluid 4He, which is used to load neutrons into the trap and as a scintillator to detect their decay. Neutrons in the trap have a lifetime of 750(+330)(-200) seconds, mainly limited by their beta decay rather than trap losses. Our experiment verifies theoretical predictions regarding the loading process and magnetic trapping of neutrons. Further refinement of this method should lead to improved precision in the neutron lifetime measurement.

Higgs cosmology

NASA Astrophysics Data System (ADS)

Rajantie, Arttu

2018-01-01

The discovery of the Higgs boson in 2012 and other results from the Large Hadron Collider have confirmed the standard model of particle physics as the correct theory of elementary particles and their interactions up to energies of several TeV. Remarkably, the theory may even remain valid all the way to the Planck scale of quantum gravity, and therefore it provides a solid theoretical basis for describing the early Universe. Furthermore, the Higgs field itself has unique properties that may have allowed it to play a central role in the evolution of the Universe, from inflation to cosmological phase transitions and the origin of both baryonic and dark matter, and possibly to determine its ultimate fate through the electroweak vacuum instability. These connections between particle physics and cosmology have given rise to a new and growing field of Higgs cosmology, which promises to shed new light on some of the most puzzling questions about the Universe as new data from particle physics experiments and cosmological observations become available. This article is part of the Theo Murphy meeting issue `Higgs cosmology'.

Atomic Mass and Nuclear Binding Energy for U-287 (Uranium)

NASA Astrophysics Data System (ADS)

Sukhoruchkin, S. I.; Soroko, Z. N.

This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope U-287 (Uranium, atomic number Z = 92, mass number A = 287).

Atomic Mass and Nuclear Binding Energy for Ac-212 (Actinium)

NASA Astrophysics Data System (ADS)

Sukhoruchkin, S. I.; Soroko, Z. N.

This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Ac-212 (Actinium, atomic number Z = 89, mass number A = 212).

THE EIGHTFOLD WAY: A THEORY OF STRONG INTERACTION SYMMETRY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gell-Mann, M.

1961-03-15

A new model of the higher symmetry of elementary particles is introduced ln which the eight known baryons are treated as a supermultiplet, degenerate in the limit of unitary symmetry but split into isotopic spin multiplets by a symmetry-breaking term. The symmetry violation is sscribed phenomenologically to the mass differences. The baryons correspond to an eight-dimensional irreducible representation of the unitary group. The pion and K meson fit into a similar set of eight particles along with a predicted pseudoscalar meson X/sup o/ having I = 0. A ninth vector meson coupled to the baryon current can be accomodated natarallymore » in the scheme. It is predicted that the eight baryons should all have the same spin and parity and that pseudoscalar and vector mesons should form octets with possible additional singlets. The mathematics of the unitary group is described by considering three fictitious leptons, nu , e/sup -/ , and mu /sup -/, which may throw light on the structure of weak interactions. (D. L.C.)« less

The Eightfold Way: A Theory of Strong Interaction Symmetry

DOE R&D Accomplishments Database

Gell-Mann, M.

1961-03-15

A new model of the higher symmetry of elementary particles is introduced ln which the eight known baryons are treated as a supermultiplet, degenerate in the limit of unitary symmetry but split into isotopic spin multiplets by a symmetry-breaking term. The symmetry violation is ascribed phenomenologically to the mass differences. The baryons correspond to an eight-dimensional irreducible representation of the unitary group. The pion and K meson fit into a similar set of eight particles along with a predicted pseudoscalar meson X {sup o} having I = 0. A ninth vector meson coupled to the baryon current can be accommodated naturally in the scheme. It is predicted that the eight baryons should all have the same spin and parity and that pseudoscalar and vector mesons should form octets with possible additional singlets. The mathematics of the unitary group is described by considering three fictitious leptons, nu , e {sup -}, and mu {sup -}, which may throw light on the structure of weak interactions. (D. L.C.)

Apparent electric charge of protein molecules. Human thyroxine - binding proteins.

PubMed

Hocman, G; Sadlon, J

1977-01-01

1. By comparison of electrophoretic mobilities of two different charged particles under the same conditions the net elementary electrostatic charge of one particle could be calculated when the charge of the other is known. 2. The electrophoretic mobility of human thyroxine - binding globulin does not depend upon the concentration of Tris - HCl buffer in the range 0.05 to 0.20 molar. The value of this mobility is 0.078 and 0.083 cm2 vol(-1) hour(-1) at pH 7.0 and 8.6, respectively. 3. The net elementary electrostatic charge of the human thyroxine - binding globulin appears to be approximately 22 negative elementary electrostatic units in mild alkaline solutions.

Current experiments in elementary particle physics. Revision

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galic, H.; Armstrong, F.E.; von Przewoski, B.

1994-08-01

This report contains summaries of 568 current and recent experiments in elementary particle physics. Experiments that finished taking data before 1988 are excluded. Included are experiments at BEPC (Beijing), BNL, CEBAF, CERN, CESR, DESY, FNAL, INS (Tokyo), ITEP (Moscow), IUCF (Bloomington), KEK, LAMPF, Novosibirsk, PNPI (St. Petersburg), PSI, Saclay, Serpukhov, SLAC, and TRIUMF, and also several underground and underwater experiments. Instructions are given for remote searching of the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

Dynamic origins of fermionic D -terms

NASA Astrophysics Data System (ADS)

Hudson, Jonathan; Schweitzer, Peter

2018-03-01

The D -term is defined through matrix elements of the energy-momentum tensor, similarly to mass and spin, yet this important particle property is experimentally not known any fermion. In this work we show that the D -term of a spin 1/2 fermion is of dynamical origin: it vanishes for a free fermion. This is in pronounced contrast to the bosonic case where already a free spin-0 boson has a non-zero intrinsic D -term. We illustrate in two simple models how interactions generate the D -term of a fermion with an internal structure, the nucleon. All known matter is composed of elementary fermions. This indicates the importance to study this interesting particle property in more detail, which will provide novel insights especially on the structure of the nucleon.

On the Limiting Markov Process of Energy Exchanges in a Rarely Interacting Ball-Piston Gas

NASA Astrophysics Data System (ADS)

Bálint, Péter; Gilbert, Thomas; Nándori, Péter; Szász, Domokos; Tóth, Imre Péter

2017-02-01

We analyse the process of energy exchanges generated by the elastic collisions between a point-particle, confined to a two-dimensional cell with convex boundaries, and a `piston', i.e. a line-segment, which moves back and forth along a one-dimensional interval partially intersecting the cell. This model can be considered as the elementary building block of a spatially extended high-dimensional billiard modeling heat transport in a class of hybrid materials exhibiting the kinetics of gases and spatial structure of solids. Using heuristic arguments and numerical analysis, we argue that, in a regime of rare interactions, the billiard process converges to a Markov jump process for the energy exchanges and obtain the expression of its generator.

Current experiments in elementary particle physics. Revised

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galic, H.; Wohl, C.G.; Armstrong, B.

This report contains summaries of 584 current and recent experiments in elementary particle physics. Experiments that finished taking data before 1986 are excluded. Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Tokyo Institute of Nuclear Studies, Moscow Institute of Theoretical and Experimental Physics, KEK, LAMPF, Novosibirsk, Paul Scherrer Institut (PSI), Saclay, Serpukhov, SLAC, SSCL, and TRIUMF, and also several underground and underwater experiments. Instructions are given for remote searching of the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

Microteaching Lesson Study: Mentor Interaction Structure and Its Relation to Elementary Preservice Mathematics Teacher Knowledge Development

ERIC Educational Resources Information Center

Molina, Roxanne V.

2012-01-01

This study investigated Microteaching Lesson Study (MLS) and three possible MLS mentor interaction structures during the debriefing sessions in relation to elementary preservice teacher development of knowledge for teaching. One hundred three elementary preservice teachers enrolled in five different sections of a mathematics methods course at a…

Making the universe safe for historians: Time travel and the laws of physics

NASA Astrophysics Data System (ADS)

Woodward, James F.

1995-02-01

The study of the hypothetical activities of arbitrarily advanced cultures, particularly in the area of space and time travel, as a means of investigating fundamental issues in physics is briefly discussed. Hawking's chronology protection conjecture as it applies to wormhole spacetimes is considered. The nature of time, especially regarding the viability of time travel, as it appears in several “interpretations” of quantum mechanics is investigated. A conjecture on the plausibility of theories of reality that admit relativistically invariant interactions and irreducibly stochastic processes is advanced. A transient inertial reaction effect that makes it technically feasible, fleetingly, to induce large concentrations of negative mass-energy is presented and discussed in the context of macroscopic wormhole formation. Other candidates for chronology protection are examined. It is pointed out that if the strong version of Mach's principle (the gravitational induction of mass) is correct, then wormhole formation employing negative mass-energy is impossible. But if the bare masses of elementary particles are large, finite and negative, as is suggested by a heuristic general relativistic model of elementary particles, then, using the transient effect, it is technically feasible to trigger a non-linear process that may lead to macroscopic wormhole formation. Such wormholes need not be destroyed by the Hawking protection mechanism.

Hyperunified field theory and gravitational gauge-geometry duality

NASA Astrophysics Data System (ADS)

Wu, Yue-Liang

2018-01-01

A hyperunified field theory is built in detail based on the postulates of gauge invariance and coordinate independence along with the conformal scaling symmetry. All elementary particles are merged into a single hyper-spinor field and all basic forces are unified into a fundamental interaction governed by the hyper-spin gauge symmetry SP(1, D_h-1). The dimension D_h of hyper-spacetime is conjectured to have a physical origin in correlation with the hyper-spin charge of elementary particles. The hyper-gravifield fiber bundle structure of biframe hyper-spacetime appears naturally with the globally flat Minkowski hyper-spacetime as a base spacetime and the locally flat hyper-gravifield spacetime as a fiber that is viewed as a dynamically emerged hyper-spacetime characterized by a non-commutative geometry. The gravitational origin of gauge symmetry is revealed with the hyper-gravifield that plays an essential role as a Goldstone-like field. The gauge-gravity and gravity-geometry correspondences bring about the gravitational gauge-geometry duality. The basic properties of hyperunified field theory and the issue on the fundamental scale are analyzed within the framework of quantum field theory, which allows us to describe the laws of nature in deriving the gauge gravitational equation with the conserved current and the geometric gravitational equations of Einstein-like type and beyond.

Self-consistent phonon theory of the crystallization and elasticity of attractive hard spheres.

PubMed

Shin, Homin; Schweizer, Kenneth S

2013-02-28

We propose an Einstein-solid, self-consistent phonon theory for the crystal phase of hard spheres that interact via short-range attractions. The approach is first tested against the known behavior of hard spheres, and then applied to homogeneous particles that interact via short-range square well attractions and the Baxter adhesive hard sphere model. Given the crystal symmetry, packing fraction, and strength and range of attractive interactions, an effective harmonic potential experienced by a particle confined to its Wigner-Seitz cell and corresponding mean square vibrational amplitude are self-consistently calculated. The crystal free energy is then computed and, using separate information about the fluid phase free energy, phase diagrams constructed, including a first-order solid-solid phase transition and its associated critical point. The simple theory qualitatively captures all the many distinctive features of the phase diagram (critical and triple point, crystal-fluid re-entrancy, low-density coexistence curve) as a function of attraction range, and overall is in good semi-quantitative agreement with simulation. Knowledge of the particle localization length allows the crystal shear modulus to be estimated based on elementary ideas. Excellent predictions are obtained for the hard sphere crystal. Expanded and condensed face-centered cubic crystals are found to have qualitatively different elastic responses to varying attraction strength or temperature. As temperature increases, the expanded entropic solid stiffens, while the energy-controlled, fully-bonded dense solid softens.

A measurement of the helicity of W bosons produced in top-quark decays

NASA Astrophysics Data System (ADS)

Goldschmidt, Nathan J.

2005-11-01

The Standard Model of particle physics is a remarkably successful description of nature. One aspect of the theory that is not well-understood is the nature and the origin of the mechanism which breaks the gauge symmetry of the electroweak interaction. According to the theory, this mechanism gives rise to the masses of elementary particles. However, we have yet to directly probe these phenomena. The top quark is the most massive known elementary particle; it decays almost exclusively via the electroweak interaction. By studying the kinematics of top-quark decays, we can indirectly probe the electroweak symmetry breaking mechanism at the highest energies presently attainable. We measure the fraction of longitudinally-polarized W bosons produced in top-quark decays by analyzing the transverse momentum spectrum of charged-lepton arising from the process t → W+b → ℓ+nu ℓb. Top-quark pairs are produced in proton-antiproton collisions with a center-of-mass energy s = 1.96 GeV at the Tevtron synchrotron at the Fermi National Accelerator Laboratory in Batavia Illinois. Top-quark candidate events are isolated in 200 pb-1 of data using the newly-upgraded CDF II detector. These data indicate that the fraction of W bosons with longitudinal polarization is F0 = 0.88+0.12-0.47 (stat. + syst.), F0 > 0.24 95% CL in events where only one W decays leptonically; F 0 < 0.52 95% CL, F0 < 0.94 99% CL in events where both W's decay leptonically, and F0 = 0.27+0.35-0.21 (stat. + syst.), F0 < 0.88 95% CL in the combined analysis. The Standard Model prediction, given a top-quark mass of 175 GeV, is F0 = 0.703. The discrepancy in the dilepton sample is suggestive of new phenomena, while the result in the single-lepton sample is fully consistent with the Standard Model expectation. Clearly, these results warrant further investigation.

Lattice QCD Thermodynamics and RHIC-BES Particle Production within Generic Nonextensive Statistics

NASA Astrophysics Data System (ADS)

Tawfik, Abdel Nasser

2018-05-01

The current status of implementing Tsallis (nonextensive) statistics on high-energy physics is briefly reviewed. The remarkably low freezeout-temperature, which apparently fails to reproduce the firstprinciple lattice QCD thermodynamics and the measured particle ratios, etc. is discussed. The present work suggests a novel interpretation for the so-called " Tsallis-temperature". It is proposed that the low Tsallis-temperature is due to incomplete implementation of Tsallis algebra though exponential and logarithmic functions to the high-energy particle-production. Substituting Tsallis algebra into grand-canonical partition-function of the hadron resonance gas model seems not assuring full incorporation of nonextensivity or correlations in that model. The statistics describing the phase-space volume, the number of states and the possible changes in the elementary cells should be rather modified due to interacting correlated subsystems, of which the phase-space is consisting. Alternatively, two asymptotic properties, each is associated with a scaling function, are utilized to classify a generalized entropy for such a system with large ensemble (produced particles) and strong correlations. Both scaling exponents define equivalence classes for all interacting and noninteracting systems and unambiguously characterize any statistical system in its thermodynamic limit. We conclude that the nature of lattice QCD simulations is apparently extensive and accordingly the Boltzmann-Gibbs statistics is fully fulfilled. Furthermore, we found that the ratios of various particle yields at extreme high and extreme low energies of RHIC-BES is likely nonextensive but not necessarily of Tsallis type.

The Interaction between Teaching Practices and the Change in Motivation of Elementary-School Children.

ERIC Educational Resources Information Center

Karsenti, Thierry P.; Thibert, Gilles

This study took an in-depth, global look at the entirety of the teaching practices of six elementary school teachers in Canada who are known to be highly motivating instructors. The study investigated the interaction between teaching practices and the change in elementary-school student motivation. Three teachers were chosen for their reputation…

Higgs cosmology

PubMed Central

2018-01-01

The discovery of the Higgs boson in 2012 and other results from the Large Hadron Collider have confirmed the standard model of particle physics as the correct theory of elementary particles and their interactions up to energies of several TeV. Remarkably, the theory may even remain valid all the way to the Planck scale of quantum gravity, and therefore it provides a solid theoretical basis for describing the early Universe. Furthermore, the Higgs field itself has unique properties that may have allowed it to play a central role in the evolution of the Universe, from inflation to cosmological phase transitions and the origin of both baryonic and dark matter, and possibly to determine its ultimate fate through the electroweak vacuum instability. These connections between particle physics and cosmology have given rise to a new and growing field of Higgs cosmology, which promises to shed new light on some of the most puzzling questions about the Universe as new data from particle physics experiments and cosmological observations become available. This article is part of the Theo Murphy meeting issue ‘Higgs cosmology’. PMID:29358352

Higgs cosmology.

PubMed

Rajantie, Arttu

2018-03-06

The discovery of the Higgs boson in 2012 and other results from the Large Hadron Collider have confirmed the standard model of particle physics as the correct theory of elementary particles and their interactions up to energies of several TeV. Remarkably, the theory may even remain valid all the way to the Planck scale of quantum gravity, and therefore it provides a solid theoretical basis for describing the early Universe. Furthermore, the Higgs field itself has unique properties that may have allowed it to play a central role in the evolution of the Universe, from inflation to cosmological phase transitions and the origin of both baryonic and dark matter, and possibly to determine its ultimate fate through the electroweak vacuum instability. These connections between particle physics and cosmology have given rise to a new and growing field of Higgs cosmology, which promises to shed new light on some of the most puzzling questions about the Universe as new data from particle physics experiments and cosmological observations become available.This article is part of the Theo Murphy meeting issue 'Higgs cosmology'. © 2018 The Author(s).

Teaching Elementary Particle Physics, Part II

ERIC Educational Resources Information Center

Hobson, Art

2011-01-01

In order to explain certain features of radioactive beta decay, Wolfgang Pauli suggested in 1930 that the nucleus emitted, in addition to a beta particle, another particle of an entirely new type. The hypothesized particle, dubbed the neutrino, would not be discovered experimentally for another 25 years. It's not easy to detect neutrinos, because…

Modern Elementary Particle Physics

NASA Astrophysics Data System (ADS)

Kane, Gordon

2017-02-01

1. Introduction; 2. Relativistic notation, Lagrangians, and interactions; 3. Gauge invariance; 4. Non-abelian gauge theories; 5. Dirac notation for spin; 6. The Standard Model Lagrangian; 7. The electroweak theory and quantum chromodynamics; 8. Masses and the Higgs mechanism; 9. Cross sections, decay widths, and lifetimes: W and Z decays; 10. Production and properties of W± and Zᴼ; 11. Measurement of electroweak and QCD parameters: the muon lifetime; 12. Accelerators - present and future; 13. Experiments and detectors; 14. Low energy and non-accelerator experiments; 15. Observation of the Higgs boson at the CERN LHC: is it the Higgs boson?; 16. Colliders and tests of the Standard Model: particles are pointlike; 17. Quarks and gluons, confinement and jets; 18. Hadrons, heavy quarks, and strong isospin invariance; 19. Coupling strengths depend on momentum transfer and on virtual particles; 20. Quark (and lepton) mixing angles; 21. CP violation; 22. Overview of physics beyond the Standard Model; 23. Grand unification; 24. Neutrino masses; 25. Dark matter; 26. Supersymmetry.

Elementary wave interactions in blood flow through artery

NASA Astrophysics Data System (ADS)

Raja Sekhar, T.; Minhajul

2017-10-01

In this paper, we consider the Riemann problem and interaction of elementary waves for the quasilinear hyperbolic system of conservation laws that arises in blood flow through arteries. We study the properties of solution involving shocks and rarefaction waves and establish the existence and uniqueness conditions. We show that the Riemann problem is solvable for arbitrary initial data under certain condition and construct the condition for no-feasible solution. Finally, we present numerical examples with different initial data and discuss all possible interactions of elementary waves.

Measuring asymmetry load pairs of top quarks-antitop in the final states dileptoniques from D0 and ATLAS detectors (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chapelain, Antoine

Particle physics aims to give a coherent description of the nature and the behavior of elementary particles of matter. Particle accelerators (colliders) allow pushing back our know- ledge in this domain producing particles that cannot be observed by other means. This thesis work contributes to this research eld and focuses on the study of the top quark which is the latest brick of matter discovered and the heaviest known elementary particle. The property of the top quark studied here, the charge asymmetry of the top quark-antiquark pairs, has driven a lot of attention in 2011 because of measurements released bymore » Tevatron experiments. These measurements showed deviations with the predictions made in the framework of the standard model of particle physics. New measurements of the charge asymmetry performed at the Tevatron (with the D0 detector) and at the LHC (with the ATLAS detector) are presented in this thesis.« less

The Effectiveness of Scaffolding Interactive Activities in Developing the English Listening Comprehension Skills of the Sixth Grade Elementary Schoolgirls in Jeddah

ERIC Educational Resources Information Center

Al-Yami, Salwa Ahmed

2008-01-01

The present study aims to investigate the effectiveness of scaffolding interactive activities in developing the English listening comprehension skills of sixth grade elementary schoolgirls in Jeddah. The subjects in this study were 50 sixth grade pupils at an elementary school in Jeddah. They were assigned to two groups--control and…

Current experiments in elementary particle physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wohl, C.G.; Armstrong, F.E., Oyanagi, Y.; Dodder, D.C.

1987-03-01

This report contains summaries of 720 recent and current experiments in elementary particle physics (experiments that finished taking data before 1980 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Moscow Institute of Theoretical and Experimental Physics, Tokyo Institute of Nuclear Studies, KEK, LAMPF, Leningrad Nuclear Physics Institute, Saclay, Serpukhov, SIN, SLAC, and TRIUMF, and also experiments on proton decay. Instructions are given for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries. Properties of the fixed-target beams at most of the laboratories are summarized.

Interactions and scattering of quantum vortices in a polariton fluid.

PubMed

Dominici, Lorenzo; Carretero-González, Ricardo; Gianfrate, Antonio; Cuevas-Maraver, Jesús; Rodrigues, Augusto S; Frantzeskakis, Dimitri J; Lerario, Giovanni; Ballarini, Dario; De Giorgi, Milena; Gigli, Giuseppe; Kevrekidis, Panayotis G; Sanvitto, Daniele

2018-04-13

Quantum vortices, the quantized version of classical vortices, play a prominent role in superfluid and superconductor phase transitions. However, their exploration at a particle level in open quantum systems has gained considerable attention only recently. Here we study vortex pair interactions in a resonant polariton fluid created in a solid-state microcavity. By tracking the vortices on picosecond time scales, we reveal the role of nonlinearity, as well as of density and phase gradients, in driving their rotational dynamics. Such effects are also responsible for the split of composite spin-vortex molecules into elementary half-vortices, when seeding opposite vorticity between the two spinorial components. Remarkably, we also observe that vortices placed in close proximity experience a pull-push scenario leading to unusual scattering-like events that can be described by a tunable effective potential. Understanding vortex interactions can be useful in quantum hydrodynamics and in the development of vortex-based lattices, gyroscopes, and logic devices.

The Birth of Elementary-Particle Physics.

ERIC Educational Resources Information Center

Brown, Laurie M.; Hoddeson, Lillian

1982-01-01

Traces the origin and development of particle physics, concentrating on the roles of cosmic rays and theory. Includes charts highlighting significant events in the development of cosmic-ray physics and quantum field theory. (SK)

Gibbsian Stationary Non-equilibrium States

NASA Astrophysics Data System (ADS)

De Carlo, Leonardo; Gabrielli, Davide

2017-09-01

We study the structure of stationary non-equilibrium states for interacting particle systems from a microscopic viewpoint. In particular we discuss two different discrete geometric constructions. We apply both of them to determine non reversible transition rates corresponding to a fixed invariant measure. The first one uses the equivalence of this problem with the construction of divergence free flows on the transition graph. Since divergence free flows are characterized by cyclic decompositions we can generate families of models from elementary cycles on the configuration space. The second construction is a functional discrete Hodge decomposition for translational covariant discrete vector fields. According to this, for example, the instantaneous current of any interacting particle system on a finite torus can be canonically decomposed in a gradient part, a circulation term and an harmonic component. All the three components are associated with functions on the configuration space. This decomposition is unique and constructive. The stationary condition can be interpreted as an orthogonality condition with respect to an harmonic discrete vector field and we use this decomposition to construct models having a fixed invariant measure.

Excitation spectrum of a mixture of two Bose gases confined in a ring potential with interaction asymmetry

NASA Astrophysics Data System (ADS)

Roussou, A.; Smyrnakis, J.; Magiropoulos, M.; Efremidis, N. K.; Kavoulakis, G. M.; Sandin, P.; Ögren, M.; Gulliksson, M.

2018-04-01

We study the rotational properties of a two-component Bose–Einstein condensed gas of distinguishable atoms which are confined in a ring potential using both the mean-field approximation, as well as the method of diagonalization of the many-body Hamiltonian. We demonstrate that the angular momentum may be given to the system either via single-particle, or ‘collective’ excitation. Furthermore, despite the complexity of this problem, under rather typical conditions the dispersion relation takes a remarkably simple and regular form. Finally, we argue that under certain conditions the dispersion relation is determined via collective excitation. The corresponding many-body state, which, in addition to the interaction energy minimizes also the kinetic energy, is dictated by elementary number theory.

Quarks, Leptons, and Bosons: A Particle Physics Primer.

ERIC Educational Resources Information Center

Wagoner, Robert; Goldsmith, Donald

1983-01-01

Presented is a non-technical introduction to particle physics. The material is adapted from chapter 3 of "Cosmic Horizons," (by Robert Wagoner and Don Goldsmith), a lay-person's introduction to cosmology. Among the topics considered are elementary particles, forces and motion, and higher level structures. (JN)

Feynman Diagrams as Metaphors: Borrowing the Particle Physicist's Imagery for Science Communication Purposes

ERIC Educational Resources Information Center

Pascolini, A.; Pietroni, M.

2002-01-01

We report on an educational project in particle physics based on Feynman diagrams. By dropping the mathematical aspect of the method and keeping just the iconic one, it is possible to convey many different concepts from the world of elementary particles, such as antimatter, conservation laws, particle creation and destruction, real and virtual…

Nuclear Checker Board Model

NASA Astrophysics Data System (ADS)

Lach, Theodore

2017-01-01

The Checkerboard model of the Nucleus has been in the public domain for over 20 years. Over those years it has been described by nuclear and particle physicists as; cute, ``the Bohr model of the nucleus'' and ``reminiscent of the Eightfold Way''. It has also been ridiculed as numerology, laughed at, and even worse. In 2000 the theory was taken to the next level by attempting to explain why the mass of the ``up'' and ``dn'' quarks were significantly heavier than the SM ``u'' and ``d'' quarks. This resulted in a paper published on arXiv.nucl-th/0008026 in 2000, predicting 5 generations of quarks, each quark and negative lepton particle related to each other by a simple geometric mean. The CBM predicts that the radii of the elementary particles are proportional to the cube root of their masses. This was realized Pythagorean musical intervals (octave, perfect 5th, perfect 4th plus two others). Therefore each generation can be explained by a simple right triangle and the height of the hypotenuse. Notice that the height of a right triangle breaks the hypotenuse into two line segments. The geometric mean of those two segments equals the length of the height of this characteristic triangle. Therefore the CBM theory now predicts that all the elementary particles mass are proportion to the cube of their radii. Therefore the mass density of all elementary particles (and perhaps black holes too) are a constant of nature.

An Alternative Proposal for the Graphical Representation of Anticolor Charge

ERIC Educational Resources Information Center

Wiener, Gergried J.; Schmeling, Sascha M.; Hopf, Martin

2017-01-01

We have developed a learning unit based on the Standard Model of particle physics, featuring novel typographic illustrations of elementary particles and particle systems. Since the unit includes antiparticles and systems of antiparticles, a visualization of anticolor charge was required. We propose an alternative to the commonly used…

Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station.

PubMed

Aguilar, M; Ali Cavasonza, L; Alpat, B; Ambrosi, G; Arruda, L; Attig, N; Aupetit, S; Azzarello, P; Bachlechner, A; Barao, F; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Başeǧmez-du Pree, S; Battarbee, M; Battiston, R; Bazo, J; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Bertucci, B; Bindi, V; Boella, G; de Boer, W; Bollweg, K; Bonnivard, V; Borgia, B; Boschini, M J; Bourquin, M; Bueno, E F; Burger, J; Cadoux, F; Cai, X D; Capell, M; Caroff, S; Casaus, J; Castellini, G; Cernuda, I; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, G M; Chen, H S; Cheng, L; Chou, H Y; Choumilov, E; Choutko, V; Chung, C H; Clark, C; Clavero, R; Coignet, G; Consolandi, C; Contin, A; Corti, C; Coste, B; Creus, W; Crispoltoni, M; Cui, Z; Dai, Y M; Delgado, C; Della Torre, S; Demirköz, M B; Derome, L; Di Falco, S; Dimiccoli, F; Díaz, C; von Doetinchem, P; Dong, F; Donnini, F; Duranti, M; D'Urso, D; Egorov, A; Eline, A; Eronen, T; Feng, J; Fiandrini, E; Finch, E; Fisher, P; Formato, V; Galaktionov, Y; Gallucci, G; García, B; García-López, R J; Gargiulo, C; Gast, H; Gebauer, I; Gervasi, M; Ghelfi, A; Giovacchini, F; Goglov, P; Gómez-Coral, D M; Gong, J; Goy, C; Grabski, V; Grandi, D; Graziani, M; Guerri, I; Guo, K H; Habiby, M; Haino, S; Han, K C; He, Z H; Heil, M; Hoffman, J; Hsieh, T H; Huang, H; Huang, Z C; Huh, C; Incagli, M; Ionica, M; Jang, W Y; Jinchi, H; Kang, S C; Kanishev, K; Kim, G N; Kim, K S; Kirn, Th; Konak, C; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; La Vacca, G; Laudi, E; Laurenti, G; Lazzizzera, I; Lebedev, A; Lee, H T; Lee, S C; Leluc, C; Li, H S; Li, J Q; Li, J Q; Li, Q; Li, T X; Li, W; Li, Z H; Li, Z Y; Lim, S; Lin, C H; Lipari, P; Lippert, T; Liu, D; Liu, Hu; Lu, S Q; Lu, Y S; Luebelsmeyer, K; Luo, F; Luo, J Z; Lv, S S; Majka, R; Mañá, C; Marín, J; Martin, T; Martínez, G; Masi, N; Maurin, D; Menchaca-Rocha, A; Meng, Q; Mo, D C; Morescalchi, L; Mott, P; Nelson, T; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Oliva, A; Orcinha, M; Palmonari, F; Palomares, C; Paniccia, M; Pauluzzi, M; Pensotti, S; Pereira, R; Picot-Clemente, N; Pilo, F; Pizzolotto, C; Plyaskin, V; Pohl, M; Poireau, V; Putze, A; Quadrani, L; Qi, X M; Qin, X; Qu, Z Y; Räihä, T; Rancoita, P G; Rapin, D; Ricol, J S; Rodríguez, I; Rosier-Lees, S; Rozhkov, A; Rozza, D; Sagdeev, R; Sandweiss, J; Saouter, P; Schael, S; Schmidt, S M; Schulz von Dratzig, A; Schwering, G; Seo, E S; Shan, B S; Shi, J Y; Siedenburg, T; Son, D; Song, J W; Sun, W H; Tacconi, M; Tang, X W; Tang, Z C; Tao, L; Tescaro, D; Ting, Samuel C C; Ting, S M; Tomassetti, N; Torsti, J; Türkoğlu, C; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vázquez Acosta, M; Vecchi, M; Velasco, M; Vialle, J P; Vitale, V; Vitillo, S; Wang, L Q; Wang, N H; Wang, Q L; Wang, X; Wang, X Q; Wang, Z X; Wei, C C; Weng, Z L; Whitman, K; Wienkenhöver, J; Willenbrock, M; Wu, H; Wu, X; Xia, X; Xiong, R Q; Xu, W; Yan, Q; Yang, J; Yang, M; Yang, Y; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, C; Zhang, J; Zhang, J H; Zhang, S D; Zhang, S W; Zhang, Z; Zheng, Z M; Zhu, Z Q; Zhuang, H L; Zhukov, V; Zichichi, A; Zimmermann, N; Zuccon, P

2016-08-26

A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500  GV, the antiproton p[over ¯], proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500  GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

NASA Astrophysics Data System (ADS)

Aguilar, M.; Ali Cavasonza, L.; Alpat, B.; Ambrosi, G.; Arruda, L.; Attig, N.; Aupetit, S.; Azzarello, P.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Başeǧmez-du Pree, S.; Battarbee, M.; Battiston, R.; Bazo, J.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Bertucci, B.; Bindi, V.; Boella, G.; de Boer, W.; Bollweg, K.; Bonnivard, V.; Borgia, B.; Boschini, M. J.; Bourquin, M.; Bueno, E. F.; Burger, J.; Cadoux, F.; Cai, X. D.; Capell, M.; Caroff, S.; Casaus, J.; Castellini, G.; Cernuda, I.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, G. M.; Chen, H. S.; Cheng, L.; Chou, H. Y.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Coste, B.; Creus, W.; Crispoltoni, M.; Cui, Z.; Dai, Y. M.; Delgado, C.; Della Torre, S.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Dimiccoli, F.; Díaz, C.; von Doetinchem, P.; Dong, F.; Donnini, F.; Duranti, M.; D'Urso, D.; Egorov, A.; Eline, A.; Eronen, T.; Feng, J.; Fiandrini, E.; Finch, E.; Fisher, P.; Formato, V.; Galaktionov, Y.; Gallucci, G.; García, B.; García-López, R. J.; Gargiulo, C.; Gast, H.; Gebauer, I.; Gervasi, M.; Ghelfi, A.; Giovacchini, F.; Goglov, P.; Gómez-Coral, D. M.; Gong, J.; Goy, C.; Grabski, V.; Grandi, D.; Graziani, M.; Guerri, I.; Guo, K. H.; Habiby, M.; Haino, S.; Han, K. C.; He, Z. H.; Heil, M.; Hoffman, J.; Hsieh, T. H.; Huang, H.; Huang, Z. C.; Huh, C.; Incagli, M.; Ionica, M.; Jang, W. Y.; Jinchi, H.; Kang, S. C.; Kanishev, K.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Konak, C.; Kounina, O.; Kounine, A.; Koutsenko, V.; Krafczyk, M. S.; La Vacca, G.; Laudi, E.; Laurenti, G.; Lazzizzera, I.; Lebedev, A.; Lee, H. T.; Lee, S. C.; Leluc, C.; Li, H. S.; Li, J. Q.; Li, J. Q.; Li, Q.; Li, T. X.; Li, W.; Li, Z. H.; Li, Z. Y.; Lim, S.; Lin, C. H.; Lipari, P.; Lippert, T.; Liu, D.; Liu, Hu; Lu, S. Q.; Lu, Y. S.; Luebelsmeyer, K.; Luo, F.; Luo, J. Z.; Lv, S. S.; Majka, R.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masi, N.; Maurin, D.; Menchaca-Rocha, A.; Meng, Q.; Mo, D. C.; Morescalchi, L.; Mott, P.; Nelson, T.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Nunes, P.; Oliva, A.; Orcinha, M.; Palmonari, F.; Palomares, C.; Paniccia, M.; Pauluzzi, M.; Pensotti, S.; Pereira, R.; Picot-Clemente, N.; Pilo, F.; Pizzolotto, C.; Plyaskin, V.; Pohl, M.; Poireau, V.; Putze, A.; Quadrani, L.; Qi, X. M.; Qin, X.; Qu, Z. Y.; Räihä, T.; Rancoita, P. G.; Rapin, D.; Ricol, J. S.; Rodríguez, I.; Rosier-Lees, S.; Rozhkov, A.; Rozza, D.; Sagdeev, R.; Sandweiss, J.; Saouter, P.; Schael, S.; Schmidt, S. M.; Schulz von Dratzig, A.; Schwering, G.; Seo, E. S.; Shan, B. S.; Shi, J. Y.; Siedenburg, T.; Son, D.; Song, J. W.; Sun, W. H.; Tacconi, M.; Tang, X. W.; Tang, Z. C.; Tao, L.; Tescaro, D.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Torsti, J.; Türkoǧlu, C.; Urban, T.; Vagelli, V.; Valente, E.; Vannini, C.; Valtonen, E.; Vázquez Acosta, M.; Vecchi, M.; Velasco, M.; Vialle, J. P.; Vitale, V.; Vitillo, S.; Wang, L. Q.; Wang, N. H.; Wang, Q. L.; Wang, X.; Wang, X. Q.; Wang, Z. X.; Wei, C. C.; Weng, Z. L.; Whitman, K.; Wienkenhöver, J.; Willenbrock, M.; Wu, H.; Wu, X.; Xia, X.; Xiong, R. Q.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Yang, Y.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zeissler, S.; Zhang, C.; Zhang, J.; Zhang, J. H.; Zhang, S. D.; Zhang, S. W.; Zhang, Z.; Zheng, Z. M.; Zhu, Z. Q.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zimmermann, N.; Zuccon, P.; AMS Collaboration

2016-08-01

A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 ×1 05 antiproton events and 2.42 ×1 09 proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ˜60 to ˜500 GV , the antiproton p ¯, proton p , and positron e+ fluxes are found to have nearly identical rigidity dependence and the electron e- flux exhibits a different rigidity dependence. Below 60 GV, the (p ¯/p ), (p ¯/e+), and (p /e+) flux ratios each reaches a maximum. From ˜60 to ˜500 GV , the (p ¯/p ), (p ¯/e+), and (p /e+) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

Gauge interaction as periodicity modulation

NASA Astrophysics Data System (ADS)

Dolce, Donatello

2012-06-01

The paper is devoted to a geometrical interpretation of gauge invariance in terms of the formalism of field theory in compact space-time dimensions (Dolce, 2011) [8]. In this formalism, the kinematic information of an interacting elementary particle is encoded on the relativistic geometrodynamics of the boundary of the theory through local transformations of the underlying space-time coordinates. Therefore gauge interactions are described as invariance of the theory under local deformations of the boundary. The resulting local variations of the field solution are interpreted as internal transformations. The internal symmetries of the gauge theory turn out to be related to corresponding space-time local symmetries. In the approximation of local infinitesimal isometric transformations, Maxwell's kinematics and gauge invariance are inferred directly from the variational principle. Furthermore we explicitly impose periodic conditions at the boundary of the theory as semi-classical quantization condition in order to investigate the quantum behavior of gauge interaction. In the abelian case the result is a remarkable formal correspondence with scalar QED.

Multivariate Relationships of Specific Impression Cues with Teacher Expectations and Dyadic Interactions in Elementary Physical Education Classes.

ERIC Educational Resources Information Center

Martinek, Thomas J.; Karper, William B.

1984-01-01

This study determined multivariate relationships of the impression cues of attractiveness and effort with teacher expectations and dyadic interaction in two groups of elementary school children. (Author/JMK)

ICPP: Identification and Quantification of Elementary Plasma Surface Processes during thin Film Growth

NASA Astrophysics Data System (ADS)

Keudell, A. V.

2000-10-01

The quantification of elementary plasma surface processes in glow discharges used for thin film deposition, is mandatory for a complete description of these low temperature plasmas. Since the surface to volume ratio in these discharge systems is often large, all particle densities in the discharge can be strongly influenced by any surface reactions. The identification and quantification of these surface processes will be illustrated for the plasma deposition of amorphous hydrogenated carbon films. A variety of experiments will be discussed ranging from plasma experiments using the cavity technique or ionization threshold mass spectrometry as well as a new class of experiments using quantified radical beams to quantify surface reactions in terms of sticking coefficients directly. It is shown that the reactivity of the hydrocarbon radicals depends strongly on the state of hybridization of the hydrocarbon growth precursor, and that the sticking coefficients for various hydrocarbon radicals are strongly influenced by the simultaneous interaction of several reactive species with the film surface. With the knowledge of these interaction mechanisms and the quantification of the corresponding cross sections, a better understanding of growth processes has become possible, ranging from the deposition of polycrystalline diamond in microwave discharges to the formation of re-deposited layers in fusion experiments.

The Effect Teaching Experience Has on Perceived Effectiveness of Interactive Television as a Distance Education Model for Elementary School Science Teacher's Professional Development: Another Digital Divide?

