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Sample records for strong collective interactions

  1. Strong interactions

    International Nuclear Information System (INIS)

    Froissart, Marcel

    1976-01-01

    Strong interactions are introduced by their more obvious aspect: nuclear forces. In hadron family, the nucleon octet, OMEGA - decuplet, and quark triply are successively considered. Pion wave having been put at the origin of nuclear forces, low energy phenomena are described, the force being explained as an exchange of structure corresponding to a Regge trajectory in a variable rotating state instead of the exchange of a well defined particle. At high energies the concepts of pomeron, parton and stratons are introduced, pionization and fragmentation are briefly differentiated [fr

  2. Experimental investigation of the dynamics in a strongly interacting Fermi gas : collective modes and rotational properties

    International Nuclear Information System (INIS)

    Riedl, S.

    2009-01-01

    This thesis explores the dynamics in an ultracold strongly interacting Fermi gas. Therefore we perform measurements on collective excitation modes and rotational properties of the gas. The strongly interacting gas is realized using an optically trapped Fermi gas of 6 Li atoms, where the interactions can be tuned using a broad Feshbach resonance. Our measurements allow to test the equation of state of the gas, study the transition from hydrodynamic to collisionless behavior, reveal almost ideal hydrodynamic behavior in the nonsuperfluid phase, investigate the lifetime of angular momentum, and show superfluidity through the quenching of the moment of inertia. (author)

  3. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  4. Instability of collective strong-interaction phenomena in hadron production as a possible origin of the weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Arnold, R.C.

    1975-12-01

    A systematic calculus of long-range Regge cut effects in multiparticle production is constructed in the form of an infrared-divergent stochastic field theory. Total cross sections and two-body overlap integrals in such a theory may depend very sensitively upon internal quantum-numbers of incident particles, resulting in a strong symmetry breaking at ultra-high energies. Such symmetry violations will influence low energy processes through dispersion relations, and a bootstrap of weak interactions becomes possible. A rough analytic estimate of the scale of thresholds for such effects yields a BCS-type gap equation, which expresses the scale of weak and electromagnetic couplings in terms of purely strong-interaction parameters

  5. Strongly interacting Fermi gases

    Directory of Open Access Journals (Sweden)

    Bakr W.

    2013-08-01

    Full Text Available Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of 23Na 40K that will feature strong dipolar interactions in their absolute ground state.

  6. Strongly interacting Higgs bosons

    International Nuclear Information System (INIS)

    Appelquist, T.; Bernard, C.

    1980-01-01

    The sensitivity of present-energy weak interactions to a strongly interacting heavy-Higgs-boson sector is discussed. The gauged nonlinear sigma model, which is the limit of the linear model as the Higgs-boson mass goes to infinity, is used to organize and catalogue all possible heavy-Higgs-boson effects. As long as the SU(2)/sub L/ x SU(2)/sub R/ symmetry of the Higgs sector is preserved, these effects are found to be small, of the order of the square of the gauge coupling times logarithms (but not powers) of the Higgs-boson mass divided by the W mass. We work in the context of a simplified model with gauge group SU(2)/sub L/; the extension to SU(2)/sub L/ x U(1) is briefly discussed

  7. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.

    1989-01-01

    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  8. Strong interaction phenomenology

    International Nuclear Information System (INIS)

    Giffon, M.

    1989-01-01

    A brief review of high energy hadronic data (Part I)is followed by an introduction to the standard (Weinberg Salam Glashow) model of electroweak interactions and its extension to the hadrons (Part II). Rudiments of QCD and of the parton model area given in Part III together with a quick review of the spectroscopy of heavy flavours whereas Part IV is devoted to the introduction to deep inelastic scattering and to the so-called EMC effects. (author)

  9. Strong interactions at high energy

    International Nuclear Information System (INIS)

    Anselmino, M.

    1995-01-01

    Spin effects in strong interaction high energy processes are subtle phenomena which involve both short and long distance physics and test perturbative and non perturbative aspects of QCD. Moreover, depending on quantities like interferences between different amplitudes and relative phases, spin observables always test a theory at a fundamental quantum mechanical level; it is then no surprise that spin data are often difficult to accommodate within the existing models. A report is made on the main issues and contributions discussed in the parallel Session on the open-quote open-quote Strong interactions at high energy close-quote close-quote in this Conference. copyright 1995 American Institute of Physics

  10. The colours of strong interaction

    International Nuclear Information System (INIS)

    1995-01-01

    The aim of this session is to draw a consistent framework about the different ways to consider strong interaction. A large part is dedicated to theoretical work and the latest experimental results obtained at the first electron collider HERA are discussed. (A.C.)

  11. Strongly interacting light dark matter

    International Nuclear Information System (INIS)

    Bruggisser, Sebastian; Riva, Francesco; Urbano, Alfredo

    2016-07-01

    In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM) can appear weakly coupled at small-energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their DM candidates (composite fermions, pseudo-Nambu-Goldstone Bosons and Goldstini) are interesting targets for LHC missing-energy searches.

  12. Scalar strong interaction hadron theory

    CERN Document Server

    Hoh, Fang Chao

    2015-01-01

    The scalar strong interaction hadron theory, SSI, is a first principles' and nonlocal theory at quantum mechanical level that provides an alternative to low energy QCD and Higgs related part of the standard model. The quark-quark interaction is scalar rather than color-vectorial. A set of equations of motion for mesons and another set for baryons have been constructed. This book provides an account of the present state of a theory supposedly still at its early stage of development. This work will facilitate researchers interested in entering into this field and serve as a basis for possible future development of this theory.

  13. Effective lagrangian for strong interactions

    International Nuclear Information System (INIS)

    Jain, P.

    1988-01-01

    We attempt to construct a realistic phenomenological Lagrangian in order to describe strong interactions. This is in general a very complicated problem and we shall explore its various aspects. We first include the vector mesons by writing down the most general chiral invariant terms proportional to the Levi-Civita symbol ε μναβ . These terms involve three unknown coefficients, which are calculated by using the experimental results of strong interaction processes. We then calculate the static nucleon properties by finding the solitonic excitations of this model. The results turn out to be, as is also the case for most other vector-pseudoscalar Lagrangians, better than the Skyrme model but are still somewhat different from the experiments. Another aspect that we shall study is the incorporation of scale anomaly of QCD into the Skyrme model. We thus introduce a scalar glueball in our Lagrangian. Here we find an interesting result that the effective glue field dynamically forms a bag for the soliton. Depending on the values of the parameters, we get either a deep bag or a shallow bag. However by including the scalar meson, we find that to get realistic scalar sector we must have the shallow bag. Finally we show some intriguing connections between the chiral quark model, in which the nucleon is described as a solitonic excitation, and the ordinary potential binding quark model

  14. Strong interactions in low dimensions

    CERN Document Server

    Baeriswyl, D

    2007-01-01

    This book provides an attempt to convey the colorful facets of condensed matter systems with reduced dimensionality. Some of the specific features predicted for interacting one-dimensional electron systems, such as charge- and spin-density waves, have been observed in many quasi-one-dimensional materials. The two-dimensional world is even richer: besides d-wave superconductivity and the Quantum Hall Effect - perhaps the most spectacular phases explored during the last two decades - many collective charge and spin states have captured the interest of researchers, such as charge stripes or spont

  15. Strongly interacting W's and Z's

    International Nuclear Information System (INIS)

    Gaillard, M.K.

    1984-01-01

    The study focussed primarily on the dynamics of a strongly interacting W, Z(SIW) sector, with the aim of sharpening predictions for total W, Z yield and W, Z multiplicities expected from WW fusion for various scenarios. Specific issues raised in the context of the general problem of modeling SIW included the specificity of the technicolor (or, equivalently, QCD) model, whether or not a composite scalar model can be evaded, and whether the standard model necessarily implies an I = J = O state (≅ Higgs particle) that is relatively ''light'' (M ≤ hundreds of TeV). The consensus on the last issue was that existing arguments are inconclusive. While the author shall briefly address compositeness and alternatives to the technicolor model, quantitative estimates will be of necessity based on technicolor or an extrapolation of pion data

  16. Strongly interacting photons and atoms

    International Nuclear Information System (INIS)

    Alge, W.

    1999-05-01

    This thesis contains the main results of the research topics I have pursued during the my PhD studies at the University of Innsbruck and partly in collaboration with the Institut d' Optique in Orsay, France. It is divided into three parts. The first and largest part discusses the possibility of using strong standing waves as a tool to cool and trap neutral atoms in optical cavities. This is very important in the field of nonlinear optics where several successful experiments with cold atoms in cavities have been performed recently. A discussion of the optical parametric oscillator in a regime where the nonlinearity dominates the evolution is the topic of the second part. We investigated mainly the statistical properties of the cavity output of the three interactive cavity modes. Very recently a system has been proposed which promises fantastic properties. It should exhibit a giant Kerr nonlinearity with negligible absorption thus leading to a photonic turnstile device based on cold atoms in cavity. We have shown that this model suffers from overly simplistic assumptions and developed several more comprehensive approaches to study the behavior of this system. Apart from the division into three parts of different contents the thesis is divided into publications, supplements and invisible stuff. The intention of the supplements is to reach researchers which work in related areas and provide them with more detailed information about the concepts and the numerical tools we used. It is written especially for diploma and PhD students to give them a chance to use the third part of our work which is actually the largest one. They consist of a large number of computer programs we wrote to investigate the behavior of the systems in parameter regions where no hope exists to solve the equations analytically. (author)

  17. Remnants of strong tidal interactions

    International Nuclear Information System (INIS)

    Mcglynn, T.A.

    1990-01-01

    This paper examines the properties of stellar systems that have recently undergone a strong tidal shock, i.e., a shock which removes a significant fraction of the particles in the system, and where the shocked system has a much smaller mass than the producer of the tidal field. N-body calculations of King models shocked in a variety of ways are performed, and the consequences of the shocks are investigated. The results confirm the prediction of Jaffe for shocked systems. Several models are also run where the tidal forces on the system are constant, simulating a circular orbit around a primary, and the development of tidal radii under these static conditions appears to be a mild process which does not dramatically affect material that is not stripped. The tidal radii are about twice as large as classical formulas would predict. Remnant density profiles are compared with a sample of elliptical galaxies, and the implications of the results for the development of stellar populations and galaxies are considered. 38 refs

  18. Physics challenges in the strong interactions

    International Nuclear Information System (INIS)

    Ellis, S.D.

    1992-01-01

    The study of strong interactions is now a mature field for which scientist now know that the correct underlying theory is QCD. Here, an overview of the challenges to be faced in the area of the strong interactions during the 1990's is presented. As an illustrative example special attention is given to the analysis of jets as studied at hadron colliders

  19. Physics challenges in the strong interactions

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, S.D. [Univ. of Washington, Seattle (United States)

    1992-12-31

    The study of strong interactions is now a mature field for which scientist now know that the correct underlying theory is QCD. Here, an overview of the challenges to be faced in the area of the strong interactions during the 1990`s is presented. As an illustrative example special attention is given to the analysis of jets as studied at hadron colliders.

  20. Algebra of strong and electroweak interactions

    International Nuclear Information System (INIS)

    Bolokhov, S.V.; Vladimirov, Yu.S.

    2004-01-01

    The algebraic approach to describing the electroweak and strong interactions is considered within the frames of the binary geometrophysics, based on the principles of the Fokker-Feynman direct interparticle interaction theories of the Kaluza-Klein multidimensional geometrical models and the physical structures theory. It is shown that in this approach the electroweak and strong elementary particles interaction through the intermediate vector bosons, are characterized by the subtypes of the algebraic classification of the complex 3 x 3-matrices [ru

  1. Physics challenges in the strong interactions

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, S.D.

    1991-01-01

    An overview of the challenges to be faced in the area of the strong interactions during the 1990`s is presented. As an illustrative example special attention is given to the analysis of jets as studied at hadron colliders.

  2. Physics challenges in the strong interactions

    International Nuclear Information System (INIS)

    Ellis, S.D.

    1991-01-01

    An overview of the challenges to be faced in the area of the strong interactions during the 1990's is presented. As an illustrative example special attention is given to the analysis of jets as studied at hadron colliders

  3. Strong interaction effects in hadronic atoms

    International Nuclear Information System (INIS)

    Kaufmann, W.B.

    1977-01-01

    The WKB method is applied to the calculation of strong interaction-induced level widths and shifts of hadronic atoms. The calculation, while elementary enough for undergraduate quantum mechanics students, gives a good account of kaonic and antiprotonic atom data

  4. The Charm and Beauty of Strong Interactions

    Science.gov (United States)

    El-Bennich, Bruno

    2018-01-01

    We briefly review common features and overlapping issues in hadron and flavor physics focussing on continuum QCD approaches to heavy bound states, their mass spectrum and weak decay constants in different strong interaction models.