ERIC Educational Resources Information Center

Annetta, Leonard A.; Minogue, James

2004-01-01

The first year of a 5 year professional development project for elementary teachers in two mid-western states integrated a bridge of two distinctly different distance education networks (T-1 and fiber optics) to provide science professional development for elementary school teachers in rural communities. "Interactive television" (ITV), the title…

Duality and 'particle' democracy

NASA Astrophysics Data System (ADS)

Castellani, Elena

2017-08-01

Weak/strong duality is usually accompanied by what seems a puzzling ontological feature: the fact that under this kind of duality what is viewed as 'elementary' in one description gets mapped to what is viewed as 'composite' in the dual description. This paper investigates the meaning of this apparent 'particle democracy', as it has been called, by adopting an historical approach. The aim is to clarify the nature of the correspondence between 'dual particles' in the light of a historical analysis of the developments of the idea of weak/strong duality, starting with Dirac's electric-magnetic duality and its successive generalizations in the context of (Abelian and non-Abelian) field theory, to arrive at its first extension to string theory. This analysis is then used as evidential basis for discussing the 'elementary/composite' divide and, after taking another historical detour by analyzing an instructive analogy case (DHS duality and related nuclear democracy), drawing some conclusions on the particle-democracy issue.

Physical Investigations of Small Particles: (I) Aerosol Particle Charging and Flux Enhancement and (II) Whispering Gallery Mode Sensing

NASA Astrophysics Data System (ADS)

Lopez-Yglesias, Xerxes

Part I: Particles are a key feature of planetary atmospheres. On Earth they represent the greatest source of uncertainty in the global energy budget. This uncertainty can be addressed by making more measurement, by improving the theoretical analysis of measurements, and by better modeling basic particle nucleation and initial particle growth within an atmosphere. This work will focus on the latter two methods of improvement. Uncertainty in measurements is largely due to particle charging. Accurate descriptions of particle charging are challenging because one deals with particles in a gas as opposed to a vacuum, so different length scales come into play. Previous studies have considered the effects of transition between the continuum and kinetic regime and the effects of two and three body interactions within the kinetic regime. These studies, however, use questionable assumptions about the charging process which resulted in skewed observations, and bias in the proposed dynamics of aerosol particles. These assumptions affect both the ions and particles in the system. Ions are assumed to be point monopoles that have a single characteristic speed rather than follow a distribution. Particles are assumed to be perfect conductors that have up to five elementary charges on them. The effects of three body interaction, ion-molecule-particle, are also overestimated. By revising this theory so that the basic physical attributes of both ions and particles and their interactions are better represented, we are able to make more accurate predictions of particle charging in both the kinetic and continuum regimes. The same revised theory that was used above to model ion charging can also be applied to the flux of neutral vapor phase molecules to a particle or initial cluster. Using these results we can model the vapor flux to a neutral or charged particle due to diffusion and electromagnetic interactions. In many classical theories currently applied to these models, the finite size of the molecule and the electromagnetic interaction between the molecule and particle, especially for the neutral particle case, are completely ignored, or, as is often the case for a permanent dipole vapor species, strongly underestimated. Comparing our model to these classical models we determine an "enhancement factor" to characterize how important the addition of these physical parameters and processes is to the understanding of particle nucleation and growth. Part II: Whispering gallery mode (WGM) optical biosensors are capable of extraordinarily sensitive specific and non-specific detection of species suspended in a gas or fluid. Recent experimental results suggest that these devices may attain single-molecule sensitivity to protein solutions in the form of stepwise shifts in their resonance wavelength, lambdaR, but present sensor models predict much smaller steps than were reported. This study examines the physical interaction between a WGM sensor and a molecule adsorbed to its surface, exploring assumptions made in previous efforts to model WGM sensor behavior, and describing computational schemes that model the experiments for which single protein sensitivity was reported. The resulting model is used to simulate sensor performance, within constraints imposed by the limited material property data. On this basis, we conclude that nonlinear optical effects would be needed to attain the reported sensitivity, and that, in the experiments for which extreme sensitivity was reported, a bound protein experiences optical energy fluxes too high for such effects to be ignored.

Current experiments in elementary particle physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wohl, C.G.; Armstrong, F.E.; Trippe, T.G.

1989-09-01

This report contains summaries of 736 current and recent experiments in elementary particle physics (experiments that finished taking data before 1982 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Tokyo Institute of Nuclear Studies, Moscow Institute of Theoretical and Experimental Physics, Joint Institute for Nuclear Research (Dubna), KEK, LAMPF, Novosibirsk, PSI/SIN, Saclay, Serpukhov, SLAC, and TRIUMF, and also several underground experiments. Also given are instructions for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries. Properties of the fixed-target beams at most of the laboratories are summarized.

Can there be massive photons? A pedagogical glance at the origin of mass

NASA Astrophysics Data System (ADS)

Robles, P.; Claro, F.

2012-09-01

Among the most startling experiences a student encounters is learning that, unlike electrons and other elementary particles, photons have no mass. Under certain circumstances, however, the light quantum behaves as if it did have a finite mass. Starting from Maxwell's equations, we discuss how this arises when light interacts with a charged plasma, or travels along a waveguide. The motion of such photons is analysed using kinematic concepts of special relativity, and we show how a cutoff frequency for effective propagation appears. Seeing how an environment may yield an apparent dynamic mass to the photon paves the way for later understanding: might the Higgs boson field provide other particles, such as the electron, with a mass? This paper is addressed to mid-level physics students, teachers and lecturers, requiring only a knowledge of classical electromagnetic and special relativity theories.

Particle physics in the very early universe

NASA Technical Reports Server (NTRS)

Schramm, D. N.

1981-01-01

Events in the very early big bang universe in which elementary particle physics effects may have been dominant are discussed, with attention to the generation of a net baryon number by way of grand unification theory, and emphasis on the possible role of massive neutrinos in increasing current understanding of various cosmological properties and of the constraints placed on neutrino properties by cosmology. It is noted that when grand unification theories are used to describe very early universe interactions, an initially baryon-symmetrical universe can evolve a net baryon excess of 10 to the -9th to 10 to the -11th per photon, given reasonable parameters. If neutrinos have mass, the bulk of the mass of the universe may be in the form of leptons, implying that the form of matter most familiar to physical science may not be the dominant form of matter in the universe.

High energy physics in cosmic rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Lawrence W.

2013-02-07

In the first half-century of cosmic ray physics, the primary research focus was on elementary particles; the positron, pi-mesons, mu-mesons, and hyperons were discovered in cosmic rays. Much of this research was carried out at mountain elevations; Pic du Midi in the Pyrenees, Mt. Chacaltaya in Bolivia, and Mt. Evans/Echo Lake in Colorado, among other sites. In the 1960s, claims of the observation of free quarks, and satellite measurements of a significant rise in p-p cross sections, plus the delay in initiating accelerator construction programs for energies above 100 GeV, motivated the Michigan-Wisconsin group to undertake a serious cosmic raymore » program at Echo Lake. Subsequently, with the succession of higher energy accelerators and colliders at CERN and Fermilab, cosmic ray research has increasingly focused on cosmology and astrophysics, although some groups continue to study cosmic ray particle interactions in emulsion chambers.« less

(Experimental studies of elementary particle interactions at high energies)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khuri, N.N.

1990-01-01

This report includes descriptions of the combined work of both Tasks B and B{sub 1} at Rockefeller University. Some highlights are worth stressing in this brief introduction. First, one should note the active involvement of two members of our group, Ren and Callaway, in understanding the problem of superconductivity, both high and low {Tc}. This reflects the broad reach of many, but perhaps not all, particle physicists. Second, spurred by the Rockefeller environment, some in our group are also looking at problems in biology. As for our main purpose, I would like to single out the results of Sanda andmore » Morozumi on the {Delta}I = {1/2} rule, the work of Bitar, Ren and myself on a new approach to the path integral, S.Y. Pi's results on Chern-Simons non-relativistic quantum mechanics, and finally the work by Lee and collaborators on the origin of Fermion masses and mixing.« less

Dark-matter QCD-axion searches

DOE PAGES

Rosenberg, Leslie J.

2015-01-12

In the late 20th century, cosmology became a precision science. At the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There’s no known such elementary particle, so the strong presumption is the darkmore » matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10 -(6–3) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. But, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. Our paper is a selective overview of the current generation of sensitive axion searches. Finally, not all techniques and experiments are discussed, but I hope to give a sense of the current experimental landscape of the search for dark-matter axions.« less

Dark-matter QCD-axion searches.

PubMed

Rosenberg, Leslie J

2015-10-06

In the late 20th century, cosmology became a precision science. Now, at the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There's no known such elementary particle, so the strong presumption is the dark matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10(-(6-3)) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. However, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. This article is a selective overview of the current generation of sensitive axion searches. Not all techniques and experiments are discussed, but I hope to give a sense of the current experimental landscape of the search for dark-matter axions.

Dark-matter QCD-axion searches

PubMed Central

Rosenberg, Leslie J

2015-01-01

In the late 20th century, cosmology became a precision science. Now, at the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There’s no known such elementary particle, so the strong presumption is the dark matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10−(6–3) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. However, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. This article is a selective overview of the current generation of sensitive axion searches. Not all techniques and experiments are discussed, but I hope to give a sense of the current experimental landscape of the search for dark-matter axions. PMID:25583487

The Particle Theory of Matter

ERIC Educational Resources Information Center

Widick, Paul R.

1969-01-01

Described are activities that are designed to help elementary children understand the possibility of the particle theory of matter. Children work with beads, marbles, B-B shot and sand; by mixing these materials and others they are led to see that it is highly possible for the existence of particles which are not visible. (BR)

Interacting with Elementary Interns about Their Perceptions of Science Teaching.

ERIC Educational Resources Information Center

Carnes, G. Nathan; Shull, Tiffany A.; Brown, Shanise N.; Munn, Wesley G.

This research investigated three elementary preservice teachers' perceptions of elementary science teachers. Three questions guided this investigation. What images did elementary Masters of Arts in Teaching (M.A.T.) interns have of science teaching at the beginning and end of science methods courses? What changes, if any, did they make in their…

Neutrino-Argon Interaction with GENIE Event Generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chesneanu, Daniela; National Institute for Nuclear Physics and Engineering 'Horia Hulubei' Bucharest-Magurele

2010-11-24

Neutrinos are very special particles, have only weak interactions, except gravity, and are produced in very different processes in Nuclear and Particle Physics. Neutrinos are, also, messengers from astrophysical objects, as well as relics from Early Universe. Therefore, its can give us information on processes happening in the Universe, during its evolution, which cannot be studied otherwise. The underground instrumentation including a variety of large and very large detectors, thanks to technical breakthroughs, have achieved new fundamental results like the solution of the solar neutrino puzzle and the evidence for Physics beyond the Standard Model of elementary interactions in themore » neutrino sector with non-vanishing neutrino masses and lepton flavour violation.Two of the LAGUNA(Large Apparatus studying Grand Unification and Neutrino Astrophysics) detectors, namely: GLACIER (Giant Liquid Argon Charge Imaging ExpeRiment) and LENA (Low Energy Neutrino Astrophysics) could be emplaced in 'Unirea' salt mine from Slanic-Prahova, Romania. A detailed analysis of the conditions and advantages is necessary. A few results have been presented previously. In the present work, we propose to generate events and compute the cross sections for interactions between neutrino and Argon-40, to estimate possible detection performances and event types. For doing this, we use the code GENIE(G lowbar enerates E lowbar vents for N lowbar eutrino I lowbar nteraction E lowbar xperiments). GENIE Code is an Object-Oriented Neutrino MC Generator supported and developed by an international collaboration of neutrino interaction experts.« less

Observation of chiral phonons.

PubMed

Zhu, Hanyu; Yi, Jun; Li, Ming-Yang; Xiao, Jun; Zhang, Lifa; Yang, Chih-Wen; Kaindl, Robert A; Li, Lain-Jong; Wang, Yuan; Zhang, Xiang

2018-02-02

Chirality reveals symmetry breaking of the fundamental interaction of elementary particles. In condensed matter, for example, the chirality of electrons governs many unconventional transport phenomena such as the quantum Hall effect. Here we show that phonons can exhibit intrinsic chirality in monolayer tungsten diselenide. The broken inversion symmetry of the lattice lifts the degeneracy of clockwise and counterclockwise phonon modes at the corners of the Brillouin zone. We identified the phonons by the intervalley transfer of holes through hole-phonon interactions during the indirect infrared absorption, and we confirmed their chirality by the infrared circular dichroism arising from pseudoangular momentum conservation. The chiral phonons are important for electron-phonon coupling in solids, phonon-driven topological states, and energy-efficient information processing. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Observation of the doubly strange b-Baryon Ω b -

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jose de Jesus Hernandez Orduna

2011-02-01

This thesis reports the first experimental evidence of the doubly strange b-baryon Ω b - (ssb) following the decay channel Ω b - → J/Ψ(1S) μ +μ - Ω - Λ K - p π - in pmore » $$\\bar{p}$$ collisions at √s = 1.96 Tev. Using approximately 1.3 fb -1 of data collected with the D0 detector at the Fermilab Tevatron Collider, they observe 17.8 ± 4.9(stat) ± 0.8(syst) Ω b - signal events at 6.165 ± 0.010(stat) ± 0.013(syst) GeV/c 2 with a corresponding significance of 5.4 σ, meaning that the probability of the signal coming from a fluctuation in the background is 6.7 x 10 -8. The theoretical model we have to describe what we believe are the building blocks of nature and the interactions between them, is known as Standard Model. The Standard Model is the combination of Electroweak Theory and Quantum Chromodynamics into a single core in the attempt to include all interactions of subatomic particles except those due to gravity in a simple framework. This model has proved highly accurate in predicting certain interactions, but it does not explain all aspects of subatomic particles. For example, it cannot say how many particles there should be or what their masses are. The search goes on for a more complete theory, and in particular an unified field theory describing the strong, weak, and electromagnetic forces. Twelve elementary particles are known in the Standard Model: the Fermions. They have spin -1/2 and obey the Pauli Exclusion Principle. Fermions are divided into six Quarks: up u, down d, charm c, strange s, top t and, bottom b; and six Leptons: electron e, muon μ, ττ, electron neutrino v e, muon neutrino v μ and, τ neutrino v τ. Quarks interact via the strong force because they carry color charge, electromagnetically because of their electric charge and via the weak nuclear interaction because of the weak isospin. Quarks form color-neutral composite particles known as Hadrons which are divided in Mesons, containing a quark and an antiquark and Baryons, made up three quarks. Leptons have no color charge and can not interact via the strong force. Only three of them have electric charge, hence interact electromagnetically. The motion of non-electrically charged leptons, the neutrinos, is influenced only by the weak nuclear interaction. Every fermion have an associated antiparticle. For quarks, the antiparticle carry opposite electric charge, color charge and baryon number. For leptons, the antiparticle carry opposite electric charge and lepton number. Fermions are suitably grouped together considering their properties and three generations of them are defined. A higher generation fermion have greater mass than those in lower generations. Charged members of the first generation do not decay and form the ultimate building blocks for all the baryonic matter we know about. Charged members of higher generations have very short half lives and are found normally in high-energy environments. Non-electrically charged fermions do not decay and rarely interact with baryonic matter. The way particles interact and influence each other in the Standard Model is result from matter particles exchanging other particles, known as Force Mediating Particles. They are believed to be the reason of the existence of the forces and interactions between particles observed in the laboratory and the universe. Force mediating particles have spin 1, i.e., they are Bosons, and do not follow the Pauli Exclusion Principle. The types of force mediating particles are: the photon γ, three gauge bosons W ± and Z and, eight gluons g. Photons have no mass, the theory of Quantum Electrodynamics describe them very well and are responsible for mediation of the electromagnetic force between electrically charged particles. Gauge bosons are massive, being Z heavier than W ±. They are responsible for the mediation of the weak interactions between particles of different flavors but W ± act only on left-handed particles and right-handed antiparticles while Z with both left-handed particles and antiparticles. Due to the electric charge of W ±, they couple also to electromagnetic interactions. Photons and the three gauge bosons are grouped together and collectively mediate the electroweak interactions. Finally, gluons have no mass, the theory of Quantum Chromodynamics describe them and are responsible for the mediation of the strong interactions between particles with color charge. Having an effective color charge, gluons can interact among themselves. The Higgs Boson is the only particle in the SM without direct experimental evidence. Its detection would help in the explanation of the difference between massive bosons mediating the weak force and the massless photon mediating the electromagnetism.« less

Towards a natural theory of electroweak interactions

NASA Astrophysics Data System (ADS)

Dobrescu, Bogdan A.

1998-01-01

I study theories of electroweak symmetry breaking that may describe naturally the electromagnetic and weak interactions of the elementary particles observed so far (quarks, leptons and gauge bosons). These theories should explain why the energy scale at which the electroweak symmetry is spontaneously broken (246 GeV), called the 'electroweak scale', is seventeen orders of magnitude smaller than the 'Planck scale', which is associated with the quantum origin of gravity. I discuss first theories where the electroweak symmetry is broken by the dynamics of new strong interactions, naturally producing the hierarchy between the Planck scale and the electroweak scale. I show that in a realistic class of models of this type, the new gauge bosons needed for generating the mass of the heaviest quark have couplings which require a careful adjustment in order to be compatible with experimental data. In the case where the strong dynamics produces a composite spinless particle ('Higgs boson') whose interactions break the electroweak symmetry, I derive an upper bound of 460 GeV on the Higgs boson mass from experimental constraints on processes sensitive to new physics. I also discuss a different type of theory that explains the hierarchy of energy scales, based on a special symmetry, called supersymmetry, which requires the existence of new particles ('superpartners'). No superpartners have been seen in experiments. Therefore, if they exist, they must have masses larger than the particles known so far, implying that supersymmetry is not exact. In the simplest models, supersymmetry breaking is transmitted to the superpartners by standard gauge interactions. I show that all known models of this type are likely to be unacceptable because they do not admit a stable and phenomenologically viable ground state of the universe ('vacuum'). I then construct modified versions of these models that permit viable stable vacua. Also, I present a new model in which supersymmetry breaking is transmitted to the superpartners by nonstandard gauge interactions, leading to distinctive predictions for the superpartner masses. Finally, I propose a model that combines a mechanism of dynamical electroweak symmetry breaking with supersymmetry, which explains some features of the quark and lepton mass spectrum.

The Model Identification Test: Perceptual Bias of Elementary School Children Using a Limited Verbal Evaluation Instrument

ERIC Educational Resources Information Center

McIntyre, Patrick J.

1974-01-01

Reported is a study to verify the pattern of bias associated with the Model Identification Test and to determine its source. This instrument is a limited verbal science test designed to determine the knowledge possessed by elementary school children of selected concepts related to "the particle nature of matter." (PEB)

Particle Diffusion in an Inhomogeneous Medium

ERIC Educational Resources Information Center

Bringuier, E.

2011-01-01

This paper is an elementary introduction to particle diffusion in a medium where the coefficient of diffusion varies with position. The introduction is aimed at third-year university courses. We start from a simple model of particles hopping on a discrete lattice, in one or more dimensions, and then take the continuous-space limit so as to obtain…

Elementary School Teachers' Perceptions toward ICT: The Case of Using Magic Board for Teaching Mathematics

ERIC Educational Resources Information Center

Yuan, Yuan; Lee, Chun-Yi

2012-01-01

This study aims at investigating elementary school teachers' perceptions toward to the use of ICT. Magic Board, an interactive web-based environment which provides a set of virtual manipulatives for elementary mathematics, is used as the case of ICT. After participating in Magic Board workshops, 250 elementary school teachers in Taiwan responded…

Using Interactive Board and Communication in Teaching English at Lower-Secondary Stage of Elementary School

ERIC Educational Resources Information Center

Dobrovolná, Alena

2015-01-01

The contribution brings part of the research results on using interactive boards in teaching English at lower-secondary stage of elementary schools in the Czech Republic. The whole research focused on ways of using this modern device, on types of interaction and mainly tried to find out whether there is sufficient space for developing…

Causality, Measurement, and Elementary Interactions

NASA Astrophysics Data System (ADS)

Gillis, Edward J.

2011-12-01

Signal causality, the prohibition of superluminal information transmission, is the fundamental property shared by quantum measurement theory and relativity, and it is the key to understanding the connection between nonlocal measurement effects and elementary interactions. To prevent those effects from transmitting information between the generating and observing process, they must be induced by the kinds of entangling interactions that constitute measurements, as implied in the Projection Postulate. They must also be nondeterministic as reflected in the Born Probability Rule. The nondeterminism of entanglement-generating processes explains why the relevant types of information cannot be instantiated in elementary systems, and why the sequencing of nonlocal effects is, in principle, unobservable. This perspective suggests a simple hypothesis about nonlocal transfers of amplitude during entangling interactions, which yields straightforward experimental consequences.

Aspects of the Antisymmetric Tensor Field

NASA Astrophysics Data System (ADS)

Lahiri, Amitabha

1991-02-01

With the possible exception of gravitation, fundamental interactions are generally described by theories of point particles interacting via massless gauge fields. Since the advent of string theories the picture of physical interaction has changed to accommodate one in which extended objects interact with each other. The generalization of the gauge theories to extended objects leads to theories of antisymmetric tensor fields. At scales corresponding to present-day laboratory experiments one expects to see only point particles, their interactions modified by the presence of antisymmetric tensor fields in the theory. Therefore, in order to establish the validity of any theory with antisymmetric tensor fields one needs to look for manifestations of these fields at low energies. The principal problem of gauge theories is the failure to provide a suitable explanation for the generation of masses for the fields in the theory. While there is a known mechanism (spontaneous symmetry breaking) for generating masses for both the matter fields and the gauge fields, the lack of experimental evidence in support of an elementary scalar field suggests that one look for alternative ways of generating masses for the fields. The interaction of gauge fields with an antisymmetric tensor field seems to be an attractive way of doing so, especially since all indications point to the possibility that there will be no remnant degrees of freedom. On the other hand the interaction of such a field with black holes suggest an independent way of verifying the existence of such fields. In this dissertation the origins of the antisymmetric tensor field are discussed in terms of string theory. The interaction of black holes with such a field is discussed next. The last chapter discusses the effects of an antisymmetric tensor field on quantum electrodynamics when the fields are minimally coupled.

Quantum Metropolis sampling.

PubMed

Temme, K; Osborne, T J; Vollbrecht, K G; Poulin, D; Verstraete, F

2011-03-03

The original motivation to build a quantum computer came from Feynman, who imagined a machine capable of simulating generic quantum mechanical systems--a task that is believed to be intractable for classical computers. Such a machine could have far-reaching applications in the simulation of many-body quantum physics in condensed-matter, chemical and high-energy systems. Part of Feynman's challenge was met by Lloyd, who showed how to approximately decompose the time evolution operator of interacting quantum particles into a short sequence of elementary gates, suitable for operation on a quantum computer. However, this left open the problem of how to simulate the equilibrium and static properties of quantum systems. This requires the preparation of ground and Gibbs states on a quantum computer. For classical systems, this problem is solved by the ubiquitous Metropolis algorithm, a method that has basically acquired a monopoly on the simulation of interacting particles. Here we demonstrate how to implement a quantum version of the Metropolis algorithm. This algorithm permits sampling directly from the eigenstates of the Hamiltonian, and thus evades the sign problem present in classical simulations. A small-scale implementation of this algorithm should be achievable with today's technology.

REMARKS ON COMPOUND MODELS, CONSERVED CURRENTS AND WEAK INTERACTIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayer, M.E.

A discussion is given of some implications of a symmetry principle, conjectured by Gamba, Marshak, and Okubo (GMO), in connection with the compound models for elementary particles, and the interpretation of weak interactions by a heavy vector meson coupled to the conserved V and A currents of the fermions. GMO observed that, for weak interactions, the three baryons LAMBDA deg , n, p are equivalent to the leptons mu /sup -/, e/sup -/, nu in the sense that any reaction permitted or observed for one of the groups is permitted for the other and conversely, no reaction forbidden for onemore » is observed in the other. This permitted the extension of the notions of isospin and strangeness to leptons and led to the expression of the electric charge in terms of the isospin projection, T/sub 3/, and the baryon and lepton numbers B and L:. Q = T/sub 3/ + 1/2(S+ B -- L). (B.O.G.)« less

Quasiparticle engineering and entanglement propagation in a quantum many-body system.

PubMed

Jurcevic, P; Lanyon, B P; Hauke, P; Hempel, C; Zoller, P; Blatt, R; Roos, C F

2014-07-10

The key to explaining and controlling a range of quantum phenomena is to study how information propagates around many-body systems. Quantum dynamics can be described by particle-like carriers of information that emerge in the collective behaviour of the underlying system, the so-called quasiparticles. These elementary excitations are predicted to distribute quantum information in a fashion determined by the system's interactions. Here we report quasiparticle dynamics observed in a quantum many-body system of trapped atomic ions. First, we observe the entanglement distributed by quasiparticles as they trace out light-cone-like wavefronts. Second, using the ability to tune the interaction range in our system, we observe information propagation in an experimental regime where the effective-light-cone picture does not apply. Our results will enable experimental studies of a range of quantum phenomena, including transport, thermalization, localization and entanglement growth, and represent a first step towards a new quantum-optic regime of engineered quasiparticles with tunable nonlinear interactions.

Young Foreign Language Learners' Interactions during Task-Based Paired Assessments

ERIC Educational Resources Information Center

Butler, Yuko Goto; Zeng, Wei

2014-01-01

Despite the popularity of task-based language teaching (TBLT) in foreign language (FL) education at elementary school, it remains unclear how young learners' FL abilities can best be evaluated with tasks. The present study seeks to understand developmental differences in interactions among elementary-school students during task-based language…

Technology Enhanced Elementary and Middle School Science (TEEMSS). What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2012

2012-01-01

"Technology Enhanced Elementary and Middle School Science" ("TEEMSS") is a physical science curriculum for grades 3-8 that utilizes computers, sensors, and interactive models to support investigations of real-world phenomena. Through 15 inquiry-based instructional units, students interact with computers, gather and analyze…

Tensor methodology and computational geometry in direct computational experiments in fluid mechanics

NASA Astrophysics Data System (ADS)

Degtyarev, Alexander; Khramushin, Vasily; Shichkina, Julia

2017-07-01

The paper considers a generalized functional and algorithmic construction of direct computational experiments in fluid dynamics. Notation of tensor mathematics is naturally embedded in the finite - element operation in the construction of numerical schemes. Large fluid particle, which have a finite size, its own weight, internal displacement and deformation is considered as an elementary computing object. Tensor representation of computational objects becomes strait linear and uniquely approximation of elementary volumes and fluid particles inside them. The proposed approach allows the use of explicit numerical scheme, which is an important condition for increasing the efficiency of the algorithms developed by numerical procedures with natural parallelism. It is shown that advantages of the proposed approach are achieved among them by considering representation of large particles of a continuous medium motion in dual coordinate systems and computing operations in the projections of these two coordinate systems with direct and inverse transformations. So new method for mathematical representation and synthesis of computational experiment based on large particle method is proposed.

Inertial mass of an elementary particle from the holographic scenario

NASA Astrophysics Data System (ADS)

Giné, Jaume

2017-03-01

Various attempts have been made to fully explain the mechanism by which a body has inertial mass. Recently, it has been proposed that this mechanism is as follows: when an object accelerates in one direction, a dynamical Rindler event horizon forms in the opposite direction, suppressing Unruh radiation on that side by a Rindler-scale Casimir effect whereas the radiation on the other side is only slightly reduced by a Hubble-scale Casimir effect. This produces a net Unruh radiation pressure force that always opposes the acceleration, just like inertia, although the masses predicted are twice those expected, see Ref. 17. In a later work, an error was corrected so that its prediction improves to within 26% of the Planck mass, see Ref. 10. In this paper, the expression of the inertial mass of a elementary particle is derived from the holographic scenario giving the exact value of the mass of a Planck particle when it is applied to a Planck particle.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perl, M.L.

This paper is based upon lectures in which I have described and explored the ways in which experimenters can try to find answers, or at least clues toward answers, to some of the fundamental questions of elementary particle physics. All of these experimental techniques and directions have been discussed fully in other papers, for example: searches for heavy charged leptons, tests of quantum chromodynamics, searches for Higgs particles, searches for particles predicted by supersymmetric theories, searches for particles predicted by technicolor theories, searches for proton decay, searches for neutrino oscillations, monopole searches, studies of low transfer momentum hadron physics atmore » very high energies, and elementary particle studies using cosmic rays. Each of these subjects requires several lectures by itself to do justice to the large amount of experimental work and theoretical thought which has been devoted to these subjects. My approach in these tutorial lectures is to describe general ways to experiment beyond the standard model. I will use some of the topics listed to illustrate these general ways. Also, in these lectures I present some dreams and challenges about new techniques in experimental particle physics and accelerator technology, I call these Experimental Needs. 92 references.« less

Non-Abelian states of matter.

PubMed

Stern, Ady

2010-03-11

Quantum mechanics classifies all elementary particles as either fermions or bosons, and this classification is crucial to the understanding of a variety of physical systems, such as lasers, metals and superconductors. In certain two-dimensional systems, interactions between electrons or atoms lead to the formation of quasiparticles that break the fermion-boson dichotomy. A particularly interesting alternative is offered by 'non-Abelian' states of matter, in which the presence of quasiparticles makes the ground state degenerate, and interchanges of identical quasiparticles shift the system between different ground states. Present experimental studies attempt to identify non-Abelian states in systems that manifest the fractional quantum Hall effect. If such states can be identified, they may become useful for quantum computation.

Batch calculations in CalcHEP

NASA Astrophysics Data System (ADS)

Pukhov, A.

2003-04-01

CalcHEP is a clone of the CompHEP project which is developed by the author outside of the CompHEP group. CompHEP/CalcHEP are packages for automatic calculations of elementary particle decay and collision properties in the lowest order of perturbation theory. The main idea prescribed into the packages is to make available passing on from the Lagrangian to the final distributions effectively with a high level of automation. According to this, the packages were created as a menu driven user friendly programs for calculations in the interactive mode. From the other side, long-time calculations should be done in the non-interactive regime. Thus, from the beginning CompHEP has a problem of batch calculations. In CompHEP 33.23 the batch session was realized by mean of interactive menu which allows to the user to formulate the task for batch. After that the not-interactive session was launched. This way is too restricted, not flexible, and leads to doubling in programming. In this article I discuss another approach how one can force an interactive program to work in non-interactive mode. This approach was realized in CalcHEP 2.1 disposed on http://theory.sinp.msu.ru/~pukhov/calchep.html.

Dirac strings and magnetic monopoles in the spin ice Dy2Ti2O7.

PubMed

Morris, D J P; Tennant, D A; Grigera, S A; Klemke, B; Castelnovo, C; Moessner, R; Czternasty, C; Meissner, M; Rule, K C; Hoffmann, J-U; Kiefer, K; Gerischer, S; Slobinsky, D; Perry, R S

2009-10-16

Sources of magnetic fields-magnetic monopoles-have so far proven elusive as elementary particles. Condensed-matter physicists have recently proposed several scenarios of emergent quasiparticles resembling monopoles. A particularly simple proposition pertains to spin ice on the highly frustrated pyrochlore lattice. The spin-ice state is argued to be well described by networks of aligned dipoles resembling solenoidal tubes-classical, and observable, versions of a Dirac string. Where these tubes end, the resulting defects look like magnetic monopoles. We demonstrated, by diffuse neutron scattering, the presence of such strings in the spin ice dysprosium titanate (Dy2Ti2O7). This is achieved by applying a symmetry-breaking magnetic field with which we can manipulate the density and orientation of the strings. In turn, heat capacity is described by a gas of magnetic monopoles interacting via a magnetic Coulomb interaction.

Principals' Opinions of Organisational Justice in Elementary Schools in Turkey

ERIC Educational Resources Information Center

Aydin, Inayet; Karaman-Kepenekci, Yasemin

2008-01-01

Purpose--This study aims to present the opinions of public elementary school principals in Turkey about the current organisational justice practices among teachers from the distributive, procedural, interactional, and rectificatory dimensions. Design/methodology/approach--The opinions of 11 public elementary school principals in Ankara about…

Evolutionary games with coordination and self-dependent interactions

NASA Astrophysics Data System (ADS)

Király, Balázs; Szabó, György

2017-01-01

Multistrategy evolutionary games are studied on a square lattice when the pair interactions are composed of coordinations between strategy pairs and an additional term with self-dependent payoff. We describe a method for determining the strength of each elementary coordination component in n -strategy potential games. Using analytical and numerical methods, the presence and absence of Ising-type order-disorder phase transitions are studied when a single pair coordination is extended by some types of self-dependent elementary games. We also introduce noise-dependent three-strategy equivalents of the n -strategy elementary coordination games.

Identification of Parent-Child Interaction Characteristics of High and Low Achieving Elementary Students.

ERIC Educational Resources Information Center

Portes, Pedro R.; And Others

The present study was designed to identify parent-child interaction patterns that might differentiate bright from below average elementary students in order to test the hypothesis that environmental processes related to regulation of executive processes influence both children's learning and developmental level. Thirty-two mother-child dyads (16…

Children, Technology, and Instruction: A Case Study of Elementary School Children Using an Online Public Access Catalog (OPAC).

ERIC Educational Resources Information Center

Solomon, Paul

1994-01-01

Examines elementary school students' use of an online public access catalog to investigate the interaction between children, technology, curriculum, instruction, and learning. Highlights include patterns of successes and breakdowns; search strategies; instructional approaches and childrens' interests; structure of interaction; search terms; and…

Temperament Clusters and Individual Differences in the Elementary Classroom: A Summary.

ERIC Educational Resources Information Center

Barclay, James R.

This study examines the interaction of individual differences in pupils' temperament and ability with variations in educational strategies used in elementary school classrooms. This interaction was analyzed by re-examining the data from 2 previous studies of the effects of various educational strategies on social and academic behavior problems.…

A grand unified model for liganded gold clusters

NASA Astrophysics Data System (ADS)

Xu, Wen Wu; Zhu, Beien; Zeng, Xiao Cheng; Gao, Yi

2016-12-01

A grand unified model (GUM) is developed to achieve fundamental understanding of rich structures of all 71 liganded gold clusters reported to date. Inspired by the quark model by which composite particles (for example, protons and neutrons) are formed by combining three quarks (or flavours), here gold atoms are assigned three `flavours' (namely, bottom, middle and top) to represent three possible valence states. The `composite particles' in GUM are categorized into two groups: variants of triangular elementary block Au3(2e) and tetrahedral elementary block Au4(2e), all satisfying the duet rule (2e) of the valence shell, akin to the octet rule in general chemistry. The elementary blocks, when packed together, form the cores of liganded gold clusters. With the GUM, structures of 71 liganded gold clusters and their growth mechanism can be deciphered altogether. Although GUM is a predictive heuristic and may not be necessarily reflective of the actual electronic structure, several highly stable liganded gold clusters are predicted, thereby offering GUM-guided synthesis of liganded gold clusters by design.

Search for electroweak single top-quark production with the CDF II experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richter, Svenja

2007-11-02

Understanding the world -- This aim drives humankind since the beginning of conscious thinking. Especially the nature of matter has been of major interest. Nowadays, we have a complex image of the constitution of matter. Atoms consist of electrons and nucleons. But even nucleons are not elementary. Their basic constituents are called quarks. Physicists developed a model describing the elementary components of matter as well as the forces between them: the standard model of elementary particle physics. The substructure of matter is only visible in scattering experiments. In high energy physics, these experiments are done at particle accelerators. The world'smore » highest energetic collider, the Tevatron, is hosted by the Fermi National Accelerator Laboratory (FNAL), also called Fermilab, in the vicinity of Chicago. The proton-antiproton collisions with a center-of-mass energy of {radical}s = 1.96 TeV are recorded by two multipurpose detectors, namely D0 and CDF II.« less

National Science Resources Center Project to Improve Science Teaching in Elementary Schools. Appendix C. Elementary Science Information Database

DTIC Science & Technology

1988-12-01

individual particles. They mix the powders with water and perform tests with heat, iodine, and vinegar in order to gain additional information about the...illusions ; light ; fermentation ; chromatography ; moon ; astronomy AN SCIENCE - A PROCESS APPROACH, PART G focuses on experimentation, incorporating all...skills ; flowers plants astronomy ; animals ; sensory perception ; vision ; optical illusions ; eyes ; density ; viscosity ; fermentation ; moon

Relative locality and the soccer ball problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amelino-Camelia, Giovanni; Freidel, Laurent; Smolin, Lee

We consider the behavior of macroscopic bodies within the framework of relative locality [G. Amelino-Camelia, L. Freidel, J. Kowalski-Glikman, and L. Smolin, arXiv:1101.0931]. This is a recent proposal for Planck scale modifications of the relativistic dynamics of particles which are described as arising from deformations in the geometry of momentum space. We consider and resolve a common objection against such proposals, which is that, even if the corrections are small for elementary particles in current experiments, they are huge when applied to composite systems such as soccer balls, planets, and stars, with energies E{sub macro} much larger than M{sub P}.more » We show that this soccer ball problem does not arise within the framework of relative locality because the nonlinear effects for the dynamics of a composite system with N elementary particles appear at most of order E{sub macro}/N{center_dot}M{sub P}.« less

GEM Detector Performance Assessment in the BM@N Experiment

NASA Astrophysics Data System (ADS)

Kapishin, Mikhail; Karjavin, Vladimir; Kulish, Elena; Lenivenko, Vasilisa; Makankin, Alexander; Maksymchuk, Anna; Palichik, Vladimir; Vasiliev, Sergey

2018-02-01

The Gas Electron Multiplier (GEM) chambers are developed for modern purposes in the elementary particle physics. In the BM@N experiment, a GEM system is used for the reconstruction of the trajectories of the charged particles. The investigation of GEM performance (efficiency and spatial resolution) is presented.

Exciton-exciton scattering: Composite boson versus elementary boson

NASA Astrophysics Data System (ADS)

Combescot, M.; Betbeder-Matibet, O.; Combescot, R.

2007-05-01

This paper shows the necessity of introducing a quantum object, the “coboson,” to properly describe, through a fermion scheme, any composite particle, such as the exciton, which is made of two fermions. Although commonly dealt with as elementary bosons, these composite bosons—cobosons in short—differ from them due to their composite nature which makes the handling of their many-body effects quite different from the existing treatments valid for elementary bosons. As a direct consequence of this composite nature, there is no correct way to describe the interaction between cobosons as a potential V . This is rather dramatic because, with the Hamiltonian not written as H=H0+V , all the usual approaches to many-body effects fail. In particular, the standard form of the Fermi golden rule, written in terms of V , cannot be used to obtain the transition rates of two cobosons. To get them, we have had to construct an unconventional expression for this Fermi golden rule in which H only appears. Making use of this expression, we give here a detailed calculation of the time evolution of two excitons. We compare the results of this exact approach with the ones obtained by using an effective bosonic Hamiltonian in which the excitons are considered as elementary bosons with effective scatterings between them, these scatterings resulting from an elaborate mapping between the two-fermion space and the ideal boson space. We show that the relation between the inverse lifetime and the sum of the transition rates for elementary bosons differs from the one of the composite bosons by a factor of 1/2 , so that it is impossible to find effective scatterings between bosonic excitons giving these two physical quantities correctly, whatever the mapping from composite bosons to elementary bosons is. The present paper thus constitutes a strong mathematical proof that, in spite of a widely spread belief, we cannot forget the composite nature of these cobosons, even in the extremely low-density limit of just two excitons. This paper also shows the (unexpected) cancellation in the Born approximation of the two-exciton transition rate for a finite value of the momentum transfer.