  5. Numerical Calculation of the Phase Space Density for the Strong-Strong Beam-Beam Interaction

    International Nuclear Information System (INIS)

    Sobol, A.; Ellison, J.A.

    2003-01-01

    We developed a parallel code to calculate the evolution of the 4D phase space density of two colliding beams, which are coupled via the collective strong-strong beam-beam interaction, in the absence of diffusion and damping, using the Perron-Frobenius (PF) operator technique

  6. Dual field theory of strong interactions

    International Nuclear Information System (INIS)

    Akers, D.

    1987-01-01

    A dual field theory of strong interactions is derived from a Lagrangian of the Yang-Mills and Higgs fields. The existence of a magnetic monopole of mass 2397 MeV and Dirac charge g = (137/2)e is incorporated into the theory. Unification of the strong, weak, and electromagnetic forces is shown to converge at the mass of the intermediate vector boson W/sup +/-/. The coupling constants of the strong and weak interactions are derived in terms of the fine-structure constant α = 1/137

  7. A theory of the strong interactions

    International Nuclear Information System (INIS)

    Gross, D.J.

    1979-01-01

    The most promising candidate for a fundamental microscopic theory of the strong interactions is a gauge theory of colored quarks-Quantum Chromodynamics (QCD). There are many excellent reasons for believing in this theory. It embodies the broken symmetries, SU(3) and chiral SU(3)xSU(3), of the strong interactions and reflects the success of (albeit crude) quark models in explaining the spectrum of the observed hadrons. The hidden quantum number of color, necessary to account for the quantum numbers of the low lying hadrons, plays a fundamental role in this theory as the SU(3) color gauge vector 'gluons' are the mediators of the strong interactions. The absence of physical quark states can be 'explained' by the hypothesis of color confinement i.e. that hadrons are permanently bound in color singlet bound states. Finally this theory is unique in being asymptotically free, thus accounting for the almost free field theory behvior of quarks observed at short distances. (Auth.)

  8. Interaction of strong electromagnetic fields with atoms

    International Nuclear Information System (INIS)

    Brandi, H.S.; Davidovich, L.; Zagury, N.

    1982-06-01

    Several non-linear processes involvoing the interaction of atoms with strong laser fields are discussed, with particular emphasis on the ionization problem. Non-perturbative methods which have been proposed to tackle this problem are analysed, and shown to correspond to an expansion in the intra-atomic potential. The relation between tunneling and multiphoton absorption as ionization mechanisms, and the generalization of Einstein's photoelectric equation to the strong-field case are discussed. (Author) [pt

  9. Physics challenges in the strong interactions

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, S.D.

    1991-01-01

    An overview of the challenges to be faced in the area of the strong interactions during the 1990's is presented. As an illustrative example special attention is given to the analysis of jets as studied at hadron colliders.

  10. Unification of electromagnetic, strong and weak interaction

    International Nuclear Information System (INIS)

    Duong Van Phi; Duong Anh Duc

    1993-09-01

    The Unification of Electromagnetic, Strong and Weak Interactions is realized in the framework of the Quantum Field Theory, established in an 8-dimensional Unified Space. Two fundamental, spinor and vector field equations are considered. The first of the matter particles and the second is of the gauge particles. Interaction Lagrangians are formed from the external and internal currents and the external and internal vector field operators. Generators of the local gauge transformations are the combinations of the matrices of the first field equation. (author). 15 refs

  11. Super symmetry in strong and weak interactions

    International Nuclear Information System (INIS)

    Seshavatharam, U.V.S.; Lakshminarayana, S.

    2010-01-01

    For strong interaction two new fermion mass units 105.32 MeV and 11450 MeV are assumed. Existence of "Integral charge quark bosons", "Integral charge effective quark fermions", "Integral charge (effective) quark fermi-gluons" and "Integral charge quark boso-gluons" are assumed and their masses are estimated. It is noticed that, characteristic nuclear charged fermion is X s · 105.32 = 938.8 MeV and corresponding charged boson is X s (105.32/x) = 415.0 where X s = 8.914 is the inverse of the strong coupling constant and x = 2.26234 is a new number by using which "super symmetry" can be seen in "strong and weak" interactions. 11450 MeV fermion and its boson of mass = 11450/x = 5060 MeV plays a crucial role in "sub quark physics" and "weak interaction". 938.8 MeV strong fermion seems to be the proton. 415 MeV strong boson seems to be the mother of the presently believed 493,496 and 547 MeV etc, strange mesons. With 11450 MeV fermion "effective quark-fermi-gluons" and with 5060 MeV boson "quark boso-gluon masses" are estimated. "Effective quark fermi-gluons" plays a crucial role in ground state charged baryons mass generation. Light quark bosons couple with these charged baryons to form doublets and triplets. "Quark boso-gluons" plays a crucial role in ground state neutral and charged mesons mass generation. Fine and super-fine rotational levels can be given by [I or (I/2)] power(1/4) and [I or (I/2)] power(1/12) respectively. Here, I = n(n+1) and n = 1, 2, 3, … (author)

  12. Strong field interaction of laser radiation

    International Nuclear Information System (INIS)

    Pukhov, Alexander

    2003-01-01

    The Review covers recent progress in laser-matter interaction at intensities above 10 18 W cm -2 . At these intensities electrons swing in the laser pulse with relativistic energies. The laser electric field is already much stronger than the atomic fields, and any material is instantaneously ionized, creating plasma. The physics of relativistic laser-plasma is highly non-linear and kinetic. The best numerical tools applicable here are particle-in-cell (PIC) codes, which provide the most fundamental plasma model as an ensemble of charged particles. The three-dimensional (3D) PIC code Virtual Laser-Plasma Laboratory runs on a massively parallel computer tracking trajectories of up to 10 9 particles simultaneously. This allows one to simulate real laser-plasma experiments for the first time. When the relativistically intense laser pulses propagate through plasma, a bunch of new physical effects appears. The laser pulses are subject to relativistic self-channelling and filamentation. The gigabar ponderomotive pressure of the laser pulse drives strong currents of plasma electrons in the laser propagation direction; these currents reach the Alfven limit and generate 100 MG quasistatic magnetic fields. These magnetic fields, in turn, lead to the mutual filament attraction and super-channel formation. The electrons in the channels are accelerated up to gigaelectronvolt energies and the ions gain multi-MeV energies. We discuss different mechanisms of particle acceleration and compare numerical simulations with experimental data. One of the very important applications of the relativistically strong laser beams is the fast ignition (FI) concept for the inertial fusion energy (IFE). Petawatt-class lasers may provide enough energy to isochorically ignite a pre-compressed target consisting of thermonuclear fuel. The FI approach would ease dramatically the constraints on the implosion symmetry and improve the energy gain. However, there is a set of problems to solve before the FI

  13. Strongly interacting matter in magnetic fields

    CERN Document Server

    Landsteiner, Karl; Schmitt, Andreas; Yee, Ho-Ung

    2013-01-01

    The physics of strongly interacting matter in an external magnetic field is presently emerging as a topic of great cross-disciplinary interest for particle, nuclear, astro- and condensed matter physicists. It is known that strong magnetic fields are created in heavy ion collisions, an insight that has made it possible to study a variety of surprising and intriguing phenomena that emerge from the interplay of quantum anomalies, the topology of non-Abelian gauge fields, and the magnetic field. In particular, the non-trivial topological configurations of the gluon field induce a non-dissipative electric current in the presence of a magnetic field. These phenomena have led to an extended formulation of relativistic hydrodynamics, called chiral magnetohydrodynamics. Hitherto unexpected applications in condensed matter physics include graphene and topological insulators. Other fields of application include astrophysics, where strong magnetic fields exist in magnetars and pulsars. Last but not least, an important ne...

  14. Alpha decay as a strong collective phenomenon

    International Nuclear Information System (INIS)

    Bulgac, A.; Carstoiu, F.; Dumitrescu, O.; Holan, S.

    1979-05-01

    A theory of the α-decay in terms of irreducible reaction amplitude of the α-particle formation in the four particle channel (Tsub(4→α)) is given. By inserting a new universal constant determined by the coupling interaction between the many body Fermi liquid state and the α-cluster state we have calculated the α-widths for some favoured and unfavoured α-transitions in the translead region. Good agreement with the experimental data is obtained. (author)

  15. A strongly interacting polaritonic quantum dot

    Science.gov (United States)

    Jia, Ningyuan; Schine, Nathan; Georgakopoulos, Alexandros; Ryou, Albert; Clark, Logan W.; Sommer, Ariel; Simon, Jonathan

    2018-06-01

    Polaritons are promising constituents of both synthetic quantum matter1 and quantum information processors2, whose properties emerge from their components: from light, polaritons draw fast dynamics and ease of transport; from matter, they inherit the ability to collide with one another. Cavity polaritons are particularly promising as they may be confined and subjected to synthetic magnetic fields controlled by cavity geometry3, and furthermore they benefit from increased robustness due to the cavity enhancement in light-matter coupling. Nonetheless, until now, cavity polaritons have operated only in a weakly interacting mean-field regime4,5. Here we demonstrate strong interactions between individual cavity polaritons enabled by employing highly excited Rydberg atoms as the matter component of the polaritons. We assemble a quantum dot composed of approximately 150 strongly interacting Rydberg-dressed 87Rb atoms in a cavity, and observe blockaded transport of photons through it. We further observe coherent photon tunnelling oscillations, demonstrating that the dot is zero-dimensional. This work establishes the cavity Rydberg polariton as a candidate qubit in a photonic information processor and, by employing multiple resonator modes as the spatial degrees of freedom of a photonic particle, the primary ingredient to form photonic quantum matter6.

  16. New strong interactions above the electroweak scale

    International Nuclear Information System (INIS)

    White, A.R.

    1994-01-01

    Theoretical arguments for a new higher-color quark sector, based on Pomeron physics in QCD, are briefly described. The electroweak symmetry-breaking, Strong CP conservation, and electroweak scale CP violation, that is naturally produced by this sector is also outlined. A further consequence is that above the electroweak scale there will be a radical change in the strong interaction. Electroweak states, in particular multiple W's and Z's, and new, semi-stable, very massive, baryons, will be commonly produced. The possible correlation of expected phenomena with a wide range of observed Cosmic Ray effects at and above the primary spectrum knee is described. Related phenomena that might be seen in the highest energy hard scattering events at the Fermilab Tevatron, some of which could be confused with top production, are also briefly discussed

  17. Many Body Structure of Strongly Interacting Systems

    CERN Document Server

    Arenhövel, Hartmuth; Drechsel, Dieter; Friedrich, Jörg; Kaiser, Karl-Heinz; Walcher, Thomas; Symposium on 20 Years of Physics at the Mainz Microtron MAMI

    2006-01-01

    This carefully edited proceedings volume provides an extensive review and analysis of the work carried out over the past 20 years at the Mainz Microtron (MAMI). This research centered around the application of Quantum Chromodynamics in the strictly nonperturbative regime at hadronic scales of about 1 fm. Due to the many degrees of freedom in hadrons at this scale the leitmotiv of this research is "Many body structure of strongly interacting systems". Further, an outlook on the research with the forthcoming upgrade of MAMI is given. This volume is an authoritative source of reference for everyone interested in the field of the electro-weak probing of the structure of hadrons.

  18. Strong Interaction Studies with PANDA at FAIR

    Science.gov (United States)

    Schönning, Karin

    2016-10-01

    The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of nuclear-, hadron- and atomic physics experiments. The future PANDA experiment at FAIR will offer a broad physics programme with emphasis on different aspects of hadron physics. Understanding the strong interaction in the perturbative regime remains one of the greatest challenges in contemporary physics and hadrons provide several important keys. In these proceedings, PANDA will be presented along with some high-lights of the planned physics programme.

  19. Strong Interaction Studies with PANDA at FAIR

    International Nuclear Information System (INIS)

    Schönning, Karin

    2016-01-01

    The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of nuclear-, hadron- and atomic physics experiments. The future PANDA experiment at FAIR will offer a broad physics programme with emphasis on different aspects of hadron physics. Understanding the strong interaction in the perturbative regime remains one of the greatest challenges in contemporary physics and hadrons provide several important keys. In these proceedings, PANDA will be presented along with some high-lights of the planned physics programme

  20. Strongly interacting Higgs sector without technicolor

    International Nuclear Information System (INIS)

    Liu Chuan; Kuti, J.