Theoretical & Experimental Research in Weak, Electromagnetic & Strong Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nandi, Satyanarayan; Babu, Kaladi; Rizatdinova, Flera

The conducted research spans a wide range of topics in the theoretical, experimental and phenomenological aspects of elementary particle interactions. Theory projects involve topics in both the energy frontier and the intensity frontier. The experimental research involves energy frontier with the ATLAS Collaboration at the Large Hadron Collider (LHC). In theoretical research, novel ideas going beyond the Standard Model with strong theoretical motivations were proposed, and their experimental tests at the LHC and forthcoming neutrino facilities were outlined. These efforts fall into the following broad categories: (i) TeV scale new physics models for LHC Run 2, including left-right symmetry andmore » trinification symmetry, (ii) unification of elementary particles and forces, including the unification of gauge and Yukawa interactions, (iii) supersummetry and mechanisms of supersymmetry breaking, (iv) superworld without supersymmetry, (v) general models of extra dimensions, (vi) comparing signals of extra dimensions with those of supersymmetry, (vii) models with mirror quarks and mirror leptons at the TeV scale, (viii) models with singlet quarks and singlet Higgs and their implications for Higgs physics at the LHC, (ix) new models for the dark matter of the universe, (x) lepton flavor violation in Higgs decays, (xi) leptogenesis in radiative models of neutrino masses, (xii) light mediator models of non-standard neutrino interactions, (xiii) anomalous muon decay and short baseline neutrino anomalies, (xiv) baryogenesis linked to nucleon decay, and (xv) a new model for recently observed diboson resonance at the LHC and its other phenomenological implications. The experimental High Energy Physics group has been, and continues to be, a successful and productive contributor to the ATLAS experiment at the LHC. Members of the group performed search for gluinos decaying to stop and top quarks, new heavy gauge bosons decaying to top and bottom quarks, and vector-like quarks produced in pairs and decaying to light quarks. Members of the OSU group played a leading role in the detailed optimization studies for the future ATLAS Inner Tracker (ITk), which will be installed during the Phase-II upgrade, replacing the current tracking system. The proposed studies aim to enhance the ATLAS discovery potential in the high-luminosity LHC era. The group members have contributed to the calibration of algorithms for identifying boosted vector bosons and b-jets, which will help expand the ATLAS reach in many searches for new physics.« less

The LHCf experiment at the LHC: Physics Goals and Status

NASA Astrophysics Data System (ADS)

Tricomi, A.; Adriani, O.; Bonechi, L.; Bongi, M.; Castellini, G.; D'Alessandro, R.; Faus, A.; Fukui, K.; Haguenauer, M.; Itow, Y.; Kasahara, K.; Macina, D.; Mase, T.; Masuda, K.; Matsubara, Y.; Menjo, H.; Mizuishi, M.; Muraki, Y.; Papini, P.; Perrot, A. L.; Ricciarini, S.; Sako, T.; Shimizu, Y.; Taki, K.; Tamura, T.; Torii, S.; Turner, W. C.; Velasco, J.; Viciani, A.; Yoshida, K.

2009-12-01

The LHCf experiment is the smallest of the six experiments installed at the Large Hadron Collider (LHC). While the general purpose detectors have been mainly designed to answer the open questions of Elementary Particle Physics, LHCf has been designed as a fully devoted Astroparticle experiment at the LHC. Indeed, thanks to the excellent performances of its double arm calorimeters, LHCf will be able to measure the flux of neutral particles produced in p-p collisions at LHC in the very forward region, thus providing an invaluable help in the calibration of air-shower Monte Carlo codes currently used for modeling cosmic rays interactions in the Earth atmosphere. Depending on the LHC machine schedule, LHCf will take data in an energy range from 900 GeV up to 14 TeV in the centre of mass system (equivalent to 10 eV in the laboratory frame), thus covering one of the most interesting and debated region of the Cosmic Ray spectrum, the region around and beyond the "knee".

Search for an Electric Dipole Moment (EDM) of 199Hg

NASA Astrophysics Data System (ADS)

Heckel, Blayne

2017-04-01

The observation of a non-zero EDM of an atom or elementary particle, at current levels of experimental sensitivity, would imply CP violation beyond the CKM matrix of the standard model of particle physics. Additional sources of CP violation have been proposed to help explain the excess of matter over anti-matter in our universe and the magnitude of ΘQCD, the strength of CP violation in the strong interaction, remains unknown. We have recently completed a set of measurements on the EDM of 199Hg, sensitive to both new sources of CP violation and ΘQCD. The experiment compares the phase accumulated by precessing Hg spins in vapor cells with electric fields parallel and anti-parallel to a common magnetic field. Our new result represents a factor of 5 improvement over previous results. A description of the EDM experiment, data, systematic error considerations will be presented. This work was supported by NSF Grant No. 1306743 and by the DOE Office of Nuclear Physics under Award No. DE-FG02-97ER41020.

All-optical observation and reconstruction of spin wave dispersion

PubMed Central

Hashimoto, Yusuke; Daimon, Shunsuke; Iguchi, Ryo; Oikawa, Yasuyuki; Shen, Ka; Sato, Koji; Bossini, Davide; Tabuchi, Yutaka; Satoh, Takuya; Hillebrands, Burkard; Bauer, Gerrit E. W.; Johansen, Tom H.; Kirilyuk, Andrei; Rasing, Theo; Saitoh, Eiji

2017-01-01

To know the properties of a particle or a wave, one should measure how its energy changes with its momentum. The relation between them is called the dispersion relation, which encodes essential information of the kinetics. In a magnet, the wave motion of atomic spins serves as an elementary excitation, called a spin wave, and behaves like a fictitious particle. Although the dispersion relation of spin waves governs many of the magnetic properties, observation of their entire dispersion is one of the challenges today. Spin waves whose dispersion is dominated by magnetostatic interaction are called pure-magnetostatic waves, which are still missing despite of their practical importance. Here, we report observation of the band dispersion relation of pure-magnetostatic waves by developing a table-top all-optical spectroscopy named spin-wave tomography. The result unmasks characteristics of pure-magnetostatic waves. We also demonstrate time-resolved measurements, which reveal coherent energy transfer between spin waves and lattice vibrations. PMID:28604690

Private Speech in Teacher-Learner Interactions in an EFL Context: A Sociocultural Perspective

ERIC Educational Resources Information Center

Gheisari, Nouzar

2017-01-01

Theoretically framed within Vygotskyan sociocultural theory (SCT) of mind, the present study investigated resurfacing of private speech markers by Iranian elementary female EFL learners in teacher-learner interactions. To this end, an elementary EFL class including 12 female learners and a same-sex teacher were selected as the participants of the…

Development, Validation and Application of a Malay Translation of an Elementary Version of the Questionnaire on Teacher Interaction

ERIC Educational Resources Information Center

Scott, Rowena H.; Fisher, Darrell L.

2004-01-01

An elementary version of the "Questionnaire on Teacher Interaction" (QTI) and a scale for determining students' "Enjoyment of their Science Lessons" (ENJ) were translated into Standard Malay. This process, together with its initial validation carried out in 136 classrooms with 3,104 students, is described in this paper.…

TPACK in Elementary and High School Teachers' Self-Reported Classroom Practices with the Interactive Whiteboard (IWB)

ERIC Educational Resources Information Center

Lefebvre, Sonia; Samson, Ghislain; Gareau, Alexandre; Brouillette, Nancy

2016-01-01

The interactive whiteboard (IWB) is increasingly used for teaching and learning in the classroom. Nevertheless, the ways that teachers incorporate this tool within their teaching practices remain poorly understood. This paper examines elementary and high school teachers' self-reported practices with the IWB. The conceptual framework centers on…

Interactive Whiteboards Produce Small Gains in Elementary Students' Self-Reported Motivation in Mathematics

ERIC Educational Resources Information Center

Torff, Bruce; Tirotta, Rose

2010-01-01

A treatment/control study (N = 773) was conducted to determine the extent to which use of interactive whiteboard technology (IWB) was associated with upper elementary students' self-reported level of motivation in mathematics. Students in the treatment group reported higher levels of motivation relative to control students, but the effect was…

The Writing Performance of Elementary Students Receiving Strategic and Interactive Writing Instruction

ERIC Educational Resources Information Center

Wolbers, Kimberly A.; Dostal, Hannah M.; Graham, Steve; Cihak, David; Kilpatrick, Jennifer R.; Saulsburry, Rachel

2015-01-01

Strategic and Interactive Writing Instruction (SIWI) has led to improved writing and language outcomes among deaf and hard of hearing (DHH) middle grades students. The purpose of this study was to examine the effects of SIWI on the written expression of DHH elementary students across recount/personal narrative, information report, and persuasive…

Using a Humanoid Robot to Develop a Dialogue-Based Interactive Learning Environment for Elementary Foreign Language Classrooms

ERIC Educational Resources Information Center

Chang, Chih-Wei; Chen, Gwo-Dong

2010-01-01

Elementary school is the critical stage during which the development of listening comprehension and oral abilities in language acquisition occur, especially with a foreign language. However, the current foreign language instructors often adopt one-way teaching, and the learning environment lacks any interactive instructional media with which to…

Parent-Child Interaction Processes Related to Scholastic Achievement in Urban Elementary Children.

ERIC Educational Resources Information Center

Portes, Pedro R.; And Others

In an attempt to identify parent-child interaction patterns that might differentiate bright from below-average elementary students, 16 high achievers and 16 low achievers were paired with their mothers and then videotaped whilst engaged in 3 sets of task situations, which involved copying of Block Design models and categorization of words and…

Parental involvement in elementary school-aged child’s creativity

NASA Astrophysics Data System (ADS)

Suparmi; Suardiman, S. P.; Kumara, A.

2018-01-01

This study aims at describing the parental involvement in cultivating elementary school-aged child’s creativity. The qualitative research was designed with multidisciplinary study approach. Eight students and some parents from public elementary schools of Ngawen 4th of Gunungkidul, Yogyakarta, and 4 students from an elementary school in Sleman, Yogyakarta were involved in the process of collecting the data. In-depth interview, observation, and documentation were used simultaneously to collect the data. The results showed that: 1) the subject had a level of intelligence quotient; the intelligence of verbal creativity above the average level, and creative behaviour on average, 2) interaction of parents and child-related discussions, experiences, and plans, academic problems in school were needed to boost the students’ creativity, 3) interactions of parents and school-related participations in school were also encouraged to implant students’ social awareness, 4) interaction among parents communicated each other to have a better result of academic awareness, and 5) Parents should install family norms to cultivate children’s intelligence quotient.

Cortical Bases of Elementary Deductive Reasoning: Inference, Memory, and Metadeduction

ERIC Educational Resources Information Center

Reverberi, Carlo; Shallice, Tim; D'Agostini, Serena; Skrap, Miran; Bonatti, Luca L.

2009-01-01

Elementary deduction is the ability of unreflectively drawing conclusions from explicit or implicit premises, on the basis of their logical forms. This ability is involved in many aspects of human cognition and interactions. To date, limited evidence exists on its cortical bases. We propose a model of elementary deduction in which logical…

A Learning Progression for Feedback Loop Reasoning at Lower Elementary Level

ERIC Educational Resources Information Center

Hokayem, Hayat; Ma, Jingjing; Jin, Hui

2015-01-01

This study examines to what extent elementary students use feedback loop reasoning, a key component of systems thinking, to reason about interactions among organisms in ecosystems. We conducted clinical interviews with 44 elementary students (1st through 4th grades). We asked students to explain how populations change in two contexts: a…

An Observational Assessment of Physical Activity Levels and Social Behaviour during Elementary School Recess

ERIC Educational Resources Information Center

Roberts, Simon J.; Fairclough, Stuart J.; Ridgers, Nicola D.; Porteous, Conor

2013-01-01

Objective: The purpose of the present study was to assess children's physical activity, social play behaviour, activity type and social interactions during elementary school recess using a pre-validated systematic observation system. Design: Cross-sectional. Setting: Two elementary schools located in Merseyside, England. Method: Fifty-six…

Elementary process and meteor train spectra

NASA Technical Reports Server (NTRS)

Ovezgeldyev, O. G.

1987-01-01

Mechanisms of excitation of individual spectral line radiation were studied experimentally and theoretically and it was demonstrated that such processes as oxidation, resonant charge exchange, dissociative recombination and others play an important part in the chemistry of excited particles. The foundation was laid toward simulating the elementary processes of meteor physics. Having a number of advantages and possibilities, this method is sure to find a wide use in the future.

Systematics of Charged Particle Production in Heavy-Ion Collisions with the PHOBOS Detector at Rhic

NASA Astrophysics Data System (ADS)

Steinberg, Peter A.; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Corbo, J.; Decowski, M. P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Henderson, C.; Hicks, D.; Hofman, D.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A.; Mülmenstädt, J.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Rafelski, M.; Rbeiz, M.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

2002-03-01

The multiplicity of charged particles produced in Au+Au collisions as a function of energy, centrality, rapidity and azimuthal angle has been measured with the PHOBOS detector at RHIC. These results contribute to our understanding of the initial state of heavy ion collisions and provide a means to compare basic features of particle production in nuclear collisions with more elementary systems.

Dark matter reflection of particle symmetry

NASA Astrophysics Data System (ADS)

Khlopov, Maxim Yu.

2017-05-01

In the context of the relationship between physics of cosmological dark matter and symmetry of elementary particles, a wide list of dark matter candidates is possible. New symmetries provide stability of different new particles and their combination can lead to a multicomponent dark matter. The pattern of symmetry breaking involves phase transitions in the very early Universe, extending the list of candidates by topological defects and even primordial nonlinear structures.

Martinus Veltman, the Electroweak Theory, and Elementary Particle Physics

Science.gov Websites

Particle Physics Resources with Additional Information Martinus Veltman Courtesy University of Michigan Martinus J.G. Veltman, the John D. MacArthur Professor Emeritus of Physics at the University of Michigan , was awarded the 1999 Nobel Prize in physics "for elucidating the quantum structure of electroweak

Constraining in-medium nucleon-nucleon interactions via nucleus-nucleus reactions

NASA Astrophysics Data System (ADS)

Sammarruca, Francesca; White, Larz

2010-11-01

The nuclear equation of state is a broadly useful tool. Besides being the main input of stellar structure calculations, it allows a direct connection to the physics of nuclei. For instance, an energy functional (such as a mass formula), together with the energy/particle in nuclear matter, can be used to predict nuclear energies and radii [1]. The single-particle properties are also a key point to link infinite nuclear matter and actual nuclei. The parameters of the single-particle potential, in particular the effective mass, enter the calculations of, for instance, in-medium effective cross sections. From the well-known Glauber reaction theory, the total nucleus-nucleus reaction cross section is expressed in terms of the nuclear transparency, which, in turn, depends on the overlap of the nuclear density distributions and the elementary nucleon-nucleon (NN) cross sections. We explore the sensitivity of the reaction calculation to medium modifications of the NN cross sections to estimate the likelihood of constraining the latter through nuclear reactions. Ultimately, we wish to incorporate isospin asymmetry in the reaction model, having in mind connections with rare isotopes. [1] F. Sammarruca, arXiv:1002.00146 [nucl-th]; International Journal of Modern Physics, in press.

Creating the Primordial Quark-Gluon Plasma at the LHC

NASA Astrophysics Data System (ADS)

Harris, John W.

2013-04-01

Ultra-relativistic collisions of heavy ions at the Large Hadron Collider (LHC) and the Relativistic Heavy Ion Collider (RHIC) create an extremely hot system at temperatures (T) expected only within the first microseconds after the Big Bang. At these temperatures (T ˜ 2 x 10^12 K), a few hundred thousand times hotter than the sun's core, the known ``elementary'' particles cannot exist and matter ``melts'' to form a ``soup'' of quarks and gluons, called the quark-gluon plasma (QGP). This ``soup'' flows easily, with extremely low viscosity, suggesting a nearly perfect hot liquid of quarks and gluons. Furthermore, the liquid is dense, highly interacting and opaque to energetic probes (fast quarks or gluons). RHIC has been in operation for twelve years and has established an impressive set of findings. Recent results from heavy ion collisions at the LHC extend the study of the QGP to higher temperatures and harder probes, such as jets (energetic clusters of particles), particles with extremely large transverse momenta and those containing heavy quarks. I will present a motivation for physics in the field and an overview of the new LHC heavy ion results in relation to results from RHIC.

Interactional Practices Used in the Teaching of Conflict Prevention and Resolution Skills in an Innovative Safe School Program at an Elementary School

ERIC Educational Resources Information Center

Shin, Annalise Grace

2010-01-01

Within the framework of language socialization, this dissertation uses conversation analytic and ethnographic methods to examine the interactional practices used by the adult safe school educator at a progressive elementary school to socialize students into beliefs and practices associated with the school's Cool Tools Safe School Program. Cool…

Understanding an Elementary School Teachers' Journey of Using Technology in the Classroom from Sand Table to Interactive Whiteboard

ERIC Educational Resources Information Center

Ersoy, Ali; Bozkurt, Mahmut

2015-01-01

The aim of this study is to understand an elementary teachers' experiences about using interactive whiteboard (IWB) in the classroom. Narrative inquiry were adopted to conduct the study. The data were collected through semi-structured interviews with the teacher and analysed through narrative analysis. In the study, two major stories emerged. The…

Atmospheric neutrinos and discovery of neutrino oscillations

PubMed Central

Kajita, Takaaki

2010-01-01

Neutrino oscillation was discovered through studies of neutrinos produced by cosmic-ray interactions in the atmosphere. These neutrinos are called atmospheric neutrinos. They are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith-angle and energy dependent deficit of muon-neutrino events. Neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. Neutrino oscillations imply that neutrinos have small but non-zero masses. The small neutrino masses have profound implications to our understanding of elementary particle physics and the Universe. This article discusses the experimental discovery of neutrino oscillations. PMID:20431258

Kissing Brides and Loving Hot Vampires: Children's Construction and Perpetuation of Heteronormativity in Elementary School Classrooms

ERIC Educational Resources Information Center

Ryan, Caitlin L.

2016-01-01

This paper explores notions of (hetero)sexuality circulating in elementary school classrooms through an analysis of students' own talk and interactions. Data collected during a multi-site ethnography in a diverse set of elementary schools demonstrate that while curricular silences and teachers contribute to heteronormative classroom environments,…

Vehicular air pollution, playgrounds, and youth athletic fields.

PubMed

Rundell, Kenneth W; Caviston, Renee; Hollenbach, Amanda M; Murphy, Kerri

2006-07-01

In spite of epidemiological evidence concerning vehicular air pollution and adverse respiratory/cardiovascular health, many athletic fields and school playgrounds are adjacent to high traffic roadways and could present long-term health risks for exercising children and young adults. Particulate matter (PM(1),0.02-1.0 microm diameter) number counts were taken serially at four elementary school athletic/playground fields and at one university soccer field. Elementary school PM1 measurements were taken over 17 days; measurements at the university soccer field were taken over 62 days. The high-traffic-location elementary school field demonstrated higher 17-day [PM1] than the moderate and 2 low traffic elementary school fields (48,890 +/- 34,260, 16,730 +/- 10,550, 11,960 +/- 6680, 10,030 +/- 6280, respective mean counts; p < .05). The 62-day mean PM1 values at the university soccer field ranged from 115,000 to 134,000 particles cm(-3). Lowest mean values were recorded at measurement sites furthest from the highway (approximately 34,000 particles cm(-3)) and followed a second-order logarithmic decay (R2 = .999) with distance away from the highway. Mean NO2 and SO2 levels were below 100 ppb, mean CO was 0.33 +/- 1.87 ppm, and mean O3 was 106 +/- 47 ppb. Ozone increased with rising temperature and was highest in the warmer afternoon hours (R = .61). Although the consequence of daily recess play and athletic activities by school children and young athletes in high ambient [PM1] conditions has not yet been clearly defined, this study is a critical component to evaluating functional effects of chronic combustion-derived PM exposure on these exercising schoolchildren and young adults. Future studies should examine threshold limits and mechanistic actions of real-world particle exposure.

Spark and HPC for High Energy Physics Data Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sehrish, Saba; Kowalkowski, Jim; Paterno, Marc

A full High Energy Physics (HEP) data analysis is divided into multiple data reduction phases. Processing within these phases is extremely time consuming, therefore intermediate results are stored in files held in mass storage systems and referenced as part of large datasets. This processing model limits what can be done with interactive data analytics. Growth in size and complexity of experimental datasets, along with emerging big data tools are beginning to cause changes to the traditional ways of doing data analyses. Use of big data tools for HEP analysis looks promising, mainly because extremely large HEP datasets can be representedmore » and held in memory across a system, and accessed interactively by encoding an analysis using highlevel programming abstractions. The mainstream tools, however, are not designed for scientific computing or for exploiting the available HPC platform features. We use an example from the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) in Geneva, Switzerland. The LHC is the highest energy particle collider in the world. Our use case focuses on searching for new types of elementary particles explaining Dark Matter in the universe. We use HDF5 as our input data format, and Spark to implement the use case. We show the benefits and limitations of using Spark with HDF5 on Edison at NERSC.« less

Open problems in active chaotic flows: Competition between chaos and order in granular materials.

PubMed

Ottino, J. M.; Khakhar, D. V.

2002-06-01

There are many systems where interaction among the elementary building blocks-no matter how well understood-does not even give a glimpse of the behavior of the global system itself. Characteristic for these systems is the ability to display structure without any external organizing principle being applied. They self-organize as a consequence of synthesis and collective phenomena and the behavior cannot be understood in terms of the systems' constitutive elements alone. A simple example is flowing granular materials, i.e., systems composed of particles or grains. How the grains interact with each other is reasonably well understood; as to how particles move, the governing law is Newton's second law. There are no surprises at this level. However, when the particles are many and the material is vibrated or tumbled, surprising behavior emerges. Systems self-organize in complex patterns that cannot be deduced from the behavior of the particles alone. Self-organization is often the result of competing effects; flowing granular matter displays both mixing and segregation. Small differences in either size or density lead to flow-induced segregation and order; similar to fluids, noncohesive granular materials can display chaotic mixing and disorder. Competition gives rise to a wealth of experimental outcomes. Equilibrium structures, obtained experimentally in quasi-two-dimensional systems, display organization in the presence of disorder, and are captured by a continuum flow model incorporating collisional diffusion and density-driven segregation. Several open issues remain to be addressed. These include analysis of segregating chaotic systems from a dynamical systems viewpoint, and understanding three-dimensional systems and wet granular systems (slurries). General aspects of the competition between chaos-enhanced mixing and properties-induced de-mixing go beyond granular materials and may offer a paradigm for other kinds of physical systems. (c) 2002 American Institute of Physics.

Unitarity limits on the mass and radius of dark matter particles

NASA Technical Reports Server (NTRS)

Griest, Kim; Kamionkowski, Marc

1989-01-01

Using partial wave unitarity and the observed density of the Universe, it is show that a stable elementary particle which was once in thermal equilibrium cannot have a mass greater than 340 TeV. An extended object which was once in thermal equilibrium cannot have a radius less than 7.5 x 10(exp -7) fm. A lower limit to the relic abundance of such particles is also found.

Quasiparticle breakdown in a quantum spin liquid.

PubMed

Stone, Matthew B; Zaliznyak, Igor A; Hong, Tao; Broholm, Collin L; Reich, Daniel H

2006-03-09

Much of modern condensed matter physics is understood in terms of elementary excitations, or quasiparticles--fundamental quanta of energy and momentum. Various strongly interacting atomic systems are successfully treated as a collection of quasiparticles with weak or no interactions. However, there are interesting limitations to this description: in some systems the very existence of quasiparticles cannot be taken for granted. Like unstable elementary particles, quasiparticles cannot survive beyond a threshold where certain decay channels become allowed by conservation laws; their spectrum terminates at this threshold. Such quasiparticle breakdown was first predicted for an exotic state of matter--super-fluid 4He at temperatures close to absolute zero, a quantum Bose liquid where zero-point atomic motion precludes crystallization. Here we show, using neutron scattering, that quasiparticle breakdown can also occur in a quantum magnet and, by implication, in other systems with Bose quasiparticles. We have measured spin excitations in a two-dimensional quantum magnet, piperazinium hexachlorodicuprate (PHCC), in which spin-1/2 copper ions form a non-magnetic quantum spin liquid, and find remarkable similarities with excitations in superfluid 4He. We observe a threshold momentum beyond which the quasiparticle peak merges with the two-quasiparticle continuum. It then acquires a finite energy width and becomes indistinguishable from a leading-edge singularity, so that excited states are no longer quasiparticles but occupy a wide band of energy. Our findings have important ramifications for understanding excitations with gapped spectra in many condensed matter systems, ranging from band insulators to high-transition-temperature superconductors.

A grand unified model for liganded gold clusters

PubMed Central

Xu, Wen Wu; Zhu, Beien; Zeng, Xiao Cheng; Gao, Yi

2016-01-01

A grand unified model (GUM) is developed to achieve fundamental understanding of rich structures of all 71 liganded gold clusters reported to date. Inspired by the quark model by which composite particles (for example, protons and neutrons) are formed by combining three quarks (or flavours), here gold atoms are assigned three ‘flavours' (namely, bottom, middle and top) to represent three possible valence states. The ‘composite particles' in GUM are categorized into two groups: variants of triangular elementary block Au3(2e) and tetrahedral elementary block Au4(2e), all satisfying the duet rule (2e) of the valence shell, akin to the octet rule in general chemistry. The elementary blocks, when packed together, form the cores of liganded gold clusters. With the GUM, structures of 71 liganded gold clusters and their growth mechanism can be deciphered altogether. Although GUM is a predictive heuristic and may not be necessarily reflective of the actual electronic structure, several highly stable liganded gold clusters are predicted, thereby offering GUM-guided synthesis of liganded gold clusters by design. PMID:27910848

Interaction of intense ultrashort pulse lasers with clusters.

NASA Astrophysics Data System (ADS)

Petrov, George

2007-11-01

The last ten years have witnessed an explosion of activity involving the interaction of clusters with intense ultrashort pulse lasers. Atomic or molecular clusters are targets with unique properties, as they are halfway between solid and gases. The intense laser radiation creates hot dense plasma, which can provide a compact source of x-rays and energetic particles. The focus of this investigation is to understand the salient features of energy absorption and Coulomb explosion by clusters. The evolution of clusters is modeled with a relativistic time-dependent 3D Molecular Dynamics (MD) model [1]. The Coulomb interaction between particles is handled by a fast tree algorithm, which allows large number of particles to be used in simulations [2]. The time histories of all particles in a cluster are followed in time and space. The model accounts for ionization-ignition effects (enhancement of the laser field in the vicinity of ions) and a variety of elementary processes for free electrons and charged ions, such as optical field and collisional ionization, outer ionization and electron recapture. The MD model was applied to study small clusters (1-20 nm) irradiated by a high-intensity (10^16-10^20 W/cm^2) sub-picosecond laser pulse. We studied fundamental cluster features such as energy absorption, x-ray emission, particle distribution, average charge per atom, and cluster explosion as a function of initial cluster radius, laser peak intensity and wavelength. Simulations of novel applications, such as table-top nuclear fusion from exploding deuterium clusters [3] and high power synchrotron radiation for biological applications and imaging [4] have been performed. The application for nuclear fusion was motivated by the efficient absorption of laser energy (˜100%) and its high conversion efficiency into ion kinetic energy (˜50%), resulting in neutron yield of 10^6 neutrons/Joule laser energy. Contributors: J. Davis and A. L. Velikovich. [1] G. M. Petrov, et al Phys. Plasmas 12 063103 (2005); 13 033106 (2006) [2] G. M. Petrov, J. Davis, European Phys. J. D 41 629 (2007) [3] G. M. Petrov, J. Davis, A. L. Velikovich, Plasma Phys. Contr. Fusion 48 1721 (2006) [4] G. M. Petrov, J. Davis, A. L. Velikovich, J. Phys. B 39 4617 (2006)

Strong dynamics and lattice gauge theory

NASA Astrophysics Data System (ADS)

Schaich, David

In this dissertation I use lattice gauge theory to study models of electroweak symmetry breaking that involve new strong dynamics. Electroweak symmetry breaking (EWSB) is the process by which elementary particles acquire mass. First proposed in the 1960s, this process has been clearly established by experiments, and can now be considered a law of nature. However, the physics underlying EWSB is still unknown, and understanding it remains a central challenge in particle physics today. A natural possibility is that EWSB is driven by the dynamics of some new, strongly-interacting force. Strong interactions invalidate the standard analytical approach of perturbation theory, making these models difficult to study. Lattice gauge theory is the premier method for obtaining quantitatively-reliable, nonperturbative predictions from strongly-interacting theories. In this approach, we replace spacetime by a regular, finite grid of discrete sites connected by links. The fields and interactions described by the theory are likewise discretized, and defined on the lattice so that we recover the original theory in continuous spacetime on an infinitely large lattice with sites infinitesimally close together. The finite number of degrees of freedom in the discretized system lets us simulate the lattice theory using high-performance computing. Lattice gauge theory has long been applied to quantum chromodynamics, the theory of strong nuclear interactions. Using lattice gauge theory to study dynamical EWSB, as I do in this dissertation, is a new and exciting application of these methods. Of particular interest is non-perturbative lattice calculation of the electroweak S parameter. Experimentally S ≈ -0.15(10), which tightly constrains dynamical EWSB. On the lattice, I extract S from the momentum-dependence of vector and axial-vector current correlators. I created and applied computer programs to calculate these correlators and analyze them to determine S. I also calculated the masses and other properties of the new particles predicted by these theories. I find S ≳ 0.1 in the specific theories I study. Although this result still disagrees with experiment, it is much closer to the experimental value than is the conventional wisdom S ≳ 0.3. These results encourage further lattice studies to search for experimentally viable strongly-interacting theories of EWSB.

Interactive Videoconferencing for Collaborative Learning at a Distance in the School of 21st Century: A Case Study in Elementary Schools in Greece

ERIC Educational Resources Information Center

Anastasiades, Panagiotes S.; Filippousis, George; Karvunis, Labros; Siakas, Spiros; Tomazinakis, Arsitokritos; Giza, Panagiota; Mastoraki, Hellen

2010-01-01

The aim of this paper is to present the design, implementation and evaluation of the methodology which focuses on the pedagogical utilization of Interactive Videoconferencing (IVC) in the contemporary elementary school. As part of the project "ODYSSEAS", during the school year 2007-2008, 46 students and 4 teachers from two elementary…

Instructional Design Using an In-House Built Teaching Assistant Robot to Enhance Elementary School English-as-a-Foreign-Language Learning

ERIC Educational Resources Information Center

Wu, Wen-Chi Vivian; Wang, Rong-Jyue; Chen, Nian-Shing

2015-01-01

This paper presents a design for a cutting-edge English program in which elementary school learners of English as a foreign language in Taiwan had lively interactions with a teaching assistant robot. Three dimensions involved in the design included (1) a pleasant and interactive classroom environment as the learning context, (2) a teaching…

Language Use in Real-time Interactions during Early Elementary Science Lessons: The Bidirectional Dynamics of the Language Complexity of Teachers and Students

ERIC Educational Resources Information Center

Menninga, Astrid; van Dijk, Marijn; Steenbeek, Henderien; van Geert, Paul

2017-01-01

This study used a dynamic approach to explore bidirectional sequential relations between the real-time language use of teachers and students in naturalistic early elementary science lessons. It also compared experienced teachers (n = 22) with novice teachers (n = 8) with respect to such relations. Verbal interactions were transcribed and coded at…

The Return of the Black Box

ERIC Educational Resources Information Center

Yayon, Malka; Scherz, Zahava

2008-01-01

"If protons, quarks, and other elementary particles are too small to be seen, how do scientists know they exist? And if these particles do exist, how can one estimate their size, structure, and or their arrangement in atoms?" These are some of the most frequently asked questions by students who study atomic theory. Atomic structure is an important…

Energy levels for Ac-212 (Actinium-212)

NASA Astrophysics Data System (ADS)

Sukhoruchkin, S. I.; Soroko, Z. N.

This document is part of Subvolume C `Tables of Excitations of Proton- and Neutron-rich Unstable Nuclei' of Volume 19 `Nuclear States from Charged Particle Reactions' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides energy levels for atomic nuclei of the isotope Ac-212 (actinium, atomic number Z = 89, mass number A = 212).

Unity of elementary particles and forces in higher dimensions.

PubMed

Gogoladze, Ilia; Mimura, Yukihiro; Nandi, S

2003-10-03

The idea of unifying all the gauge and Yukawa forces as well as the gauge, Higgs, and fermionic matter particles naturally leads us to a simple gauge symmetry in higher dimensions with supersymmetry. We present a model in which, for the first time, such a unification is achieved in the framework of quantum field theory.

Donald Glaser, the Bubble Chamber, and Elementary Particles

Science.gov Websites

Effects of Ionizing Radiation on the Formation of Bubbles in Liquids Physical Review, Vol. 87, Issue 4 , 665, August 15, 1952 Characteristics of Bubble Chambers Physical Review, Vol. 97, Issue 2, 474-479 Chambers Physical Review, Vol. 102, Issue 6, 1653-1658, June 15, 1956 Methods of Particle Detection for

The Million-Body Problem: Particle Simulations in Astrophysics

ScienceCinema

Rasio, Fred

2018-05-21

Computer simulations using particles play a key role in astrophysics. They are widely used to study problems across the entire range of astrophysical scales, from the dynamics of stars, gaseous nebulae, and galaxies, to the formation of the largest-scale structures in the universe. The 'particles' can be anything from elementary particles to macroscopic fluid elements, entire stars, or even entire galaxies. Using particle simulations as a common thread, this talk will present an overview of computational astrophysics research currently done in our theory group at Northwestern. Topics will include stellar collisions and the gravothermal catastrophe in dense star clusters.

Clustering of low-valence particles: structure and kinetics.

PubMed

Markova, Olga; Alberts, Jonathan; Munro, Edwin; Lenne, Pierre-François

2014-08-01

We compute the structure and kinetics of two systems of low-valence particles with three or six freely oriented bonds in two dimensions. The structure of clusters formed by trivalent particles is complex with loops and holes, while hexavalent particles self-organize into regular and compact structures. We identify the elementary structures which compose the clusters of trivalent particles. At initial stages of clustering, the clusters of trivalent particles grow with a power-law time dependence. Yet at longer times fusion and fission of clusters equilibrates and clusters form a heterogeneous phase with polydispersed sizes. These results emphasize the role of valence in the kinetics and stability of finite-size clusters.

Phase transition of light in cavity QED lattices.

PubMed

Schiró, M; Bordyuh, M; Oztop, B; Türeci, H E

2012-08-03

Systems of strongly interacting atoms and photons, which can be realized wiring up individual cavity QED systems into lattices, are perceived as a new platform for quantum simulation. While sharing important properties with other systems of interacting quantum particles, here we argue that the nature of light-matter interaction gives rise to unique features with no analogs in condensed matter or atomic physics setups. By discussing the physics of a lattice model of delocalized photons coupled locally with two-level systems through the elementary light-matter interaction described by the Rabi model, we argue that the inclusion of counterrotating terms, so far neglected, is crucial to stabilize finite-density quantum phases of correlated photons out of the vacuum, with no need for an artificially engineered chemical potential. We show that the competition between photon delocalization and Rabi nonlinearity drives the system across a novel Z(2) parity symmetry-breaking quantum criticality between two gapped phases that share similarities with the Dicke transition of quantum optics and the Ising critical point of quantum magnetism. We discuss the phase diagram as well as the low-energy excitation spectrum and present analytic estimates for critical quantities.

Lie, Santilli, and nanotechnology: From the elementary particles to the periodic table of the elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trell, Erik, E-mail: erik.trell@gmail.com

2014-12-10

Santilli’s revolutionary iso-, geno- and hypermathematics have provided the original straight line Lie groups and algebras with a span and coherence in all dimensions, and thus already at the infinitesimal level an extension in the Cartesian sense, allowing a continuous self-similar cyclical realization of matter from the elementary particle threshold level via the atomic to molecular and visible scale where it meets and marries with modern nanotechnology in the form of an isotropic vector matrix of space-filling octahedron-tetrahedron composition. This is distributed as an electron transition matrix with Bohr shell model stratified signature and is here directly outlining a new,more » centrally coordinated organic composition and chart of the periodic system as specifically exemplified by the noble gases.« less

Electroscavenging and Inferred Effects on Precipitation Efficiency

NASA Astrophysics Data System (ADS)

Tinsley, B. A.

2002-12-01

The evaporation of charged droplets leaves charged aerosol particles that can act as cloud condensation nuclei and ice forming nuclei. New calculations of scavenging of such charged particles by droplets have been made, that now include the effects of inertia and variable particle density, and variable cloud altitudes ranging into the stratosphere. They show that the Greenfield Gap closes for particles of low density, or for high altitude clouds, or for a few hundred elementary charges on the particles. A few tens of elementary charges on the particles gives collision efficiencies typically an order of magnitude greater than that due to phoretic forces alone. The numerical integrations show that electroscavenging of ice forming nuclei leading to contact ice nucleation is competitive with deposition ice nucleation, for cloud top temperatures in the range 0§C to -15§C and droplet size distributions extending past 10-15 mm radius. This implies that for marine stratocumulus or nimbostratus clouds with tops just below freezing temperature, where precipitation is initiated by the Wegener-Bergeron-Findeisen process, the precipitation efficiency can be affected by the amount of charge on the ice-forming nuclei. This in turn depends on the extent of the (weak) electrification of the cloud. Similarly, electroscavenging of condensation nuclei can increase the average droplet size in successive cycles of cloud evaporation and formation, and can also affect precipitation efficiency.

From the necessary to the possible: the genesis of the spin-statistics theorem

NASA Astrophysics Data System (ADS)

Blum, Alexander

2014-12-01

The spin-statistics theorem, which relates the intrinsic angular momentum of a single particle to the type of quantum statistics obeyed by a system of many such particles, is one of the central theorems in quantum field theory and the physics of elementary particles. It was first formulated in 1939/40 by Wolfgang Pauli and his assistant Markus Fierz. This paper discusses the developments that led up to this first formulation, starting from early attempts in the late 1920s to explain why charged matter particles obey Fermi-Dirac statistics, while photons obey Bose-Einstein statistics. It is demonstrated how several important developments paved the way from such general philosophical musings to a general (and provable) theorem, most notably the use of quantum field theory, the discovery of new elementary particles, and the generalization of the notion of spin. It is also discussed how the attempts to prove a spin-statistics connection were driven by Pauli from formal to more physical arguments, culminating in Pauli's 1940 proof. This proof was a major success for the beleaguered theory of quantum field theory and the methods Pauli employed proved essential for the renaissance of quantum field theory and the development of renormalization techniques in the late 1940s.

Equivalence principle for quantum systems: dephasing and phase shift of free-falling particles

NASA Astrophysics Data System (ADS)

Anastopoulos, C.; Hu, B. L.

2018-02-01

We ask the question of how the (weak) equivalence principle established in classical gravitational physics should be reformulated and interpreted for massive quantum objects that may also have internal degrees of freedom (dof). This inquiry is necessary because even elementary concepts like a classical trajectory are not well defined in quantum physics—trajectories originating from quantum histories become viable entities only under stringent decoherence conditions. From this investigation we posit two logically and operationally distinct statements of the equivalence principle for quantum systems. Version A: the probability distribution of position for a free-falling particle is the same as the probability distribution of a free particle, modulo a mass-independent shift of its mean. Version B: any two particles with the same velocity wave-function behave identically in free fall, irrespective of their masses. Both statements apply to all quantum states, including those without a classical correspondence, and also for composite particles with quantum internal dof. We also investigate the consequences of the interaction between internal and external dof induced by free fall. For a class of initial states, we find dephasing occurs for the translational dof, namely, the suppression of the off-diagonal terms of the density matrix, in the position basis. We also find a gravitational phase shift in the reduced density matrix of the internal dof that does not depend on the particle’s mass. For classical states, the phase shift has a natural classical interpretation in terms of gravitational red-shift and special relativistic time-dilation.

"Technically, I'm the One Who Came up with the Group": The Development of a Classroom Culture of Reading and Writing in an Elementary Classroom

ERIC Educational Resources Information Center

Ramirez-DelToro, Ginny

2017-01-01

This dissertation reports on how features of interactions and instruction contributed to an elementary classroom culture of reading and writing that students and their teacher worked together to develop. Positioning theory informed analysis of participants' interactions as they used texts in social and academic ways. The theory of figured worlds…

An Investigation of the Potential of Interactive Simulations for Developing System Thinking Skills in Elementary School: A Case Study with Fifth-Graders and Sixth-Graders

ERIC Educational Resources Information Center

Evagorou, Maria; Korfiatis, Kostas; Nicolaou, Christiana; Constantinou, Costas

2009-01-01

The purpose of this study was to investigate the impact of a simulation-based learning environment on elementary school students' (11-12 years old) development of system thinking skills. The learning environment included interactive simulations using the Stagecast Creator software to simulate the ecosystem of a marsh. Simulations are an important…

Hurwitz Algebras and the Octonion Algebra

NASA Astrophysics Data System (ADS)

Burdik, Čestmir; Catto, Sultan

2018-02-01

We explore some consequences of a theory of internal symmetries for elementary particles constructed on exceptional quantum mechanical spaces based on Jordan algebra formulation that admit exceptional groups as gauge groups.

homepage of A Ismail

Science.gov Websites

@anl.gov Ahmed Ismail Research Associate at the ANL High Energy Physics Theory Group and UIC ELEMENTARY PARTICLE PHYSICS THEORY High Energy Phenomenology Updated October 2013 aismail@anl.gov

The role of multivalency in the association kinetics of patchy particle complexes.

PubMed

Newton, Arthur C; Groenewold, Jan; Kegel, Willem K; Bolhuis, Peter G

2017-06-21

Association and dissociation of particles are elementary steps in many natural and technological relevant processes. For many such processes, the presence of multiple binding sites is essential. For instance, protein complexes and regular structures such as virus shells are formed from elementary building blocks with multiple binding sites. Here we address a fundamental question concerning the role of multivalency of binding sites in the association kinetics of such complexes. Using single replica transition interface sampling simulations, we investigate the influence of the multivalency on the binding kinetics and the association mechanism of patchy particles that form polyhedral clusters. When the individual bond strength is fixed, the kinetics naturally is very dependent on the multivalency, with dissociation rate constants exponentially decreasing with the number of bonds. In contrast, we find that when the total bond energy per particle is kept constant, association and dissociation rate constants turn out rather independent of multivalency, although of course still very dependent on the total energy. The association and dissociation mechanisms, however, depend on the presence and nature of the intermediate states. For instance, pathways that visit intermediate states are less prevalent for particles with five binding sites compared to the case of particles with only three bonds. The presence of intermediate states can lead to kinetic trapping and malformed aggregates. We discuss implications for natural forming complexes such as virus shells and for the design of artificial colloidal patchy particles.

The role of multivalency in the association kinetics of patchy particle complexes

NASA Astrophysics Data System (ADS)

Newton, Arthur C.; Groenewold, Jan; Kegel, Willem K.; Bolhuis, Peter G.

2017-06-01

Association and dissociation of particles are elementary steps in many natural and technological relevant processes. For many such processes, the presence of multiple binding sites is essential. For instance, protein complexes and regular structures such as virus shells are formed from elementary building blocks with multiple binding sites. Here we address a fundamental question concerning the role of multivalency of binding sites in the association kinetics of such complexes. Using single replica transition interface sampling simulations, we investigate the influence of the multivalency on the binding kinetics and the association mechanism of patchy particles that form polyhedral clusters. When the individual bond strength is fixed, the kinetics naturally is very dependent on the multivalency, with dissociation rate constants exponentially decreasing with the number of bonds. In contrast, we find that when the total bond energy per particle is kept constant, association and dissociation rate constants turn out rather independent of multivalency, although of course still very dependent on the total energy. The association and dissociation mechanisms, however, depend on the presence and nature of the intermediate states. For instance, pathways that visit intermediate states are less prevalent for particles with five binding sites compared to the case of particles with only three bonds. The presence of intermediate states can lead to kinetic trapping and malformed aggregates. We discuss implications for natural forming complexes such as virus shells and for the design of artificial colloidal patchy particles.

A Descriptive Study of Multicultural Elementary Student Playground Behaviors and Their Relationship to Gender, Age, Race and Socioeconomic Status.

ERIC Educational Resources Information Center

Dahmes, Victoria M.

This paper examines the observable play behaviors of elementary school students to determine how children interact within and among cultural groups. Observations were conducted during the recess period at an urban elementary school attended by 623 boys and girls age 6 through 12. Recess periods and play areas were segregated by grade and sex. Data…

Nambu mechanism of dynamical symmetry breaking by the top quark

NASA Astrophysics Data System (ADS)

Pham, Xuan-Yem

1990-05-01

It may be possible that the gauge symmetry breaking of the standard electroweak interactions is not due to the elementary scalar Higgs fields but has a dynamic origin intimately involving the top quark. A prototype of this dynamical scenario is the Nambu and Jona-Lasinio model in which both the top quark and the gauge bosons become massive by some strong attractive nonlinear interactions similar to the gap energy produced in BCS superconductivity. Self-consistent equations for the charged Goldstone boson and for the vector meson are used to get an upper bound for the top quark mass. In the bubble approximation of keeping only fermion loops, we obtain an equation relating the top quark mass to the W boson one; from the top mass is found to be around 84 GeV. Its typical dominant decay mode t→W+s then follows. Also discussed are distinctive signatures of the scalar overlinett bound state identified as the physical Higgs particle whose mass is twice that of the top quark.

Contact enhancement of locomotion in spreading cell colonies

NASA Astrophysics Data System (ADS)

D'Alessandro, Joseph; Solon, Alexandre P.; Hayakawa, Yoshinori; Anjard, Christophe; Detcheverry, François; Rieu, Jean-Paul; Rivière, Charlotte

2017-10-01

The dispersal of cells from an initially constrained location is a crucial aspect of many physiological phenomena, ranging from morphogenesis to tumour spreading. In such processes, cell-cell interactions may deeply alter the motion of single cells, and in turn the collective dynamics. While contact phenomena like contact inhibition of locomotion are known to come into play at high densities, here we focus on the little explored case of non-cohesive cells at moderate densities. We fully characterize the spreading of micropatterned colonies of Dictyostelium discoideum cells from the complete set of individual trajectories. From data analysis and simulation of an elementary model, we demonstrate that contact interactions act to speed up the early population spreading by promoting individual cells to a state of higher persistence, which constitutes an as-yet unreported contact enhancement of locomotion. Our findings also suggest that the current modelling paradigm of memoryless active particles may need to be extended to account for the history-dependent internal state of motile cells.

Review of the Elementary Particles Physics in the External Electromagnetic Fields Studies at KEK

NASA Astrophysics Data System (ADS)

Konstantinova, O. Tanaka

2017-03-01

High Energy Accelerator Research Organization (KEK [1]) is a world class accelerator-based research laboratory. The field of its scientific interests spreads widely from the study of fundamental properties of matter, particle physics, nuclear physics to materials science, life science, technical researches, and industrial applications. Research outcomes from the laboratory achieved making use of high-energy particle beams and synchrotron radiation. Two synchrotron facilities of KEK, the Photon Factory (PF) ring and the Photon Factory Advanced Ring (PF-AR) are the second biggest synchrotron light source in Japan. A very wide range of the radiated light, from visible light to X-ray, is provided for a variety of materials science, biology, and life science [2]. KEK strives to work closely with national and international research institutions, promoting collaborative research activities. Advanced research and facilities provision are key factors to be at the frontier of the accelerator science. In this review I am going to discuss KEK overall accelerator-based science, and to consider light sources research and development. The state of arts of the current projects with respect to the elementary particles physics in the external electromagnetic fields is also stressed here.

Low-Mass Dark Matter Search Results and Radiogenic Backgrounds for the Cryogenic Dark Matter Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pepin, Mark David

An ever-increasing amount of evidence suggests that approximately one quarter of the energy in the universe is composed of some non-luminous, and hitherto unknown, “dark matter”. Physicists from numerous sub-fields have been working on and trying to solve the dark matter problem for decades. The common solution is the existence of some new type of elementary particle with particular focus on weakly interacting massive particles (WIMPs). One avenue of dark matter research is to create an extremely sensitive particle detector with the goal of directly observing the interaction of WIMPs with standard matter. The Cryogenic Dark Matter Search (CDMS) projectmore » operated at the Soudan Underground Laboratory from 2003–2015, under the CDMS II and SuperCDMS Soudan experiments, with this goal of directly detecting dark matter. The next installation, SuperCDMS SNOLAB, is planned for near-future operation. The reason the dark-matter particle has not yet been observed in traditional particle physics experiments is that it must have very small cross sections, thus making such interactions extremely rare. In order to identify these rare events in the presence of a background of known particles and interactions, direct detection experiments employ various types and amounts of shielding to prevent known backgrounds from reaching the instrumented detector(s). CDMS utilized various gamma and neutron shielding to such an effect that the shielding, and other experimental components, themselves were sources of background. These radiogenic backgrounds must be understood to have confidence in any WIMP-search result. For this dissertation, radiogenic background studies and estimates were performed for various analyses covering CDMS II, SuperCDMS Soudan, and SuperCDMS SNOLAB. Lower-mass dark matter t c2 inent in the past few years. The CDMS detectors can be operated in an alternative, higher-biased, mode v to decrease their energy thresholds and correspondingly increase their sensitivity to low-mass WIMPs. This is the CDMS low ionization threshold experiment (CDMSlite), which has pushed the frontier at lower WIMP masses. This dissertation describes the second run of CDMSlite at Soudan: its hardware, operations, analysis, and results. The results include new WIMP mass-cross section upper limits on the spin-independent and spin-dependent WIMP-nucleon interactions. Thanks to the lower background and threshold in this run compared to the first CDMSlite run, these limits are the most sensitive in the world below WIMP masses of ~4 GeV/c 2. This demonstrates also the great promise and utility of the high-voltage operating mode in the SuperCDMS SNOLAB experiment.« less

Committor of elementary reactions on multistate systems

NASA Astrophysics Data System (ADS)

Király, Péter; Kiss, Dóra Judit; Tóth, Gergely

2018-04-01

In our study, we extend the committor concept on multi-minima systems, where more than one reaction may proceed, but the feasible data evaluation needs the projection onto partial reactions. The elementary reaction committor and the corresponding probability density of the reactive trajectories are defined and calculated on a three-hole two-dimensional model system explored by single-particle Langevin dynamics. We propose a method to visualize more elementary reaction committor functions or probability densities of reactive trajectories on a single plot that helps to identify the most important reaction channels and the nonreactive domains simultaneously. We suggest a weighting for the energy-committor plots that correctly shows the limits of both the minimal energy path and the average energy concepts. The methods also performed well on the analysis of molecular dynamics trajectories of 2-chlorobutane, where an elementary reaction committor, the probability densities, the potential energy/committor, and the free-energy/committor curves are presented.

Spontaneous skyrmion ground states in magnetic metals.

PubMed

Rössler, U K; Bogdanov, A N; Pfleiderer, C

2006-08-17

Since the 1950s, Heisenberg and others have addressed the problem of how to explain the appearance of countable particles in continuous fields. Stable localized field configurations were searched for an ingredient for a general field theory of elementary particles, but the majority of nonlinear field models were unable to predict them. As an exception, Skyrme succeeded in describing nuclear particles as localized states, so-called 'skyrmions'. Skyrmions are a characteristic of nonlinear continuum models ranging from microscopic to cosmological scales. Skyrmionic states have been found under non-equilibrium conditions, or when stabilized by external fields or the proliferation of topological defects. Examples are Turing patterns in classical liquids, spin textures in quantum Hall magnets, or the blue phases in liquid crystals. However, it has generally been assumed that skyrmions cannot form spontaneous ground states, such as ferromagnetic or antiferromagnetic order, in magnetic materials. Here, we show theoretically that this assumption is wrong and that skyrmion textures may form spontaneously in condensed-matter systems with chiral interactions without the assistance of external fields or the proliferation of defects. We show this within a phenomenological continuum model based on a few material-specific parameters that can be determined experimentally. Our model has a condition not considered before: we allow for softened amplitude variations of the magnetization, characteristic of, for instance, metallic magnets. Our model implies that spontaneous skyrmion lattice ground states may exist generally in a large number of materials, notably at surfaces and in thin films, as well as in bulk compounds, where a lack of space inversion symmetry leads to chiral interactions.

Spontaneous Symmetry Breaking as a Basis of Particle Mass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quigg, Chris; /Fermilab /CERN

2007-04-01

Electroweak theory joins electromagnetism with the weak force in a single quantum field theory, ascribing the two fundamental interactions--so different in their manifestations--to a common symmetry principle. How the electroweak gauge symmetry is hidden is one of the most urgent and challenging questions facing particle physics. The provisional answer incorporated in the ''standard model'' of particle physics was formulated in the 1960s by Higgs, by Brout & Englert, and by Guralnik, Hagen, & Kibble: The agent of electroweak symmetry breaking is an elementary scalar field whose self-interactions select a vacuum state in which the full electroweak symmetry is hidden, leavingmore » a residual phase symmetry of electromagnetism. By analogy with the Meissner effect of the superconducting phase transition, the Higgs mechanism, as it is commonly known, confers masses on the weak force carriers W{sup {+-}} and Z. It also opens the door to masses for the quarks and leptons, and shapes the world around us. It is a good story--though an incomplete story--and we do not know how much of the story is true. Experiments that explore the Fermi scale (the energy regime around 1 TeV) during the next decade will put the electroweak theory to decisive test, and may uncover new elements needed to construct a more satisfying completion of the electroweak theory. The aim of this article is to set the stage by reporting what we know and what we need to know, and to set some ''Big Questions'' that will guide our explorations.« less

Elementary Particle Spectroscopy in Regular Solid Rewrite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trell, Erik

The Nilpotent Universal Computer Rewrite System (NUCRS) has operationalized the radical ontological dilemma of Nothing at All versus Anything at All down to the ground recursive syntax and principal mathematical realisation of this categorical dichotomy as such and so governing all its sui generis modalities, leading to fulfilment of their individual terms and compass when the respective choice sequence operations are brought to closure. Focussing on the general grammar, NUCRS by pure logic and its algebraic notations hence bootstraps Quantum Mechanics, aware that it ''is the likely keystone of a fundamental computational foundation'' also for e.g. physics, molecular biology andmore » neuroscience. The present work deals with classical geometry where morphology is the modality, and ventures that the ancient regular solids are its specific rewrite system, in effect extensively anticipating the detailed elementary particle spectroscopy, and further on to essential structures at large both over the inorganic and organic realms. The geodetic antipode to Nothing is extension, with natural eigenvector the endless straight line which when deployed according to the NUCRS as well as Plotelemeian topographic prescriptions forms a real three-dimensional eigenspace with cubical eigenelements where observed quark-skewed quantum-chromodynamical particle events self-generate as an Aristotelean phase transition between the straight and round extremes of absolute endlessness under the symmetry- and gauge-preserving, canonical coset decomposition SO(3)xO(5) of Lie algebra SU(3). The cubical eigen-space and eigen-elements are the parental state and frame, and the other solids are a range of transition matrix elements and portions adapting to the spherical root vector symmetries and so reproducibly reproducing the elementary particle spectroscopy, including a modular, truncated octahedron nano-composition of the Electron which piecemeal enter into molecular structures or compressed to each other fuse into atomic honeycombs of periodic table signature.« less

Advanced Concepts in Quantum Mechanics

NASA Astrophysics Data System (ADS)

Esposito, Giampiero; Marmo, Giuseppe; Miele, Gennaro; Sudarshan, George

2014-11-01

Preface; 1. Introduction: the need for a quantum theory; 2. Experimental foundations of quantum theory; 3. Waves and particles; 4. Schrödinger picture, Heisenberg picture and probabilistic aspects; 5. Integrating the equations of motion; 6. Elementary applications: 1-dimensional problems; 7. Elementary applications: multidimensional problems; 8. Coherent states and related formalism; 9. Introduction to spin; 10. Symmetries in quantum mechanics; 11. Approximation methods; 12. Modern pictures of quantum mechanics; 13. Formulations of quantum mechanics and their physical implications; 14. Exam problems; Glossary of geometric concepts; References; Index.

Is Systemic Operation Design Capable of Reducing Significantly Bias in Operational Level Planning Caused by Military Organizational Culture?

DTIC Science & Technology

2006-05-25

73See Emile Durkheim , The Elementary Forms of the Religious Life, (New York: Collier, 1961) and Erving Goffman, Interaction Ritual, (New York: Doubleday... Durkheim , Emile . The Elementary Forms of the Religious Life. New York: Collier, 1961. Foerster, Heinz von. Understanding. Essays on Cybernetics and...he examined. Utilizing Erving Goffman’s phrase (interaction ritual) he quoted Emile Durkheim’s famous observation of the ritualistic element of

The Higgs Boson.

ERIC Educational Resources Information Center

Veltman, Martinus J. G.

1986-01-01

Reports recent findings related to the particle Higgs boson and examines its possible contribution to the standard mode of elementary processes. Critically explores the strengths and uncertainties of the Higgs boson and proposed Higgs field. (ML)

Service Learning is also Elementary!

ERIC Educational Resources Information Center

Social Studies Review, 1997

1997-01-01

Presents 10 ideas for service learning projects designed for elementary schools. Includes having students do local history projects complete with interviews and artifacts, learn about community volunteering, interact with the elderly, care for the environment, recycle materials, and hold canned food drives. (MJP)

The Handedness of the Universe.

ERIC Educational Resources Information Center

Hegstrom, Roger A.; Kondepudi, Dilip K.

1990-01-01

Discusses how handedness at one level may give rise to handedness at another. Presents examples from plants and animals, molecules, atoms, to elementary particles. Examines the chiral symmetry in life and when it starts. (YP)

Exact solution for the quench dynamics of a nested integrable system

NASA Astrophysics Data System (ADS)

Mestyán, Márton; Bertini, Bruno; Piroli, Lorenzo; Calabrese, Pasquale

2017-08-01

Integrable models provide an exact description for a wide variety of physical phenomena. For example nested integrable systems contain different species of interacting particles with a rich phenomenology in their collective behavior, which is the origin of the unconventional phenomenon of spin-charge separation. So far, however, most of the theoretical work in the study of non-equilibrium dynamics of integrable systems has focussed on models with an elementary (i.e. not nested) Bethe ansatz. In this work we explicitly investigate quantum quenches in nested integrable systems, by generalizing the application of the quench action approach. Specifically, we consider the spin-1 Lai-Sutherland model, described, in the thermodynamic limit, by the theory of two different species of Bethe-ansatz particles, each one forming an infinite number of bound states. We focus on the situation where the quench dynamics starts from a simple matrix product state for which the overlaps with the eigenstates of the Hamiltonian are known. We fully characterize the post-quench steady state and perform several consistency checks for the validity of our results. Finally, we provide predictions for the propagation of entanglement and mutual information after the quench, which can be used as signature of the quasi-particle content of the model.

Correlation energy for elementary bosons: Physics of the singularity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiau, Shiue-Yuan, E-mail: syshiau@mail.ncku.edu.tw; Combescot, Monique; Chang, Yia-Chung, E-mail: yiachang@gate.sinica.edu.tw

2016-04-15

We propose a compact perturbative approach that reveals the physical origin of the singularity occurring in the density dependence of correlation energy: like fermions, elementary bosons have a singular correlation energy which comes from the accumulation, through Feynman “bubble” diagrams, of the same non-zero momentum transfer excitations from the free particle ground state, that is, the Fermi sea for fermions and the Bose–Einstein condensate for bosons. This understanding paves the way toward deriving the correlation energy of composite bosons like atomic dimers and semiconductor excitons, by suggesting Shiva diagrams that have similarity with Feynman “bubble” diagrams, the previous elementary bosonmore » approaches, which hide this physics, being inappropriate to do so.« less

Properties of the Top Quark

DOE PAGES

Déliot, Frédéric; Hadley, Nicholas; Parke, Stephen; ...

2014-10-19

We report that the top quark is the heaviest known elementary particle, and it is often seen as a window to search for new physics processes in particle physics. A large program to study the top-quark properties has been performed both at the Tevatron and LHC colliders by the D0, CDF, ATLAS and CMS experiments. The most recent results are discussed here in this article.

Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics

NASA Astrophysics Data System (ADS)

Saviano, G.; Ferrini, M.; Benussi, L.; Bianco, S.; Piccolo, D.; Colafranceschi, S.; KjØlbro, J.; Sharma, A.; Yang, D.; Chen, G.; Ban, Y.; Li, Q.; Grassini, S.; Parvis, M.

2018-03-01

Gas detectors for elementary particles require F-based gases for optimal performance. Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. This work studies properties of potential eco-friendly gas replacements by computing the physical and chemical parameters relevant for use as detector media, and suggests candidates to be considered for experimental investigation.

THE USE OF STATIC AND DYNAMIC MECHANICAL MODELS IN TEACHING ASPECTS OF THE THEORETICAL CONCEPT, THE PARTICLE NATURE OF MATTER.

ERIC Educational Resources Information Center

PELLA, MILTON O.; ZIEGLER, ROBERT E.

THE RELATIVE EFFECTIVENESS OF TWO TYPES OF MECHANICAL MODELS FOR TEACHING ELEMENTARY SCHOOL STUDENTS TO USE THE PARTICLE IDEA OF MATTER TO EXPLAIN CERTAIN PHYSICAL PHENOMENA WAS INVESTIGATED. SUBJECTS WERE RANDOMLY SELECTED FROM STUDENTS ENROLLED IN GRADES TWO THROUGH SIX IN A SCHOOL SYSTEM. A SERIES OF DEMONSTRATIONS AND RELATED QUESTIONS WERE…

Spinor Structure and Internal Symmetries

NASA Astrophysics Data System (ADS)

Varlamov, V. V.

2015-10-01

Spinor structure and internal symmetries are considered within one theoretical framework based on the generalized spin and abstract Hilbert space. Complex momentum is understood as a generating kernel of the underlying spinor structure. It is shown that tensor products of biquaternion algebras are associated with the each irreducible representation of the Lorentz group. Space-time discrete symmetries P, T and their combination PT are generated by the fundamental automorphisms of this algebraic background (Clifford algebras). Charge conjugation C is presented by a pseudoautomorphism of the complex Clifford algebra. This description of the operation C allows one to distinguish charged and neutral particles including particle-antiparticle interchange and truly neutral particles. Spin and charge multiplets, based on the interlocking representations of the Lorentz group, are introduced. A central point of the work is a correspondence between Wigner definition of elementary particle as an irreducible representation of the Poincaré group and SU(3)-description (quark scheme) of the particle as a vector of the supermultiplet (irreducible representation of SU(3)). This correspondence is realized on the ground of a spin-charge Hilbert space. Basic hadron supermultiplets of SU(3)-theory (baryon octet and two meson octets) are studied in this framework. It is shown that quark phenomenologies are naturally incorporated into presented scheme. The relationship between mass and spin is established. The introduced spin-mass formula and its combination with Gell-Mann-Okubo mass formula allows one to take a new look at the problem of mass spectrum of elementary particles.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levay, Peter; Nagy, Szilvia; Pipek, Janos

An elementary formula for the von Neumann and Renyi entropies describing quantum correlations in two-fermionic systems having four single-particle states is presented. An interesting geometric structure of fermionic entanglement is revealed. A connection with the generalized Pauli principle is established.

The Quark's Model and Confinement

ERIC Educational Resources Information Center

Novozhilov, Yuri V.

1977-01-01

Quarks are elementary particles considered to be components of the proton, the neutron, and others. This article presents the quark model as a mathematical concept. Also discussed are gluons and bag models. A bibliography is included. (MA)

The top quark, 20 years after its discovery

DOE PAGES

Denisov, Dmitri; Vellidis, Costas

2015-04-01

In this article, the heaviest of nature’s elementary particles plays an outsized role in many fundamental processes. But because the top quark is so massive, it eluded experimental detection for nearly two decades.

Tendency to occupy a statistically dominant spatial state of the flow as a driving force for turbulent transition.

PubMed

Chekmarev, Sergei F

2013-03-01

The transition from laminar to turbulent fluid motion occurring at large Reynolds numbers is generally associated with the instability of the laminar flow. On the other hand, since the turbulent flow characteristically appears in the form of spatially localized structures (e.g., eddies) filling the flow field, a tendency to occupy such a structured state of the flow cannot be ruled out as a driving force for turbulent transition. To examine this possibility, we propose a simple analytical model that treats the flow as a collection of localized spatial structures, each of which consists of elementary cells in which the behavior of the particles (atoms or molecules) is uncorrelated. This allows us to introduce the Reynolds number, associating it with the ratio between the total phase volume for the system and that for the elementary cell. Using the principle of maximum entropy to calculate the most probable size distribution of the localized structures, we show that as the Reynolds number increases, the elementary cells group into the localized structures, which successfully explains turbulent transition and some other general properties of turbulent flows. An important feature of the present model is that a bridge between the spatial-statistical description of the flow and hydrodynamic equations is established. We show that the basic assumptions underlying the model, i.e., that the particles are indistinguishable and elementary volumes of phase space exist in which the state of the particles is uncertain, are involved in the derivation of the Navier-Stokes equation. Taking into account that the model captures essential features of turbulent flows, this suggests that the driving force for the turbulent transition is basically the same as in the present model, i.e., the tendency of the system to occupy a statistically dominant state plays a key role. The instability of the flow at high Reynolds numbers can then be a mechanism to initiate structural rearrangement of the flow to find this state.

The effects of computer-assisted instruction and locus of control upon preservice elementary teachers' acquisition of the integrated science process skills

NASA Astrophysics Data System (ADS)

Wesley, Beth Eddinger; Krockover, Gerald H.; Devito, Alfred

The purpose of this study was to determine the effects of computer-assisted instruction (CAI) versus a text mode of programmed instruction (PI), and the cognitive style of locus of control, on preservice elementary teachers' achievement of the integrated science process skills. Eighty-one preservice elementary teachers in six sections of a science methods class were classified as internally or externally controlled. The sections were randomly assigned to receive instruction in the integrated science process skills via a microcomputer or printed text. The study used a pretest-posttest control group design. Before assessing main and interaction effects, analysis of covariance was used to adjust posttest scores using the pretest scores. Statistical analysis revealed that main effects were not significant. Additionally, no interaction effects between treatments and loci of control were demonstrated. The results suggest that printed PI and tutorial CAI are equally effective modes of instruction for teaching internally and externally oriented preservice elementary teachers the integrated science process skills.

Experimental Studies of Elementary Particle Interactions at High Energies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goulianos, Konstantin

This is the final report of a program of research on "Experimental Studies of Elementary Particle Interactions at High Energies'' of the High Energy Physics (HEP) group of The Rockefeller University. The research was carried out using the Collider Detector at Fermilab (CDF) and the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) at CERN. Three faculty members, two research associates, and two postdoctoral associates participated in this project. At CDF, we studied proton-antiproton collisions at an energy of 1.96 TeV. We focused on diffractive interactions, in which the colliding antiproton loses a small fraction of itsmore » momentum, typically less than 1%, while the proton is excited into a high mass state retaining its quantum numbers. The study of such collisions provides insight into the nature of the diffractive exchange, conventionally referred to as Pomeron exchange. In studies of W and Z production, we found results that point to a QCD-based interpretation of the diffractive exchange, as predicted in a data-driven phenomenology developed within the Rockefeller HEP group. At CMS, we worked on diffraction, supersymmetry (SUSY), dark matter, large extra dimensions, and statistical applications to data analysis projects. In diffraction, we extended our CDF studies to higher energies working on two fronts: measurement of the single/double diffraction and of the rapidity gap cross sections at 7 TeV, and development of a simulation of diffractive processes along the lines of our successful model used at CDF. Working with the PYTHIA8 Monte Carlo simulation authors, we implemented our model as a PYTHIA8-MBR option in PYTHIA8 and used it in our data analysis. Preliminary results indicate good agreement. We searched for SUSY by measuring parameters in the Constrained Minimal Supersymmetric extension of the Standard Model (CMSSM) and found results which, combined with other experimental constraints and theoretical considerations, indicate that the CMSSM is not a viable model. Expressing our results in terms of simple topologies, we exclude squark masses below 0.75 TeV and gluino masses below 1.1 TeV. Astrophysical measurements suggest that about 80% of the matter density of the Universe is non-luminous. One of the theories on dark matter attributes it to Weakly Interacting Massive Particles (WIMPs). We searched for WIMPs in 7 TeV and 8 TeV collisions at CMS and set limits on WIMP production rates, which are competitive and complementary to those of direct detection experiments. Searching for monojets (events with only one jet), which in a popular model could be produced by a jet paired by a gravitino that escapes into extra dimensions, we significantly improved the previously set limit. Our results have been used to set limits on Higgs decay to invisible particles and on production of top squarks in compressed SUSY scenarios. Statistics. We computed Bayesian reference priors for several types of measurement and used them in the analysis of CMS data; investigated the applicability of bootstrap methods to HEP measurements; studied several issues associated with simple-versus-simple hypothesis testing and applied the resulting methods to the measurement of some properties of the top quark and Higgs boson.« less

Work distributions of one-dimensional fermions and bosons with dual contact interactions

NASA Astrophysics Data System (ADS)

Wang, Bin; Zhang, Jingning; Quan, H. T.

2018-05-01

We extend the well-known static duality [M. Girardeau, J. Math. Phys. 1, 516 (1960), 10.1063/1.1703687; T. Cheon and T. Shigehara, Phys. Rev. Lett. 82, 2536 (1999), 10.1103/PhysRevLett.82.2536] between one-dimensional (1D) bosons and 1D fermions to the dynamical version. By utilizing this dynamical duality, we find the duality of nonequilibrium work distributions between interacting 1D bosonic (Lieb-Liniger model) and 1D fermionic (Cheon-Shigehara model) systems with dual contact interactions. As a special case, the work distribution of the Tonks-Girardeau gas is identical to that of 1D noninteracting fermionic system even though their momentum distributions are significantly different. In the classical limit, the work distributions of Lieb-Liniger models (Cheon-Shigehara models) with arbitrary coupling strength converge to that of the 1D noninteracting distinguishable particles, although their elementary excitations (quasiparticles) obey different statistics, e.g., the Bose-Einstein, the Fermi-Dirac, and the fractional statistics. We also present numerical results of the work distributions of Lieb-Liniger model with various coupling strengths, which demonstrate the convergence of work distributions in the classical limit.

Gauge Invariance and the Goldstone Theorem

NASA Astrophysics Data System (ADS)

Guralnik, Gerald S.

This paper was originally created for and printed in the "Proceedings of seminar on unified theories of elementary particles" held in Feldafing, Germany from July 5 to 16, 1965 under the auspices of the Max-Planck-Institute for Physics and Astrophysics in Munich. It details and expands upon the 1964 Guralnik, Hagen, and Kibble paper demonstrating that the Goldstone theorem does not require physical zero mass particles in gauge theories.

A pedagogical derivation of the matrix element method in particle physics data analysis

NASA Astrophysics Data System (ADS)

Sumowidagdo, Suharyo

2018-03-01

The matrix element method provides a direct connection between the underlying theory of particle physics processes and detector-level physical observables. I am presenting a pedagogically-oriented derivation of the matrix element method, drawing from elementary concepts in probability theory, statistics, and the process of experimental measurements. The level of treatment should be suitable for beginning research student in phenomenology and experimental high energy physics.

From lepton protoplasm to the genesis of hadrons

NASA Astrophysics Data System (ADS)

Eliseev, S. M.; Kosmachev, O. S.

2016-01-01

Theory of matter under extreme conditions opens a new stage in particle physics. It is necessary here to combine Dirac's elementary particle physics with Prigogine's dynamics of nonequilibrium systems. In the article we discuss the problem of the hierarchy of complexity. What can be considered as the lowest level of the organization of extreme matter on the basis of which the self-organization of the complex form occur?

Time reversibility in the quantum frame

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masot-Conde, Fátima

2014-12-04

Classic Mechanics and Electromagnetism, conventionally taken as time-reversible, share the same concept of motion (either of mass or charge) as the basis of the time reversibility in their own fields. This paper focuses on the relationship between mobile geometry and motion reversibility. The goal is to extrapolate the conclusions to the quantum frame, where matter and radiation behave just as elementary mobiles. The possibility that the asymmetry of Time (Time’s arrow) is an effect of a fundamental quantum asymmetry of elementary particles, turns out to be a consequence of the discussion.

The Model Identification Test: A Limited Verbal Science Test

ERIC Educational Resources Information Center

McIntyre, P. J.

1972-01-01

Describes the production of a test with a low verbal load for use with elementary school science students. Animated films were used to present appropriate and inappropriate models of the behavior of particles of matter. (AL)

Science Exhibitions Promote College and Community Interaction.

ERIC Educational Resources Information Center

Stout, Dorothy LaLonde

1991-01-01

Science exhibitions presented by college students at local elementary schools foster goodwill in the community; give college students an opportunity to share their science as role models; provide elementary school children with a positive, enjoyable approach to science; and can be organized rather easily following guidelines that outline…

ELECTRON AS A FUNDAMENTAL ELEMENTARY PARTICLE. PART I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kakinuma, U.

1962-12-01

Elementary particles may be nothing but an electron existing under a certain condition, or a group of electrons that are formed to a certain combined state. Therefore, the knowledge of the electron structure is the starting point of our investigation about matter. To obtain the structure, the electron in an absolutely statical state is considered first and is studied by use of the gage- transformation defined in a modified way. This leads to the discovery oi a revised expression for the electromagnetic energy-tensor inside the electron as well as the wave equation for the electron formally similar to the Schrodingermore » equation for the hydrogen atom. However, our wave equation is interpreted as indicating the mode of energy distribution in the electron. To linearize the wave equation, a complex Riemannian geometry has been developed with results promising to be serviceable for further studies. (auth)« less

Everybody else is: Networks, power laws and peer contagion in the aggressive recess behavior of elementary school boys.

PubMed

Warren, Keith; Craciun, Gheorghe; Anderson-Butcher, Dawn

2005-04-01

This paper develops a simple random network model of peer contagion in aggressive behavior among inner-city elementary school boys during recess periods. The model predicts a distribution of aggressive behaviors per recess period with a power law tail beginning at two aggressive behaviors and having a slope of approximately -1.5. Comparison of these values with values derived from observations of aggressive behaviors during recess at an inner-city elementary school provides empirical support for the model. These results suggest that fluctuations in aggressive behaviors during recess arise from the interactions between students, rather than from variations in the behavior of individual students. The results therefore support those interventions that aim to change the pattern of interaction between students.

Improving the Acceptance in the Single Top Quark Analysis using 7.5 fb$$^{-1}$$ of CDF data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronzani, Manfredi

2012-01-01

The Top quark was observed at the Fermilab Tevatron by the CDF and D0 collaboration in 1995 via strong production of top quarks pairs at center-of-mass energy of √s=1.8 Tev, using 60 pb−1 of data [1]. Standard Model of elementary particles predicts top quark to be produced individually via electroweak interactions in three different channels (s, t and Wt). This is defined as ”single top” (from now on also ST). ST was observed by CDF collaboration in 2009 at center-of-mass energy of √s=1.96 Tev using 3.2 fb−1 of p¯p collected data [2]. This thesis concerns the upgrade of this measurementmore » using 7.5 fb−1 of data.« less

Techniques used to search for a permanent electric dipole moment of the 199Hg atom and the implications for CP violation

NASA Astrophysics Data System (ADS)

Swallows, M. D.; Loftus, T. H.; Griffith, W. C.; Heckel, B. R.; Fortson, E. N.; Romalis, M. V.

2013-01-01

We discuss in detail the search for a permanent electric dipole moment (EDM) of the 199Hg atom reported by Griffith [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.102.101601 102, 101601 (2009)]. The upper bound, d(199Hg)<3.1×10-29 e cm (95% C.L.), is a factor of 7 improvement over the best previous EDM limit for 199Hg, provides the most sensitive probe to date for EDMs in diamagnetic atoms, and sets new limits on time-reversal symmetry violation in extensions to the standard model. This paper provides extensive discussion of the techniques used to search for the 199Hg EDM and the implications of the new 199Hg EDM limit for CP violation in elementary particle interactions.

FINAL REPORT: GEOMETRY AND ELEMENTARY PARTICLE PHYSICS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singer, Isadore M.

2008-03-04

The effect on mathematics of collaborations between high-energy theoretical physics and modern mathematics has been remarkable. Mirror symmetry has revolutionized enumerative geometry, and Seiberg-Witten invariants have greatly simplified the study of four manifolds. And because of their application to string theory, physicists now need to know cohomology theory, characteristic classes, index theory, K-theory, algebraic geometry, differential geometry, and non-commutative geometry. Much more is coming. We are experiencing a deeper contact between the two sciences, which will stimulate new mathematics essential to the physicists’ quest for the unification of quantum mechanics and relativity. Our grant, supported by the Department of Energymore » for twelve years, has been instrumental in promoting an effective interaction between geometry and string theory, by supporting the Mathematical Physics seminar, postdoc research, collaborations, graduate students and several research papers.« less

Effects of Positive and Negative Adult-Child Interactions on Children's Social Preference

ERIC Educational Resources Information Center

Redd, William H.; And Others

1975-01-01

Studied the effects of positive and negative interaction on the performance of preschool and elementary school children and their preferences for the adults associated with each type of interaction. (Author/SDH)

L2 (IM)Politeness in the Synchronous Chat of Elementary School Learners

ERIC Educational Resources Information Center

Howard, Craig D.; Do, Jaewoo

2017-01-01

Participation in interactive games, especially those in immersive environments, is often employed in learning contexts to stochastically develop L2 learners' language ability. However, typical measures of language ability often do not reflect pragmatic competencies. This study juxtaposes two elementary school ESL learners' language ability, and…

Student Teacher Thinking: A Comparative Study of Elementary and Secondary Student Teachers.

ERIC Educational Resources Information Center

Galluzzo, Gary L.; Minix, Nancy A.

1992-01-01

Using videotaped simulated recall interviews, researchers assessed elementary and secondary student teachers' thoughts and concerns. Both groups considered pupil learning the greatest concern. There were consistent differences in how the groups perceived classroom interactions. Both groups addressed a narrower range of concerns regarding teaching…

Emotional Experience, Expression, and Regulation of High-Quality Japanese Elementary School Teachers

ERIC Educational Resources Information Center

Hosotani, Rika; Imai-Matsumura, Kyoko

2011-01-01

The present study investigates the emotional experience, expression, and regulation processes of high-quality Japanese elementary school teachers while they interact with children, in terms of teachers' emotional competence. Qualitative analysis of interview data demonstrated that teachers had various emotional experiences including self-elicited…

Hybrid-Mentoring Programs for Beginning Elementary Science Teachers

ERIC Educational Resources Information Center

Bang, EunJin

2013-01-01

This study examines four induction models and teacher changes in science teaching practices, as a result of several mentoring programs. It explores three different computer-mediated mentoring programs, and a traditional offline induction program--in terms of interactivity, inquiry-based teaching, and topics of knowledge. Fifteen elementary science…

Wanted: A Revolution in Elementary Science Teaching.

ERIC Educational Resources Information Center

Triangle Coalition for Science and Technology Education, College Park, MD.

Children come to school with a foundation for formal learning from their early experiences with interactions of the natural and technological world. Failure of elementary schools to build on this experience can discourage children, especially those who do not identify readily with the science establishment (girls, blacks, Hispanics, and the…

The International Pencil: Elementary Level Unit on Global Interdependence.

ERIC Educational Resources Information Center

Wolken, Lawrence C.

1984-01-01

The production of an American pencil is the result of complex interactions involving many people, places, and resources. Learning activities dealing with the making of a pencil that will help students learn about global interdependence are described. The activities can be adapted to fit any elementary grade level. (RM)

Elementary Quantum Mechanics in a High-Energy Process

ERIC Educational Resources Information Center

Denville, A.; And Others

1978-01-01

Compares two approaches to strong absorption in elementary quantum mechanics; the black sphere and a model based on the continuum theory of nuclear reactions. Examines the application to proton-antiproton interactions at low momenta and concludes that the second model is the appropriate and simplest to use. (Author/GA)

The Efficacy of Institutionally Dispensed Rewards in Elementary School Teaching.

ERIC Educational Resources Information Center

Kasten, Katherine Lewellyn

1984-01-01

Teachers' attitudes towards incentives should be analyzed before programs involving such incentives as merit pay or master teachers are implemented. Elementary school teachers were interviewed to help identify the value and effectiveness of institutional rewards. The interaction between personal life events and career choices was also examined.…

Upscaling the diffusion equations in particulate media made of highly conductive particles. II. Application to fibrous materials.