    1994-12-01

    Simulation results are presented on Higgs mass calculations in the spontaneously broken phase of the Higgs sector in the minimal Standard Model with a higher derviative regulator. A heavy Higgs particle is found in the TeV mass range in the presence of a complex conjugate ghost pair at higher energies. The ghost pair evades easy experimental detection. As a finite and unitary theory in the continuum, this model serves as an explicit and simple example of a strong interacting Higgs sector without technicolor. (orig.)

  1. Strong Interactions Physics at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Pioppi, M.

    2005-03-14

    Recent results obtained by BABAR experiment and related to strong interactions physics are presented, with particular attention to the extraction of the first four hadronic-mass moments and the first three lepton-energy moments in semileptonic decays. From a simultaneous fit to the moments, the CKM element |V{sub cb}|, the inclusive B {yields} X{sub c}lv and other heavy quark parameters are derived. The second topic is the ambiguity-free measurement of cos(2{beta}) in B {yields} J/{Psi}K* decays. With approximately 88 million of B{bar B} pairs, negative solutions for cos(2{beta}) are excluded at 89%.

  2. Strong Interactive Massive Particles from a Strong Coupled Theory

    DEFF Research Database (Denmark)

    Yu. Khlopov, Maxim; Kouvaris, Christoforos

    2008-01-01

    (-2). These excessive techniparticles are all captured by $^4He$, creating \\emph{techni-O-helium} $tOHe$ ``atoms'', as soon as $^4He$ is formed in Big Bang Nucleosynthesis. The interaction of techni-O-helium with nuclei opens new paths to the creation of heavy nuclei in Big Bang Nucleosynthesis. Due...

  3. Finite temperature system of strongly interacting baryons

    International Nuclear Information System (INIS)

    Bowers, R.L.; Gleeson, A.M.; Pedigo, R.D.; Wheeler, J.W.

    1976-07-01

    A fully relativistic finite temperature many body theory is constructed and used to examine the bulk properties of a system of strongly interacting baryons. The strong interactions are described by a two parameter phenomenological model fit to a simple description of nuclear matter at T = 0. The zero temperature equation of state for such a system which has already been discussed in the literature was developed to give a realistic description of nuclear matter. The model presented here is the exact finite temperature extension of that model. The effect of the inclusion of baryon pairs for T greater than or equal to 2mc 2 /k is discussed in detail. The phase transition identified with nuclear matter vanishes for system temperatures in excess of T/sub C/ = 1.034 x 10 11 0 K. All values of epsilon (P,T) correspond to systems that are causal in the sense that the locally determined speed of sound never exceeds the speed of light

  4. Finite temperature system of strongly interacting baryons

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, R.L.; Gleeson, A.M.; Pedigo, R.D.; Wheeler, J.W.

    1976-07-01

    A fully relativistic finite temperature many body theory is constructed and used to examine the bulk properties of a system of strongly interacting baryons. The strong interactions are described by a two parameter phenomenological model fit to a simple description of nuclear matter at T = 0. The zero temperature equation of state for such a system which has already been discussed in the literature was developed to give a realistic description of nuclear matter. The model presented here is the exact finite temperature extension of that model. The effect of the inclusion of baryon pairs for T greater than or equal to 2mc/sup 2//k is discussed in detail. The phase transition identified with nuclear matter vanishes for system temperatures in excess of T/sub C/ = 1.034 x 10/sup 11/ /sup 0/K. All values of epsilon (P,T) correspond to systems that are causal in the sense that the locally determined speed of sound never exceeds the speed of light.

  5. Combinatorial description of space and strong interactions

    International Nuclear Information System (INIS)

    Zenczykowski, P.

    1988-01-01

    A reinterpretation is given of a successful phenomenological approach to hadron self-energy effects known as the unitarized quark model. General arguments are given that the proper description of strong interactions may require abandoning the assignment of a primary role to continuous concepts such as position and momentum in favor of discrete ones such as spin or W-spin. The reinterpretation exploits an analogy between the W-spin diagrams occurring in the calculations of hadronic loop effects and the spin network idea of Penrose. A connection between the S-matrix approach to hadron masses and the purely algebraic approach characteristic of the quark model is indicated. Several hadron mass relations generated by a resulting SU(6)/sub w/-group-theoretic expression are presented and discussed. Results of an attempt to generalize the scheme to the description of hadron vertices are reported

  6. Transport coefficients of strongly interacting matter

    International Nuclear Information System (INIS)

    Heckmann, Klaus

    2011-01-01

    In this thesis, we investigate the dissipative transport phenomena of strongly interacting matter. The special interest is in the shear viscosity and its value divided by entropy density. The performed calculations are based on effective models for Quantum Chromodynamics, mostly focused on the 2-flavor Nambu-Jona-Lasinio model. This allows us to study the hadronic sector as well as the quark sector within one single model. We expand the models up to next-to-leading order in inverse numbers of colors. We present different possibilities of calculating linear transport coefficients and give an overview over qualitative properties as well as over recent ideas concerning ideal fluids. As present methods are not able to calculate the quark two-point function in Minkowski space-time in the self-consistent approximation scheme of the Nambu-Jona-Lasinio model, a new method for this purpose is developed. This self-energy parametrization method is applied to the expansion scheme, yielding the quark spectral function with meson back-coupling effects. The usage of this spectral function in the transport calculation is only one result of this work. We also test the application of different transport approaches in the NJL model, and find an interesting behavior of the shear viscosity at the critical end point of the phase diagram. We also use the NJL model to calculate the viscosity of a pion gas in the dilute regime. After an analysis of other models for pions and their interaction, we find that the NJL-result leads to an important modification of transport properties in comparison with the calculations which purely rely on pion properties in the vacuum. (orig.)

  7. Strong and Electromagnetic Interactions at SPS Energies

    CERN Document Server

    Ribicki, Andrzej

    2009-01-01

    Particle production in peripheral Pb+Pb collisions has been measured at a beam energy of 158 GeV per nucleon, corresponding to psNN 17.3 GeV. The measurements provide full double differential coverage in a wide range of longitudinal and transverse momenta, including the central (“mid-rapidity”) area and extending far into the projectile fragmentation region. The resulting analysis shows the heavy ion reaction as a mixture of different processes. In particular, surprising phenomena, like the presence of large and strongly varying structures in the shape of the double differential cross section d2s /dxFd pT , are induced by the final state electromagnetic interaction between produced particles and the charged spectator system. This effect is largest at low transverse momenta, where it results in a deep valley in the xF -dependence of the produced p+/p− ratio. The basic characteristics of the electromagnetic phenomenon described above agree with the results of a theoretical analysis, performed by means of ...

  8. Conduction properties of strongly interacting Fermions

    Science.gov (United States)

    Brantut, Jean-Philippe; Stadler, David; Krinner, Sebastian; Meineke, Jakob; Esslinger, Tilman

    2013-05-01

    We experimentally study the transport process of ultracold fermionic atoms through a mesoscopic, quasi two-dimensional channel connecting macroscopic reservoirs. By observing the current response to a bias applied between the reservoirs, we directly access the resistance of the channel in a manner analogous to a solid state conduction measurement. The resistance is further controlled by a gate potential reducing the atomic density in the channel, like in a field effect transistor. In this setup, we study the flow of a strongly interacting Fermi gas, and observe a striking drop of resistance with increasing density in the channel, as expected at the onset of superfluidity. We relate the transport properties to the in-situ evolution of the thermodynamic potential, providing a model independant thermodynamic scale. The resistance is compared to that of an ideal Fermi gas in the same geometry, which shows an order of magnitude larger resistance, originating from the contact resistance between the channel and the reservoirs. The extension of this study to a channel containing a tunable disorder is briefly outlined.

  9. Toward a Strongly Interacting Scalar Higgs Particle

    International Nuclear Information System (INIS)

    Shalaby, Abouzeid M.; El-Houssieny, M.

    2008-01-01

    We calculate the vacuum energy of the non-Hermitian and PT symmetric (-gφ 4 ) 2+1 scalar field theory. Rather than the corresponding Hermitian theory and due to the asymptotic freedom property of the theory, the vacuum energy does not blow up for large energy scales which is a good sign to solve the hierarchy problem when using this model to break the U(1)xSU(2) symmetry in the standard model. The theory is strongly interacting and in fact, all the dimensionful parameters in the theory like mass and energy are finite even for very high energy scales. Moreover, relative to the vacuum energy for the Hermitian φ 4 theory, the vacuum energy of the non-Hermitian and PT symmetric (-gφ 4 ) 2+1 theory is tiny, which is a good sign toward the solution of the cosmological constant problem. Remarkably, these features of the non-Hermitian and PT symmetric (-gφ 4 ) 2+1 scalar field theory make it very plausible to be employed as a Higgs mechanism in the standard model instead of the problematic Hermitian Higgs mechanism

  10. De Sitter vacua of strongly interacting QFT

    Energy Technology Data Exchange (ETDEWEB)

    Buchel, Alex [Department of Applied Mathematics, University of Western Ontario,London, Ontario N6A 5B7 (Canada); Department of Physics and Astronomy, University of Western Ontario,London, Ontario N6A 5B7 (Canada); Perimeter Institute for Theoretical Physics,Waterloo, Ontario N2J 2W9 (Canada); Karapetyan, Aleksandr [Department of Applied Mathematics, University of Western Ontario,London, Ontario N6A 5B7 (Canada)

    2017-03-22

    We use holographic correspondence to argue that Euclidean (Bunch-Davies) vacuum is a late-time attractor of the dynamical evolution of quantum gauge theories at strong coupling. The Bunch-Davies vacuum is not an adiabatic state, if the gauge theory is non-conformal — the comoving entropy production rate is nonzero. Using the N=2{sup ∗} gauge theory holography, we explore prospects of explaining current accelerated expansion of the Universe as due to the vacuum energy of a strongly coupled QFT.

  11. Electromagnetic probes of strongly interacting matter

    Indian Academy of Sciences (India)

    2015-05-07

    May 7, 2015 ... Collisions between two nuclei at relativistic energies will create charged particles – either in .... The thermal cutting rules give a systematic procedure to express ...... mesons due to its interaction with the thermal partons [80] and employment of running .... [16] J Deng, Q Wang, N Xu and P Zhuang, Phys. Lett.

  12. Relativistic rapprochement of electromagnetic and strong interactions

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1995-01-01

    On the basis of the Lienard-Wiechert potential and the relativistic Yukawa potential it is shown that the corresponding interactions with velocity growth increase differently (the electromagnetic one increases faster). According to preliminary estimations they are equivalent, at distances of the 'action radius' of nuclear forces, at γ≅ 960, where γ is the Lorentz factor. 2 refs

  13. Relativistic rapprochement of weak and strong interactions

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1995-01-01

    On the basis of the relativistic Yukawa potentials for the nuclear (quark) field and the field of intermediate vector W-, Z-bosons, it is shown that the interactions described by them increase differently with growing velocity (the weak one increases more rapidly). According to the estimates, they are compared (at distances of the 'action radius' of nuclear forces) at an energy of about 10 12 GeV (10 6 GeV for the pion field) what is smaller than the corresponding value in the model of 'grand unification'. 3 refs., 2 tabs

  14. Strong Interactions, (De)coherence and Quarkonia

    CERN Document Server

    Bellucci, Stefano; Tiwari, Bhupendra Nath

    2011-01-01

    Quarkonia are the central objects to explore the non-perturbative nature of non-abelian gauge theories. We describe the confinement-deconfinement phases for heavy quarkonia in a hot QCD medium and thereby the statistical nature of the inter-quark forces. In the sense of one-loop quantum effects, we propose that the "quantum" nature of quark matters follows directly from the thermodynamic consideration of Richardson potential. Thereby we gain an understanding of the formation of hot and dense states of quark gluon plasma matter in heavy ion collisions and the early universe. In the case of the non-abelian theory, the consideration of the Sudhakov form factor turns out to be an efficient tool for soft gluons. In the limit of the Block-Nordsieck resummation, the strong coupling obtained from the Sudhakov form factor yields the statistical nature of hadronic bound states, e.g. kaons and Ds particles.

  15. Strong and electromagnetic interactions in hadron systems

    International Nuclear Information System (INIS)

    Aissat, N.; Amghar, A.; Cano, F.; Gonzalez, F.; Noguera, S.; Carbonell, J.; Desplanques, B.; Silvestre-Brac, B.; Karmanov, V.; Mathiot, J.F.