PubMed

Vassal, J-P; Orgéas, L; Favier, D; Auriault, J-L; Le Corre, S

2008-01-01

In paper I [Vassal, Phys. Rev. E77, 011302 (2008)] of this contribution, the effective diffusion properties of particulate media with highly conductive particles and particle-particle interfacial barriers have been investigated with the homogenization method with multiple scale asymptotic expansions. Three different macroscopic models have been proposed depending on the quality of contacts between particles. However, depending on the nature and the geometry of particles contained in representative elementary volumes of the considered media, localization problems to be solved to compute the effective conductivity of the two first models can rapidly become cumbersome, time and memory consuming. In this second paper, the above problem is simplified and applied to networks made of slender, wavy and entangled fibers. For these types of media, discrete formulations of localization problems for all macroscopic models can be obtained leading to very efficient numerical calculations. Semianalytical expressions of the effective conductivity tensors are also proposed under simplifying assumptions. The case of straight monodisperse and homogeneously distributed slender fibers with a circular cross section is further explored. Compact semianalytical and analytical estimations are obtained when fiber-fiber contacts are perfect or very poor. Moreover, two discrete element codes have been developed and used to solve localization problems on representative elementary volumes for the same types of contacts. Numerical results underline the significant roles of the fiber content, the orientation of fibers as well as the relative position and orientation of contacting fibers on the effective conductivity tensors. Semianalytical and analytical predictions are discussed and compared with numerical results.

Nanoparticle interaction potentials constructed by multiscale computation

NASA Astrophysics Data System (ADS)

Lee, Cheng K.; Hua, Chi C.

2010-06-01

The van der Waals (vdW) potentials governing macroscopic objects have long been formulated in the context of classical theories, such as Hamaker's microscopic theory and Lifshitz's continuum theory. This work addresses the possibility of constructing the vdW interaction potentials of nanoparticle species using multiscale simulation schemes. Amorphous silica nanoparticles were considered as a benchmark example for which a series of (SiO2)n (n being an integer) has been systematically surveyed as the potential candidates of the packing units that reproduce known bulk material properties in atomistic molecular dynamics simulations. This strategy led to the identification of spherical Si6O12 molecules, later utilized as the elementary coarse-grained (CG) particles to compute the pair interaction potentials of silica nanoparticles ranging from 0.62 to 100 nm in diameter. The model nanoparticles so built may, in turn, serve as the children CG particles to construct nanoparticles assuming arbitrary sizes and shapes. Major observations are as follows. The pair interaction potentials for all the investigated spherical silica nanoparticles can be cast into a semiempirical, generalized Lennard-Jones 2α-α potential (α being a size-dependent, large integral number). In its reduced form, we discuss the implied universalities for the vdW potentials governing a certain range of amorphous nanoparticle species as well as how thermodynamic transferability can be fulfilled automatically. In view of future applications with colloidal suspensions, we briefly evaluated the vdW potential in the presence of a "screening" medium mimicking the effects of electrical double layers or grafting materials atop the nanoparticle core. The general observations shed new light on strategies to attain a microscopic control over interparticle attractions. In future perspectives, the proposed multiscale computation scheme shall help bridge the current gap between the modeling of polymer chains and macroscopic objects by introducing molecular models coarse-grained at a similar level so that the interactions between these two can be treated in a consistent and faithful way.

[Lipoproteins as a specific circulatory transport system].

PubMed

Titov, V N

1998-01-01

In accordance with the systemic approach, each circulatory transport system is highly specific and transports an elementary substance from cell to cell in the hydrated medium. In the author's opinion, the lipoprotein system has also a functional specificity and carries the elementary substance fatty acid in the blood stream. A great variety of fatty acids, the individuality of their physicochemical properties, great stereochemic differences of saturated and polyenic fatty acids make their transport virtually impossible. The steric individuality of fatty acids can be reduced if the acids are covalently bonded by a matrix as complex lipids. For formation of complex lipids, nature prefers esterification of fatty acids with alcohols which have a varying hydrophoby, such as glycerol, sphingosine, cholesterol, cetyl alcohol. The steric differences of saturated and polyenic fatty acids form a basis for their being structurized in different lipids. Triacyl glycerides are a transport form of saturated, monounsaturated fatty acids and their transforms and give rise to a crystalline phase. Phospholipids and cholesterol esters are a transport form of mainly polyunsaturated fatty acids in the polar phase in the former case and in the crystalline phase in the latter one. The individual apolipoproteins structure complex lipids into individual lipoprotein particles and transport them in the hydrated medium of blood flow. Saturated fatty acids chiefly transport lipoprotein particles formed by apoB-48- and apoB-100-isoproteins. Polyenic acids transport mainly high-density apoA-1-lipoprotein particles, which makes up a main physiological function of the latter. Cholesterol is nothing more than a matrix; it reesterifies polyenic fatty acids from the polar transport form of phospholipids into the unpolar transport form of cholesterol esters. Cholesterol esterification of polyenic fatty acids may structure complex lipid in the unpolar phase and transport it to the cells via apoB-100-ligand-receptor interaction, which is considered to be a key stage in the multistage process of active transport to the cells of polyenic fatty acids. However, the significant differences of active and inactive transport of polyenic fatty acids in the blood stream await a separate consideration.

A bottom-up approach to the strong CP problem

NASA Astrophysics Data System (ADS)

Diaz-Cruz, J. L.; Hollik, W. G.; Saldana-Salazar, U. J.

2018-05-01

The strong CP problem is one of many puzzles in the theoretical description of elementary particle physics that still lacks an explanation. While top-down solutions to that problem usually comprise new symmetries or fields or both, we want to present a rather bottom-up perspective. The main problem seems to be how to achieve small CP violation in the strong interactions despite the large CP violation in weak interactions. In this paper, we show that with minimal assumptions on the structure of mass (Yukawa) matrices, they do not contribute to the strong CP problem and thus we can provide a pathway to a solution of the strong CP problem within the structures of the Standard Model and no extension at the electroweak scale is needed. However, to address the flavor puzzle, models based on minimal SU(3) flavor groups leading to the proposed flavor matrices are favored. Though we refrain from an explicit UV completion of the Standard Model, we provide a simple requirement for such models not to show a strong CP problem by construction.

Pions to Quarks

NASA Astrophysics Data System (ADS)

Brown, Laurie Mark; Dresden, Max; Hoddeson, Lillian

2009-01-01

Part I. Introduction; 1. Pions to quarks: particle physics in the 1950s Laurie M Brown, Max Dresden and Lillian Hoddeson; 2. Particle physics in the early 1950s Chen Ning Yang; 3. An historian's interest in particle physics J. L. Heilbron; Part II. Particle discoveries in cosmic rays; 4. Cosmic-ray cloud-chamber contributions to the discovery of the strange particles in the decade 1947-1957 George D. Rochester; 5. Cosmic-ray work with emulsions in the 1940s and 1950s Donald H. Perkins; Part III. High-energy nuclear physics; Learning about nucleon resonances with pion photoproduction Robert L. Walker; 7. A personal view of nucleon structure as revealed by electron scattering Robert Hofstadter; 8. Comments on electromagnetic form factors of the nucleon Robert G. Sachs and Kameshwar C. Wali; Part IV. The new laboratory; 9. The making of an accelerator physicist Matthew Sands; 10. Accelerator design and construction in the 1950s John P. Blewett; 11. Early history of the Cosmotron and AGS Ernest D. Courant; 12. Panel on accelerators and detectors in the 1950s Lawrence W. Jones, Luis W. Alvarez, Ugo Amaldi, Robert Hofstadter, Donald W. Kerst, Robert R. Wilson; 13. Accelerators and the Midwestern Universities Research Association in the 1950s Donald W. Kerst; 14. Bubbles, sparks and the postwar laboratory Peter Galison; 15. Development of the discharge (spark) chamber in Japan in the 1950s Shuji Fukui; 16. Early work at the Bevatron: a personal account Gerson Goldhaber; 17. The discovery of the antiproton Owen Chamberlain; 18. On the antiproton discovery Oreste Piccioni; Part V. The Strange Particles; 19. The hydrogen bubble chamber and the strange resonances Luis W. Alvarez; 20. A particular view of particle physics in the fifties Jack Steinberger; 21. Strange particles William Chinowsky; 22. Strange particles: production by Cosmotron beams as observed in diffusion cloud chambers William B. Fowler; 23. From the 1940s into the 1950s Abraham Pais; Part VI. Detection of the neutrino Frederick Reines; 25. Recollections on the establishment of the weak-interaction notion Bruno M. Pontecorvo; 26. Symmetry and conservation laws in particle physics in the fifties Louis Michel; 27. A connection between the strong and weak interactions Sam B. Treiman; Part VII. Weak interactions and parity nonconservation; 29. The nondiscovery of parity nonconservation Allan Franklin; 30. K-meson decays and parity violation Richard H. Dalitz; 31. An Experimentalist's Perspective Val L. Fitch; 32. The early experiments leading to the V - A interaction Valentine L. Telegdi; 33. Midcentury adventures in particles physics E. C. G. Sudarshan; Part VIII. The particle physics community; 34. The postwar political economy of high-energy physics Robert Seidel; 35. The history of CERN during the early 1950s Edoardo Amaldi; 36. Arguments pro and contra the European laboratory in the participating countries Armin Hermann; 37. Physics and excellences of the life it brings Abdus Salam; 38. Social aspects of Japanese particle physics in the 1950s Michiji Konuma; Part IX. Theories of hadrons; 39. The early S-matrix theory and its propagation (1942-1952) Helmut Rechenberg; 40. From field theory to phenomenology: the history of dispersion relations Andy Pickering; 41. Particles as S-matrix poles: hadron democracy Geoffrey F. Chew; 42. The general theory of quantised fields in the 1950s Arthur S. Wrightman; 43. The classification and structure of hadrons Yuval Ne'eman; 44. Gauge principle, vector-meson dominance and spontaneous symmetry breaking Yoichiro Nambu; Part X. Personal overviews; 45. Scientific impact of the first decade of the Rochester conferences (1950-1960) Robert E. Marshak; 46. Some reflections on the history of particle physics in the 1950s Silvan S. Schweber; 47. Progress in elementary particle theory 1950-1964 Murray Gell-Mann.

Higgs Boson: god particle or divine comedy?

NASA Astrophysics Data System (ADS)

Rangacharyulu, Chary

2013-10-01

While particle physicists around the world rejoice the announcement of discovery of Higgs particle as a momentous event, it is also an opportune moment to assess the physicists' conception of nature. Particle theorists, in their ingenious efforts to unravel mysteries of the physical universe at a very fundamental level, resort to macroscopic many body theoretical methods of solid state physicists. Their efforts render the universe a superconductor of correlated quasi-particle pairs. Experimentalists, devoted to ascertain the elementary constituents and symmetries, depend heavily on numerical simulations based on those models and conform to theoretical slang in planning and interpretation of measurements . It is to the extent that the boundaries between theory/modeling and experiment are blurred. Is it possible that they are meandering in Dante's Inferno?

Classroom Interaction: A Sociological Approach

ERIC Educational Resources Information Center

Calonico, James M.; Calonico, Beth Ann

1972-01-01

The authors employ Bales' IPA and apply hypotheses from Homans' Human Group'' to present a sociological approach to the scientific study of classroom interaction at the elementary school level. (Authors)

Elementary Particle Physics at Syracuse. Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Catterall, Simon; Hubisz, Jay; Balachandran, Aiyalam

2013-01-05

This final report describes the activities of the high energy theory group at Syracuse University for the period 1 January 2010 through April 30 2013. The research conducted by the group includes lattice gauge theory, non-commutative geometry, phenomenology and mathematical physics.

Composite Structural Motifs of Binding Sites for Delineating Biological Functions of Proteins

PubMed Central

Kinjo, Akira R.; Nakamura, Haruki

2012-01-01

Most biological processes are described as a series of interactions between proteins and other molecules, and interactions are in turn described in terms of atomic structures. To annotate protein functions as sets of interaction states at atomic resolution, and thereby to better understand the relation between protein interactions and biological functions, we conducted exhaustive all-against-all atomic structure comparisons of all known binding sites for ligands including small molecules, proteins and nucleic acids, and identified recurring elementary motifs. By integrating the elementary motifs associated with each subunit, we defined composite motifs that represent context-dependent combinations of elementary motifs. It is demonstrated that function similarity can be better inferred from composite motif similarity compared to the similarity of protein sequences or of individual binding sites. By integrating the composite motifs associated with each protein function, we define meta-composite motifs each of which is regarded as a time-independent diagrammatic representation of a biological process. It is shown that meta-composite motifs provide richer annotations of biological processes than sequence clusters. The present results serve as a basis for bridging atomic structures to higher-order biological phenomena by classification and integration of binding site structures. PMID:22347478

Teaching and Learning Science in Authoritative Classrooms: Teachers' Power and Students' Approval in Korean Elementary Classrooms

NASA Astrophysics Data System (ADS)

Lee, Jeong-A.; Kim, Chan-Jong

2017-09-01

This study aims to understand interactions in Korean elementary science classrooms, which are heavily influenced by Confucianism. Ethnographic observations of two elementary science teachers' classrooms in Korea are provided. Their classes are fairly traditional teaching, which mean teacher-centered interactions are dominant. To understand the power and approval in science classroom discourse, we have adopted Critical Discourse Analysis (CDA). Based on CDA, form and function analysis was adopted. After the form and function analysis, all episodes were analyzed in terms of social distance. The results showed that both teachers exercised their power while teaching. However, their classes were quite different in terms of getting approval by students. When a teacher got students' approval, he could conduct the science lesson more effectively. This study highlights the importance of getting approval by students in Korean science classrooms.

Teacher-Student Interactions during Read Alouds in the Elementary Classroom

ERIC Educational Resources Information Center

Rouech, Kristina E.

2013-01-01

Reading aloud to students is an important topic in educational research. Previous research clearly identified effective components and benefits of reading aloud to elementary students; however, very little data addresses the exact wording of the kinds of questions teachers ask and the responses that students give during a read aloud. This study…

The GALAXY Classroom: An Interactive, Thematic Approach to Literacy Instruction.

ERIC Educational Resources Information Center

Lewison, Mitzi

The GALAXY Classroom, developed as a nation-wide reform effort, was designed to make a significant positive difference in the educational lives of elementary school students who have traditionally been labeled "at-risk." As part of a 2-year demonstration and research phase, 39 elementary schools across the United States (and one school…

Pedagogy, Performance and Politics: Issues in the Study of Primary Education.

ERIC Educational Resources Information Center

Campbell, R. J.; Kyriakides, L.

2000-01-01

Presents an essay review of Inside the Primary Classroom, 20 Years On, which reports on a 1976 study of teacher-student interaction in English elementary classrooms (the ORACLE project) and discusses the next 20 years of elementary education in England, examining curriculum reform, educational policy, educational research, and related politics.…

Gifted Elementary Students' Interactions with Female and Male Scientists in a Biochemistry Enrichment Program.

ERIC Educational Resources Information Center

She, Candace Hsiao-Ching; Barrow, Lloyd H.

1997-01-01

Examines how gender and self-concept relate to gifted elementary students' participation in a biochemistry enrichment program taught by female and male scientists. Students with low self-concepts asked more questions and received more feedback than students with high self-concepts. Student-initiated questions and gender differences in interaction…

Change in Elementary School Students' Misconceptions on Material Systems after a Theoretical-Practical Instruction

ERIC Educational Resources Information Center

Cañada-Cañada, Florentina; González-Gómez, David; Airado-Rodríguez, Diego; Melo Niño, Lina Viviana; Dávila Acedo, María Antonia

2017-01-01

Students get to Elementary School with a series of misconceptions which are not necessarily in agreement with the scientific knowledge. Misconceptions result from the student's attempts to understand their previous experiences resulting from their interaction with their environment and they must be taken into account in educational practice to…

Improving the Self-Concept and Social Interaction of Low Incidence Children in a Rural Elementary School through Education in the Least Restrictive Environment.

ERIC Educational Resources Information Center

Hulme, Bruce W.

1989-01-01

Describes procedures for mainstreaming multihandicapped children at the elementary level in a program designed to meet children's individual needs while developing positive social skills, self-esteem, communication skills, and daily living skills. Notes benefits for regular education students. (Author/SV)

The Roles of Nondisabled Peers in Promoting the Social Competence of Students with Intellectual Disabilities in Inclusive Classrooms.

ERIC Educational Resources Information Center

Cozzul, Marilyn Challis; Freeze, Rick; Lutfiyya, Zana Marie; Van Walleghem, John

2004-01-01

Educators often expect students with intellectual disabilities in inclusive elementary school classrooms to develop social competence through interactions with their peers. In this qualitative study, semi structured indepth interviews were used to investigate elementary school teachers' perspectives on student social competence, the quality of…

Elementary Teachers' Use of Formative Assessment to Support Students' Learning about Interactions between the Hydrosphere and Geosphere

ERIC Educational Resources Information Center

Forbes, Cory T.; Sabel, Jaime L.; Biggers, Mandy

2015-01-01

Students' thinking should serve as the foundation of effective science curriculum and instruction. To promote science learning, particularly in the geosciences, teachers must attend to students' existing ideas about natural phenomena through the use of ''high-leverage'' instructional practices such as formative assessment. Elementary teachers need…

Figuring the World of Designing: Expert Participation in Elementary Classroom

ERIC Educational Resources Information Center

Kangas, Kaiju; Seitamaa-Hakkarainen, Pirita; Hakkarainen, Kai

2013-01-01

The purpose of the present article was to analyze the interaction between elementary students and a professional design expert. The expert was present in the classroom, facilitating a collaborative lamp designing process together with the teacher. Using the notion of "figured worlds" (Holland et al. 1998), we explored how learning could be…

Factors Affecting the Happiness of Urban Elementary School Students: An Exploratory Study

ERIC Educational Resources Information Center

Tenney, Jodiann K.

2011-01-01

The purpose of this transformative mixed methods study was to examine the school happiness of upper elementary students in three Connecticut urban demonstration schools. The study examined the differences in students' happiness based on ethnicity, gender, and their interaction. It also investigated the factors that affect students' happiness in…

Examining How Activity Shapes Students' Interactions While Creating Representations in Early Elementary Science

ERIC Educational Resources Information Center

Danish, Joshua Adam; Saleh, Asmalina

2014-01-01

It is common practice in elementary science classrooms to have students create representations, such as drawings, as a way of exploring new content. While numerous studies suggest the benefits of representation in science, the majority focus on specific, canonical representations, such as graphs. Few offer insight or guidance regarding how…

Interactive Augmented Reality System for Enhancing Library Instruction in Elementary Schools

ERIC Educational Resources Information Center

Chen, Chih-Ming; Tsai, Yen-Nung

2012-01-01

Due to limited budgets and manpower, most elementary schools in Taiwan do not plan or provide library instruction for students. Although students can use libraries, they typically lack the knowledge needed to use library resources effectively. Consequently, students have difficulty finding the books they need and can easily become overwhelmed by…

Design, Customization and Implementation of Energy Simulation with 5E Model in Elementary Classroom

ERIC Educational Resources Information Center

Lye, Sze Yee; Wee, Loo Kang; Kwek, Yao Chie; Abas, Suriati; Tay, Lee Yong

2014-01-01

Science simulations are popular among educators as such simulations afford for multiple visual representation and interactivity. Despite the popularity and abundance on the internet, our literature review suggested little research has been conducted on the use of simulation in elementary school. Thus, an exploratory pilot case study was conducted…

Teacher Management of Elementary Classroom Social Dynamics: Associations with Changes in Student Adjustment

ERIC Educational Resources Information Center

Gest, Scott D.; Madill, Rebecca A.; Zadzora, Kathleen M.; Miller, Aaron M.; Rodkin, Philip C.

2014-01-01

Teachers and students in 54 elementary school classrooms (first, third, and fifth grades) participated in a multi-method longitudinal study of classroom social dynamics. At each of three assessments within a single school year, observers rated teacher-student interaction quality, students completed sociometric assessments and reported on their…

Interacting with a Suite of Educative Features: Elementary Science Teachers' Use of Educative Curriculum Materials

ERIC Educational Resources Information Center

Arias, Anna Maria; Bismack, Amber Schultz; Davis, Elizabeth A.; Palincsar, Annemarie Sullivan

2016-01-01

New reform documents underscore the importance of learning both the practices and content of science. This integration of practices and content requires sophisticated teaching that does not often happen in elementary classrooms. Educative curriculum materials--materials explicitly designed to support teacher and student learning--have been posited…

Observing Emotional Interactions between Teachers and Students in Elementary School Classrooms

ERIC Educational Resources Information Center

Yan, Elizabeth M.; Evans, Ian M.; Harvey, Shane T.

2011-01-01

Fostering emotional skills in the elementary (primary) school classroom can lead to improved learning outcomes, more prosocial behavior, and positive emotional development. Incorporating emotional skill development into the naturalistic and implicit teaching environment is a key feature of what is meant by the emotional climate of the classroom.…

Promoting Social Norms for Scientific Discourse: Planning Decisions of an Urban Elementary Teacher

ERIC Educational Resources Information Center

Mangiante, Elaine Silva

2015-01-01

This case study examined planning decisions made and challenges faced by an elementary teacher in a high-poverty urban district to promote students' adoption of social norms of interaction for scientific discourse. Through interviews, document analyses, and observations during a science unit, the findings indicated that the teacher's planning…

Social and Emotional Learning around Technology in a Cross-Cultural, Elementary Classroom

ERIC Educational Resources Information Center

Iaosanurak, Chuanpob; Chanchalor, Sumalee; Murphy, Elizabeth

2016-01-01

The purpose of the study reported on in this paper was to design and test an intervention with elementary-aged children to promote social and emotional learning around technology. The intervention structured learning around technology as a catalyst and scaffolding tool that engages learners in cross-cultural, collaborative interaction, dialogue,…

Electrostatic effects on dust particles in space

NASA Astrophysics Data System (ADS)

Leung, Philip; Wuerker, Ralph

1992-02-01

The star scanner of the Magellan spacecraft experienced operational anomalies continuously during Magellan's journey to Venus. These anomalies were attributed to the presence of dust particles in the vicinity of the spacecraft. The dust particles, which were originated from the surface of thermal blankets, were liberated when the electrostatic force acting on them was of sufficient magnitude. In order to verify this hypothesis, an experimental program was initiated to study the mechanisms responsible for the release of dust particles from a spacecraft surface. In the experiments, dust particles were immersed in a plasma and/or subjected to ultra-violet irradiation. Results showed that the charging state of a dust particle was strongly dependent on the environment, and the charge on a dust particle was approximately 10(exp 3) elementary charges. Consequently, in the space environment, electrostatic force could be the most dominant force acting on a dust particle.

We teach as we are taught: exploring the potential for emotional climate to enhance elementary science preservice teacher education

NASA Astrophysics Data System (ADS)

Olitsky, Stacy

2013-09-01

Bellocchi, Ritchie, Tobin, Sandhu and Sandhu's (2013) study highlights the crucial role that emotions play in learning at the university level in a preservice secondary science teacher education class. They examine the classroom structures that tended to lead to both a positive valence and a high level of intensity of the emotional climate (EC). This article explores the implications of their study for better understanding how to foster a positive classroom emotional climate for elementary level preservice teachers, given the specifics of elementary school environments. Drawing on theories of interactional solidarity. I explore the implications of EC for increasing pre-service teachers' capacity to avoid order-giving rituals and to create science-centered communities in their classrooms. I also suggest possible areas for future research, such as the role of expectations in EC, the different EC outcomes of lectures, EC and the development of confidence in science, and the ways in which teacher candidates are positioned within interaction rituals in elementary science methods classes.

Experimental benchmark of kinetic simulations of capacitively coupled plasmas in molecular gases

NASA Astrophysics Data System (ADS)

Donkó, Z.; Derzsi, A.; Korolov, I.; Hartmann, P.; Brandt, S.; Schulze, J.; Berger, B.; Koepke, M.; Bruneau, B.; Johnson, E.; Lafleur, T.; Booth, J.-P.; Gibson, A. R.; O'Connell, D.; Gans, T.

2018-01-01

We discuss the origin of uncertainties in the results of numerical simulations of low-temperature plasma sources, focusing on capacitively coupled plasmas. These sources can be operated in various gases/gas mixtures, over a wide domain of excitation frequency, voltage, and gas pressure. At low pressures, the non-equilibrium character of the charged particle transport prevails and particle-based simulations become the primary tools for their numerical description. The particle-in-cell method, complemented with Monte Carlo type description of collision processes, is a well-established approach for this purpose. Codes based on this technique have been developed by several authors/groups, and have been benchmarked with each other in some cases. Such benchmarking demonstrates the correctness of the codes, but the underlying physical model remains unvalidated. This is a key point, as this model should ideally account for all important plasma chemical reactions as well as for the plasma-surface interaction via including specific surface reaction coefficients (electron yields, sticking coefficients, etc). In order to test the models rigorously, comparison with experimental ‘benchmark data’ is necessary. Examples will be given regarding the studies of electron power absorption modes in O2, and CF4-Ar discharges, as well as on the effect of modifications of the parameters of certain elementary processes on the computed discharge characteristics in O2 capacitively coupled plasmas.

TOWARD THE FORMATION OF CARBONACEOUS REFRACTORY MATTER IN HIGH TEMPERATURE HYDROCARBON-RICH ATMOSPHERES OF EXOPLANETS UPON MICROMETEOROID IMPACT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dangi, Beni B.; Kim, Yong S.; Krasnokutski, Serge A.

2015-05-20

We report on laboratory simulation experiments mimicking the chemical processing of model atmospheres of exoplanets containing C3 and C4 hydrocarbons at moderate temperatures of 400 K upon interaction of catalytic surfaces of micrometeoroids. By utilizing an ultrasonic levitator device and heating singly levitated particles under simulated microgravity conditions, Raman spectroscopy is utilized as a non-invasive tool to probe on line and in situ the conversion of C3 and C4 hydrocarbons to refractory carbonaceous matter on the surfaces of levitated particles. Secondary Ion Mass Spectrometry and electron microscopic imaging were also conducted to gain further insight into the elementary composition andmore » structures of the refractories formed. Our results provide compelling evidence that in the presence of a catalytic surface, which can be supplied in the form of micrometeoroids and atmospheric dust particles, hydrocarbon gases present in the atmospheres of exoplanets can be converted to refractory, carbon-rich carbonaceous matter of mainly graphitic structure with a carbon content of at least 90% at elevated temperatures. This finding might explain the low methane to carbon monoxide (CH{sub 4}–CO) ratio in the hot Neptune GJ 436b, where the abundant methane photochemically converts to higher order hydrocarbons and ultimately to refractory graphite-like carbon in the presence of a silicon surface.« less

A discovery! The Higgs? Why is this important? How it was done.

ScienceCinema

Dawson, Sally; Gordan, Howard

2017-12-09

Data collected during 2011 and 2012 at the Large Hadron Collider (LHC) at CERN in Switzerland, the world's highest-energy proton collider, has culminated in the discovery of a new particle that is about 135 times heavier than a proton. But is it really the Higgs particle predicted by the theory that explains the origin of the mass of most elementary particles in the universe? The discovery and its possible identity is discussed by two Brookhaven Lab physicists, Sally Dawson and Howard Gordon, with deep roots in the hunt for the Higgs.

An Alternative Proposal for the Graphical Representation of Anticolor Charge

NASA Astrophysics Data System (ADS)

Wiener, Gerfried J.; Schmeling, Sascha M.; Hopf, Martin

2017-11-01

We have developed a learning unit based on the Standard Model of particle physics, featuring novel typographic illustrations of elementary particles and particle systems. Since the unit includes antiparticles and systems of antiparticles, a visualization of anticolor charge was required. We propose an alternative to the commonly used complementary-color method, whereby antiparticles and antiparticle systems are identified through the use of stripes instead of a change in color. We presented our proposal to high school students and physics teachers, who evaluated it to be a more helpful way of distinguishing between color charge and anticolor charge.

Modeling Bose-Einstein correlations via elementary emitting cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Utyuzh, Oleg; Wilk, Grzegorz; Wlodarczyk, Zbigniew

2007-04-01

We propose a method of numerical modeling Bose-Einstein correlations by using the notion of the elementary emitting cell (EEC). They are intermediary objects containing identical bosons and are supposed to be produced independently during the hadronization process. Only bosons in the EEC, which represents a single quantum state here, are subjected to the effects of Bose-Einstein (BE) statistics, which forces them to follow a geometrical distribution. There are no such effects between particles from different EECs. We illustrate our proposition by calculating a representative number of typical distributions and discussing their sensitivity to EECs and their characteristics.

E-Invariant Quantized Motion of Valence Quarks

NASA Astrophysics Data System (ADS)

Kreymer, E. L.

2018-06-01

In sub-proton space wave processes are impossible. The analog of the Klein-Gordon equation in sub-proton space is elliptical and describes a stationary system with a constant number of particles. For dynamical processes, separation of variables is used and in each quantum of motion of the quark two states are distinguished: a localization state and a translation state with infinite velocity. Alternation of these states describes the motion of a quark. The mathematical expectations of the lifetimes of the localization states and the spatial extents of the translation states for a free quark and for a quark in a centrally symmetric potential are found. The action after one quantum of motion is equal to the Planck constant. The one-sided Laplace transform is used to determine the Green's function. Use of path integrals shows that the quantized trajectory of a quark is a broken line enveloping the classical trajectory of oscillation of the quark. Comparison of the calculated electric charge distribution in a proton with its experimental value gives satisfactory results. A hypothesis is formulated, according to which the three Grand Geometries of space correspond to the three main interactions of elementary particles.

Liouville master equation for multi-electron dynamics during ion-surface interactions

NASA Astrophysics Data System (ADS)

Wirtz, L.; Reinhold, C. O.; Lemell, C.; Burgdorfer, J.

2003-05-01

We present a simulation of the neutralization of highly charged ions in front of a LiF(100) surface including the close-collision regime above the surface. Our approach employs a Monte-Carlo solution of the Liouville master equation for the joint probability density of the ionic motion and the electronic population of the projectile and the target surface. It includes single as well as double particle-hole (de)excitation processes and incorporates electron correlation effects through the conditional dynamics of population strings. The input in terms of elementary one- and two-electron transfer rates is determined from CTMC calculations as well as quantum mechanical Auger calculations. For slow projectiles and normal incidence, the ionic motion depends sensitively on the interplay between image acceleration towards the surface and repulsion by an ensemble of positive hole charges in the surface (``trampoline effect"). For Ne10+ ions we find that image acceleration dominates and no collective backscattering high above the surface takes place. For grazing incidence, our simulation delineates the pathways to complete neutralization. In accordance with recent experimental observations, most ions are reflected as neutrals or even as singly charged negative particles, irrespective of the charge state of the incoming ion.

Teaching the mole concept with sub-micro level: Do the students perform better?

NASA Astrophysics Data System (ADS)

Indriyanti, Nurma Yunita; Barke, Hans-Dieter

2017-08-01

The concept of mole is an abstract concept of sub-micro level. The main problem in chemistry that should be encounter by educators is students' inability to transfer understanding between macro level and sub-micro level. Particle-oriented approach is created due to improper expression in the term of mole on books and classroom learning. A mole is the amount of substance of a system, which contains as many elementary entities as there are atoms in 0,012 kg of carbon-12. When the mole is used, the elementary entities must be specified; they may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles. The study presented here focuses on students' activity and response taught by mole triangle implemented in German and Indonesian classroom. Two classes of grade-10 were involved in each country. The way of students perform in the test was analyzed. Hands-on activities were used as an entrance and followed by particle-oriented expression. In worksheets of each hands-on experience, students should write the correct expression of mole concept. The results of the study indicated that there is different level of understanding in representing knowledge in learning the mole. The use of correct expression will ensure that students see meaningful relationships and can easily go back and forth between macro, sub-micro and symbolic level.

Measurement of CKM-angle γ with Charmed B 0 Meson Decays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baak, Max Arjen

2007-02-05

This thesis reports measurements of the time-dependent CP asymmetries in fully reconstructed B 0 → (D (*)∓π ± and B 0 → D ∓ ρ ± ) decays in approximately 232 million Y(4S) → Bmore » $$\\bar{B}$$ events, collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the Stanford Linear Accelerator Center in California, as published in Ref. [14]. The phenomenon of CP violation allows one to distinguish between matter and antimatter, and, as such, is one of the essential ingredients needed to explain the apparent abundance of matter over antimatter in the universe. The Standard Model describes the observed elementary particles in terms of three generations of quarks and leptons, as well as the weak, electromagnetic, and strong interactions between them. In the Standard Model, CP violation is incorporated in the Cabibbo-Kobayashi-Maskawa (CKM) matrix, which describes the weak interactions between the quarks. The weak interactions between quarks are described by coupling constants that are functions of three real parameters and one irreducible complex phase. The magnitude of all CP violating effects in the Standard Model is related to this complex phase. The measurement of the CP violating phase of the CKM matrix is an important part of the present scientific program in particle physics. Violation of the CP symmetry manifests itself as a non-zero area of the Unitarity Triangle. The Unitarity Triangle needs to be overconstrained by experimental measurements in order to demonstrate that the CKM mechanism is the correct explanation of this phenomenon. No stringent measurement of the CKM-angle γ is yet available.« less

MPPhys—A many-particle simulation package for computational physics education

NASA Astrophysics Data System (ADS)

Müller, Thomas

2014-03-01

In a first course to classical mechanics elementary physical processes like elastic two-body collisions, the mass-spring model, or the gravitational two-body problem are discussed in detail. The continuation to many-body systems, however, is deferred to graduate courses although the underlying equations of motion are essentially the same and although there is a strong motivation for high-school students in particular because of the use of particle systems in computer games. The missing link between the simple and the more complex problem is a basic introduction to solve the equations of motion numerically which could be illustrated, however, by means of the Euler method. The many-particle physics simulation package MPPhys offers a platform to experiment with simple particle simulations. The aim is to give a principle idea how to implement many-particle simulations and how simulation and visualization can be combined for interactive visual explorations. Catalogue identifier: AERR_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AERR_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 111327 No. of bytes in distributed program, including test data, etc.: 608411 Distribution format: tar.gz Programming language: C++, OpenGL, GLSL, OpenCL. Computer: Linux and Windows platforms with OpenGL support. Operating system: Linux and Windows. RAM: Source Code 4.5 MB Complete package 242 MB Classification: 14, 16.9. External routines: OpenGL, OpenCL Nature of problem: Integrate N-body simulations, mass-spring models Solution method: Numerical integration of N-body-simulations, 3D-Rendering via OpenGL. Running time: Problem dependent

Geometrization of quantum physics

NASA Astrophysics Data System (ADS)

Ol'Khov, O. A.

2009-12-01

It is shown that the Dirac equation for free particle can be considered as a description of specific distortion of the space euclidean geometry (space topological defect). This approach is based on possibility of interpretation of the wave function as vector realizing representation of the fundamental group of the closed topological space-time 4-manifold. Mass and spin appear to be topological invariants. Such concept explains all so called “strange” properties of quantum formalism: probabilities, wave-particle duality, nonlocal instantaneous correlation between noninteracting particles (EPR-paradox) and so on. Acceptance of suggested geometrical concept means rejection of atomistic concept where all matter is considered as consisting of more and more small elementary particles. There is no any particles a priori, before measurement: the notions of particles appear as a result of classical interpretation of the contact of the region of the curved space with a device.

Big Bang Day: 5 Particles - 1. The Electron

ScienceCinema

None

2017-12-09

Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 1. The Electron Just over a century ago, British physicist J.J. Thompson experimenting with electric currents and charged particles inside empty glass tubes, showed that atoms are divisible into indivisible elementary particles. But how could atoms be built up of these so called "corpuscles"? An exciting 30 year race ensued, to grasp the planetary model of the atom with its orbiting electrons, and the view inside the atom was born. Whilst the number of electrons around the nucleus of an atom determines their the chemistry of all elements, the power of electrons themselves have been harnessed for everyday use: electron beams for welding,cathode ray tubes and radiation therapy.

Effect of Stochastic Charge Fluctuations on Dust Dynamics

NASA Astrophysics Data System (ADS)

Matthews, Lorin; Shotorban, Babak; Hyde, Truell

2017-10-01

The charging of particles in a plasma environment occurs through the collection of electrons and ions on the particle surface. Depending on the particle size and the plasma density, the standard deviation of the number of collected elementary charges, which fluctuates due to the randomness in times of collisions with electrons or ions, may be a significant fraction of the equilibrium charge. We use a discrete stochastic charging model to simulate the variations in charge across the dust surface as well as in time. The resultant asymmetric particle potentials, even for spherical grains, has a significant impact on the particle coagulation rate as well as the structure of the resulting aggregates. We compare the effects on particle collisions and growth in typical laboratory and astrophysical plasma environments. This work was supported by the National Science Foundation under Grant PHY-1414523.

Identification and Reporting of Child Sexual Abuse: The Role of Elementary School Professionals

ERIC Educational Resources Information Center

Hinkelman, Lisa; Bruno, Michelle

2008-01-01

The purpose of this article is to summarize aspects of theory and research on child sexual abuse that suggest best practices for identifying and addressing abuse involving elementary school children. Teachers and school counselors often have the most interaction with children this age, yet they may feel inadequately prepared to intervene…

Effects of Pedagogical Agent Gestures on Social Acceptance and Learning: Virtual Real Relationships in an Elementary Foreign Language Classroom

ERIC Educational Resources Information Center

Davis, Robert; Antonenko, Pavlo

2017-01-01

Pedagogical agents (PAs) are lifelike characters in virtual environments that help facilitate learning through social interactions and the virtual real relationships with the learners. This study explored whether and how PA gesture design impacts learning and agent social acceptance when used with elementary students learning foreign language…

Elementary Teachers' Formative Evaluation Practices in an Era of Curricular Reform in Quebec, Canada

ERIC Educational Resources Information Center

Thomas, Lynn; Deaudelin, Colette; Desjardins, Julie; Dezutter, Olivier

2011-01-01

This study examines the formative evaluation practices of 13 experienced elementary school teachers in Quebec, Canada at the level of teacher-student interaction. The qualitative study is based on both semi-structured and stimulated recall interviews as well as videotapes of classroom activities. The participating teachers were found to be using…

Learning without Boundaries: Developing Mobile Learning Scenarios for Elementary and Middle School Language Arts & Mathematics

ERIC Educational Resources Information Center

Evans, Michael A.; Gracanin, Denis

2009-01-01

This article provides an overview to a collaborative knowledge building project using iPod Touches in elementary and secondary language arts and mathematics classrooms, working with 4 teachers and over 80 students. The interactive technologies for embodied Learning in Reading and Mathematics (iteL*RM) project intends to facilitate student…

FACILITATING LEARNING AND INDIVIDUAL DEVELOPMENT, TOWARD A THEORY FOR ELEMENTARY GUIDANCE. MINNESOTA GUIDANCE SERIES.

ERIC Educational Resources Information Center

GRAMS, ARMIN

A THEORY UPON WHICH ELEMENTARY GUIDANCE PROGRAMS CAN BE SOUNDLY DESIGNED IS PRESENTED. A MAJOR THEME IS THAT PSYCHOLOGICAL WELL-BEING OR GOOD ADJUSTMENT IS RELATED TO LEARNED, INDIVIDUAL COMPETENCIES SUCH AS COMMUNICATION AND INTERACTION IN DEPTH WITH OTHERS. THE APPROPRIATE CONCERN OF GUIDANCE THEN BECOMES TO FOSTER THESE COMPETENCIES, THUS…

Development of a Peer-Assisted Learning Strategy in Computer-Supported Collaborative Learning Environments for Elementary School Students

ERIC Educational Resources Information Center

Tsuei, Mengping

2011-01-01

This study explores the effects of Electronic Peer-Assisted Learning for Kids (EPK), on the quality and development of reading skills, peer interaction and self-concept in elementary students. The EPK methodology uses a well-developed, synchronous computer-supported, collaborative learning system to facilitate students' learning in Chinese. We…

Group Tasks, Activities, Dynamics, and Interactions in Collaborative Robotics Projects with Elementary and Middle School Children

ERIC Educational Resources Information Center

Yuen, Timothy T.; Boecking, Melanie; Stone, Jennifer; Tiger, Erin Price; Gomez, Alvaro; Guillen, Adrienne; Arreguin, Analisa

2014-01-01

Robotics provide the opportunity for students to bring their individual interests, perspectives and areas of expertise together in order to work collaboratively on real-world science, technology, engineering and mathematics (STEM) problems. This paper examines the nature of collaboration that manifests in groups of elementary and middle school…

Teacher Consultation and Coaching within Mental Health Practice: Classroom and Child Effects in Urban Elementary Schools

ERIC Educational Resources Information Center

Cappella, Elise; Hamre, Bridget K.; Kim, Ha Yeon; Henry, David B.; Frazier, Stacy L.; Atkins, Marc S.; Schoenwald, Sonja K.

2012-01-01

Objective: To examine effects of a teacher consultation and coaching program delivered by school and community mental health professionals on change in observed classroom interactions and child functioning across one school year. Method: Thirty-six classrooms within 5 urban elementary schools (87% Latino, 11% Black) were randomly assigned to…

Scholarly Practice and Inquiry: Dynamic Interactions in an Elementary Mathematics Methods Course

ERIC Educational Resources Information Center

Tyminski, Andrew M.; Brittain, McKenzie H.

2017-01-01

This paper represents research that exists at the crossroad of scholarly practice and scholarly inquiry. We share the design, enactment and empirical examination of an elementary methods course activity, Exploring and Supporting Student Thinking (ESST) which engaged 18 prospective teachers in two sessions of one on one problem posing with 3rd…

Educational Possibilities of Keeping Goats in Elementary Schools in Japan

PubMed Central

Koda, Naoko; Kutsumi, Shiho; Hirose, Toshiya; Watanabe, Gen

2016-01-01

Many Japanese elementary schools keep small animals for educational purposes, and the effects and challenges have been investigated. Although goats are medium-sized animals that are familiar to Japanese, few practical studies have been conducted on keeping goats in schools. This study investigated the effects and challenges of keeping goats in elementary schools and discussed its educational possibilities. A semi-structured interview survey was conducted with 11 personnel that were responsible for keeping goats in 6 elementary schools in urban areas. They described benefits, problems, and tips related to keeping goats. Participant observation was also conducted on daily human–goat interactions in these schools. The results indicated that children in all six grades were able to care for goats. Goats were used for various school subjects and activities. As a result of keeping goats, children developed affection for them, attitude of respect for living things, greater sense of responsibility, and enhanced interpersonal interactional skills. Stronger ties between the schools and parents and community were developed through cooperation in goat-keeping. Some anxieties existed about the risk of injury to children when interacting with goats. Other challenges included the burden of taking care of the goats on holidays and insufficient knowledge about treatment in case of their illness or injury. The results suggested similarities to the benefits and challenges associated with keeping small animals in elementary schools, although the responsibility and the burden on the schools were greater for keeping goats than small animals because of their larger size and the need for children to consider the goats’ inner state and to cooperate with others when providing care. At the same time, goats greatly stimulated interest, cooperation, and empathy in children. Goats can expand educational opportunities and bring about many positive effects on child development. PMID:28083538

Educational Possibilities of Keeping Goats in Elementary Schools in Japan.

PubMed

Koda, Naoko; Kutsumi, Shiho; Hirose, Toshiya; Watanabe, Gen

2016-01-01

Many Japanese elementary schools keep small animals for educational purposes, and the effects and challenges have been investigated. Although goats are medium-sized animals that are familiar to Japanese, few practical studies have been conducted on keeping goats in schools. This study investigated the effects and challenges of keeping goats in elementary schools and discussed its educational possibilities. A semi-structured interview survey was conducted with 11 personnel that were responsible for keeping goats in 6 elementary schools in urban areas. They described benefits, problems, and tips related to keeping goats. Participant observation was also conducted on daily human-goat interactions in these schools. The results indicated that children in all six grades were able to care for goats. Goats were used for various school subjects and activities. As a result of keeping goats, children developed affection for them, attitude of respect for living things, greater sense of responsibility, and enhanced interpersonal interactional skills. Stronger ties between the schools and parents and community were developed through cooperation in goat-keeping. Some anxieties existed about the risk of injury to children when interacting with goats. Other challenges included the burden of taking care of the goats on holidays and insufficient knowledge about treatment in case of their illness or injury. The results suggested similarities to the benefits and challenges associated with keeping small animals in elementary schools, although the responsibility and the burden on the schools were greater for keeping goats than small animals because of their larger size and the need for children to consider the goats' inner state and to cooperate with others when providing care. At the same time, goats greatly stimulated interest, cooperation, and empathy in children. Goats can expand educational opportunities and bring about many positive effects on child development.

Elementary Particles and the Universe

NASA Astrophysics Data System (ADS)

Schwarz, John H.

2005-07-01

1. Excess baggage J. Hartle; 2. Through the clouds E. Witten; 3. Covariant foundations of the superparticle L. Brink; 4. Chiral symmetry and confinement T. Goldman; 5. The original fifth interaction Y. Neeman; 6. The mass hierarchy of leptons and quarks H. Fritzsch; 7. Spacetime duality in string theory J. H. Schwarz; 8. Symmetry and quasi-symmetry Y. Nambu; 9. On an exceptional non-associative superspace M. Gunaydin; 10. Algebra of reparametrization-invariant and normal ordered operators in open string field theory P. Ramond; 11. Superconductivity of an ideal charged boson system T. D. Lee; 12. Some remarks on the symmetry approach to nuclear rotational motion L. C. Biedebharn and P. Truini; 13. Uncomputability, intractability and the efficiency of heat engines S. Lloyd; 14. The new mathematical physics I. Singer; 15. For the birds V. Telegdi; 16. Gell-Mann's approach to physics A. Salam; 17. Remarks M. Goldberger.

The Inertia Reaction Force and Its Vacuum Origin

NASA Astrophysics Data System (ADS)

Rueda, Alfonso; Haisch, Bernard

By means of a covariant approach we show that there must be a contribution to the inertial mass and to the inertial reaction force on an accelerated massive object by the zero-point electromagnetic field. This development does not require any detailed model of the accelerated object other than the knowledge that it interacts electromagnetically. It is shown that inertia can indeed be construed as an opposition of the vacuum fields to any change to the uniform state of motion of an object. Interesting insights originating from this result are discussed. It is argued why the proposed existence of a Higgs field in no way contradicts or is at odds with the above statements. The Higgs field is responsible for assigning mass to elementary particles. It is argued that still the underlying reason for the opposition to acceleration that massive objects present requires an explanation. The explanation proposed here fulfills that requirement.

PuMA: the Porous Microstructure Analysis software

NASA Astrophysics Data System (ADS)

Ferguson, Joseph C.; Panerai, Francesco; Borner, Arnaud; Mansour, Nagi N.

2018-01-01

The Porous Microstructure Analysis (PuMA) software has been developed in order to compute effective material properties and perform material response simulations on digitized microstructures of porous media. PuMA is able to import digital three-dimensional images obtained from X-ray microtomography or to generate artificial microstructures. PuMA also provides a module for interactive 3D visualizations. Version 2.1 includes modules to compute porosity, volume fractions, and surface area. Two finite difference Laplace solvers have been implemented to compute the continuum tortuosity factor, effective thermal conductivity, and effective electrical conductivity. A random method has been developed to compute tortuosity factors from the continuum to rarefied regimes. Representative elementary volume analysis can be performed on each property. The software also includes a time-dependent, particle-based model for the oxidation of fibrous materials. PuMA was developed for Linux operating systems and is available as a NASA software under a US & Foreign release.

Quadratic time dependent Hamiltonians and separation of variables

NASA Astrophysics Data System (ADS)

Anzaldo-Meneses, A.

2017-06-01

Time dependent quantum problems defined by quadratic Hamiltonians are solved using canonical transformations. The Green's function is obtained and a comparison with the classical Hamilton-Jacobi method leads to important geometrical insights like exterior differential systems, Monge cones and time dependent Gaussian metrics. The Wei-Norman approach is applied using unitary transformations defined in terms of generators of the associated Lie groups, here the semi-direct product of the Heisenberg group and the symplectic group. A new explicit relation for the unitary transformations is given in terms of a finite product of elementary transformations. The sequential application of adequate sets of unitary transformations leads naturally to a new separation of variables method for time dependent Hamiltonians, which is shown to be related to the Inönü-Wigner contraction of Lie groups. The new method allows also a better understanding of interacting particles or coupled modes and opens an alternative way to analyze topological phases in driven systems.

Localized states and their stability in an anharmonic medium with a nonlinear defect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerasimchuk, I. V., E-mail: igor.gera@gmail.com

2015-10-15

A comprehensive analysis of soliton states localized near a plane defect (a defect layer) possessing nonlinear properties is carried out within a quasiclassical approach for different signs of nonlinearity of the medium and different characters of interaction of elementary excitations of the medium with the defect. A quantum interpretation is given to these nonlinear localized modes as a bound state of a large number of elementary excitations. The domains of existence of such states are determined, and their properties are analyzed as a function of the character of interaction of elementary excitations between each other and with the defect. Amore » full analysis of the stability of all the localized states with respect to small perturbations of amplitude and phase is carried out analytically, and the frequency of small oscillations of the state localized on the defect is determined.« less

Health Risk Assessment of Lead Ingestion Exposure by Particle Sizes in Crumb Rubber on Artificial Turf Considering Bioavailability

PubMed Central

Kim, Sunduk; Yang, Ji-Yeon; Kim, Ho-Hyun; Yeo, In-Young; Shin, Dong-Chun

2012-01-01

Objectives The purpose of this study was to assess the risk of ingestion exposure of lead by particle sizes of crumb rubber in artificial turf filling material with consideration of bioavailability. Methods This study estimated the ingestion exposure by particle sizes (more than 250 um or less than 250 um) focusing on recyclable ethylene propylene diene monomer crumb rubber being used as artificial turf filling. Analysis on crumb rubber was conducted using body ingestion exposure estimate method in which total content test method, acid extraction method and digestion extraction method are reflected. Bioavailability which is a calibrating factor was reflected in ingestion exposure estimate method and applied in exposure assessment and risk assessment. Two methods using acid extraction and digestion extraction concentration were compared and evaluated. Results As a result of the ingestion exposure of crumb rubber material, the average lead exposure amount to the digestion extraction result among crumb rubber was calculated to be 1.56×10-4 mg/kg-day for low grade elementary school students and 4.87×10-5 mg/kg-day for middle and high school students in 250 um or less particle size, and that to the acid extraction result was higher than the digestion extraction result. Results of digestion extraction and acid extraction showed that the hazard quotient was estimated by about over 2 times more in particle size of lower than 250 um than in higher than 250 um. There was a case of an elementary school student in which the hazard quotient exceeded 0.1. Conclusions Results of this study confirm that the exposure of lead ingestion and risk level increases as the particle size of crumb rubber gets smaller. PMID:22355803

Uses for Free Film Cans

ERIC Educational Resources Information Center

Batoff, Mitchell E.; Harmen, Jerry

1973-01-01

Describes multiple uses of empty film cans for equipping an elementary school science classroom. Instructional units in which film cans may be useful include buoyancy, mobiles, growing seeds, peas and particles, rocks and minerals, structures, field studies, sound, balancing, electricity, pedulums, chemical change, and optics, light, color. (PS)

The Mathematical Structure of Elementary Particles.

DTIC Science & Technology

1983-10-01

Physical Mathematics) *Instituto de Matematica Pura e Aplicada, Estrada Dona Castorina 110, 22460 Rio de Janeiro, Brazil Sponsored by the United...is the basic method of analysis to be employed in this work. *Instituto de Matematica Pura e Aplicada, Estrada Dona Castorina 110, 22460 Rio de Janeiro

Fermilab Today

Science.gov Websites

go back to my regular existence." The complete interview and Nobel Prize Veltman book Martinus Veltman's book was published in 2003. autobiography are available online. The title of Veltman's colloquium is taken from his recently published book. "Facts and Mysteries in Elementary Particle Physics

Physics News in 1983.

ERIC Educational Resources Information Center

Schewe, Phillip F., Ed.

Information is provided on some of the interesting and newsworthy developments in physics and its related fields during 1983. Areas considered include: (1) acoustics; (2) astrophysics; (3) condensed matter physics; (4) crystallography; (5) physics education; (6) electron and atomic physics; (7) elementary particle physics; (8) fluid dynamics; (9)…

75 FR 63865 - Proposal Review Panel for Physics; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-18

... NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Physics; Notice of Meeting In accordance... announces the following meeting. Name: Michigan State University Site Visit in Physics (1208). Date and Time... Reidy, Program Director for Elementary Particle Physics, National Science Foundation, 4201 Wilson Blvd...

75 FR 70952 - Proposal Review Panel for Physics; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-19

... NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Physics; Notice of Meeting In accordance with the Federal Advisory Committee Act (Pub. L. 92- 463, as amended), the National Science Foundation... Director for Elementary Particle Physics, National Science Foundation, 4201 Wilson Blvd., Arlington, VA...

75 FR 63865 - Proposal Review Panel for Physics; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-18

... NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Physics; Notice of Meeting In accordance... announces the following meeting. Name: University of Chicago Site Visit in Physics (1208). Date and Time..., Program Director for Elementary Particle Physics, National Science Foundation, 4201 Wilson Blvd...

75 FR 3493 - Proposal Review Panel for Physics; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-21

... NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Physics; Notice of Meeting In accordance... announces the following meeting. Name: University of Nebraska Site Visit in Physics (1208). Date and Time... Director for Elementary Particle Physics, National Science Foundation, 4201 Wilson Blvd., Arlington, VA...

75 FR 70952 - Proposal Review Panel for Physics; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-19

... NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Physics; Notice of Meeting In accordance with the Federal Advisory Committee Act (Pub. L. 92- 463, as amended), the National Science Foundation... for Elementary Particle Physics, National Science Foundation, 4201 Wilson Blvd., Arlington, VA 22230...

Spatial localization of nanoparticle growth in photoinduced nanocomposites

NASA Astrophysics Data System (ADS)

Smirnov, Anton A.; Pikulin, Alexander; Bityurin, Nikita

2018-02-01

Photoinduced nanocomposites are the polymer materials where the nanoparticles can be generated by the light irradiation. The single atoms of metal are formed due to the photoreduction of the metal-containing precursor added to the polymer matrix. Then the atoms precipitate into the nanoparticles (NPs). Similarly, semiconductor NPs are assembled from the monomer species such as CdS, which can be released due to the photodestruction of the appropriate precursor. We analyze theoretically the possibility of spatial confinement of growing nanoparticles in a domain where the elementary species are generated by a three-dimensionally localized source. It is shown that the effective confinement can be achieved only if the size of the generation domain exceeds some critical spatial scale determined by the parameters of the system. The confinement is provided by the trapping of the diffusing elementary species by the growing nanoparticles. The proposed model considers the irreversible particle growth, typical for the noble metals. Both the nucleation and the particle growth processes are suggested to be diffusion controlled.

Space Exploration

NASA Technical Reports Server (NTRS)

Davis, Jeffrey R.

2006-01-01

This abstract covers a one hour presentation on Space Exploration. The audience is elementary students; therefore there are few words on the slides, mostly pictures of living and working in space. The presentation opens with a few slides describing a day in the life of a space explorer. It begins with a launch, discussions of day-night cycles, eating, exercising, housekeeping, EVA, relaxation, and sleeping. The next section of the presentation shows photos of astronauts performing experiments on the ISS. Yokomi Elementary School launched this fall with the most advanced educational technology tools available in schools today. The science and technology magnet school is equipped with interactive white boards, digital projectors, integrated sound systems and several computers for use by teachers and students. The only elementary school in Fresno Unified with a science focus also houses dedicated science classrooms equipped specifically for elementary students to experience hands-on science instruction in addition to the regular elementary curriculum.

Solitary solutions including spatially localized chaos and their interactions in two-dimensional Kolmogorov flow.

PubMed

Hiruta, Yoshiki; Toh, Sadayoshi

2015-12-01

Two-dimensional Kolmogorov flow in wide periodic boxes is numerically investigated. It is shown that the total flow rate in the direction perpendicular to the force controls the characteristics of the flow, especially the existence of spatially localized solitary solutions such as traveling waves, periodic solutions, and chaotic solutions, which can behave as elementary components of the flow. We propose a procedure to construct approximate solutions consisting of solitary solutions. It is confirmed by direct numerical simulations that these solutions are stable and represent interactions between elementary components such as collisions, coexistence, and collapse of chaos.

Thermo-optically induced interactions in photon Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Alaeian, Hadiseh; Bartels, Clara; Weitz, Martin

Bose-Einstein condensation (BEC), a new state of matter, emerges when the de Broglie wavelength of bosons becomes larger than the particle separation, leading to a macroscopic occupation of the system ground state. Followed by the first experimental demonstrations of BEC in cold atomic gases, this phase transition has been observed in other bosonic gases, as polaritons and phonons. The most recent one, photon BEC, is a promising candidate for a new generation of coherent photon sources. Due to their infancy, however, many of their properties are still unknown or only partly explored. In this talk I will present my latest results on the implications of photon interactions in photon BECs. In particular, I will investigate the effect of a thermo-optic non-linearity, leading to spatially non-local and delayed interactions. Starting from the steady state behavior, I will explore the spectrum of elementary excitations as a small perturbation. Moreover, I will discuss the resulting effective photon dispersion, manifesting various properties including possible superfluidity, as well as roton and maxon modes. The implications of physical parameters as absorption, number of photons in the condensate, and cavity trap on the dispersion will be discussed. The results of this study shed new light on the implication of interactions in photonic many-body systems. Hadiseh Alaeian acknowledges the generous support from Alexander von Humboldt Foundation.

Mass generation, the cosmological constant problem, conformal symmetry, and the Higgs boson

NASA Astrophysics Data System (ADS)

Mannheim, Philip D.

2017-05-01

In 2013 the Nobel Prize in Physics was awarded to Francois Englert and Peter Higgs for their work in 1964 along with the late Robert Brout on the mass generation mechanism (the Higgs mechanism) in local gauge theories. This mechanism requires the existence of a massive scalar particle, the Higgs boson, and in 2012 the Higgs boson was finally discovered at the Large Hadron Collider after being sought for almost half a century. In this article we review the work that led to the discovery of the Higgs boson and discuss its implications. We approach the topic from the perspective of a dynamically generated Higgs boson that is a fermion-antifermion bound state rather than an elementary field that appears in an input Lagrangian. In particular, we emphasize the connection with the Bardeen-Cooper-Schrieffer theory of superconductivity. We identify the double-well Higgs potential not as a fundamental potential but as a mean-field effective Lagrangian with a dynamical Higgs boson being generated through a residual interaction that accompanies the mean-field Lagrangian. We discuss what we believe to be the key challenge raised by the discovery of the Higgs boson, namely determining whether it is elementary or composite, and through study of a conformal invariant field theory model as realized with critical scaling and anomalous dimensions, suggest that the width of the Higgs boson might serve as a suitable diagnostic for discriminating between an elementary Higgs boson and a composite one. We discuss the implications of Higgs boson mass generation for the cosmological constant problem, as the cosmological constant receives contributions from the very mechanism that generates the Higgs boson mass in the first place. We show that the contribution to the cosmological constant due to a composite Higgs boson is more tractable and under control than the contribution due to an elementary Higgs boson, and is potentially completely under control if there is an underlying conformal symmetry not just in a critical scaling matter sector (which there would have to be if all mass scales are to be dynamical), but equally in the gravity sector to which the matter sector couples.

New fermionic dark matters, extended Standard Model and cosmic rays

NASA Astrophysics Data System (ADS)

Hwang, Jae-Kwang

2017-08-01

Three generations of leptons and quarks correspond to the lepton charges (LCs) in this work. Then, the leptons have the electric charges (ECs) and LCs. The quarks have the ECs, LCs and color charges (CCs). Three heavy leptons and three heavy quarks are introduced to make the missing third flavor of EC. Then the three new particles which have the ECs are proposed as the bastons (dark matters) with the rest masses of 26.121 eV/c2, 42.7 GeV/c2 and 1.9 × 1015 eV/c2. These new particles are applied to explain the origins of the astrophysical observations like the ultra-high energy cosmic rays and supernova 1987A anti-neutrino data. It is concluded that the 3.5 keV X-ray peak observed from the cosmic X-ray background spectra is originated not from the pair annihilations of the dark matters but from the X-ray emission of the Q1 baryon atoms which are similar in the atomic structure to the hydrogen atom. The presence of the 3.5 keV cosmic X-ray supports the presence of the Q1 quark with the EC of -4/3. New particles can be indirectly seen from the astrophysical observations like the cosmic ray and cosmic gamma ray. In this work, the systematic quantized charges of EC, LC and CC for the elementary particles are used to consistently explain the decay and reaction schemes of the elementary particles. Also, the strong, weak and dark matter forces are consistently explained.

Across-horizon scattering and information transfer

NASA Astrophysics Data System (ADS)

Emelyanov, V. A.; Klinkhamer, F. R.

2018-06-01

We address the question whether or not two electrically charged elementary particles can Coulomb scatter if one of these particles is inside the Schwarzschild black-hole horizon and the other outside. It can be shown that the quantum process is consistent with the local energy–momentum conservation law. This result implies that across-horizon scattering is a physical effect, relevant to astrophysical black holes. We propose a Gedankenexperiment which uses the quantum scattering process to transfer information from inside the black-hole horizon to outside.

The symmetry and simplicity of the laws of physics and the Higgs boson

DOE PAGES

Maldacena, Juan

2015-11-12

We describe the theoretical ideas, developed between the 1950s–1970s, which led to the prediction of the Higgs boson, the particle that was discovered in 2012. The forces of nature are based on symmetry principles. We explain the nature of these symmetries through an economic analogy. We also discuss the Higgs mechanism, which is necessary to avoid some of the naive consequences of these symmetries, and to explain various features of elementary particles.

An exact solution of the Currie-Hill equations in 1 + 1 dimensional Minkowski space

NASA Astrophysics Data System (ADS)

Balog, János

2014-11-01

We present an exact two-particle solution of the Currie-Hill equations of Predictive Relativistic Mechanics in 1 + 1 dimensional Minkowski space. The instantaneous accelerations are given in terms of elementary functions depending on the relative particle position and velocities. The general solution of the equations of motion is given and by studying the global phase space of this system it is shown that this is a subspace of the full kinematic phase space.

Particle count and black carbon measurements at schools in Las Vegas, NV and in the greater Salt Lake City, UT area.

PubMed

Brown, Steven G; Vaughn, David L; Roberts, Paul T

2017-11-01

As part of two separate studies aimed to characterize ambient pollutant concentrations at schools in urban areas, we compare black carbon and particle count measurements at Adcock Elementary in Las Vegas, NV (April-June 2013), and Hunter High School in the West Valley City area of greater Salt Lake City, UT (February 2012). Both schools are in urban environments, but Adcock Elementary is next to the U.S. 95 freeway. Black carbon (BC) concentrations were 13% higher at Adcock compared to Hunter, while particle count concentrations were 60% higher. When wind speeds were low-less than 2 m/sec-both BC and particle count concentrations were significantly higher at Adcock, while concentrations at Hunter did not have as strong a variation with wind speed. When wind speeds were less than 2 m/sec, emissions from the adjacent freeway greatly affected concentrations at Adcock, regardless of wind direction. At both sites, BC and particle count concentrations peaked in the morning during commute hours. At Adcock, particle count also peaked during midday or early afternoon, when BC was low and conditions were conducive to new particle formation. While this midday peak occurred at Adcock on roughly 45% of the measured days, it occurred on only about 25% of the days at Hunter, since conditions for particle formation (higher solar radiation, lower wind speeds, lower relative humidity) were more conducive at Adcock. Thus, children attending these schools are likely to be exposed to pollution peaks during school drop-off in the morning, when BC and particle count concentrations peak, and often again during lunchtime recess when particle count peaks again. Particle count concentrations at two schools were shown to typically be independent of BC or other pollutants. At a school in close proximity to a major freeway, particle count concentrations were high during the midday and when wind speeds were low, regardless of wind direction, showing a large area of effect from roadway emissions even when the school was not downwind of the roadway. At the second school, which sits in an urban neighborhood away from freeways, high particle counts occurred even though solar radiation was low during wintertime conditions, meaning that exposure to high particle counts can occur throughout the year.

Modeling the Influences of Upper-Elementary School Students' Digital Reading Literacy, Socioeconomic Factors, and Self-Regulated Learning Strategies

ERIC Educational Resources Information Center

Chen, Shin-Feng

2017-01-01

Background: Reading is an interactive and constructive process of making meaning by engaging a variety of materials and sources and by participating in reading communities at school or in daily life. Aim: The purpose of this study was to explore the factors affecting digital reading literacy among upper-elementary school students. Method: A…

A Study of Implicit Theories and Beliefs about Teaching in Elementary School Teachers.

ERIC Educational Resources Information Center

Marcelo, Carlos

In this study interactive teaching of two math teachers at elementary schools in Spain was observed. Focus was on the description of the principles of the practice which guide the teaching activities of the subjects, because it was felt these principles form the base of teachers' theories with respect to the teaching and the students. During a…

The Power of Knowledge: A Critical Analysis of the Depiction of Ethnic Minorities in China's Elementary Textbooks

ERIC Educational Resources Information Center

Chu, Yiting

2015-01-01

This study critically analyzes knowledge about: (1) ethnic minority groups; (2) the dominant Han group; and (3) the interaction between ethnic minorities and Han presented in three types of elementary textbooks used in China. The analysis reveals that the knowledge about and the values and beliefs of the Han people are overwhelmingly dominant in…

Staff Perceptions of the Effect of the Leader in Me on Student Motivation and Peer Relationships in Elementary School

ERIC Educational Resources Information Center

Tidd, Charlene

2016-01-01

Staff and student surveys at Lane Elementary School (pseudonym) confirm that students lack motivation to complete class work and often struggle to interact appropriately with one another. Similar concerns are reported across the United States as indicated by national Gallup Poll results on student motivation, peer relationships, and feelings of…

Studying the Effects of Quantitatively Defined Teaching Strategies on Students in Elementary School Science Using Macro-Interaction Analysis Techniques.

ERIC Educational Resources Information Center

Penick, John E.; And Others

The effects of two patterns of teacher behavior on student behavior were investigated, using eight elementary teachers (grades 1-5) and their 250 students. The teacher behavior was conceptualized in terms of the amount of restriction placed on the activities of science students. Fifty students were randomly assigned, with equalizing restrictions…

Adopting Just-in-Time Teaching in the Context of an Elementary Science Education Methodology Course

ERIC Educational Resources Information Center

Osmond, Pamela; Goodnough, Karen

2011-01-01

In this self-study, Pamela, a new science teacher educator, adopted Just-in-Time Teaching (JiTT) in the context of an elementary science education methodology course. JiTT is a teaching and learning strategy involving interaction between web-based study assignments and face-to-face class sessions. Students respond electronically to web-based…

The American Cowboy: Developing Small Group Social Studies Interaction Experiences in the Elementary Classroom.

ERIC Educational Resources Information Center

Holmes, Edward, Jr.

Appropriate for elementary school students, this resource unit on the American cowboy provides four activities for small group work. The unit also lists objectives and discusses the organization and dynamics of small groups. The general objective is for the student to learn how to work within groups and how to resolve group conflict. The…

Elementary School Industrial Arts Interaction Technology for Children. A Positive Approach to Education for a Changing Society.

ERIC Educational Resources Information Center

Louisiana State Dept. of Education, Baton Rouge.

Prepared by the vocational education division of a state department of education and compiled by industrial arts educators, this resource guide provides a conceptual basis for the elementary teacher using industrial arts as a means of introducing children to industrial processes and orienting them to the physical and material world. Included in…

Elementary School Students' Interaction with the Planned Curriculum Through Their Valuing, Adapting, and Modifying Subject Matter.

ERIC Educational Resources Information Center

Zuga, Karen F.

Ways in which elementary school students value, adapt, and modify the curriculum are revealed by reporting statements of children in grades 2 through 4 in a midwestern parochial school. Over 250 hours of observation as well as interviews with students, teachers, parents, and the principal formed the basis of research. Data were assembled through…

Elastic collisions of classical point particles on a finite frictionless linear track with perfectly reflecting endpoints

NASA Astrophysics Data System (ADS)

DeLuca, R.

2006-03-01

Repeated elastic collisions of point particles on a finite frictionless linear track with perfectly reflecting endpoints are considered. The problem is analysed by means of an elementary linear algebra approach. It is found that, starting with a state consisting of a projectile particle in motion at constant velocity and a target particle at rest in a fixed known position, the points at which collisions occur on track, when plotted versus progressive numerals, corresponding to the collisions themselves, show periodic patterns for a rather large choice of values of the initial position x(0) and on the mass ratio r. For certain values of these parameters, however, only regular behaviour over a large number of collisions is detected.

Hybrid architecture for encoded measurement-based quantum computation

PubMed Central

Zwerger, M.; Briegel, H. J.; Dür, W.

2014-01-01

We present a hybrid scheme for quantum computation that combines the modular structure of elementary building blocks used in the circuit model with the advantages of a measurement-based approach to quantum computation. We show how to construct optimal resource states of minimal size to implement elementary building blocks for encoded quantum computation in a measurement-based way, including states for error correction and encoded gates. The performance of the scheme is determined by the quality of the resource states, where within the considered error model a threshold of the order of 10% local noise per particle for fault-tolerant quantum computation and quantum communication. PMID:24946906

Tree-level S-matrix of Pohlmeyer reduced form of AdS 5 × S 5 superstring theory

NASA Astrophysics Data System (ADS)

Hoare, B.; Tseytlin, A. A.

2010-02-01

With a motivation to find a 2-d Lorentz-invariant solution of the AdS 5 × S 5 superstring we continue the study of the Pohlmeyer-reduced form of this theory. The reduced theory is constructed from currents of the superstring sigma model and is classically equivalent to it. Its action is that of G/ H = Sp(2, 2) × Sp(4)/[SU(2)]4 gauged WZW model deformed by an integrable potential and coupled to fermions. This theory is UV finite and is conjectured to be related to the superstring theory also at the quantum level. Expanded near the trivial vacuum it has the same elementary excitations (8+8 massive bosonic and fermionic 2-d degrees of freedom) as the AdS 5 × S 5 superstring in the S 5 light-cone gauge or near plane-wave expansion. In contrast to the superstring case, the interaction terms in the reduced action are manifestly 2-d Lorentz invariant. Since the theory is integrable, its S-matrix should be effectively determined by the two-particle scattering. Here we explicitly compute the tree-level two-particle S-matrix for the elementary excitations of the reduced theory. We find that this S-matrix has the same index structure and group factorization properties as the superstring S-matrix computed in hep-th/0611169 but has simpler coefficients, depending only on the difference of two rapidities. While the gauge-fixed form of the reduced action has only the bosonic [SU(2)]4 part of the PSU(2|2) × PSU(2|2) symmetry of the light-cone superstring spectrum as its manifest symmetry we conjecture that it should also have a hidden fermionic symmetry that effectively interchanges bosons and fermions and which should guide us towards understanding the relation between the two S-matrices.

Detailing Relational Interactions in Urban Elementary Mathematics Classrooms

ERIC Educational Resources Information Center

Battey, Dan; Neal, Rebecca A.

2018-01-01

The lack of quality of instruction in urban mathematics classrooms in the United States has received much attention in the scholarly literature. Other classroom mechanisms such as relational interactions, however, have not received much attention of mathematics education researchers. Relational interactions go above and beyond content instruction…

Big Bang Day: 5 Particles - 1. The Electron

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2009-10-07

Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 1. The Electron Just over a century ago, British physicist J.J. Thompson experimenting with electric currents and charged particles inside empty glass tubes, showed that atoms are divisible into indivisible elementary particles. But how could atoms be built up of these so called "corpuscles"? An exciting 30 year race ensued, to grasp the planetary model of the atom with its orbiting electrons, and the view inside the atom was born.more » Whilst the number of electrons around the nucleus of an atom determines their the chemistry of all elements, the power of electrons themselves have been harnessed for everyday use: electron beams for welding,cathode ray tubes and radiation therapy.« less

Event-chain Monte Carlo algorithms for three- and many-particle interactions

NASA Astrophysics Data System (ADS)

Harland, J.; Michel, M.; Kampmann, T. A.; Kierfeld, J.

2017-02-01

We generalize the rejection-free event-chain Monte Carlo algorithm from many-particle systems with pairwise interactions to systems with arbitrary three- or many-particle interactions. We introduce generalized lifting probabilities between particles and obtain a general set of equations for lifting probabilities, the solution of which guarantees maximal global balance. We validate the resulting three-particle event-chain Monte Carlo algorithms on three different systems by comparison with conventional local Monte Carlo simulations: i) a test system of three particles with a three-particle interaction that depends on the enclosed triangle area; ii) a hard-needle system in two dimensions, where needle interactions constitute three-particle interactions of the needle end points; iii) a semiflexible polymer chain with a bending energy, which constitutes a three-particle interaction of neighboring chain beads. The examples demonstrate that the generalization to many-particle interactions broadens the applicability of event-chain algorithms considerably.

Effect of alkali on the structure of cell envelopes of Chlamydia psittaci elementary bodies.

PubMed Central

Narita, T; Wyrick, P B; Manire, G P

1976-01-01

Suspensions of isolated cell envelopes of infectious elementary bodies (EB) of Chlamydia psittaci at alkaline pH showed a rapid, extensive decrease in absorbance, accompanied by the release of a cell envelope component in a sedimentable form. This phenomenon was observed both at 0 C and with envelopes which had been previously heated to 100 C. Monovalent and divalent cations effectively inhibited the turbidity loss, whereas ethylenediaminetetraacetate (EDTA) caused an accelerated decrease in turbidity. The turbidity loss observed after incubation of the envelopes at alkaline pH could be reversed to the level of the initial value by dialysis against distilled water containing Mg2+. Thin-section electron photomicrographs of purified EB exposed to alkaline buffer with EDTA revealed the loss of the internal contents of cells, but these cells still maintained their round shapes. The cell surface of treated EB appeared pitted in negatively stained preparations, whereas intact EB had a smooth surface. Electron microscopic studies on negatively stained preparations of the clear supernatant obtained after the treatment of the envelope with alkaline buffer containing EDTA demonstrated the presence of spherical particles, approximately 6 to 7 nm in diameter, and rodlike particles, which appeared to be made up of two or more spherical particles. Images PMID:1375

The Discovery of Subatomic Particles Revised Edition

NASA Astrophysics Data System (ADS)

Weinberg, Steven

2003-09-01

This commentary on the discovery of the atom's constituents provides an historical account of key events in the physics of the twentieth century that led to the discoveries of the electron, proton and neutron. Steven Weinberg introduces the fundamentals of classical physics that played crucial roles in these discoveries. Connections are shown throughout the book between the historic discoveries of subatomic particles and contemporary research at the frontiers of physics, including the most current discoveries of new elementary particles. Steven Weinberg was Higgins Professor of Physics at Harvard before moving to The University of Texas at Austin, where he founded its Theory Group. At Texas he holds the Josey Regental Chair of Science and is a member of the Physics and Astronomy Departments. His research has spanned a broad range of topics in quantum field theory, elementary particle physics, and cosmology, and has been honored with numerous awards, including the Nobel Prize in Physics, the National Medal of Science, the Heinemann Prize in Mathematical Physics, the Cresson Medal of the Franklin Institute, the Madison Medal of Princeton University, and the Oppenheimer Prize. In addition to the well-known treatise, Gravitation and Cosmololgy, he has written several books for general readers, including the prize-winning The First Three Minutes (now translated into 22 foreign languages), and most recently Dreams of a Final Theory (Pantheon Books, 1993). He has also written a textbook The Quantum Theory of Fields, Vol.I, Vol. II, and Vol. III (Cambridge).

The Elusive Neutrino, Understanding the Atom Series.

ERIC Educational Resources Information Center

Bernstein, Jeremy

This booklet is one of the booklets in the "Understanding the Atom Series" published by the U. S. Atomic Energy Commission for high school science teachers and their students. The discovery of the neutrino and the research involving this important elementary particle of matter is discussed. The introductory section reviews topics basic…

Prospects for Physics in the 1990's Surveyed.

ERIC Educational Resources Information Center

Robinson, Arthur L.

1986-01-01

A National Academy of Science report ("Physics Through the 1990's") says that American physics has been a highly diversified and productive enterprise, but continued excellence cannot be taken for granted. Progress in six subfields (elementary particle, nuclear, condensed-matter, atomic/molecular, plasma/fluid, and gravitation/cosmology physics)…

Physics: A Career for You?

ERIC Educational Resources Information Center

American Inst. of Physics, New York, NY.

Information is provided for students who may be interested in pursuing a career in physics. This information includes the type of work done and areas studied by physicists in the following areas: nuclear physics, solid-state physics, elementary-particle physics, atomic/molecular/electron physics, fluid/plasma physics, space/planetary physics,…

Moments in the Life of a Scientist

NASA Astrophysics Data System (ADS)

Rossi, Bruno

2008-07-01

List of plates; Foreword; Preface; Prehistory; 1. Arcetri (1928-32); 2. Padua, Copenhagen, Manchester; 3. Physics of elementary particles in the Age of Innocence (1939-46); 4. Los Alamos (1943-46); 5. Cosmic rays at MIT (1946- ); 6. Physics in space; Postscript; As for me … Nora Rossi; Index.

SIMULTANEOUS PARTICLE AND MOLECULE MODELING (SPAMM): AN APPROACH FOR COMBINING SECTIONAL AEROSOL EQUATIONS AND ELEMENTARY GAS-PHASE REACTIONS. (R824970)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Main and Interaction Effects of Metallic Pollutants on Cognitive Functioning.

ERIC Educational Resources Information Center

Moon, Charles; And Others

1985-01-01

A study involving 69 randomly selected elementary students indicated that increases in arsenic and interaction of arsenic lead were significantly related to decreased reading and spelling achievement, and increases in aluminum and the interaction of aluminum with lead were significantly related to decreased visual-motor performance. (Author/CL)

The Nature of Interactions between Students with Severe Disabilities and Their Friends and Acquaintances without Disabilities.

ERIC Educational Resources Information Center

Grenot-Scheyer, Marquita

1994-01-01

This study of 20 elementary-school children with severe disabilities examined differences in their interactions with friends without disabilities compared with interactions with acquaintances without disabilities. Friends and acquaintances did not differ in developmental level, language age, functional movement, or social competence. Group…

Deaf Children in Communication: A Study of Communicative Strategies Used by Deaf Children in Social Interactions.

ERIC Educational Resources Information Center

Preisler, Gunilla

1984-01-01

Fifteen deaf elementary-age children were observed in free play, and their interactions were videotaped. Differences were noted in the interaction and communication skills of children with early sign language experience and orally trained deaf children with late sign language experience. (CL)

Electron Generation of Leptons and Hadrons with Conjugate α-QUANTIZED Lifetimes and Masses

NASA Astrophysics Data System (ADS)

Mac Gregor, Malcolm H.

In elementary particle theories the fine structure constant α = e2/ℏc serves as the coupling constant for lepton interactions (QED), but is assumed to play no role in hadron interactions (QCD). However, experiments have long indicated an α spacing in the lifetimes of the long-lived threshold-state hadrons, and they also suggest an α-related mass structure. Lifetimes and masses are conjugate quantum mechanical variables, so the α-dependence of these two variables is a mutual property. The relevance of α to hadron interactions is an experimental question, independent of theory. In the present paper we first make a detailed analysis of the experimental lifetime data. This analysis demonstrates that out of 156 particles with well-determined lifetimes τ, the 120 short excited-state lifetimes τ<10-21 sec have a continuum of values, but the 36 long threshold-state lifetimes τ>10-21 sec occur in α-spaced groups that cleanly sort out the s, c, b quark flavors. These 36 metastable lifetimes also exhibit a factor-of-3 c-to-b "flavor structure" and a pervasive factor-of-2 "hyperfine structure." We then invoke the conjugate relationship between lifetimes and masses to trace out an α-defined set of mass quanta that tie together leptons and hadrons. Mass generation occurs via an initial "α-leap" from an electron pair to a "platform state" M, and then subsequent excitations by a dominant quantum X. The low-mass "MX octet" of particles — μ, p, τ, π, η, η‧, K, ϕ — is reproduced to an average accuracy of 0.4%, with no adjustable parameters except a small binding energy for hadronic pairs. Without the inclusion of lepton masses, the spectrum of hadron masses is difficult to understand. These conjugate α-quantized results reinforce the reality of the spin 1/2 u, d, s, c, b quarks, and they also lead to the identification of a closely-related set of spinless mass quanta for the pseudoscalar mesons.