    1997-01-01

    The pionic strong decay amplitudes of baryon resonances are studied in a constituent quark model. Particular attention is given to the operator describing the transition. The nucleon form factors are calculated in a non-relativistic approach, with emphasis on the highest momentum transfers. The aim is to determine the ingredients that are essential in getting correct results and are likely to be required for a more realistic estimate in a fully relativistic approach. The deuteron form factors have been calculated in the light-front approach using wave functions determined in a perturbative way. The derivation of the neutron charge form factor from the deuteron structure function, A(q 2 ), is reanalyzed including further mesonic exchange contributions. (authors)

  16. "Strong interaction" for particle physics laboratories

    CERN Multimedia

    2003-01-01

    A new Web site pooling the communications resources of particle physics centres all over the world has just been launched. The official launching of the new particle physics website Interactions.org during the Lepton-Proton 2003 Conference at the American laboratory Fermilab was accompanied by music and a flurry of balloons. On the initiative of Fermilab, the site was created by a collaboration of communication teams from over fifteen of the world's particle physics laboratories, including KEK, SLAC, INFN, JINR and, of course, CERN, who pooled their efforts to develop the new tool. The spectacular launching of the new particle physics website Interactions.org at Fermilab on 12 August 2003. A real gateway to particle physics, the site not only contains all the latest news from the laboratories but also offers images, graphics and a video/animation link. In addition, it provides information about scientific policies, links to the universities, a very useful detailed glossary of particle physics and astrophysic...

  17. Supersymmetry and weak, electromagnetic and strong interactions

    International Nuclear Information System (INIS)

    Fayet, P.

    1977-01-01

    A supersymmetric theory of particle interactions is discussed. It is based on the earlier model which involves gauge (or vector) superfields, and matter (or chiral) superfields; each of them describes a vector and a Majorana spinor in the first case, or a two-component Dirac spinor and a complex scalar in the second case. The new theory suggests the possible existence of spin - 1/2 gluons and heavy spin-0 quarks, besides spin - 1 gluons and spin - 1/2 quarks. To prevent scalar particles to be exchanged in processes such as μ or β decays a new class of leptons with its own quantum number is introduced; it includes charged leptons and a ''photonic neutrino''

  18. Signatures for strongly interacting W's and Z's

    International Nuclear Information System (INIS)

    Gaillard, M.K.

    1985-09-01

    The observed structure of the electroweak interactions is understood in terms of a spontaneously broken gauge theory. Although we have as yet no experimental indication as to the nature of the phenomenon responsible for symmetry breaking, general theoretical arguments set an upper limit of 1 or 2 TeV on the energy scale at which some manifestation of this phenomenon must occur. This scale defines a target for the effective hard collision energy that should be achieved in the next accelerator facility; the work reported here was aimed at sharpening this requirement by studying the minimal manifestations of electroweak symmetry breaking that can be expected to occur in the TeV energy region if a Higgs particle with m/sub H/ < 1 TeV is not found. While we used the minimal Higgs model as a guide, the results obtained are of far more general validity. Our analysis relied on three tools, briefly discussed. These are: the equivalence at high energies of longitudinally polarized W's and Z's to their scalar counterparts, the Goldstone bosons; the symmetries of the scalar sector; and the vector boson fusion process. 8 refs

  19. QCD : the theory of strong interactions Conference MT17

    CERN Multimedia

    2001-01-01

    The theory of strong interactions,Quantum Chromodynamics (QCD), predicts that the strong interaction is transmitted by the exchange of particles called gluons. Unlike the messengers of electromagnetism photons, which are electrically neutral - gluons carry a strong charge associated with the interaction they mediate. QCD predicts that the strength of the interaction between quarks and gluons becomes weaker at higher energies. LEP has measured the evolution of the strong coupling constant up to energies of 200 GeV and has confirmed this prediction.

  20. Dynamics of Strong Interactions and the S-Matrix

    Energy Technology Data Exchange (ETDEWEB)

    Omnes, R. [Laboratoire de Physique Theorique et Hautes Energies, Universite de Paris, Orsay (France)

    1969-08-15

    The physical principles underlying the S-matrix theory of strong interactions are reviewed. In particular, the problem of whether these principles are sufficient to completely determine the S-matrix, i.e. to yield a dynamical theory of strong interactions, is discussed. (author)

  1. Strong enhancement of transport by interaction on contact links

    DEFF Research Database (Denmark)

    Bohr, Dan; Schmitteckert, P.

    2007-01-01

    Strong repulsive interactions within a one-dimensional Fermi system in a two-probe configuration normally lead to a reduced off-resonance conductance. We show that if the repulsive interaction extends to the contact regions, a strong increase of the conductance may occur, even for systems where o...

  2. QCD : the theory of strong interactions Exhibition LEPFest 2000

    CERN Multimedia

    2000-01-01

    The theory of strong interactions,Quantum Chromodynamics (QCD),predicts that the strong interac- tion is transmitted by the exchange of particles called glu- ons.Unlike the messengers of electromagnetism -pho- tons,which are electrically neutral -gluons carry a strong charge associated with the interaction they mediate. QCD predicts that the strength of the interaction between quarks and gluons becomes weaker at higher energies.LEP has measured the evolution of the strong coupling constant up to energies of 200 GeV and has confirmed this prediction.

  3. Effective interactions in strongly-coupled quantum systems

    International Nuclear Information System (INIS)

    Chen, J.M.C.

    1986-01-01

    In this thesis, they study the role of effective interactions in strongly-coupled Fermi systems where the short-range correlations introduce difficulties requiring special treatment. The correlated basis function method provides the means to incorporate the short-range correlations and generate the matrix elements of the Hamiltonian and identity operators in a nonorthogonal basis of states which are so important to their studies. In the first half of the thesis, the particle-hole channel is examined to elucidate the effects of collective excitations. Proceeding from a least-action principle, a generalization of the random-phase approximation is developed capable of describing such strongly-interacting Fermi systems as nuclei, nuclear matter, neutron-star matter, and liquid 3 He. A linear response of dynamically correlated system to a weak external perturbation is also derived based on the same framework. In the second half of the thesis, the particle-particle channel is examined to elucidate the effects of pairing in nuclear and neutron-star matter

  4. Strong coupling of collection of emitters on hyperbolic meta-material

    Science.gov (United States)

    Biehs, Svend-Age; Xu, Chenran; Agarwal, Girish S.

    2018-04-01

    Recently, considerable effort has been devoted to the realization of a strong coupling regime of the radiation matter interaction in the context of an emitter at a meta surface. The strong interaction is well realized in cavity quantum electrodynamics, which also show that strong coupling is much easier to realize using a collection of emitters. Keeping this in mind, we study if emitters on a hyperbolic meta materials can yield a strong coupling regime. We show that strong coupling can be realized for densities of emitters exceeding a critical value. A way to detect strong coupling between emitters and hyperbolic metamaterials is to use the Kretschman-Raether configuration. The strong coupling appears as the splitting of the reflectivity dip. In the weak coupling regime, the dip position shifts. The shift and splitting can be used to sense active molecules at surfaces.

  5. Collective hypersonic excitations in strongly multiple scattering colloids.

    Science.gov (United States)

    Still, T; Gantzounis, G; Kiefer, D; Hellmann, G; Sainidou, R; Fytas, G; Stefanou, N

    2011-04-29

    Unprecedented low-dispersion high-frequency acoustic excitations are observed in dense suspensions of elastically hard colloids. The experimental phononic band structure for SiO(2) particles with different sizes and volume fractions is well represented by rigorous full-elastodynamic multiple-scattering calculations. The slow phonons, which do not relate to particle resonances, are localized in the surrounding liquid medium and stem from coherent multiple scattering that becomes strong in the close-packing regime. Such rich phonon-matter interactions in nanostructures, being still unexplored, can open new opportunities in phononics.

  6. Processes of Individualization in the Presence of Strong Collective Identities

    Directory of Open Access Journals (Sweden)

    Atanasov, Petar

    2016-04-01

    Full Text Available In the contemporary societies people try to build an individualized approach through life, while the collective identity coercions starts to pale. This ratio consists of many aspects like the intensity of the existing collective identities, the consistency of transmission of the parent’s way of living to their children and the individual choices that are available for the young people in the specific social context. In Macedonian society there are some modern processes concerning the development of stronger personal identities of the youth, and their attempts to change the way of living comparing the way their parents did. Having in mind that in Macedonia live citizens that are members of different cultural and ethnic groups the analysis will show even local differences elaborating these phenomena. There are indications that there is some fluctuation towards bigger individualization among youth and the evidence that the young people still lives their parent’s collective identities. The target group of the research is the student population, in the study that was done on the sample of 707 respondents, chosen by quotas, from the six universities in the country. The main thesis is that the students are still “overshadowed of the successes” of their parents past social experience, that is strongly connected with the collective nature of their identities. The main research questions are the state of the collective identities, the relation between the parents and the student’s collective identification, and the evidence of stronger development of the self-confidence among students.

  7. Prospects for strong interaction physics at ISABELLE. [Seven papers

    Energy Technology Data Exchange (ETDEWEB)

    Sidhu, D P; Trueman, T L

    1977-01-01

    Seven papers are presented resulting from a conference intended to stimulate thinking about how ISABELLE could be used for studying strong interactions. A separate abstract was prepared for each paper for inclusion in DOE Energy Research Abstracts (ERA). (PMA)

  8. A theory of strong interactions ''from'' general relativity

    International Nuclear Information System (INIS)

    Caldirola, P.; Recami, E.

    1979-01-01

    In this paper a previous letter (where, among other things, a classical ''quark confinement'' was derived from general relativity plus dilatation-covariance), is completed by showing that the theory is compatible also with quarks ''asymptotic freedom''. Then -within a bi-scale theory of gravitational and strong interactions- a classical field theory is proposed for the (strong) interactions between hadrons. Various consequences are briefly analysed

  9. Measurement of strong interaction effects in antiprotonic helium atoms

    International Nuclear Information System (INIS)

    Davies, J.D.; Gorringe, T.P.; Lowe, J.; Nelson, J.M.; Playfer, S.M.; Pyle, G.J.; Squier, G.T.A.

    1984-01-01

    The strong interaction shift and width for the 2 p level and the width for the 3d level have been measured for antiprotonic helium atoms. The results are compared with optical model calculations. The possible existence of strongly bound antiproton states in nuclei is discussed. (orig.)

  10. Interaction between Electron Holes in a Strongly Magnetized Plasma

    DEFF Research Database (Denmark)

    Lynov, Jens-Peter; Michelsen, Poul; Pécseli, Hans

    1980-01-01

    The interaction between electron holes in a strongly magnetized, plasma-filled waveguide is investigated by means of computer simulation. Two holes may or may not coalesce, depending on their amplitudes and velocities. The interaction between holes and Trivelpiece-Gould solitons is demonstrated...

  11. Quark imprisonment as the origin of strong interactions

    CERN Document Server

    Amati, Daniele

    1974-01-01

    A formal scheme is suggested in which the only dynamical ingredients are weak and electro-magnetic interactions with quarks and leptons treated on the same footing. Strong interactions are generated by the requirement that quarks do not appear physically. (7 refs).

  12. Substructure and strong interactions at the TeV scale

    International Nuclear Information System (INIS)

    Peskin, M.E.

    1985-12-01

    A review is given of the current status of the three main theoretical ideas relevant to strong-interaction 1 TeV physics. These are composite vector bosons, Higgs bosons (''Technicolor''), and matter fermions. All involve the assumption that some object which is assumed to be fundamental in the standard model actually has dynamical internal structure. Complex, mechanistic models of the new physics are discussed. A brief digression is then made on how the weak interaction allows probing for this new structure. Direct manifestations of new 1 TeV strong interactions are discussed. 125 refs., 18 figs

  13. Semicalssical quantization of interacting anyons in a strong magnetic field

    International Nuclear Information System (INIS)

    Levit, S.; Sivan, N.

    1992-01-01

    We represent a semiclassical theory of charged interacting anyons in strong magnetic fields. We apply this theory to a number of few anyons systems including two interacting anyons in the presence of an impurity and three interacting anyons. We discuss the dependence of their energy levels on the statistical parameter and find regions in which this dependence follows very different patterns. The semiclassical arguments allow to correlate these patterns with the change in the character of the classical motion of the system. (author)

  14. Mixtures of Strongly Interacting Bosons in Optical Lattices

    International Nuclear Information System (INIS)

    Buonsante, P.; Penna, V.; Giampaolo, S. M.; Illuminati, F.; Vezzani, A.