Preparing perservice teachers to teach elementary school science

NASA Astrophysics Data System (ADS)

Lewis, Amy D.

The development of scientifically literate citizens begins in the elementary school. Yet elementary school teachers are ill prepared to teach science (Trygstad, Smith, Banilower, Nelson, & Horizon Research, Inc., 2013). The research base on teacher preparation finds that programs designed to prepare elementary teachers are inadequate in providing both the content knowledge and pedagogical content knowledge necessary to teach science effectively (Baumgartner, 2010; Bodzin & Beerer, 2003; Bulunuz & Jarrett 2009). This mixed methods study examined what happened when a science methods course was interactively co-taught by an expert in elementary teaching methods and a physics expert. This study also aimed to discover what aspects of the curriculum pre-service teachers (PSTs) said helped them in developing their understanding of science content and scientific reasoning, and how to implement inquiry practices to teach science. A nested case study of three PSTs provided descriptive portraits of student experiences in the class. A whole class case analysis was used to examine what PSTs learned in terms of science, scientific reasoning skills, and pedagogical content knowledge (PCK) from their experiences in the course. It was found that students often conflated science content with the experiences they had in learning the content. Although PSTs felt the interactive co-teaching model effectively created a balance between theory and practice, it was their experiences doing science--conducting physical experiments, developing and discussing scientific models, and the use of inquiry-based instruction--that they credited for their learning. Even with careful curriculum planning, and a course purposely designed to bridge the theory to practice gap, this study found one semester-long methods course to be insufficient in providing the vast content knowledge and PCK elementary school science teachers need.

An Interactive Geometry Program and Its Effect on Elementary Students' Achievement and Understanding of Geometry: A Comparative Study

ERIC Educational Resources Information Center

DeMarinis, Matthew David

2011-01-01

While many studies examining the effectiveness of using dynamic geometry software exist, few studies exist at the elementary school level. An extensive data analysis of student performance on New York State Math Assessments revealed that students in the fifth grade may not have had a clear understanding of interior angles sums of polygons, more…

The Impact of Prolonged Participation in a Pro-Social Cognitive Behavioral Skills Program on Elementary Age Students, with Behavior Related Disorders, Behavior Accelerative, Behavior Reductive, and Return to Regular Classroom Outcomes

ERIC Educational Resources Information Center

Esser, Ted H.

2012-01-01

Overall, pretest-posttest results indicated statistically significant pretest beginning program compared to posttest ending program percentage of behavioral improvement for on task, following directions, and positive interactions outcomes improvement for individual students who completed the elementary grades pro-social cognitive behavioral skills…

Orbital Exponent Optimization in Elementary VB Calculations of the Chemical Bond in the Ground State of Simple Molecular Systems

ERIC Educational Resources Information Center

Magnasco, Valerio

2008-01-01

Orbital exponent optimization in the elementary ab-initio VB calculation of the ground states of H[subscript 2][superscript +], H[subscript 2], He[subscript 2][superscript +], He[subscript 2] gives a fair description of the exchange-overlap component of the interatomic interaction that is important in the bond region. Correct bond lengths and…

Patterns of Students' and Teachers' Interactions in Learning Centres: A Case Study of Three Teacher Leaders in an Elementary School

ERIC Educational Resources Information Center

Badger, James

2016-01-01

This study investigated the instructional practices of three teacher leaders employed in a diverse, elementary school in the USA. Through extended observations, it was found that learning centres occupied a central role in the organisation and learning in each of the classrooms. Bernstein's theory of classification and framing was used to analyse…

Unity in the Elementary School Classroom: Building Community Through Increasing Positive Social Interactions Between and Among Students

ERIC Educational Resources Information Center

Piatt-Jaeger, Sally

2011-01-01

Children's sense of a community is essential in elementary schools. This helps gives students a sense of belonging and control over their environment. The purpose of this study is to examine the impact of several strategies from the Toolbox Project and their effect on building community in the classroom. Collin (2003b) discusses his Toolbox…

Analysis of solid particles falling down and interacting in a channel with sedimentation using fictitious boundary method

NASA Astrophysics Data System (ADS)

Usman, K.; Walayat, K.; Mahmood, R.; Kousar, N.

2018-06-01

We have examined the behavior of solid particles in particulate flows. The interaction of particles with each other and with the fluid is analyzed. Solid particles can move freely through a fixed computational mesh using an Eulerian approach. Fictitious boundary method (FBM) is used for treating the interaction between particles and the fluid. Hydrodynamic forces acting on the particle's surface are calculated using an explicit volume integral approach. A collision model proposed by Glowinski, Singh, Joseph and coauthors is used to handle particle-wall and particle-particle interactions. The particulate flow is computed using multigrid finite element solver FEATFLOW. Numerical experiments are performed considering two particles falling and colliding and sedimentation of many particles while interacting with each other. Results for these experiments are presented and compared with the reference values. Effects of the particle-particle interaction on the motion of the particles and on the physical behavior of the fluid-particle system has been analyzed.

The Standard Model and Higgs physics

NASA Astrophysics Data System (ADS)

Torassa, Ezio

2018-05-01

The Standard Model is a consistent and computable theory that successfully describes the elementary particle interactions. The strong, electromagnetic and weak interactions have been included in the theory exploiting the relation between group symmetries and group generators, in order to smartly introduce the force carriers. The group properties lead to constraints between boson masses and couplings. All the measurements performed at the LEP, Tevatron, LHC and other accelerators proved the consistency of the Standard Model. A key element of the theory is the Higgs field, which together with the spontaneous symmetry breaking, gives mass to the vector bosons and to the fermions. Unlike the case of vector bosons, the theory does not provide prediction for the Higgs boson mass. The LEP experiments, while providing very precise measurements of the Standard Model theory, searched for the evidence of the Higgs boson until the year 2000. The discovery of the top quark in 1994 by the Tevatron experiments and of the Higgs boson in 2012 by the LHC experiments were considered as the completion of the fundamental particles list of the Standard Model theory. Nevertheless the neutrino oscillations, the dark matter and the baryon asymmetry in the Universe evidence that we need a new extended model. In the Standard Model there are also some unattractive theoretical aspects like the divergent loop corrections to the Higgs boson mass and the very small Yukawa couplings needed to describe the neutrino masses. For all these reasons, the hunt of discrepancies between Standard Model and data is still going on with the aim to finally describe the new extended theory.

Equation of state of wet granular matter.

PubMed

Fingerle, A; Herminghaus, S

2008-01-01

An expression for the near-contact pair correlation function of D -dimensional weakly polydisperse hard spheres is presented, which arises from elementary free-volume arguments. Its derivative at contact agrees very well with our simulations for D=2 . For jammed states, the expression predicts that the number of exact contacts is equal to 2D, in agreement with established simulations. When the particles are wetted, they interact by the formation and rupture of liquid capillary bridges. Since formation and rupture events of capillary bonds are well separated in configuration space, the interaction is hysteretic with a characteristic energy loss Ecb. The pair correlation is strongly affected by this capillary interaction depending on the liquid-bond status of neighboring particles. A theory is derived for the nonequilibrium probability currents of the capillary interaction which determines the pair correlation function near contact. This finally yields an analytic expression for the equation of state, P=P(N/V,T), of wet granular matter for D=2, valid in the complete density range from gas to jamming. Driven wet granular matter exhibits a van der Waals-like unstable branch at granular temperatures TT, is of relevance for aggregation in general, simulations have been performed which show very good agreement with the theoretically predicted coordination K of capillary bonds as a function of the bond length scrit. This result implies that particles that stick at the surface, scrit=0, form isostatic clusters. An extension of the theory in which the bridge coordination number K plays the role of a self-consistent mean-field is proposed.

Equation of state of wet granular matter

NASA Astrophysics Data System (ADS)

Fingerle, A.; Herminghaus, S.

2008-01-01

An expression for the near-contact pair correlation function of D -dimensional weakly polydisperse hard spheres is presented, which arises from elementary free-volume arguments. Its derivative at contact agrees very well with our simulations for D=2 . For jammed states, the expression predicts that the number of exact contacts is equal to 2D, in agreement with established simulations. When the particles are wetted, they interact by the formation and rupture of liquid capillary bridges. Since formation and rupture events of capillary bonds are well separated in configuration space, the interaction is hysteretic with a characteristic energy loss Ecb . The pair correlation is strongly affected by this capillary interaction depending on the liquid-bond status of neighboring particles. A theory is derived for the nonequilibrium probability currents of the capillary interaction which determines the pair correlation function near contact. This finally yields an analytic expression for the equation of state, P=P(N/V,T) , of wet granular matter for D=2 , valid in the complete density range from gas to jamming. Driven wet granular matter exhibits a van der Waals-like unstable branch at granular temperatures T

Change of Electroweak Nuclear Reaction Rates by CP- and Isospin Symmetry Breaking - A Model Calculation

NASA Astrophysics Data System (ADS)

Stumpf, Harald

2006-09-01

Based on the assumption that electroweak bosons, leptons and quarks possess a substructure of elementary fermionic constituents, in previous papers the effect of CP-symmetry breaking on the effective dynamics of these particles was calculated. Motivated by the phenomenological procedure in this paper, isospin symmetry breaking will be added and the physical consequences of these calculations will be discussed. The dynamical law of the fermionic constituents is given by a relativistically invariant nonlinear spinor field equation with local interaction, canonical quantization, selfregularization and probability interpretation. The corresponding effective dynamics is derived by algebraic weak mapping theorems. In contrast to the commonly applied modifications of the quark mass matrices, CP-symmetry breaking is introduced into this algebraic formalism by an inequivalent vacuum with respect to the CP-invariant case, represented by a modified spinor field propagator. This leads to an extension of the standard model as effective theory which contains besides the "electric" electroweak bosons additional "magnetic" electroweak bosons and corresponding interactions. If furthermore the isospin invariance of the propagator is broken too, it will be demonstrated in detail that in combination with CP-symmetry breaking this induces a considerable modification of electroweak nuclear reaction rates.

Study of the production of the Σ b *± with the CDF detector at the Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calancha Paredes, Constantino

The composition of matter is a topic in which the man has been interested throughout History. Since the introduction of the atom by Democritus in the 5th century BC until the establishment of the Standard Model, our successful theory that contains our current knowledge on the matter and their interactions, it has come a long way trying to solve this fundamental question. The efforts of many of the greatest minds to perform crucial experiments and develop theoretical models have helped to get deeper insight into the origin of the matter. Today we know that indivisible atoms postulated by Democritus aremore » no longer true, and they are actually composed of a nucleus made of protons and neutrons (nucleons) with orbiting electrons through electromagnetic interactions. Also the nucleons are not fundamental particles but are composed of more fundamental ones called quarks. According to the present state of our knowledge, matter is composed of two types of particles: quarks and leptons. Leptons are believed to be fundamental particles and can occur freely in nature. Quarks are also fundamental particles, and there are no free in nature, but are confined to form hadrons. The hadrons may consist of a quark and an antiquark (mesons) or three quarks or three antiquarks (baryons). These quarks and leptons interact through the exchange of particles called bosons. Figure 1.1 summary the elementary particles in the Standard Model. Despite its enormous success we know that the Standard Model is incomplete. Some of the issues left unresolved by the Standard Model are the mechanism for electroweak symmetry breaking, the mass spectrum of the Standard Model or that the Universe is much more matter than antimatter. That means that it should exist a more general theory which include the Standard Model as a valid approximation for low energy. This more general theory must give answers to the previous unresolved questions. Accumulate more experimental information is crucial to get a deeper understanding of the Standard Model and its limitations. In particular, it is very important the measurement of those observables which they are not able to be calculated from theory by perturbation theory. Particle accelerators have played and play nowadays a major role for past and new physics discoverements and has been for many years the source of many precision measurements. Unprecedent discoveries have been made and are yet to come. These measurements allow to select the models that best fit the results and also they can be used as input for those models to get further predictions. Tevatron has been for many years the highest energy particle collider operational in the world. It is located in the high energy physics laboratory Fermilab in Batavia, in the State of Illinois (USA). Tevatron produce proton-antiproton collisions with an energy of 1.96 TeV at the center of the mass. This thesis is based on the data taken by the CDF II detector, one of the two multipurpose detectors located in the two interaction points at Tevatron. In this thesis a precise measurement of the mass and width of four heavy baryon states are performed. These states are described together by the symbol Σ b *±. They are built by two light quarks and one heavy b quark as it is shown in Fig. 1.2. Baryons containing one bottom quark and two light quarks are described by Heavy Quark Effective Theories (HQET).« less

Science education in an urban elementary school: Case studies of teacher beliefs and classroom practices

NASA Astrophysics Data System (ADS)

King, Ken; Shumow, Lee; Lietz, Stephanie

2001-03-01

Through a case study approach, the state of science education in an urban elementary school was examined in detail. Observations made from the perspective of a science education specialist, an educational psychologist, and an expert elementary teacher were triangulated to provide a set of perspectives from which elementary science instruction could be examined. Findings revealed that teachers were more poorly prepared than had been anticipated, both in terms of science content knowledge and instructional skills, but also with respect to the quality of classroom pedagogical and management skills. Particularly significant, from a science education perspective, was the inconsistency between how they perceived their teaching practice (a hands-on, inquiry-based approach) and the investigator-observed expository nature of the lessons. Lessons were typically expository in nature, with little higher-level interaction of significance. Implications for practice and the associated needs for staff development among urban elementary teachers is discussed within the context of these findings.

ICCD: interactive continuous collision detection between deformable models using connectivity-based culling.

PubMed

Tang, Min; Curtis, Sean; Yoon, Sung-Eui; Manocha, Dinesh

2009-01-01

We present an interactive algorithm for continuous collision detection between deformable models. We introduce multiple techniques to improve the culling efficiency and the overall performance of continuous collision detection. First, we present a novel formulation for continuous normal cones and use these normal cones to efficiently cull large regions of the mesh as part of self-collision tests. Second, we introduce the concept of "procedural representative triangles" to remove all redundant elementary tests between nonadjacent triangles. Finally, we exploit the mesh connectivity and introduce the concept of "orphan sets" to eliminate redundant elementary tests between adjacent triangle primitives. In practice, we can reduce the number of elementary tests by two orders of magnitude. These culling techniques have been combined with bounding volume hierarchies and can result in one order of magnitude performance improvement as compared to prior collision detection algorithms for deformable models. We highlight the performance of our algorithm on several benchmarks, including cloth simulations, N-body simulations, and breaking objects.

LECTURES ON PHYSICS, BIOPHYSICS, AND CHEMISTRY FOR HIGH SCHOOL SCIENCE TEACHERS GIVEN AT THE ERNEST O. LAWRENCE RADIATION LABORATORY, BERKELEY, CALIFORNIA, JUNE-AUGUST 1959

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calhoon, E.C.; Starring, P.W. eds.

1959-08-01

Lectures given at the Ernest 0. Lawrence Radiation Laboratory on physics, biophysics, and chemistry for high school science teachers are presented. Topics covered include a mathematics review, atomic physics, nuclear physics, solid-state physics, elementary particles, antiparticies, design of experiments, high-energy particle accelerators, survey of particle detectors, emulsion as a particle detector, counters used in high-energy physics, bubble chambers, computer programming, chromatography, the transuranium elements, health physics, photosynthesis, the chemistry and physics of virus, the biology of virus, lipoproteins and heart disease, origin and evolution of the solar system, the role of space satellites in gathering astronomical data, and radiation andmore » life in space. (M.C.G.)« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perl, M.L.

This article is thoughts from the author on particle physics work from his perspective. It is not a summary of his work on the tau lepton, but rather a look at what makes good science, experimental and theoretical, from his experiences in the field. The section titles give a good summary on the topics the author chooses to touch upon. They are: the state of elementary particle physics; getting good ideas in experimental science; a difficult field; experiments and experimenting; 10% of the money and 30% of the time; the dictatorship of theory; technological dreams; last words.

Particle physics meets cosmology - The search for decaying neutrinos

NASA Technical Reports Server (NTRS)

Henry, R. C.

1982-01-01

The fundamental physical implications of the possible detection of massive neutrinos are discussed, with an emphasis on the Grand Unified Theories (GUTs) of matter. The Newtonian and general-relativistic pictures of the fundamental forces are compared, and the reduction of electromagnetic and weak forces to one force in the GUTs is explained. The cosmological consequences of the curved-spacetime gravitation concept are considered. Quarks, leptons, and neutrinos are characterized in a general treatment of elementary quantum mechanics. The universe is described in terms of quantized fields, the noninteractive 'particle' fields and the force fields, and cosmology becomes the study of the interaction of gravitation with the other fields, of the 'freezing out' of successive fields with the expansion and cooling of the universe. While the visible universe is the result of the clustering of the quark and electron fields, the distribution of the large number of quanta in neutrino field, like the mass of the neutrino, are unknown. Cosmological models which attribute anomalies in the observed motions of galaxies and stars to clusters or shells of massive neutrinos are shown to be consistent with a small but nonzero neutrino mass and a universe near the open/closed transition point, but direct detection of the presence of massive neutrinos by the UV emission of their decay is required to verify these hypotheses.

Scaling theory for the quasideterministic limit of continuous bifurcations.

PubMed

Kessler, David A; Shnerb, Nadav M

2012-05-01

Deterministic rate equations are widely used in the study of stochastic, interacting particles systems. This approach assumes that the inherent noise, associated with the discreteness of the elementary constituents, may be neglected when the number of particles N is large. Accordingly, it fails close to the extinction transition, when the amplitude of stochastic fluctuations is comparable with the size of the population. Here we present a general scaling theory of the transition regime for spatially extended systems. We demonstrate this through a detailed study of two fundamental models for out-of-equilibrium phase transitions: the Susceptible-Infected-Susceptible (SIS) that belongs to the directed percolation equivalence class and the Susceptible-Infected-Recovered (SIR) model belonging to the dynamic percolation class. Implementing the Ginzburg criteria we show that the width of the fluctuation-dominated region scales like N^{-κ}, where N is the number of individuals per site and κ=2/(d_{u}-d), d_{u} is the upper critical dimension. Other exponents that control the approach to the deterministic limit are shown to be calculable once κ is known. The theory is extended to include the corrections to the front velocity above the transition. It is supported by the results of extensive numerical simulations for systems of various dimensionalities.

Hybrid method to resolve the neutrino mass hierarchy by supernova (anti)neutrino induced reactions

NASA Astrophysics Data System (ADS)

Vale, D.; Rauscher, T.; Paar, N.

2016-02-01

We introduce a hybrid method to determine the neutrino mass hierarchy by simultaneous measurements of responses of at least two detectors to antineutrino and neutrino fluxes from accretion and cooling phases of core-collapse supernovae. The (anti)neutrino-nucleus cross sections for 56Fe and 208Pb are calculated in the framework of the relativistic nuclear energy density functional and weak interaction Hamiltonian, while the cross sections for inelastic scattering on free protons p(bar nue,e+)n are obtained using heavy-baryon chiral perturbation theory. The modelling of (anti)neutrino fluxes emitted from a protoneutron star in a core-collapse supernova include collective and Mikheyev-Smirnov-Wolfenstein effects inside the exploding star. The particle emission rates from the elementary decay modes of the daughter nuclei are calculated for normal and inverted neutrino mass hierarchy. It is shown that simultaneous use of (anti)neutrino detectors with different target material allows to determine the neutrino mass hierarchy from the ratios of νe- and bar nue-induced particle emissions. This hybrid method favors neutrinos from the supernova cooling phase and the implementation of detectors with heavier target nuclei (208Pb) for the neutrino sector, while for antineutrinos the use of free protons in mineral oil or water is the appropriate choice.

Particle Simulations on Plasma and Dust Environment near Lunar Vertical Holes

NASA Astrophysics Data System (ADS)

Miyake, Y.; Funaki, Y.; Nishino, M. N.

2016-12-01

The Japanese lunar orbiter KAGUYA has revealed the existence of vertical holes on the Moon, which have spatial scales of tens of meters and are possible lava tube skylights. The hole structure has recently received particular attention, because the structure is regarded as evidence for past existence of underground lava flows. Furthermore, the holes have high potential as locations for constructing future lunar bases, because of fewer extra-lunar rays/particles and micrometeorites reaching the hole bottoms. In this sense, these holes are not only of significance in selenology, but are also interesting from the viewpoint of plasma environments. The dayside electrostatic environment near the lunar surface is governed by interactions among the solar wind plasma, photoelectrons, and the charged lunar surface, providing topologically complex boundaries to the plasma. Thus we applied three-dimensional, massively-parallelized, particle-in-cell simulations to the near-hole environment on the Moon. This year we have introduced a horizontal cavern opened at the vertical wall of the hole, assuming the presence of a subsurface lave tube. We will show some preliminary results on the surface potential and its nearly plasma environments. We also started to study the dynamics of submicron-sized charged dust grains around the distinctive landscape. We particularly focus on an effect of a stochastic charging process of such small dust grains. Because of their small surface areas, the dusts will get/lose one elementary charge infrequently, and thus charge amount owned by each dust should be a stochastic variable unlike a widely-known spacecraft charging process. We develop a numerical model of such a charging process, which will be embedded into the test particle analysis of the dust dynamics. We report some results from our simulations on the dust charging process and dynamics around the lunar hole.

Curvature-Mediated Assembly of Janus Nanoparticles on Membrane Vesicles.

PubMed

Bahrami, Amir Houshang; Weikl, Thomas R

2018-02-14

Besides direct particle-particle interactions, nanoparticles adsorbed to biomembranes experience indirect interactions that are mediated by the membrane curvature arising from particle adsorption. In this Letter, we show that the curvature-mediated interactions of adsorbed Janus particles depend on the initial curvature of the membrane prior to adsorption, that is, on whether the membrane initially bulges toward or away from the particles in our simulations. The curvature-mediated interaction can be strongly attractive for Janus particles adsorbed to the outside of a membrane vesicle, which initially bulges away from the particles. For Janus particles adsorbed to the vesicle inside, in contrast, the curvature-mediated interactions are repulsive. We find that the area fraction of the adhesive Janus particle surface is an important control parameter for the curvature-mediated interaction and assembly of the particles, besides the initial membrane curvature.

Differentiated Staffing and Non-Teamed Organizational Structures as They Affect Elementary School Teacher-Pupil Interaction.

ERIC Educational Resources Information Center

Petrie, Thomas A.; And Others

A study was conducted of the differences in the frequency of selected student-teacher interaction in differentiated staffs and in non-teamed schools. The interaction processes studied were synthesized from Erikson's four stages of childhood: student behaviors--information processing, choice-making, reflection, problem solving, and procedures or…

The Effect of the Interactive Functions of Whiteboards on Elementary Students' Learning

ERIC Educational Resources Information Center

Luo, Yi-Fang; Yang, Shu Ching

2016-01-01

In recent years, the interactive whiteboard (IWB) has been regarded as the most prominent information and communication technology auxiliary instruction device. It is touted as elevating the traditional teaching environment to a digital teaching environment because of its highly interactive features. The purpose of this study is to investigate…

Temperament in early childhood and peer interactions in third grade: the role of teacher-child relationships in early elementary grades.

PubMed

Rudasill, Kathleen Moritz; Niehaus, Kate; Buhs, Eric; White, Jamie M

2013-12-01

Children's interactions with peers in early childhood have been consistently linked to their academic and social outcomes. Although both child and classroom characteristics have been implicated as contributors to children's success, there has been scant research linking child temperament, teacher-child relationship quality, and peer interactions in the same study. The purpose of this study is to examine children's early temperament, rated at preschool age, as a predictor of interactions with peers (i.e., aggression, relational aggression, victimization, and prosociality) in third grade while considering teacher-child relationship quality in kindergarten through second grades as a moderator and mediator of this association. The sample (N=1364) was drawn from the NICHD Study of Early Child Care and Youth Development. Results from structural equation models indicated that teacher-child conflict in early elementary grades mediated links between children's temperament and later peer interactions. Findings underscore the importance of considering children's temperament traits and teacher-child relationship quality when examining the mechanisms of the development of peer interactions. © 2013.

Interaction Activities in the Foreign Classroom, or How to Grow a Tulip-Rose

ERIC Educational Resources Information Center

Paulston, Christina Bratt; Selekman, Howard R.

1976-01-01

A report is made on the use of foreign language for spontaneous communication in an elementary language class. Four correction-free, peer communicative/interaction activities are outlined according to procedures, objectives, and evaluations. (Author/RM)

Elementary Student Self Efficacy Scale Development and Validation Focused on Student Learning, Peer Relations, and Resisting Drug Use

ERIC Educational Resources Information Center

Fertman, Carl I.; Primack, Brian A.

2009-01-01

The purpose of this study was to investigate the psychometric properties of a child self efficacy scale for learning, peer interactions, and resisting pressure to use drugs, to use in an elementary school drug prevention education program based on social cognitive theory. A diverse cohort of 392 4th and 5th grade students completed the 20-item…

Technology-Rich Learning Environments in Elementary and Secondary Schools: An Interactive Study of Physical Settings and Educational Change.

ERIC Educational Resources Information Center

Stuebing, Susan; And Others

This paper reviews an ongoing study on the physical settings of education with technology at the elementary and high school levels. The study, which is multi-disciplinary in nature, is based in sites in the process of change in teaching strategies, using learning technology as a catalyst for this change to take place. The focus of the study is on…

A Case Study of the Impact of Quaver's Marvelous World of Music on an Elementary School Music Program

ERIC Educational Resources Information Center

Foster, Stephen Darryl

2017-01-01

This case study examined the impact of Quaver's Marvelous World of Music on an elementary school music program. Quaver's Marvelous World of Music is a software music curriculum designed to be used in Grades K-8. The purpose of the study was to examine the impact on the students' musical self-efficacy, interactive engagement, enjoyment of music…

Expanding Horizons and Encouraging New Perspectives through Myths: Experiments in Interactive Storytelling in an Elementary School Library

ERIC Educational Resources Information Center

Giffard, Sue

2016-01-01

The scenario that the author encountered when she began working in her present position was not unusual for an elementary school library: the students study a culture, and the librarian reads the stories of that culture to them to enrich the study and to make the culture come alive. The fourth-graders studied the Maya in the fall and the ancient…

Optimization of chemical displacement deposition of copper on porous silicon.

PubMed

Bandarenka, Hanna; Redko, Sergey; Nenzi, Paolo; Balucani, Marco; Bondarenko, Vitaly

2012-11-01

Copper (II) sulfate was used as a source of copper to achieve uniform distribution of Cu particles deposited on porous silicon. Layers of the porous silicon were formed by electrochemical anodization of Si wafers in a mixture of HF, C3H7OH and deionized water. The well-known chemical displacement technique was modified to grow the copper particles of specific sizes. SEM and XRD analysis revealed that the outer surface of the porous silicon was covered with copper particles of the crystal orientation inherited from the planes of porous silicon skeleton. The copper crystals were found to have the cubic face centering elementary cell. In addition, the traces of Cu2O cubic primitive crystalline phases were identified. The dimensions of Cu particles were determined by the Feret's analysis of the SEM images. The sizes of the particles varied widely from a few to hundreds of nanometers. A phenomenological model of copper deposition was proposed.

Basics of particle therapy I: physics

PubMed Central

Park, Seo Hyun

2011-01-01

With the advance of modern radiation therapy technique, radiation dose conformation and dose distribution have improved dramatically. However, the progress does not completely fulfill the goal of cancer treatment such as improved local control or survival. The discordances with the clinical results are from the biophysical nature of photon, which is the main source of radiation therapy in current field, with the lower linear energy transfer to the target. As part of a natural progression, there recently has been a resurgence of interest in particle therapy, specifically using heavy charged particles, because these kinds of radiations serve theoretical advantages in both biological and physical aspects. The Korean government is to set up a heavy charged particle facility in Korea Institute of Radiological & Medical Sciences. This review introduces some of the elementary physics of the various particles for the sake of Korean radiation oncologists' interest. PMID:22984664

The Physical Sciences. Report of the National Science Board Submitted to the Congress.

ERIC Educational Resources Information Center

Handler, Philip

Recent advances in the physical sciences, including astronomy, chemical synthesis, chemical dynamics, solid-state sciences, atomic and nuclear science, and elementary particles and high-energy physics are summarized in this report to Congress. The nature of physical science, including its increasing unity, the relationship between science and…

METHODOLOGICAL NOTES: Rotation of the swing plane of Foucault's pendulum and Thomas spin precession: two sides of one coin

NASA Astrophysics Data System (ADS)

Krivoruchenko, Mikhail I.

2009-08-01

Using elementary geometric tools, we apply essentially the same methods to derive expressions for the rotation angle of the swing plane of Foucault's pendulum and the rotation angle of the spin of a relativistic particle moving in a circular orbit (the Thomas precession effect).

Neutrinos

NASA Astrophysics Data System (ADS)

Winter, K.; Murdin, P.

2000-11-01

Neutrinos are electrically neutral ELEMENTARY PARTICLES which experience only the weak nuclear force and gravity. Their existence was introduced as a hypothesis by Wolfgang Pauli in 1930 to explain the apparent violation of energy conservation in radioactive beta decay. Chadwick had discovered in 1914 that the energy spectrum of electrons emitted in beta decay was not monoenergetic but continuous...

Misconceptions of Selected Science Concepts Held by Elementary School Students

ERIC Educational Resources Information Center

Doran, Rodney L.

1972-01-01

Describes a test, administered as a motion picture, designed to measure misconceptions about the particle model of matter held by students in grades two through six. Reliability values for tests of eight misconceptions are given and the correlations of misconception scores with measures of IQ, reading, mathematics, and science ability reported.…

The Heat Is On! Using Particle Models to Change Students' Conceptions of Heat and Temperature

ERIC Educational Resources Information Center

Hitt, Austin Manning; Townsend, J. Scott

2015-01-01

Elementary, middle-level, and high school science teachers commonly find their students have misconceptions about heat and temperature. Unfortunately, student misconceptions are difficult to modify or change and can prevent students from learning the accurate scientific explanation. In order to improve our students' understanding of heat and…

Suggestions for Evaluating the Quality of the Army’s Science and Technology Program: The Portfolio and Its Execution

DTIC Science & Technology

2013-01-01

definition of 6.1 research apply. Namely, the work is curiosity work with no specific application in mind. The two extramural categories include...direct interest in relativity and gravitation, cosmology , elementary particles, nuclear physics, astronomy, or astrophysics, since they generally have

The Conceptual Foundations of Quantum Mechanics.

ERIC Educational Resources Information Center

Eisenbud, Leonard

This monograph was written for the Conference on the New Instructional Materials in Physics, held at the University of Washington in summer, 1965. It is intended for use by college students at the Junior and Senior levels. There are nine chapters in this monograph. The failure of classical theory in dealing with elementary particles physics is…

Book Review: The genius of science: a portrait gallery of twentieth-century physicists. Abraham Pais, Oxford University Press, New York, 2000, 365 pp., UK £26.50, ISBN 0-19-850614-7

NASA Astrophysics Data System (ADS)

Kragh, Helge

Abraham Pais made important contributions to the physics of elementary particles and other areas of theoretical physics before he turned, in the 1970s, to the history of modern physics, a field he cultivated energetically and successfully until his death in 2000. Among the best works of the prolific physicist-historian (a better term, in this case, than historian of physics) is the acclaimed Einstein biography Subtle is the Lord (1982) and Inward Bound (1986), a comprehensive chronicle of elementary particle physics. More recently his autobiography, A Tale of Two Continents (1997), appeared, a book to a large extent based on Pais's friendship and acquaintance with many of the greatest physicists of the twentieth century. In the present book, the physicists who appeared as supporting cast in his autobiography are presented in their own right, chapter by chapter. Yet Pais himself is present throughout the book and the reader is constantly reminded of his friendship with the physicists portrayed.

Repulsive four-body interactions of α particles and quasistable nuclear α -particle condensates in heavy self-conjugate nuclei

NASA Astrophysics Data System (ADS)

Bai, Dong; Ren, Zhongzhou

2018-05-01

We study the effects of repulsive four-body interactions of α particles on nuclear α -particle condensates in heavy self-conjugate nuclei using a semianalytic approach, and find that the repulsive four-body interactions could decrease the critical number of α particles, beyond which quasistable α -particle condensate states can no longer exist, even if these four-body interactions make only tiny contributions to the total energy of the Hoyle-like state of 16O. Explicitly, we study eight benchmark parameter sets, and find that the critical number Ncr decreases by |Δ Ncr|˜1 -4 from Ncr˜11 with vanishing four-body interactions. We also discuss the effects of four-body interactions on energies and radii of α -particle condensates. Our study can be useful for future experiments to study α -particle condensates in heavy self-conjugate nuclei. Also, the experimental determination of Ncr will eventually help establish a better understanding on the α -particle interactions, especially the four-body interactions.

The variational method in quantum mechanics: an elementary introduction

NASA Astrophysics Data System (ADS)

Borghi, Riccardo

2018-05-01

Variational methods in quantum mechanics are customarily presented as invaluable techniques to find approximate estimates of ground state energies. In the present paper a short catalogue of different celebrated potential distributions (both 1D and 3D), for which an exact and complete (energy and wavefunction) ground state determination can be achieved in an elementary way, is illustrated. No previous knowledge of calculus of variations is required. Rather, in all presented cases the exact energy functional minimization is achieved by using only a couple of simple mathematical tricks: ‘completion of square’ and integration by parts. This makes our approach particularly suitable for undergraduates. Moreover, the key role played by particle localization is emphasized through the entire analysis. This gentle introduction to the variational method could also be potentially attractive for more expert students as a possible elementary route toward a rather advanced topic on quantum mechanics: the factorization method. Such an unexpected connection is outlined in the final part of the paper.

Web-Based Interactive Writing Environment: Development and Evaluation

ERIC Educational Resources Information Center

Yang, Jie Chi; Ko, Hwa Wei; Chung, I. Ling

2005-01-01

This study reports the development and evaluation of a web-based interactive writing environment designed for elementary school students. The environment includes three writing themes, "story pass on", "story chameleon" and "thousand ideas", to encourage reading comprehension, creativity and problem-solving skills of…

Matter and Interactions: A Particle Physics Perspective

ERIC Educational Resources Information Center

Organtini, Giovanni

2011-01-01

In classical mechanics, matter and fields are completely separated; matter interacts with fields. For particle physicists this is not the case; both matter and fields are represented by particles. Fundamental interactions are mediated by particles exchanged between matter particles. In this article we explain why particle physicists believe in…

Instability of Bose-Einstein condensation into the one-particle ground state on quantum graphs under repulsive perturbations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolte, Jens, E-mail: jens.bolte@rhul.ac.uk; Kerner, Joachim, E-mail: joachim.kerner@fernuni-hagen.de

In this paper we investigate Bose-Einstein condensation into the one-particle ground state in interacting quantum many-particle systems on graphs. We extend previous results obtained for particles on an interval and show that even arbitrarily small repulsive two-particle interactions destroy the condensate in the one-particle ground state present in the non-interacting Bose gas. Our results also cover singular two-particle interactions, such as the well-known Lieb-Liniger model, in the thermodynamic limit.

Principal Leadership and Its Link to the Development of a School's Teacher Culture and Teaching Effectiveness: A Case Study of an Award-Winning Teaching Team at an Elementary School

ERIC Educational Resources Information Center

Lee, Hsin-Hsiange; Li, Mao-neng Fred

2015-01-01

This study aimed 1) to describe a school principal's leadership and the context of the school's overall teacher culture that cultivated an award-winning team at an elementary school; 2) to analyze the award-winning team's learning behaviors, shared goals, values, beliefs, mutual interactions or dialogues, and sharing of experiences; and 3) to…

Fitting the Elementary Rate Constants of the P-gp Transporter Network in the hMDR1-MDCK Confluent Cell Monolayer Using a Particle Swarm Algorithm

PubMed Central

Agnani, Deep; Acharya, Poulomi; Martinez, Esteban; Tran, Thuy Thanh; Abraham, Feby; Tobin, Frank; Ellens, Harma; Bentz, Joe

2011-01-01

P-glycoprotein, a human multidrug resistance transporter, has been extensively studied due to its importance to human health and disease. In order to understand transport kinetics via P-gp, confluent cell monolayers overexpressing P-gp are widely used. The purpose of this study is to obtain the mass action elementary rate constants for P-gp's transport and to functionally characterize members of P-gp's network, i.e., other transporters that transport P-gp substrates in hMDR1-MDCKII confluent cell monolayers and are essential to the net substrate flux. Transport of a range of concentrations of amprenavir, loperamide, quinidine and digoxin across the confluent monolayer of cells was measured in both directions, apical to basolateral and basolateral to apical. We developed a global optimization algorithm using the Particle Swarm method that can simultaneously fit all datasets to yield accurate and exhaustive fits of these elementary rate constants. The statistical sensitivity of the fitted values was determined by using 24 identical replicate fits, yielding simple averages and standard deviations for all of the kinetic parameters, including the efflux active P-gp surface density. Digoxin required additional basolateral and apical transporters, while loperamide required just a basolateral tranporter. The data were better fit by assuming bidirectional transporters, rather than active importers, suggesting that they are not MRP or active OATP transporters. The P-gp efflux rate constants for quinidine and digoxin were about 3-fold smaller than reported ATP hydrolysis rate constants from P-gp proteoliposomes. This suggests a roughly 3∶1 stoichiometry between ATP hydrolysis and P-gp transport for these two drugs. The fitted values of the elementary rate constants for these P-gp substrates support the hypotheses that the selective pressures on P-gp are to maintain a broad substrate range and to keep xenobiotics out of the cytosol, but not out of the apical membrane. PMID:22028772

Explaining electric conductivity using the particle-in-a-box model: quantum superposition is the key

NASA Astrophysics Data System (ADS)

Sivanesan, Umaseh; Tsang, Kin; Izmaylov, Artur F.

2017-12-01

Most of the textbooks explaining electric conductivity in the context of quantum mechanics provide either incomplete or semi-classical explanations that are not connected with the elementary concepts of quantum mechanics. We illustrate the conduction phenomena using the simplest model system in quantum dynamics, a particle in a box (PIB). To induce the particle dynamics, a linear potential tilting the bottom of the box is introduced, which is equivalent to imposing a constant electric field for a charged particle. Although the PIB model represents a closed system that cannot have a flow of electrons through the system, we consider the oscillatory dynamics of the particle probability density as the analogue of the electric current. Relating the amplitude and other parameters of the particle oscillatory dynamics with the gap between the ground and excited states of the PIB model allows us to demonstrate one of the most basic dependencies of electric conductivity on the valence-conduction band gap of the material.

The expanding materials multiverse

NASA Astrophysics Data System (ADS)

Powell, Ben J.

2018-06-01

High-energy physicists are limited to studying a single vacuum and its excitations, the particles of the standard model. For condensed-matter physicists, every new phase of matter brings a new “‘vacuum.” Remarkably, the low-energy excitations of these new vacua can be very different from the individual electrons, protons, and neutrons that constitute the material. The materials multiverse contains universes where the particle-like excitations carry only a fraction of the elementary electronic charge (1), are magnetic monopoles (2), or are their own antiparticles (3). None of these properties have ever been observed in the particles found in free space. Often, emergent gauge fields accompany these “fractionalized” particles (2, 4, 5), just as electromagnetic gauge fields accompany charged particles. On page 1101 of this issue, Hassan et al. (6) provide a glimpse of the emergent behaviors of a putative new phase of matter, the dipole liquid. What particles live in this universe, and what new physics is found in this and neighboring parts of the multiverse?