    2008-01-01

    We investigate the properties of strongly interacting heteronuclear boson-boson mixtures loaded in realistic optical lattices, with particular emphasis on the physics of interfaces. In particular, we numerically reproduce the recent experimental observation that the addition of a small fraction of 41 K induces a significant loss of coherence in 87 Rb, providing a simple explanation. We then investigate the robustness against the inhomogeneity typical of realistic experimental realizations of the glassy quantum emulsions recently predicted to occur in strongly interacting boson-boson mixtures on ideal homogeneous lattices

  15. New results on strong-interaction effects in antiprotonic hydrogen

    CERN Document Server

    Gotta, D; Augsburger, M A; Borchert, G L; Castelli, C M; Chatellard, D; El-Khoury, P; Egger, J P; Gorke, H; Hauser, P R; Indelicato, P J; Kirch, K; Lenz, S; Nelms, N; Rashid, K; Schult, O W B; Siems, T; Simons, L M

    1999-01-01

    Lyman and Balmer transitions of antiprotonic hydrogen and deuterium have been measured at the low-energy antiproton ring LEAR at CERN in order to determine the strong interaction effects. The X-rays were detected using charge-coupled devices (CCDs) and a reflection type crystal spectrometer. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction. (33 refs).

  16. New results on strong-interaction effects in antiprotonic hydrogen

    International Nuclear Information System (INIS)

    Anagnostopoulos, D. F.; Augsburger, M.; Borchert, G.; Castelli, C.; Chatellard, D.; El-Khoury, P.; Egger, J.-P.; Gorke, H.; Gotta, D.; Hauser, P.; Indelicato, P.; Kirch, K.; Lenz, S.; Nelms, N.; Rashid, K.; Schult, O. W. B.; Siems, Th.; Simons, L. M.

    1999-01-01

    Lyman and Balmer transitions of antiprotonic hydrogen and deuterium have been measured at the Low-Energy Antiproton Ring LEAR at CERN in order to determine the strong interaction effects. The X-rays were detected using Charge-Coupled Devices (CCDs) and a reflection type crystal spectrometer. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction

  17. H. David Politzer, Asymptotic Freedom, and Strong Interaction

    Science.gov (United States)

    dropdown arrow Site Map A-Z Index Menu Synopsis H. David Politzer, Asymptotic Freedom, and Strong Interaction Resources with Additional Information H. David Politzer Photo Credit: California Institute of Technology H. David Politzer has won the 2004 Nobel Prize in Physics 'for the discovery of asymptotic freedom

  18. Emergence of junction dynamics in a strongly interacting Bose mixture

    DEFF Research Database (Denmark)

    Barfknecht, Rafael Emilio; Foerster, Angela; Zinner, Nikolaj Thomas

    We study the dynamics of a one-dimensional system composed of a bosonic background and one impurity in single- and double-well trapping geometries. In the limit of strong interactions, this system can be modeled by a spin chain where the exchange coefficients are determined by the geometry of the...

  19. Interplay of Anderson localization and strong interaction in disordered systems

    International Nuclear Information System (INIS)

    Henseler, Peter

    2010-01-01

    We study the interplay of disorder localization and strong local interactions within the Anderson-Hubbard model. Taking into account local Mott-Hubbard physics and static screening of the disorder potential, the system is mapped onto an effective single-particle Anderson model, which is studied within the self-consistent theory of electron localization. For fermions, we find rich nonmonotonic behavior of the localization length ξ, particularly in two-dimensional systems, including an interaction-induced exponential enhancement of ξ for small and intermediate disorders and a strong reduction of ξ due to hopping suppression by strong interactions. In three dimensions, we identify for half filling a Mott-Hubbard-assisted Anderson localized phase existing between the metallic and the Mott-Hubbard-gapped phases. For small U there is re-entrant behavior from the Anderson localized phase to the metallic phase. For bosons, the unrestricted particle occupation number per lattice site yields a monotonic enhancement of ξ as a function of decreasing interaction, which we assume to persist until the superfluid Bose-Einstein condensate phase is entered. Besides, we study cold atomic gases expanding, by a diffusion process, in a weak random potential. We show that the density-density correlation function of the expanding gas is strongly affected by disorder and we estimate the typical size of a speckle spot, i.e., a region of enhanced or depleted density. Both a Fermi gas and a Bose-Einstein condensate (in a mean-field approach) are considered. (orig.)

  20. Interplay of Anderson localization and strong interaction in disordered systems

    Energy Technology Data Exchange (ETDEWEB)

    Henseler, Peter

    2010-01-15

    We study the interplay of disorder localization and strong local interactions within the Anderson-Hubbard model. Taking into account local Mott-Hubbard physics and static screening of the disorder potential, the system is mapped onto an effective single-particle Anderson model, which is studied within the self-consistent theory of electron localization. For fermions, we find rich nonmonotonic behavior of the localization length {xi}, particularly in two-dimensional systems, including an interaction-induced exponential enhancement of {xi} for small and intermediate disorders and a strong reduction of {xi} due to hopping suppression by strong interactions. In three dimensions, we identify for half filling a Mott-Hubbard-assisted Anderson localized phase existing between the metallic and the Mott-Hubbard-gapped phases. For small U there is re-entrant behavior from the Anderson localized phase to the metallic phase. For bosons, the unrestricted particle occupation number per lattice site yields a monotonic enhancement of {xi} as a function of decreasing interaction, which we assume to persist until the superfluid Bose-Einstein condensate phase is entered. Besides, we study cold atomic gases expanding, by a diffusion process, in a weak random potential. We show that the density-density correlation function of the expanding gas is strongly affected by disorder and we estimate the typical size of a speckle spot, i.e., a region of enhanced or depleted density. Both a Fermi gas and a Bose-Einstein condensate (in a mean-field approach) are considered. (orig.)

  1. Quantum transport in strongly interacting one-dimensional nanostructures

    NARCIS (Netherlands)

    Agundez, R.R.

    2015-01-01

    In this thesis we study quantum transport in several one-dimensional systems with strong electronic interactions. The first chapter contains an introduction to the concepts treated throughout this thesis, such as the Aharonov-Bohm effect, the Kondo effect, the Fano effect and quantum state transfer.

  2. Discriminative deep inelastic tests of strong interaction field theories

    International Nuclear Information System (INIS)

    Glueck, M.; Reya, E.

    1979-02-01

    It is demonstrated that recent measurements of ∫ 0 1 F 2 (x, Q 2 )dx eliminate already all strong interaction field theories except QCD. A detailed study of scaling violations of F 2 (x, Q 2 ) in QCD shows their insensitivity to the gluon content of the hadron at presently measured values of Q 2 . (orig.) [de

  3. Two-dimensional QCD as a model for strong interaction

    International Nuclear Information System (INIS)

    Ellis, J.

    1977-01-01

    After an introduction to the formalism of two-dimensional QCD, its applications to various strong interaction processes are reviewed. Among the topics discussed are spectroscopy, deep inelastic cross-sections, ''hard'' processes involving hadrons, ''Regge'' behaviour, the existence of the Pomeron, and inclusive hadron cross-sections. Attempts are made to abstracts features useful for four-dimensional QCD phenomenology. (author)

  4. Measurement of strong interaction parameters in antiprotonic hydrogen and deuterium

    CERN Document Server

    Augsburger, M A; Borchert, G L; Chatellard, D; Egger, J P; El-Khoury, P; Gorke, H; Gotta, D; Hauser, P R; Indelicato, P J; Kirch, K; Lenz, S; Siems, T; Simons, L M

    1999-01-01

    In the PS207 experiment at CERN, X-rays from antiprotonic hydrogen and deuterium have been measured at low pressure. The strong interaction shift and the broadening of the K/sub alpha / transition in antiprotonic hydrogen were $9 determined. Evidence was found for the individual hyperfine components of the protonium ground state. (7 refs).

  5. A systematic study of the strong interaction with PANDA

    NARCIS (Netherlands)

    Messchendorp, J. G.; Hosaka, A; Khemchandani, K; Nagahiro, H; Nawa, K

    2011-01-01

    The theory of Quantum Chromo Dynamics (QCD) reproduces the strong interaction at distances much shorter than the size of the nucleon. At larger distance scales, the generation of hadron masses and confinement cannot yet be derived from first principles on basis of QCD. The PANDA experiment at FAIR

  6. Two Methods For Simulating the Strong-Strong Beam-Beam Interaction in Hadron Colliders

    International Nuclear Information System (INIS)

    Warnock, Robert L.

    2002-01-01

    We present and compare the method of weighted macro particle tracking and the Perron-Frobenius operator technique for simulating the time evolution of two beams coupled via the collective beam-beam interaction in 2-D and 4-D (transverse) phase space. The coherent dipole modes, with and without lattice nonlinearities and external excitation, are studied by means of the Vlasov-Poisson system

  7. On the strong crack-microcrack interaction problem

    Science.gov (United States)

    Gorelik, M.; Chudnovsky, A.

    1992-07-01

    The problem of the crack-microcrack interaction is examined with special attention given to the iterative procedure described by Chudnovsky and Kachanov (1983), Chudnovsky et al. (1984), and Horii and Nemat-Nasser (1983), which yields erroneous results as the crack tips become closer (i.e., for strong crack interaction). To understand the source of error, the traction distributions along the microcrack line on the n-th step of iteration representing the exact and asymptotic stress fields are compared. It is shown that the asymptotic solution gives a gross overestimation of the actual traction.

  8. Ruling out a strongly interacting standard Higgs model

    International Nuclear Information System (INIS)

    Riesselmann, K.; Willenbrock, S.

    1997-01-01

    Previous work has suggested that perturbation theory is unreliable for Higgs- and Goldstone-boson scattering, at energies above the Higgs-boson mass, for relatively small values of the Higgs quartic coupling λ(μ). By performing a summation of nonlogarithmic terms, we show that perturbation theory is in fact reliable up to relatively large coupling. This eliminates the possibility of a strongly interacting standard Higgs model at energies above the Higgs-boson mass, complementing earlier studies which excluded strong interactions at energies near the Higgs-boson mass. The summation can be formulated in terms of an appropriate scale in the running coupling, μ=√(s)/e∼√(s)/2.7, so it can be incorporated easily in renormalization-group-improved tree-level amplitudes as well as higher-order calculations. copyright 1996 The American Physical Society

  9. Atom-Pair Kinetics with Strong Electric-Dipole Interactions.

    Science.gov (United States)

    Thaicharoen, N; Gonçalves, L F; Raithel, G

    2016-05-27

    Rydberg-atom ensembles are switched from a weakly to a strongly interacting regime via adiabatic transformation of the atoms from an approximately nonpolar into a highly dipolar quantum state. The resultant electric dipole-dipole forces are probed using a device akin to a field ion microscope. Ion imaging and pair-correlation analysis reveal the kinetics of the interacting atoms. Dumbbell-shaped pair-correlation images demonstrate the anisotropy of the binary dipolar force. The dipolar C_{3} coefficient, derived from the time dependence of the images, agrees with the value calculated from the permanent electric-dipole moment of the atoms. The results indicate many-body dynamics akin to disorder-induced heating in strongly coupled particle systems.

  10. The hadronic standard model for strong and electroweak interactions

    International Nuclear Information System (INIS)

    Raczka, R.

    1993-01-01

    We propose a new model for strong and electro-weak interactions. First, we review various QCD predictions for hadron-hadron and lepton-hadron processes. We indicate that the present formulation of strong interactions in the frame work of Quantum Chromodynamics encounters serious conceptual and numerical difficulties in a reliable description of hadron-hadron and lepton-hadron interactions. Next we propose to replace the strong sector of Standard Model based on unobserved quarks and gluons by the strong sector based on the set of the observed baryons and mesons determined by the spontaneously broken SU(6) gauge field theory model. We analyse various properties of this model such as asymptotic freedom, Reggeization of gauge bosons and fundamental fermions, baryon-baryon and meson-baryon high energy scattering, generation of Λ-polarization in inclusive processes and others. Finally we extend this model by electro-weak sector. We demonstrate a remarkable lepton and hadron anomaly cancellation and we analyse a series of important lepton-hadron and hadron-hadron processes such as e + + e - → hadrons, e + + e - → W + + W - , e + + e - → p + anti-p, e + p → e + p and p + anti-p → p + anti-p processes. We obtained a series of interesting new predictions in this model especially for processes with polarized particles. We estimated the value of the strong coupling constant α(M z ) and we predicted the top baryon mass M Λ t ≅ 240 GeV. Since in our model the proton, neutron, Λ-particles, vector mesons like ρ, ω, φ, J/ψ ect. and leptons are elementary most of experimentally analysed lepton-hadron and hadron-hadron processes in LEP1, LEP2, LEAR, HERA, HERMES, LHC and SSC experiments may be relatively easily analysed in our model. (author). 252 refs, 65 figs, 1 tab

  11. A connection between the strong and weak interactions

    International Nuclear Information System (INIS)

    Treiman, S.B.