The Effects of Using the Kinect Motion-Sensing Interactive System to Enhance English Learning for Elementary Students

ERIC Educational Resources Information Center

Pan, Wen Fu

2017-01-01

The objective of this study was to test whether the Kinect motion-sensing interactive system (KMIS) enhanced students' English vocabulary learning, while also comparing the system's effectiveness against a traditional computer-mouse interface. Both interfaces utilized an interactive game with a questioning strategy. One-hundred and twenty…

Teacher/Student Interactions in Public Elementary Schools When Class Size is a Factor.

ERIC Educational Resources Information Center

Krieger, Jean D.

This report describes a study designed to discover the nature of teacher-student interactions in regular-size classes with 25 or more students and small-size classes with fewer than 18 students. Eleven public-school primary classrooms were observed, and the interactions between the teachers and students were studied. Verbal and nonverbal…

Self-consistent Models of Strong Interaction with Chiral Symmetry

DOE R&D Accomplishments Database

Nambu, Y.; Pascual, P.

1963-04-01

Some simple models of (renormalizable) meson-nucleon interaction are examined in which the nucleon mass is entirely due to interaction and the chiral ( gamma {sub 5}) symmetry is "broken'' to become a hidden symmetry. It is found that such a scheme is possible provided that a vector meson is introduced as an elementary field. (auth)

One-Particle Representation of Heat Conduction Described within the Scope of the Second Law.

PubMed

Jesudason, Christopher Gunaseelan

2016-01-01

The Carnot cycle and its deduction of maximum conversion efficiency of heat inputted and outputted isothermally at different temperatures necessitated the construction of isothermal and adiabatic pathways within the cycle that were mechanically "reversible", leading eventually to the Kelvin-Clausius development of the entropy function S with differential dS = dq/T such that [symbol: see text]C dS = 0 where the heat absorption occurs at the isothermal paths of the elementary Carnot cycle. Another required condition is that the heat transfer processes take place infinitely slowly and "reversibly", implying that rates of transfer are not explicitly featured in the theory. The definition of 'heat' as that form of energy that is transferred as a result of a temperature difference suggests that the local mode of transfer of "heat" in the isothermal segments of the pathway implies a Fourier-like heat conduction mechanism which is apparently irreversible, leading to an increase in entropy of the combined reservoirs at either end of the conducting material, and which is deemed reversible mechanically. These paradoxes are circumvented here by first clarifying the terms used before modeling heat transfer as a thermodynamically reversible but mechanically irreversible process and applied to a one dimensional atomic lattice chain of interacting particles subjected to a temperature difference exemplifying Fourier heat conduction. The basis of a "recoverable trajectory" i.e. that which follows a zero entropy trajectory is identified. The Second Law is strictly maintained in this development. A corollary to this zero entropy trajectory is the generalization of the Zeroth law for steady state non-equilibrium systems with varying temperature, and thus to a statement about "equilibrium" in steady state non-thermostatic conditions. An energy transfer rate term is explicitly identified for each particle and agrees quantitatively (and independently) with the rate of heat absorbed at the reservoirs held at different temperatures and located at the two ends of the lattice chain in MD simulations, where all energy terms in the simulation refer to a single particle interacting with its neighbors. These results validate the theoretical model and provides the necessary boundary conditions (for instance with regard to temperature differentials and force fields) that thermodynamical variables must comply with to satisfy the conditions for a recoverable trajectory, and thus determines the solution of the differential and integral equations that are used to model these processes. These developments and results, if fully pursued would imply that not only can the Carnot cycle be viewed as describing a local process of energy-work conversion by a single interacting particle which feature rates of energy transfer and conversion not possible in the classical Carnot development, but that even irreversible local processes might be brought within the scope of this cycle, implying a unified treatment of thermodynamically (i) irreversible (ii) reversible (iii) isothermal and (iv) adiabatic processes by conflating the classically distinct concept of work and heat energy into a single particle interactional process. A resolution to the fundamental and long-standing conjecture of Benofy and Quay concerning the Fourier principle is one consequence of the analysis.

One-Particle Representation of Heat Conduction Described within the Scope of the Second Law

PubMed Central

Jesudason, Christopher Gunaseelan

2016-01-01

The Carnot cycle and its deduction of maximum conversion efficiency of heat inputted and outputted isothermally at different temperatures necessitated the construction of isothermal and adiabatic pathways within the cycle that were mechanically “reversible”, leading eventually to the Kelvin-Clausius development of the entropy function S with differential dS=dq/T such that ∮CdS=0 where the heat absorption occurs at the isothermal paths of the elementary Carnot cycle. Another required condition is that the heat transfer processes take place infinitely slowly and “reversibly”, implying that rates of transfer are not explicitly featured in the theory. The definition of ‘heat’ as that form of energy that is transferred as a result of a temperature difference suggests that the local mode of transfer of “heat” in the isothermal segments of the pathway implies a Fourier-like heat conduction mechanism which is apparently irreversible, leading to an increase in entropy of the combined reservoirs at either end of the conducting material, and which is deemed reversible mechanically. These paradoxes are circumvented here by first clarifying the terms used before modeling heat transfer as a thermodynamically reversible but mechanically irreversible process and applied to a one dimensional atomic lattice chain of interacting particles subjected to a temperature difference exemplifying Fourier heat conduction. The basis of a “recoverable trajectory” i.e. that which follows a zero entropy trajectory is identified. The Second Law is strictly maintained in this development. A corollary to this zero entropy trajectory is the generalization of the Zeroth law for steady state non-equilibrium systems with varying temperature, and thus to a statement about “equilibrium” in steady state non-thermostatic conditions. An energy transfer rate term is explicitly identified for each particle and agrees quantitatively (and independently) with the rate of heat absorbed at the reservoirs held at different temperatures and located at the two ends of the lattice chain in MD simulations, where all energy terms in the simulation refer to a single particle interacting with its neighbors. These results validate the theoretical model and provides the necessary boundary conditions (for instance with regard to temperature differentials and force fields) that thermodynamical variables must comply with to satisfy the conditions for a recoverable trajectory, and thus determines the solution of the differential and integral equations that are used to model these processes. These developments and results, if fully pursued would imply that not only can the Carnot cycle be viewed as describing a local process of energy-work conversion by a single interacting particle which feature rates of energy transfer and conversion not possible in the classical Carnot development, but that even irreversible local processes might be brought within the scope of this cycle, implying a unified treatment of thermodynamically (i) irreversible (ii) reversible (iii) isothermal and (iv) adiabatic processes by conflating the classically distinct concept of work and heat energy into a single particle interactional process. A resolution to the fundamental and long-standing conjecture of Benofy and Quay concerning the Fourier principle is one consequence of the analysis. PMID:26760507

Acoustically mediated long-range interaction among multiple spherical particles exposed to a plane standing wave

NASA Astrophysics Data System (ADS)

Zhang, Shenwei; Qiu, Chunyin; Wang, Mudi; Ke, Manzhu; Liu, Zhengyou

2016-11-01

In this work, we study the acoustically mediated interaction forces among multiple well-separated spherical particles trapped in the same node or antinode plane of a standing wave. An analytical expression of the acoustic interaction force is derived, which is accurate even for the particles beyond the Rayleigh limit. Interestingly, the multi-particle system can be decomposed into a series of independent two-particle systems described by pairwise interactions. Each pairwise interaction is a long-range interaction, as characterized by a soft oscillatory attenuation (at the power exponent of n = -1 or -2). The vector additivity of the acoustic interaction force, which is not well expected considering the nonlinear nature of the acoustic radiation force, is greatly useful for exploring a system consisting of a large number of particles. The capability of self-organizing a big particle cluster can be anticipated through such acoustically controllable long-range interaction.

Colloid interaction energies for physically and chemically heterogeneous porous media

USDA-ARS?s Scientific Manuscript database

The mean and variance of the colloid interaction energy (phi*) as a function of separation distance (h) were calculated on physically and/or chemically heterogeneous solid surfaces at the representative elementary area (REA) scale. Nanoscale roughness was demonstrated to have a significant influence...

Elementary and middle school science improvement project

NASA Technical Reports Server (NTRS)

Mcguire, Saundra Y.

1989-01-01

The Alabama A and M University Elementary and Middle School Science Improvement Project (Project SIP) was instituted to improve the science knowledge of elementary and middle school teachers using the experimental or hands-on approach. Summer workshops were conducted during the summers of 1986, 1987, and 1988 in the areas of biology, chemistry, physics, and electricity, and magnetism. Additionally, a manual containing 43 lessons which included background information, experiments and activities for classroom and home use was provided to each teacher. During the course of the project activities, the teachers interacted with various university faculty members, scientists, and NASA staff. The administrative aspects of the program, the delivery of the services to participating teachers, and the project outcome are addressed.

Hot particles attract in a cold bath

NASA Astrophysics Data System (ADS)

Tanaka, Hidenori; Lee, Alpha A.; Brenner, Michael P.

2017-04-01

Controlling interactions out of thermodynamic equilibrium is crucial for designing addressable and functional self-organizing structures. These active interactions also underpin collective behavior in biological systems. Here we study a general setting of active particles in a bath of passive particles and demonstrate a mechanism for long-range attraction between active particles. The mechanism operates when the translational persistence length of the active particle motion is smaller than the particle diameter. In this limit, the system reduces to particles of higher diffusivity ("hot" particles) in a bath of particles with lower diffusivity ("cold" particles). This attractive interaction arises as a hot particle pushes cold particles away to create a large hole around itself, and the holes interact via a depletion-like attraction. Strikingly, the interaction range is more than an order of magnitude larger than the particle radius, well beyond the range of the conventional depletion force. Although the mechanism occurs outside the parameter regime of typical biological swimmers, the mechanism could be realized in the laboratory.

The Particle Adventure | What is fundamental? | Fundamental

Science.gov Websites

Quiz - What particles are made of The four interactions How does matter interact? The unseen effect Half life Missing mass Particle decay mediators Virtual particles Different interactions Annihilations

Pathomechanisms in rheumatoid arthritis--time for a string theory?

PubMed

Weyand, Cornelia M; Goronzy, Jörg J

2006-04-01

RA is a quintessential autoimmune disease with a growing number of cells, mediators, and pathways implicated in this tissue-injurious inflammation. Now Kuhn and colleagues have provided convincing evidence that autoantibodies reacting with citrullinated proteins, known for their sensitivity and specificity as biomarkers in RA, enhance tissue damage in collagen-induced arthritis (see the related article beginning on page 961). This study adds yet another soldier to the growing army of autoaggressive mechanisms that underlie RA. With great success researchers have dismantled the pathogenic subunits of RA, adding gene to gene, molecule to molecule, and pathway to pathway in an ever more complex scheme of dysfunction. The complexity of the emerging disease model leaves us speechless. It seems that with this wealth of data available, we need to develop a new theory for this disease. We may want to seek guidance from our colleagues in physics and mathematics who have successfully integrated their knowledge of elementary particles and the complexity of their interacting forces by formulating the string theory.

Lattices for fractional Chern insulators

NASA Astrophysics Data System (ADS)

Repellin, Cécile; Regnault, Nicolas

2018-04-01

Individual electrons are elementary particles, but in some solid-state systems, electrons can act collectively as though they had a fraction of an electron's charge. This emergent behavior is spectacularly observed in two-dimensional (2D) electron gases as the fractional quantum Hall (FQH) effect in the form of a fractional quantized transverse (or Hall) conductivity and in shot-noise experiments. These experiments require low temperatures and very large magnetic fields in order to create strong electron interactions. This latter condition now appears not to be as essential as originally thought. On page 62 of this issue, Spanton et al. (1) report on an experimental platform based on bilayer graphene that forms a moiré pattern with an encapsulating hexagonal boron nitride layer. They observed incompressible phases with a fractional filling of the band structure with a nonzero Chern number (it has quantized properties robust to local perturbations, or topologically invariant). Some of which have no analog in traditional FQH systems (see the figure).

Pathomechanisms in rheumatoid arthritis — time for a string theory?

PubMed Central

Weyand, Cornelia M.; Goronzy, Jörg J.

2006-01-01

RA is a quintessential autoimmune disease with a growing number of cells, mediators, and pathways implicated in this tissue-injurious inflammation. Now Kuhn and colleagues have provided convincing evidence that autoantibodies reacting with citrullinated proteins, known for their sensitivity and specificity as biomarkers in RA, enhance tissue damage in collagen-induced arthritis (see the related article beginning on page 961). This study adds yet another soldier to the growing army of autoaggressive mechanisms that underlie RA. With great success researchers have dismantled the pathogenic subunits of RA, adding gene to gene, molecule to molecule, and pathway to pathway in an ever more complex scheme of dysfunction. The complexity of the emerging disease model leaves us speechless. It seems that with this wealth of data available, we need to develop a new theory for this disease. We may want to seek guidance from our colleagues in physics and mathematics who have successfully integrated their knowledge of elementary particles and the complexity of their interacting forces by formulating the string theory. PMID:16585957

Collisional dark matter and the origin of massive black holes

PubMed

Ostriker

2000-06-05

If the cosmological dark matter is primarily in the form of an elementary particle which has mass m(p) and cross section for self-interaction sigma, then seed black holes (formed in stellar collapse) will grow in a Hubble time t(H) due to accretion of the dark matter to a mass, M(H) = sqrt[IC(9)(A)t(H)(sigma/G(3)m(p)c(2))] = 7.1x10(6)(sigma/m(p))(1/2)V(9/2)(c)t(1/2)(H,15) solar masses. Here I is a numerical factor, C(A) the galactic velocity dispersion, and V(c) its rotation velocity. For the same values of ( sigma/m(p)) that are attractive with respect to other cosmological desiderata, this produces massive black holes in the (10(6)-10(9))M( middle dot in circle) range observed, with the same dependence on a V(c) seen, and with a time dependence consistent with observations. Other astrophysical consequences of collisional dark matter and tests of the idea are noted.

Producing coherent excitations in pumped Mott antiferromagnetic insulators

DOE PAGES

Wang, Yao; Claassen, Martin; Moritz, B.; ...

2017-12-15

Nonequilibrium dynamics in correlated materials has attracted attention due to the possibility of characterizing, tuning, and creating complex ordered states. To understand the photoinduced microscopic dynamics, especially the linkage under realistic pump conditions between transient states and remnant elementary excitations, we performed nonperturbative simulations of various time-resolved spectroscopies. We used the Mott antiferromagnetic insulator as a model platform. The transient dynamics of multi-particle excitations can be attributed to the interplay between Floquet virtual states and a modification of the density of states, in which interactions induce a spectral weight transfer. Using an autocorrelation of the time-dependent spectral function, we showmore » that resonance of the virtual states with the upper Hubbard band in the Mott insulator provides the route towards manipulating the electronic distribution and modifying charge and spin excitations. In conclusion, our results link transient dynamics to the nature of many-body excitations and provide an opportunity to design nonequilibrium states of matter via tuned laser pulses.« less

REVIEWS OF TOPICAL PROBLEMS: The neutrino mass in elementary-particle physics and in big bang cosmology

NASA Astrophysics Data System (ADS)

Zel'dovich, Ya B.; Khlopov, M. Yu

1981-09-01

Some theoretical aspects of a nonzero value for the neutrino rest mass and its possible implications for physics are discussed. The nature of the neutrino mass is analyzed, as well as the physical consequences that may derive from the existence of new helicity states for the neutrino or from lepton charge nonconservation if the mass is of Dirac or Majorana character, respectively. Massive neutrinos are examined in the context of grand unified theories combining the weak, strong, and electromagnetic interactions. Searches for neutrino-mass effects in β decay and for neutrino oscillations are reviewed. Several astrophysical effects of the neutrino mass are described: solar-neutrino oscillations, the decay of primordial neutrinos, the feasibility of detecting massive primordial neutrinos experimentally. The predictions of big bang theory regarding the neutrino number density in the universe are analyzed, and a discussion is given of the influence neutrino oscillations might have on the neutrino density and on cosmological nucleosynthesis.

Chern-Simons Term: Theory and Applications.

NASA Astrophysics Data System (ADS)

Gupta, Kumar Sankar

1992-01-01

We investigate the quantization and applications of Chern-Simons theories to several systems of interest. Elementary canonical methods are employed for the quantization of abelian and nonabelian Chern-Simons actions using ideas from gauge theories and quantum gravity. When the spatial slice is a disc, it yields quantum states at the edge of the disc carrying a representation of the Kac-Moody algebra. We next include sources in this model and their quantum states are shown to be those of a conformal family. Vertex operators for both abelian and nonabelian sources are constructed. The regularized abelian Wilson line is proved to be a vertex operator. The spin-statistics theorem is established for Chern-Simons dynamics using purely geometrical techniques. Chern-Simons action is associated with exotic spin and statistics in 2 + 1 dimensions. We study several systems in which the Chern-Simons action affects the spin and statistics. The first class of systems we study consist of G/H models. The solitons of these models are shown to obey anyonic statistics in the presence of a Chern-Simons term. The second system deals with the effect of the Chern -Simons term in a model for high temperature superconductivity. The coefficient of the Chern-Simons term is shown to be quantized, one of its possible values giving fermionic statistics to the solitons of this model. Finally, we study a system of spinning particles interacting with 2 + 1 gravity, the latter being described by an ISO(2,1) Chern-Simons term. An effective action for the particles is obtained by integrating out the gauge fields. Next we construct operators which exchange the particles. They are shown to satisfy the braid relations. There are ambiguities in the quantization of this system which can be exploited to give anyonic statistics to the particles. We also point out that at the level of the first quantized theory, the usual spin-statistics relation need not apply to these particles.

Radiation measurement above the lunar surface by Kaguya gamma-ray spectrometer

NASA Astrophysics Data System (ADS)

Hasebe, Nobuyuki; Nagaoka, Hiroshi; Kusano, Hiroki; Hareyama, Matoko; Ideguchi, Yusuke; Shimizu, Sota; Shibamura, Eido

The lunar surface is filled with various ionizing radiations such as high energy galactic particles, albedo particles and secondary radiations of neutrons, gamma rays and other elementary particles. A high-resolution Kaguya Gamma-Ray Spectrometer (KGRS) was carried on the Japan’s lunar explorer SELENE (Kaguya), the largest lunar orbiter since the Apollo missions. The KGRS instrument employed, for the first time in lunar exploration, a high-purity Ge crystal to increase the identification capability of elemental gamma-ray lines. The Ge detector is surrounded by BGO and plastic counters as for anticoincidence shields. The KGRS measured gamma rays in the energy range from 200 keV to 13 MeV with high precision to determine the chemical composition of the lunar surface. It provided data on the abundance of major elements over the entire lunar surface. In addition to the gamma-ray observation by the KGRS, it successfully measured the global distribution of fast neutrons. In the energy spectra of gamma-rays observed by the KGRS, several saw-tooth- peaks of Ge are included, which are formed by the collision interaction of lunar fast neutrons with Ge atoms in the Ge crystal. With these saw-tooth-peaks analysis, global distribution of neutrons emitted from the lunara surface was successfully created, which was compared with the previous results obtained by Lunar Prospector neutron maps. Another anticoincidence counter, the plastic counter with 5 mm thickness, was used to veto radiation events mostly generated by charged particles. A single photomultiplier serves to count scintillation light from the plastic scintillation counter. The global map of counting rates observed by the plastic counter was also created, implying that the radiation counting rate implies the geological distribution, in spite that the plastic counter mostly measures high energy charged particles and energetic neutrons. These results are presented and discussed.

Continuous time random walk with local particle-particle interaction

NASA Astrophysics Data System (ADS)

Xu, Jianping; Jiang, Guancheng

2018-05-01

The continuous time random walk (CTRW) is often applied to the study of particle motion in disordered media. Yet most such applications do not allow for particle-particle (walker-walker) interaction. In this paper, we consider a CTRW with particle-particle interaction; however, for simplicity, we restrain the interaction to be local. The generalized Chapman-Kolmogorov equation is modified by introducing a perturbation function that fluctuates around 1, which models the effect of interaction. Subsequently, a time-fractional nonlinear advection-diffusion equation is derived from this walking system. Under the initial condition of condensed particles at the origin and the free-boundary condition, we numerically solve this equation with both attractive and repulsive particle-particle interactions. Moreover, a Monte Carlo simulation is devised to verify the results of the above numerical work. The equation and the simulation unanimously predict that this walking system converges to the conventional one in the long-time limit. However, for systems where the free-boundary condition and long-time limit are not simultaneously satisfied, this convergence does not hold.

Cosmology and the large-mass problem of the five-dimensional Kaluza-Klein theory

NASA Astrophysics Data System (ADS)

Lukács, B.; Pacher, T.

1985-12-01

It is shown that in five-dimensional Kaluza-Klein theories the large-mass problem leads to circulus vitiosus: the huge recent e2/G value produces the large mass problem, which restricts the ratio e2/Gm2 to the order of unity, in contradiction with the present 1040 value for elementary particles.

A Physics Show Performed by Students for Kids: "From Mechanics to Elementary Particle Physics"

ERIC Educational Resources Information Center

Dreiner, Herbi K.

2008-01-01

Physics students spend the early part of their training attending physics and mathematics lectures, solving problem sets, and experimenting in laboratory courses. The program is typically intensive and fairly rigid. They have little opportunity to follow their own curiosity or apply their knowledge. There have been many attempts to address this…

Potential applications of electron emission membranes in medicine

NASA Astrophysics Data System (ADS)

Bilevych, Yevgen; Brunner, Stefan E.; Chan, Hong Wah; Charbon, Edoardo; van der Graaf, Harry; Hagen, Cornelis W.; Nützel, Gert; Pinto, Serge D.; Prodanović, Violeta; Rotman, Daan; Santagata, Fabio; Sarro, Lina; Schaart, Dennis R.; Sinsheimer, John; Smedley, John; Tao, Shuxia; Theulings, Anne M. M. G.

2016-02-01

With a miniaturised stack of transmission dynodes, a noise free amplifier is being developed for the detection of single free electrons, with excellent time- and 2D spatial resolution and efficiency. With this generic technology, a new family of detectors for individual elementary particles may become possible. Potential applications of such electron emission membranes in medicine are discussed.

Introducing 12 Year-Olds to Elementary Particles

ERIC Educational Resources Information Center

Wiener, Gerfried J.; Schmeling, Sascha M.; Hopf, Martin

2017-01-01

We present a new learning unit, which introduces 12 year-olds to the subatomic structure of matter. The learning unit was iteratively developed as a design-based research project using the technique of probing acceptance. We give a brief overview of the unit's final version, discuss its key ideas and main concepts, and conclude by highlighting the…

Lorentz violating Julia-Toulouse mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaete, Patricio; Wotzasek, Clovis; Instituto de Fisica, Universidade Federal do Rio de Janeiro

2007-03-01

We study a Lorentz invariance violating extension for the pure photonic sector of the standard model. A phenomenological proposal is made for the condensation of topological defects in the presence of a constant rank-m tensor in the context of the Julia-Toulouse mechanism. Possible physical consequences leading to direct measurable effects over the confining properties of the elementary particles are explored.

Robert R. Wilson Prize II: A Quantum Field Theory Approach to Intrabeam Scattering

NASA Astrophysics Data System (ADS)

Bjorken, James

2017-01-01

My involvement in the intrabeam scattering problem was very brief, from the autumn of 1981 to the summer of 1982. It occurred during my tenure at Fermilab. I entered the subject as an amateur in accelerator theory. But my experience in elementary-particle theory turned out to be of help in advancing the subject.

A Measurement of Charged and Neutral Elementary Particles Emitted from Antiproton Annihilation at Rest in Heavy Nuclei

DTIC Science & Technology

1989-06-15

ithbothourmeaureentfor steinslid. A.. Myklebost. K.. Olsen. J.M.. Breivik . F.O.. Jacobsen, carbon and the prediction for oxygen. T_. Sorensen. S.O.: CERN preprint EP...M., Fujitani. T., Iwahori, L,. Kawaguti. .Koba~ashi, steinslid, A.. Myklebost, K., Olsen. J.M., Breivik , F.O.. Jacobsen, M., Kurokawa, S., Nagashima

Physics in perspective. Volume 2, part A: The core subfields of physics

NASA Technical Reports Server (NTRS)

1972-01-01

Panel reports to the Survey Committee are presented to provide detailed technical background and documentation for committee findings, and to indicate the vitality and strength of the subfields of physics. Included are the core subfields of acoustics, optics, condensed matter, plasmas and fluids, atomic molecular and electron physics, nuclear physics, and elementary particle physics.

Student involvement in learning: Collaboration in science for PreService elementary teachers

NASA Astrophysics Data System (ADS)

Roychoudhury, Anita; Roth, Wolff-Michael

1992-03-01

The present study provided insights regarding the interactions that take place in collaborative science laboratory and regarding the outcome of such interactions. Science laboratory experiences structured by teachers have been criticized for allowing very little, if any, meaningful learning. However, this study showed that even structured laboratory experiments can provide insightful experience for students when conducted in a group setting that demanded interactive participation from all its members. The findings of the present study underscored the synergistic and supportive nature of collaborative groups. Here, students patiently repeated explanations to support the meaning construction on the part of their slower peers and elaborated their own understanding in the process; groups negotiated the meaning of observations and the corresponding theoretical explanations; students developed and practiced a range of social skills necessary in today’s workplace; and off-task behavior was thwarted by the group members motivated to work toward understanding rather than simply generating answers for task completion. The current findings suggest an increased use of collaborative learning environments for the teaching of science to elementary education majors. Some teachers have already made use of such settings in their laboratory teaching. However, collaborative learning should not be limited to the laboratory only, but be extended to more traditionally structured classes. The effects of such a switch in activity structures, increased quality of peer interaction, mastery of subject matter content, and decreased anxiety levels could well lead to better attitudes toward science among preservice elementary school teachers and eventually among their own students.

Search for the Higgs Boson and Technicolor Particles in p anti-p Colisions at √s = 1.8 TeV (in SPANISH)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cortabitarte, Rocio Vilar

1999-11-01

In the Standard Model (SM) of the elementary particles, the interactions among the known fundamental fermions (leptons and quarks) are mediated through gauge bosons which obey the symmetry: SU(3) Ⓧ SU(2) Ⓧ U(1). More precisely, the electroweak interaction [4-6] is described by a gauge symmetry SU(2) Ⓧ U(1) which is broken spontaneously. The electroweak symmetry breaking is implemented by the introduction of a complex scalar Higgs field which has a non-zero vacuum expectation value (vev). This way, the lagrangian of the theory remains invariant under SU(2) transformations, but quantization of the fields must start from a ground state which does not exhibit this symmetry, and therefore the full symmetry of the lagrangian is not manifest. Invariance of the theory under local SU(2) transformations implies the presence of vectorial gauge fields which mediate the electroweak interactions. The so called spontaneous symmetry breaking allows the quanta of these gauge fields, the W and Z bosons, to acquire a finite mass. The photon, the particle which mediates the electromagnetic interaction, remains massless. The Higgs boson is one of only two particles in the SM which have not yet been directly observed (the other is the v τ, although there is indirect evidence of its existence). Although the SM does not predict the Higgs mass, a lower limit ~ 100 GeV/c 2 is set by LEPII data, and theoretical considerations prefer Higgs masses not higher than a few hundred GeV/c 2. At the Tevatron, a search for the Higgs boson is hard due to the small production cross section and the huge backgrounds that do not allow to see the signal clearly. It is still interesting, however, to perform sensitivity studies at the Tevatron. The easiest production channel to observe at the Tevatron is the associated production of Higgs with weak (W or Z) bosons. The Higgs boson coupling to the fermions increases with fermion mass, so the most likely decay in the mass range they are interested, M(H 0) ~ 100 GeV/c 2, in is H → bmore » $$\\bar{b}$$. There are different possible final states depending on the decay of the associated vector boson: two jets plus lepton plus missing transverse energy (leptonic channel) and four jets (hadronic channel). In the former, the presence of a highly energetic, isolated lepton makes it relatively easy to reduce the background, while the latter has a larger production cross section times branching fraction, but it also has a huge amount of irreducible QCD background. CDF has searched for the Higgs boson in both final states, setting upper limits on the production cross sections.« less

Microstates of D1-D5(-P) black holes, as interacting D-branes

NASA Astrophysics Data System (ADS)

Morita, Takeshi; Shiba, Shotaro

2015-07-01

In our previous study (Morita et al., 2014 [1]), we figured out that the thermodynamics of the near extremal black p-branes can be explained as the collective motions of gravitationally interacting elementary p-branes (the p-soup proposal). We test this proposal in the near-extremal D1-D5 and D1-D5-P black holes and show that their thermodynamics also can be explained in a similar fashion, i.e. via the collective motions of the interacting elementary D1-branes and D5-branes (and waves). It may imply that the microscopic origins of these intersecting black branes and the black p-brane are explained in the unified picture. We also argue the relation between the p-soup proposal and the conformal field theory calculations of the D1-D5(-P) black holes in superstring theory.

An Exploration of Interactions between Virtual Mentors and Preservice Teachers

ERIC Educational Resources Information Center

Reese, Jill

2017-01-01

This study describes interactions between preservice music teachers and experienced teachers during virtual mentoring sessions embedded in field experiences for an elementary general music methods course. Participants were preservice music teachers (mentees) and experienced teachers (mentors). Videos of six mentoring sessions were transcribed,…

Computer simulation of space charge

NASA Astrophysics Data System (ADS)

Yu, K. W.; Chung, W. K.; Mak, S. S.

1991-05-01

Using the particle-mesh (PM) method, a one-dimensional simulation of the well-known Langmuir-Child's law is performed on an INTEL 80386-based personal computer system. The program is coded in turbo basic (trademark of Borland International, Inc.). The numerical results obtained were in excellent agreement with theoretical predictions and the computational time required is quite modest. This simulation exercise demonstrates that some simple computer simulation using particles may be implemented successfully on PC's that are available today, and hopefully this will provide the necessary incentives for newcomers to the field who wish to acquire a flavor of the elementary aspects of the practice.

Spin Path Integrals and Generations

NASA Astrophysics Data System (ADS)

Brannen, Carl

2010-11-01

The spin of a free electron is stable but its position is not. Recent quantum information research by G. Svetlichny, J. Tolar, and G. Chadzitaskos have shown that the Feynman position path integral can be mathematically defined as a product of incompatible states; that is, as a product of mutually unbiased bases (MUBs). Since the more common use of MUBs is in finite dimensional Hilbert spaces, this raises the question “what happens when spin path integrals are computed over products of MUBs?” Such an assumption makes spin no longer stable. We show that the usual spin-1/2 is obtained in the long-time limit in three orthogonal solutions that we associate with the three elementary particle generations. We give applications to the masses of the elementary leptons.

Inclusive reconstruction of hadron resonances in elementary and heavy-ion collisions with HADES

NASA Astrophysics Data System (ADS)

Kornakov, Georgy

2016-11-01

The unambiguous identification of hadron modifications in hot and dense QCD matter is one of the important goals in nuclear physics. In the regime of 1 - 2 GeV kinetic energy per nucleon, HADES has measured rare and penetrating probes in elementary and heavy-ion collisions. The main creation mechanism of mesons is the excitation and decay of baryonic resonances throughout the fireball evolution. The reconstruction of shortlived (≈ 1 fm/c) resonance states through their decay products is notoriously difficult. We have developed a new iterative algorithm, which builds the best hypothesis of signal and background by distortion of individual particle properties. This allows to extract signals with signal-to-background ratios of <1%.

Quantum Mechanics, vacuum, particles, Gödel-Cohen incompleteness and the Universe

NASA Astrophysics Data System (ADS)

Gonzalez-Mestres, Luis

2017-12-01

Are the standard laws of Physics really fundamental principles? Does the physical vacuum have a more primordial internal structure? Are quarks, leptons, gauge bosons… ultimate elementary objects? These three basic questions are actually closely related. If the deep vacuum structure and dynamics turn out to be less trivial than usually depicted, the conventional "elementary" particles will most likely be excitations of such a vacuum dynamics that remains by now unknown. We then expect relativity and quantum mechanics to be low-energy limits of a more fundamental dynamical pattern that generates them at a deeper level. It may even happen that vacuum drives the expansion of the Universe from its own inner dynamics. Inside such a vacuum structure, the speed of light would not be the critical speed for vacuum constituents and propagating signals. The natural scenario would be the superbradyon (superluminal preon) pattern we postulated in 1995, with a new critical speed cs much larger than the speed of light c just as c is much larger than the speed of sound. Superbradyons are assumed to be the bradyons of a super-relativity associated to cs (a Lorentz invariance with cs as the critical speed). Similarly, the standard relativistic space-time with four real coordinates would not necessarily hold beyond low-energy and comparatively local distance scales. Instead, the spinorial space-time (SST) with two complex coordinates we introduced in 1996-97 may be the suitable one to describe the internal structure of vacuum and standard "elementary" particles and, simultaneously, Cosmology at very large distance scales. If the constituents of the preonic vacuum are superluminal, quantum entanglement appears as a natural property provided cs ≫ c . The value of cs can even be possibly found experimentally by studying entanglement at large distances. It is not excluded that preonic constituents of vacuum can exist in our Universe as free particles ("free" superbradyons), in which case we expect them to be weakly coupled to standard matter. If a preonic vacuum is actually leading the basic dynamics of Particle Physics and Cosmology, and standard particles are vacuum excitations, the Gödel-Cohen incompleteness will apply to vacuum dynamics whereas the conventional laws of physics will actually be approximate and have error bars. We discuss here the possible role of the superbradyonic vacuum and of the SST in generating Quantum Mechanics, as well as the implications of such a dynamical origin of the conventional laws of Physics and possible evidences in experiments and observations. Black holes, gravitational waves, possible "free" superbradyons or preonic waves, unconventional vacuum radiation… are considered from this point of view paying particular attention to LIGO, VIRGO and CERN experiments. This lecture is dedicated to the memory of John Bell

Equation of state for two-dimensional dusty plasma liquids and its applications

NASA Astrophysics Data System (ADS)

Feng, Yan

2017-10-01

Laboratory dusty plasma consists of free electrons, free ions, and micro-sized dust particles with thousands of negative elementary charges. Due to their extremely low charge-to-mass ratio, these dust particles are strongly coupled, arranging themselves like atoms in liquids or solids. Due to the shielding effects of electrons and ions, dust particles interact with each other through the Yukawa potential, so that simulations of Yukawa liquids or solids are used to study properties of dusty plasmas. In the past two decades, the properties of liquid 2D dusty plasmas have been widely studied from experiments to theories and simulations. However, from our literature search, we have not found a quantitative and comprehensive study of properties of 2D liquid dusty plasmas over a wide range of plasma conditions. Here, from molecular-dynamics simulations of Yukawa liquids, we have obtained a concise equation of state (EOS) for the 2D liquid dusty plasmas from empirical fitting, which contains three quantities of the internal pressure, the coupling parameter, and the screening parameter. From this EOS, different thermodynamical processes can be directly derived, such as isotherms, isobars and isochores. Also, various physical properties of 2D liquid dusty plasmas, like the bulk modulus of elasticity, can be analytically derived, so that the sound speeds can be obtained. Finally, an analytical expression of the specific heat for 2D liquid dusty plasmas has been achieved. Work supported by the National Natural Science Foundation of China under Grant No. 11505124, the 1000 Youth Talents Plan, and the startup funds from Soochow University.

The Discovery of the Point-Like Structure of Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Richard E

2000-09-28

The organizers of this workshop have invited me here to reminisce. The assigned subject is the proton and how it lost its identity as an elementary particle. In its youth, the proton was very much neglected. It was overweight and introverted, and all the attention went to its lighter and more gregarious companion, the electron. The electron was noticed first and was accepted as a constituent of all matter almost immediately. As a result, the chemical ''elements'' lost their elementary status. With Rutherford's discovery of the nuclear atom it became clear that there was something rather small inside the hydrogenmore » atom with nearly 2000 times the mass of the electron, and equal but opposite charge. That something was called the ''positive electron'' or ''H-particle'' until 1930 or so. The Standard Model in those days had only two elementary particles with mass (whether light quanta might also be a particle was a subject of debate) and the only known forces were electromagnetic and gravitational. In the early days it was assumed that there were some extra positive electrons (each paired with a negative electron) inside nuclei other than hydrogen, to account for the observation that the atomic weight is equal to or greater than twice the atomic number. In 1914, Rutherford's group at Manchester turned its attention to alpha-particle scattering experiments on light nuclei. The group was intrigued by a calculation predicting that forward-scattered H-particles would have a much greater range than the incoming alpha particles. An experiment, the very first on the proton, verified the prediction experimentally and Marsden and Lantsberry concluded that the Coulomb field of the H particle could account for their results (at distances of closest approach that approximated 10{sup -13} cms.) World War I stopped most of the research in Rutherford's laboratory when many of the young scientists left to serve in the armed forces. Rutherford himself continued to do some research in parallel with his war work and in his spare time he discovered the first nuclear reaction on a nitrogen target along with anomalies in the scattering of alpha particles from hydrogen. Much improved measurements on hydrogen came after the war when Chadwick and Bieler, (now with Rutherford at the Cavendish) redid the earlier experiments, finding that there were too many H particles at large angles when the distance of closest approach was less than 3.5 x 10{sup -13} cms. In their 1921 paper, Chadwick and Bieler stated that there must be ''forces of very great intensity'' acting at small distances. Great significance was attached to the fact that such distances are about the same as the classical electron radius. Compare the modest activity on the proton with the intense effort (both experimental and theoretical) on electrons after the war. Progress was swift and by 1929, the basics needed for understanding the atom were in place, although the nucleus was still not understood at all. Only the charge, mass and spin (but not the magnetic moment) of the proton were known. In 1920 Rutherford had suggested that combinations of positive and negative electrons in the nucleus formed a neutral entity where the ''ordinary properties of the electrons are suppressed''. By the end of the decade there was growing recognition of the problems inherent in assuming the presence of electrons in the nucleus though it still seemed obvious that they had to be in there somewhere.« less

ICT media design for higher grade of elementary school mathematics learning using CS6 program

NASA Astrophysics Data System (ADS)

Zainil, M.; Prahmana, R. C. I.; Helsa, Y.; Hendri, S.

2017-12-01

Technological innovation contributes to the emerging of new possibilities to change the learning process. The development of technology could bring the higher quality of education through the integration of technology in the learning. The purpose of this research is to create an interactive multimedia using CS6 program for mathematics learning in higher grade of elementary school. It was a development research using ADDIE model which consists of analysis, design, and evaluation stages. It has successfully developed interactive multimedia in a form of learning CD used in the material of plane figures and solid figures. The prototype has been validated and then tested for the 4th grade of elementary schools. Two schools were involved and the students taught by utilizing the prototype, and then, in the end of learning, they are examined to determine the learning result. There were 72% of the students passed the examination as they classified at good and excellent categories. Finally, the use of CS6 program is promising to help the students learning plane and solid figure in mathematics learning.

Self assembly of anisotropic colloidal particles

NASA Astrophysics Data System (ADS)

Florea, Daniel; Wyss, Hans

2012-02-01

Colloidal particles have been successfully used as ''model atoms'', as their behavior can be more directly studied than that of atoms or molecules by direct imaging in a confocal microscope. Most studies have focussed on spherical particles with isotropic interactions. However, a range of interesting materials such as many supramolecular polymers or biopolymers exhibit highly directional interactions. To capture their behavior in colloidal model systems, particles with anisotropic interactions are clearly required. Here we use a colloidal system of nonspherical colloids, where highly directional interactions can be induced via depletion. By biaxially stretching spherical PMMA particles we create oblate spheroidal particles. We induce attractive interactions between these particles by adding a non-adsorbing polymer to the background liquid. The resulting depletion interaction is stronger along the minor axis of the oblate spheroids. We study the phase behavior of these materials as a function of the ellipsoid aspect ratio, the strength of the depletion interactions, and the particle concentration. The resulting morphologies are qualitatively different from those observed with spherical particles. This can be exploited for creating new materials with tailored structures.