    1989-01-01

    By studying weak scattering reactions (such as pion-nucleon scattering), the author and his colleague Marvin L Goldberger became renowned in the 1950s for work on dispersion relations. As a result of their collaboration a remarkable and unexpected connection was found between strong and weak interaction quantities. Agreement with experiment was good. Work by others found the same result, but via the partially conserved axial reactor current relation between the axial current divergence and the canonical pion field. (UK)

  12. Relative Nonlinear Electrodynamics Interaction of Charged Particles with Strong and Super Strong Laser Fields

    CERN Document Server

    Avetissian, Hamlet

    2006-01-01

    This book covers a large class of fundamental investigations into Relativistic Nonlinear Electrodynamics. It explores the interaction between charged particles and strong laser fields, mainly concentrating on contemporary problems of x-ray lasers, new type small set-up high-energy accelerators of charged particles, as well as electron-positron pair production from super powerful laser fields of relativistic intensities. It will also discuss nonlinear phenomena of threshold nature that eliminate the concurrent inverse processes in the problems of Laser Accelerator and Free Electron Laser, thus creating new opportunities for solving these problems.

  13. The Electron-Phonon Interaction in Strongly Correlated Systems

    International Nuclear Information System (INIS)

    Castellani, C.; Grilli, M.

    1995-01-01

    We analyze the effect of strong electron-electron repulsion on the electron-phonon interaction from a Fermi-liquid point of view and show that the electron-electron interaction is responsible for vertex corrections, which generically lead to a strong suppression of the electron-phonon coupling in the v F q/ω >>1 region, while such effect is not present when v F q/ω F is the Fermi velocity and q and ω are the transferred momentum and frequency respectively. In particular the e-ph scattering is suppressed in transport properties which are dominated by low-energy-high-momentum processes. On the other hand, analyzing the stability criterion for the compressibility, which involves the effective interactions in the dynamical limit, we show that a sizable electron-phonon interaction can push the system towards a phase-separation instability. Finally a detailed analysis of these ideas is carried out using a slave-boson approach for the infinite-U three-band Hubbard model in the presence of a coupling between the local hole density and a dispersionless optical phonon. (author)

  14. Joule-Thomson Coefficient for Strongly Interacting Unitary Fermi Gas

    International Nuclear Information System (INIS)

    Liao Kai; Chen Jisheng; Li Chao

    2010-01-01

    The Joule-Thomson effect reflects the interaction among constituent particles of macroscopic system. For classical ideal gas, the corresponding Joule-Thomson coefficient is vanishing while it is non-zero for ideal quantum gas due to the quantum degeneracy. In recent years, much attention is paid to the unitary Fermi gas with infinite two-body scattering length. According to universal analysis, the thermodynamical law of unitary Fermi gas is similar to that of non-interacting ideal gas, which can be explored by the virial theorem P = 2E/3V. Based on previous works, we further study the unitary Fermi gas properties. The effective chemical potential is introduced to characterize the nonlinear levels crossing effects in a strongly interacting medium. The changing behavior of the rescaled Joule-Thomson coefficient according to temperature manifests a quite different behavior from that for ideal Fermi gas. (general)

  15. Experimental reduction in interaction intensity strongly affects biotic selection.

    Science.gov (United States)

    Sletvold, Nina; Ågren, Jon

    2016-11-01

    The link between biotic interaction intensity and strength of selection is of fundamental interest for understanding biotically driven diversification and predicting the consequences of environmental change. The strength of selection resulting from biotic interactions is determined by the strength of the interaction and by the covariance between fitness and the trait under selection. When the relationship between trait and absolute fitness is constant, selection strength should be a direct function of mean population interaction intensity. To test this prediction, we excluded pollinators for intervals of different length to induce five levels of pollination intensity within a single plant population. Pollen limitation (PL) increased from 0 to 0.77 across treatments, accompanied by a fivefold increase in the opportunity for selection. Trait-fitness covariance declined with PL for number of flowers, but varied little for other traits. Pollinator-mediated selection on plant height, corolla size, and spur length increased by 91%, 34%, and 330%, respectively, in the most severely pollen-limited treatment compared to open-pollinated plants. The results indicate that realized biotic selection can be predicted from mean population interaction intensity when variation in trait-fitness covariance is limited, and that declines in pollination intensity will strongly increase selection on traits involved in the interaction. © 2016 by the Ecological Society of America.

  16. Nonperturbative Dynamics of Strong Interactions from Gauge/Gravity Duality

    Energy Technology Data Exchange (ETDEWEB)

    Grigoryan, Hovhannes [Louisiana State Univ., Baton Rouge, LA (United States)

    2008-08-01

    This thesis studies important dynamical observables of strong interactions such as form factors. It is known that Quantum Chromodynamics (QCD) is a theory which describes strong interactions. For large energies, one can apply perturbative techniques to solve some of the QCD problems. However, for low energies QCD enters into the nonperturbative regime, where di erent analytical or numerical tools have to be applied to solve problems of strong interactions. The holographic dual model of QCD is such an analytical tool that allows one to solve some nonperturbative QCD problems by translating them into a dual ve-dimensional theory de ned on some warped Anti de Sitter (AdS) background. Working within the framework of the holographic dual model of QCD, we develop a formalism to calculate form factors and wave functions of vector mesons and pions. As a result, we provide predictions of the electric radius, the magnetic and quadrupole moments which can be directly veri ed in lattice calculations or even experimentally. To nd the anomalous pion form factor, we propose an extension of the holographic model by including the Chern-Simons term required to reproduce the chiral anomaly of QCD. This allows us to nd the slope of the form factor with one real and one slightly o -shell photon which appeared to be close to the experimental ndings. We also analyze the limit of large virtualities (when the photon is far o -shell) and establish that predictions of the holographic model analytically coincide with those of perturbative QCD with asymptotic pion distribution amplitude. We also study the e ects of higher dimensional terms in the AdS/QCD model and show that these terms improve the holographic description towards a more realistic scenario. We show this by calculating corrections to the vector meson form factors and corrections to the observables such as electric radii, magnetic and quadrupole moments.

  17. The hadronic standard model for strong and electroweak interactions

    Energy Technology Data Exchange (ETDEWEB)

    Raczka, R. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

    1993-12-31

    We propose a new model for strong and electro-weak interactions. First, we review various QCD predictions for hadron-hadron and lepton-hadron processes. We indicate that the present formulation of strong interactions in the frame work of Quantum Chromodynamics encounters serious conceptual and numerical difficulties in a reliable description of hadron-hadron and lepton-hadron interactions. Next we propose to replace the strong sector of Standard Model based on unobserved quarks and gluons by the strong sector based on the set of the observed baryons and mesons determined by the spontaneously broken SU(6) gauge field theory model. We analyse various properties of this model such as asymptotic freedom, Reggeization of gauge bosons and fundamental fermions, baryon-baryon and meson-baryon high energy scattering, generation of {Lambda}-polarization in inclusive processes and others. Finally we extend this model by electro-weak sector. We demonstrate a remarkable lepton and hadron anomaly cancellation and we analyse a series of important lepton-hadron and hadron-hadron processes such as e{sup +} + e{sup -} {yields} hadrons, e{sup +} + e{sup -} {yields} W{sup +} + W{sup -}, e{sup +} + e{sup -} {yields} p + anti-p, e + p {yields} e + p and p + anti-p {yields} p + anti-p processes. We obtained a series of interesting new predictions in this model especially for processes with polarized particles. We estimated the value of the strong coupling constant {alpha}(M{sub z}) and we predicted the top baryon mass M{sub {Lambda}{sub t}} {approx_equal} 240 GeV. Since in our model the proton, neutron, {Lambda}-particles, vector mesons like {rho}, {omega}, {phi}, J/{psi} ect. and leptons are elementary most of experimentally analysed lepton-hadron and hadron-hadron processes in LEP1, LEP2, LEAR, HERA, HERMES, LHC and SSC experiments may be relatively easily analysed in our model. (author). 252 refs, 65 figs, 1 tab.

  18. The hadronic standard model for strong and electroweak interactions

    Energy Technology Data Exchange (ETDEWEB)

    Raczka, R [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

    1994-12-31

    We propose a new model for strong and electro-weak interactions. First, we review various QCD predictions for hadron-hadron and lepton-hadron processes. We indicate that the present formulation of strong interactions in the frame work of Quantum Chromodynamics encounters serious conceptual and numerical difficulties in a reliable description of hadron-hadron and lepton-hadron interactions. Next we propose to replace the strong sector of Standard Model based on unobserved quarks and gluons by the strong sector based on the set of the observed baryons and mesons determined by the spontaneously broken SU(6) gauge field theory model. We analyse various properties of this model such as asymptotic freedom, Reggeization of gauge bosons and fundamental fermions, baryon-baryon and meson-baryon high energy scattering, generation of {Lambda}-polarization in inclusive processes and others. Finally we extend this model by electro-weak sector. We demonstrate a remarkable lepton and hadron anomaly cancellation and we analyse a series of important lepton-hadron and hadron-hadron processes such as e{sup +} + e{sup -} {yields} hadrons, e{sup +} + e{sup -} {yields} W{sup +} + W{sup -}, e{sup +} + e{sup -} {yields} p + anti-p, e + p {yields} e + p and p + anti-p {yields} p + anti-p processes. We obtained a series of interesting new predictions in this model especially for processes with polarized particles. We estimated the value of the strong coupling constant {alpha}(M{sub z}) and we predicted the top baryon mass M{sub {Lambda}{sub t}} {approx_equal} 240 GeV. Since in our model the proton, neutron, {Lambda}-particles, vector mesons like {rho}, {omega}, {phi}, J/{psi} ect. and leptons are elementary most of experimentally analysed lepton-hadron and hadron-hadron processes in LEP1, LEP2, LEAR, HERA, HERMES, LHC and SSC experiments may be relatively easily analysed in our model. (author). 252 refs, 65 figs, 1 tab.

  19. Results from ATLAS and CMS: Strong Interactions and New Physics

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00179262

    2016-01-01

    Measurements on global properties and precision results on fundamental parameters related to the Strong Interaction sector of the Standard Model of particle physics, and searches for new phenomena beyond the Standard Model, performed by the two large multi-purpose particle detectors at the Large Hadron Collider (LHC), are summarised in this review. Special attention is payed to the new data obtained at $\\sqrt{s}$ = 13~TeV in 2015, which offer a first glimpse at the large physics potential offered by the high-energy running of the LHC.

  20. The kaon factory - towards the physics of strongly interacting systems

    International Nuclear Information System (INIS)

    Vogt, Erich

    1988-01-01

    With the advent of the standard model for quarks and leptons and unified forces there are profound new questions for the physics of strongly interacting systems: the nature of the nucleon, the physics of quark confinement, fundamental symmetries governing hadron decay and the effect of quarks and gluons on nuclear behaviour. Of the new large facilities now planned to respond to these questions the kaon factory is central. It uses very intense (∼100 μA) primary proton beams (∼30 GeV) to generate intense secondary beams of various hadrons and leptons. (author)

  1. Strongly modified plasmon-matter interaction with mesoscopic quantum emitters

    DEFF Research Database (Denmark)

    Andersen, Mads Lykke; Stobbe, Søren; Søndberg Sørensen, Anders

    2011-01-01

    Semiconductor quantum dots (QDs) provide useful means to couple light and matter in applications such as light-harvesting1, 2 and all-solid-state quantum information processing3, 4. This coupling can be increased by placing QDs in nanostructured optical environments such as photonic crystals...... or metallic nanostructures that enable strong confinement of light and thereby enhance the light–matter interaction. It has thus far been assumed that QDs can be described in the same way as atomic photon emitters—as point sources with wavefunctions whose spatial extent can be disregarded. Here we demonstrate...

  2. Discriminative deep inelastic tests of strong interaction field theories

    International Nuclear Information System (INIS)

    Glueck, M.; Reya, E.

    1979-02-01

    It is demonstrated that recent measurements of F 2 (x,Q 2 ) dx eliminate already all strong interaction field theories which do not include colored quarks as well as colored vector gluons. Detailed studies of scaling violations in F 2 (x,Q 2 ) cannot discriminate between a local gauge invariant theory (QCD) and one which has no local color gauge invariance, i.e. no triple-gluon coupling. This implies that all calculations on scaling violations done so far are insensitive to the gluon self-coupling, the latter might perhaps be delineated with future ep colliding beam facilities. (orig.) [de

  3. A strong viscous–inviscid interaction model for rotating airfoils

    DEFF Research Database (Denmark)

    Ramos García, Néstor; Sørensen, Jens Nørkær; Shen, Wen Zhong

    2014-01-01

    Two-dimensional (2D) and quasi-three dimensional (3D), steady and unsteady, viscous–inviscid interactive codes capable of predicting the aerodynamic behavior of wind turbine airfoils are presented. The model is based on a viscous–inviscid interaction technique using strong coupling between...... a boundary-layer trip or computed using an en envelope transition method. Validation of the incompressible 2D version of the code is carried out against measurements and other numerical codes for different airfoil geometries at various Reynolds numbers, ranging from 0.9 ⋅ 106 to 8.2 ⋅ 106. In the quasi-3D...... version, a parametric study on rotational effects induced by the Coriolis and centrifugal forces in the boundary-layer equations shows that the effects of rotation are to decrease the growth of the boundary-layer and delay the onset of separation, hence increasing the lift coefficient slightly while...

  4. Dynamical equilibration in strongly-interacting parton-hadron matter

    Directory of Open Access Journals (Sweden)

    Gorenstein M.

    2011-04-01

    Full Text Available We study the kinetic and chemical equilibration in 'infinite' parton-hadron matter within the Parton-Hadron-String Dynamics transport approach, which is based on a dynamical quasiparticle model for partons matched to reproduce lattice-QCD results – including the partonic equation of state – in thermodynamic equilibrium. The 'infinite' matter is simulated within a cubic box with periodic boundary conditions initialized at different baryon density (or chemical potential and energy density. The transition from initially pure partonic matter to hadronic degrees of freedom (or vice versa occurs dynamically by interactions. Different thermody-namical distributions of the strongly-interacting quark-gluon plasma (sQGP are addressed and discussed.

  5. On the mixed phase of strongly interacting matter

    International Nuclear Information System (INIS)

    Suleymanov, M.K.; Abdinov, O.B.; Belashev, B.Z.; Guseynaliyev, Y.G.; Vodoplanov, A.S.

    2005-01-01

    Full text : The studying of the behavior of some characteristics of hadron-nuclear and nuclear-nuclear interactions as a function of the collision centrality Q is an important experimental method to get information about the changes of nuclear matter phase, because the increasing of the centrality could lead to the growth of the nuclear matter baryon density. The regime change in the behavior of some centrality depending characteristics of events is expected by the varying the Q. It would be the signal about the phase transition. This method is considered as the best tool reaching the quark-gluon plasma phase of strongly interacting matter. Some experimental results demonstrate already the existence of the regime changes in the event characteristics behavior as a function of collision centrality

  6. Local condensate depletion at trap center under strong interactions

    Science.gov (United States)

    Yukalov, V. I.; Yukalova, E. P.

    2018-04-01

    Cold trapped Bose-condensed atoms, interacting via hard-sphere repulsive potentials are considered. Simple mean-field approximations show that the condensate distribution inside a harmonic trap always has the shape of a hump with the maximum condensate density occurring at the trap center. However, Monte Carlo simulations at high density and strong interactions display the condensate depletion at the trap center. The explanation of this effect of local condensate depletion at trap center is suggested in the frame of self-consistent theory of Bose-condensed systems. The depletion is shown to be due to the existence of the anomalous average that takes into account pair correlations and appears in systems with broken gauge symmetry.

  7. Universal structure of a strongly interacting Fermi gas

    Energy Technology Data Exchange (ETDEWEB)

    Kuhnle, Eva; Dyke, Paul; Hoinka, Sascha; Mark, Michael; Hu Hui; Liu Xiaji; Drummond, Peter; Hannaford, Peter; Vale, Chris, E-mail: cvale@swin.edu.au [ARC Centre of Excellence for Quantum Atom Optics, Swinburne University of Technology, Hawthorn 3122 (Australia)

    2011-01-10

    This paper presents studies of the universal properties of strongly interacting Fermi gases using Bragg spectroscopy. We focus on pair-correlations, their relationship to the contact C introduced by Tan, and their dependence on both the momentum and temperature. We show that short-range pair correlations obey a universal law, first derived by Tan through measurements of the static structure factor, which displays a universal scaling with the ratio of the contact to the momentum C/q. Bragg spectroscopy of ultracold {sup 6}Li atoms is employed to measure the structure factor for a wide range of momenta and interaction strengths, providing broad confirmation of this universal law. We show that calibrating our Bragg spectra using the f-sum rule leads to a dramatic improvement in the accuracy of the structure factor measurement. We also measure the temperature dependence of the contact in a unitary gas and compare our results to calculations based on a virial expansion.

  8. Theoretical Studies of Strongly Interacting Fine Particle Systems

    Science.gov (United States)

    Fearon, Michael

    Available from UMI in association with The British Library. A theoretical analysis of the time dependent behaviour of a system of fine magnetic particles as a function of applied field and temperature was carried out. The model used was based on a theory assuming Neel relaxation with a distribution of particle sizes. This theory predicted a linear variation of S_{max} with temperature and a finite intercept, which is not reflected by experimental observations. The remanence curves of strongly interacting fine-particle systems were also investigated theoretically. It was shown that the Henkel plot of the dc demagnetisation remanence vs the isothermal remanence is a useful representation of interactions. The form of the plot was found to be a reflection of the magnetic and physical microstructure of the material, which is consistent with experimental data. The relationship between the Henkel plot and the noise of a particulate recording medium, another property dependent on the microstructure, is also considered. The Interaction Field Factor (IFF), a single parameter characterising the non-linearity of the Henkel plot, is investigated. These results are consistent with a previous experimental study. Finally the results of the noise power spectral density for erased and saturated recording media are presented, so that characterisation of interparticle interactions may be carried out with greater accuracy.

  9. Non-equilibrium magnetic interactions in strongly correlated systems

    Energy Technology Data Exchange (ETDEWEB)

    Secchi, A., E-mail: a.secchi@science.ru.nl [Institute for Molecules and Materials, Radboud University Nijmegen, 6525 AJ Nijmegen (Netherlands); Brener, S.; Lichtenstein, A.I. [Institut für Theoretische Physik, Universitat Hamburg, Jungiusstraße 9, D-20355 Hamburg (Germany); Katsnelson, M.I. [Institute for Molecules and Materials, Radboud University Nijmegen, 6525 AJ Nijmegen (Netherlands)

    2013-06-15

    We formulate a low-energy theory for the magnetic interactions between electrons in the multi-band Hubbard model under non-equilibrium conditions determined by an external time-dependent electric field which simulates laser-induced spin dynamics. We derive expressions for dynamical exchange parameters in terms of non-equilibrium electronic Green functions and self-energies, which can be computed, e.g., with the methods of time-dependent dynamical mean-field theory. Moreover, we find that a correct description of the system requires, in addition to exchange, a new kind of magnetic interaction, that we name twist exchange, which formally resembles Dzyaloshinskii–Moriya coupling, but is not due to spin–orbit, and is actually due to an effective three-spin interaction. Our theory allows the evaluation of the related time-dependent parameters as well. -- Highlights: •We develop a theory for magnetism of strongly correlated systems out of equilibrium. •Our theory is suitable for laser-induced ultrafast magnetization dynamics. •We write time-dependent exchange parameters in terms of electronic Green functions. •We find a new magnetic interaction, a “twist exchange”. •We give general expressions for magnetic noise in itinerant-electron systems.

  10. Strong interactions and electromagnetism in low-energy hadron physics

    International Nuclear Information System (INIS)

    Kubis, B.

    2002-10-01

    In the present work, we study various aspects of the entanglement of the strong and electromagnetic interactions as it is manifest in low-energy hadron physics. In the framework of chiral perturbation theory, two aspects are investigated: the test of the structure of baryons as probed by external electromagnetic currents, and the modification of reactions mediated by the strong interactions in the presence of internal (virtual) photons. In the first part of this work, we study the electromagnetic form factors of nucleons and the ground state baryon octet, as well as strangeness form factors of the nucleon. Emphasis is put on the comparison of a new relativistic scheme for the calculation of loop diagrams to the heavy-baryon formalism, and on the convergence of higher-order corrections in both schemes. The new scheme is shown to yield both a phenomenologically more successful description of the data and better convergence behaviour. In the second part, we study isospin violation in pion-kaon scattering as mediated by virtual photon effects and the light quark mass difference. This investigation is of particular importance for the extraction of scattering lengths from measurements of lifetime and energy levels in pion-kaon atoms. The isospin breaking corrections are shown to be small and sufficiently well under control. (orig.)

  11. Properties of hot and dense strongly interacting matter

    Energy Technology Data Exchange (ETDEWEB)

    Almasi, Gabor Andras

    2017-06-19

    In this thesis we consider effective models of quantum chromodynamics to learn about the chiral- and deconfinement phase transitions. In Chapter 1 we review basic properties of strongly interacting matter and the foundations of finite temperature field theory. We review furthermore the nonperturbative functional renormalization group (FRG) approach. In Chapter 2 we introduce the quark-meson (QM) model and its extensions including the Polyakov-loop variables and repulsive vector interactions between quarks. We then discuss features of the model both in the mean-field approximation and in the renormalization group treatment. A novel method to solve the renormalization group equations based on the Chebyshev polynomials is presented at the end of the chapter. In Chapter 3 the scaling behavior of the order parameter at the chiral phase transition is studied within effective models. We explore universal and nonuniversal structures near the critical point. These include the scaling functions, the leading corrections to scaling and the corresponding size of the scaling window as well as their dependence on an external symmetry breaking field. We consider two models in the mean-field approximation, the QM and the Polyakov-loop-extended quark-meson (PQM) models, and compare their critical properties with a purely bosonic theory, the O(N) linear sigma model in the N → ∞ limit. In these models the order parameter scaling function is found analytically using the high temperature expansion of the thermodynamic potential. The effects of a gluonic background on the nonuniversal scaling parameters are studied within the PQM model. Furthermore, numerical calculations of the scaling function and the scaling window are performed in the QM model using the FRG. Chapter 4 contains a study of the critical properties of net-baryon-number fluctuations at the chiral restoration transition in a medium at finite temperature and net baryon density. The chiral dynamics of quantum

  12. Relativistic strings and dual models of strong interactions

    International Nuclear Information System (INIS)

    Marinov, M.S.

    1977-01-01

    The theory of strong interactions,based on the model depicting a hardon as a one-dimentional elastic relativistic system(''string'') is considered. The relationship between this model and the concepts of quarks and partons is discussed. Presented are the principal results relating to the Veneziano dual theory, which may be considered as the consequence of the string model, and to its modifications. The classical string theory is described in detail. Attention is focused on questions of importance to the construction of the quantum theory - the Hamilton mechanisms and conformal symmetry. Quantization is described, and it is shown that it is not contradictory only in the 26-dimentional space and with a special requirement imposed on the spectrum of states. The theory of a string with a distributed spin is considered. The spin is introduced with the aid of the Grassman algebra formalism. In this case quantization is possible only in the 10-dimentional space. The strings interact by their ruptures and gluings. A method for calculating the interaction amplitudes is indicated

  13. Noise in strong laser-atom interactions: Phase telegraph noise

    International Nuclear Information System (INIS)

    Eberly, J.H.; Wodkiewicz, K.; Shore, B.W.

    1984-01-01

    We discuss strong laser-atom interactions that are subjected to jump-type (random telegraph) random-phase noise. Physically, the jumps may arise from laser fluctuations, from collisions of various kinds, or from other external forces. Our discussion is carried out in two stages. First, direct and partially heuristic calculations determine the laser spectrum and also give a third-order differential equation for the average inversion of a two-level atom on resonance. At this stage a number of general features of the interaction are able to be studied easily. The optical analog of motional narrowing, for example, is clearly predicted. Second, we show that the theory of generalized Poisson processes allows laser-atom interactions in the presence of random telegraph noise of all kinds (not only phase noise) to be treated systematically, by means of a master equation first used in the context of quantum optics by Burshtein. We use the Burshtein equation to obtain an exact expression for the two-level atom's steady-state resonance fluorescence spectrum, when the exciting laser exhibits phase telegraph noise. Some comparisons are made with results obtained from other noise models. Detailed treatments of the effects ofmly jumps, or as a model of finite laser bandwidth effects, in which the laser frequency exhibits random jumps. We show that these two types of frequency noise can be distinguished in light-scattering spectra. We also discuss examples which demonstrate both temporal and spectral motional narrowing, nonexponential correlations, and non-Lorentzian spectra. Its exact solubility in finite terms makes the frequency-telegraph noise model an attractive alternative to the white-noise Ornstein-Uhlenbeck frequency noise model which has been previously applied to laser-atom interactions

  14. Extreme states of matter in strong interaction physics an introduction

    CERN Document Server

    Satz, Helmut

    2018-01-01

    This book is a course-tested primer on the thermodynamics of strongly interacting matter – a profound and challenging area of both theoretical and experimental modern physics. Analytical and numerical studies of statistical quantum chromodynamics provide the main theoretical tool, while in experiments, high-energy nuclear collisions are the key for extensive laboratory investigations. As such, the field straddles statistical, particle and nuclear physics, both conceptually and in the methods of investigation used. The book addresses, above all, the many young scientists starting their scientific research in this field, providing them with a general, self-contained introduction that highlights the basic concepts and ideas and explains why we do what we do. Much of the book focuses on equilibrium thermodynamics: first it presents simplified phenomenological pictures, leading to critical behavior in hadronic matter and to a quark-hadron phase transition. This is followed by elements of finite temperature latti...

  15. Stability of Dirac Liquids with Strong Coulomb Interaction.

    Science.gov (United States)

    Tupitsyn, Igor S; Prokof'ev, Nikolay V

    2017-01-13

    We develop and apply the diagrammatic Monte Carlo technique to address the problem of the stability of the Dirac liquid state (in a graphene-type system) against the strong long-range part of the Coulomb interaction. So far, all attempts to deal with this problem in the field-theoretical framework were limited either to perturbative or random phase approximation and functional renormalization group treatments, with diametrically opposite conclusions. Our calculations aim at the approximation-free solution with controlled accuracy by computing vertex corrections from higher-order skeleton diagrams and establishing the renormalization group flow of the effective Coulomb coupling constant. We unambiguously show that with increasing the system size L (up to ln(L)∼40), the coupling constant always flows towards zero; i.e., the two-dimensional Dirac liquid is an asymptotically free T=0 state with divergent Fermi velocity.

  16. Screening important inputs in models with strong interaction properties

    International Nuclear Information System (INIS)

    Saltelli, Andrea; Campolongo, Francesca; Cariboni, Jessica

    2009-01-01

    We introduce a new method for screening inputs in mathematical or computational models with large numbers of inputs. The method proposed here represents an improvement over the best available practice for this setting when dealing with models having strong interaction effects. When the sample size is sufficiently high the same design can also be used to obtain accurate quantitative estimates of the variance-based sensitivity measures: the same simulations can be used to obtain estimates of the variance-based measures according to the Sobol' and the Jansen formulas. Results demonstrate that Sobol' is more efficient for the computation of the first-order indices, while Jansen performs better for the computation of the total indices.

  17. Screening important inputs in models with strong interaction properties

    Energy Technology Data Exchange (ETDEWEB)

    Saltelli, Andrea [European Commission, Joint Research Centre, 21020 Ispra, Varese (Italy); Campolongo, Francesca [European Commission, Joint Research Centre, 21020 Ispra, Varese (Italy)], E-mail: francesca.campolongo@jrc.it; Cariboni, Jessica [European Commission, Joint Research Centre, 21020 Ispra, Varese (Italy)

    2009-07-15

    We introduce a new method for screening inputs in mathematical or computational models with large numbers of inputs. The method proposed here represents an improvement over the best available practice for this setting when dealing with models having strong interaction effects. When the sample size is sufficiently high the same design can also be used to obtain accurate quantitative estimates of the variance-based sensitivity measures: the same simulations can be used to obtain estimates of the variance-based measures according to the Sobol' and the Jansen formulas. Results demonstrate that Sobol' is more efficient for the computation of the first-order indices, while Jansen performs better for the computation of the total indices.

  18. Towards a unified gauge theory of gravitational and strong interactions

    International Nuclear Information System (INIS)

    Hehl, F.W.; Sijacki, D.

    1980-01-01

    The space-time properties of leptons and hadrons is studied and it is found necessary to extend general relativity to the gauge theory based on the four-dimensional affine group. This group translates and deforms the tetrads of the locally Minkowskian space-time. Its conserved currents, momentum, and hypermomentum, act as sources in the two field equations of gravity. A Lagrangian quadratic in torsion and curvature allows for the propagation of two independent gauge fields: translational e-gravity mediated by the tetrad coefficients, and deformational GAMMA-gravity mediated by the connection coefficients. For macroscopic matter e-gravity coincides with general relativity up to the post-Newtonian approximation of fourth order. For microscopic matter GAMMA-gravity represents a strong Yang-Mills type interaction. In the linear approximation, for a static source, a confinement potential is found. (author)

  19. Are Higgs particles strongly interacting(question mark)

    International Nuclear Information System (INIS)

    Shanker, O.

    1982-02-01

    The order of magnitude of Yukawa couplings in some theories with flavour violating Higgs particles is estimated. Based on these couplings, mass bounds for flavour violating Higgs particles are derived from the Ksub(L)-Ksub(S) mass difference. The Higgs particles have to be very heavy, implying that the Higgs sector quartic couplings are very large. Thus, these theories seem to require a strongly interacting Higgs sector unless one adjusts to the Higgs-fermion Yukawa couplings to within two orders of magnitude, so as to suppress the coupling of Higgs particles to the flavour-violating anti sd current. Most models with flavour violating Higgs particles have the same general features, so the conclusions are likely to hold for a wide class of models with flavour violating Higgs particles

  20. Ion Motion in a Plasma Interacting with Strong Magnetic Fields

    International Nuclear Information System (INIS)

    Weingarten, A.; Grabowski, C.; Chakrabarti, N.; Maron, Y.; Fruchtmant, A.

    1999-01-01

    The interaction of a plasma with strong magnetic fields takes place in many laboratory experiments and astrophysical plasmas. Applying a strong magnetic field to the plasma may result in plasma displacement, magnetization, or the formation of instabilities. Important phenomena in plasma, such as the energy transport and the momentum balance, take a different form in each case. We study this interaction in a plasma that carries a short-duration (80-ns) current pulse, generating a magnetic field of up to 17 kG. The evolution of the magnetic field, plasma density, ion velocities, and electric fields are determined before and during the current pulse. The dependence of the plasma limiting current on the plasma density and composition are studied and compared to theoretical models based on the different phenomena. When the plasma collisionality is low, three typical velocities should be taken into consideration: the proton and heavier-ion Alfven velocities (v A p and v A h , respectively) and the EMHD magnetic-field penetration velocity into the plasma (v EMHD ). If both Alfven velocities are larger than v EMHD the plasma is pushed ahead of the magnetic piston and the magnetic field energy is dissipated into ion kinetic energy. If v EMHD is the largest of three velocities, the plasma become magnetized and the ions acquire a small axial momentum only. Different ion species may drift in different directions along the current lines. In this case, the magnetic field energy is probably dissipated into electron thermal energy. When vs > V EMHD > vi, as in the case of one of our experiments, ion mass separation occurs. The protons are pushed ahead of the piston while the heavier-ions become magnetized. Since the plasma electrons are unmagnetized they cannot cross the piston, and the heavy ions are probably charge-neutralized by electrons originating from the cathode that are 'born' magnetized

  1. Kaonic atoms – studies of the strong interaction with strangeness

    Directory of Open Access Journals (Sweden)

    Marton J.

    2014-01-01

    Full Text Available The strong interaction of charged antikaons (K− with nucleons and nuclei in the low-energy regime is a fascinating topic. The antikaon plays a peculiar role in hadron physics due to the strong attraction antikaon-nucleon which is a key question for possible kaonic nuclear bound states. A rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions to low-lying states in light kaonic atoms like kaonic hydrogen and deuterium. After the successful completion of precision measurements on kaonic hydrogen and helium isotopes by SIDDHARTA at DAΦNE/LNF, new X-ray studies with the focus on kaonic deuterium are in preparation (SIDDHARTA2. In the future with kaonic deuterium data the antikaon-nucleon isospin-dependent scattering lengths can be extracted for the first time. An overview of the experimental results of SIDDHARTA and an outlook to future perspectives in the SIDDHARTA2 experiments in this frontier research field will be given.

  2. Chemical Evolution of Strongly Interacting Quark-Gluon Plasma

    International Nuclear Information System (INIS)

    Pan, Ying-Hua; Zhang, Wei-Ning

    2014-01-01

    At very initial stage of relativistic heavy ion collisions a wave of quark-gluon matter is produced from the break-up of the strong color electric field and then thermalizes at a short time scale (~1 fm/c). However, the quark-gluon plasma (QGP) system is far out of chemical equilibrium, especially for the heavy quarks which are supposed to reach chemical equilibrium much late. In this paper a continuing quark production picture for strongly interacting QGP system is derived, using the quark number susceptibilities and the equation of state; both of them are from the results calculated by the Wuppertal-Budapest lattice QCD collaboration. We find that the densities of light quarks increase by 75% from the temperature T=400 MeV to T=150 MeV, while the density of strange quark annihilates by 18% in the temperature region. We also offer a discussion on how this late production of quarks affects the final charge-charge correlations

  3. Universal contact of strongly interacting fermions at finite temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Hu Hui; Liu Xiaji; Drummond, Peter D, E-mail: hhu@swin.edu.au, E-mail: xiajiliu@swin.edu.au, E-mail: pdrummond@swin.edu.au [ARC Centre of Excellence for Quantum-Atom Optics, Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne 3122 (Australia)

    2011-03-15

    The recently discovered universal thermodynamic behavior of dilute, strongly interacting Fermi gases also implies a universal structure in the many-body pair-correlation function at short distances, as quantified by the contact I. Here, we theoretically calculate the temperature dependence of this universal contact for a Fermi gas in free space and in a harmonic trap. At high temperatures above the Fermi degeneracy temperature, T{approx}>T{sub F}, we obtain a reliable non-perturbative quantum virial expansion up to third order. At low temperatures, we compare different approximate strong-coupling theories. These make different predictions, which need to be tested either by future experiments or by advanced quantum Monte Carlo simulations. We conjecture that in the universal unitarity limit, the contact or correlation decreases monotonically with increasing temperature, unless the temperature is significantly lower than the critical temperature, T<

  4. Air-sea interactions during strong winter extratropical storms

    Science.gov (United States)

    Nelson, Jill; He, Ruoying; Warner, John C.; Bane, John

    2014-01-01

    A high-resolution, regional coupled atmosphere–ocean model is used to investigate strong air–sea interactions during a rapidly developing extratropical cyclone (ETC) off the east coast of the USA. In this two-way coupled system, surface momentum and heat fluxes derived from the Weather Research and Forecasting model and sea surface temperature (SST) from the Regional Ocean Modeling System are exchanged via the Model Coupling Toolkit. Comparisons are made between the modeled and observed wind velocity, sea level pressure, 10 m air temperature, and sea surface temperature time series, as well as a comparison between the model and one glider transect. Vertical profiles of modeled air temperature and winds in the marine atmospheric boundary layer and temperature variations in the upper ocean during a 3-day storm period are examined at various cross-shelf transects along the eastern seaboard. It is found that the air–sea interactions near the Gulf Stream are important for generating and sustaining the ETC. In particular, locally enhanced winds over a warm sea (relative to the land temperature) induce large surface heat fluxes which cool the upper ocean by up to 2 °C, mainly during the cold air outbreak period after the storm passage. Detailed heat budget analyses show the ocean-to-atmosphere heat flux dominates the upper ocean heat content variations. Results clearly show that dynamic air–sea interactions affecting momentum and buoyancy flux exchanges in ETCs need to be resolved accurately in a coupled atmosphere–ocean modeling framework.

  5. Realization of collective strong coupling with ion Coulomb crystals in an optical cavity

    DEFF Research Database (Denmark)

    Herskind, Peter Fønss; Dantan, Aurélien; Marler, Joan

    2009-01-01

    Cavity quantum electrodynamics (CQED) focuses on understanding the interactions between matter and the electromagnetic field in cavities at the quantum level 1, 2 . In the past years, CQED has attracted attention 3, 4, 5, 6, 7, 8, 9 especially owing to its importance for the field of quantum...... information 10 . At present, photons are the best carriers of quantum information between physically separated sites 11, 12 and quantum-information processing using stationary qubits 10 is most promising, with the furthest advances having been made with trapped ions 13, 14, 15 . The implementation of complex...... quantum-information-processing networks 11, 12 hence requires devices to efficiently couple photons and stationary qubits. Here, we present the first CQED experiments demonstrating that the collective strong-coupling regime 2 can be reached in the interaction between a solid in the form of an ion Coulomb...

  6. A non-linear theory of strong interactions

    International Nuclear Information System (INIS)

    Skyrme, T.H.R.

    1994-01-01

    A non-linear theory of mesons, nucleons and hyperons is proposed. The three independent fields of the usual symmetrical pseudo-scalar pion field are replaced by the three directions of a four-component field vector of constant length, conceived in an Euclidean four-dimensional isotopic spin space. This length provides the universal scaling factor, all other constants being dimensionless; the mass of the meson field is generated by a φ 4 term; this destroys the continuous rotation group in the iso-space, leaving a 'cubic' symmetry group. Classification of states by this group introduces quantum numbers corresponding to isotopic spin and to 'strangeness'; one consequences is that, at least in elementary interactions, charge is only conserved module 4. Furthermore, particle states have not a well-defined parity, but parity is effectively conserved for meson-nucleon interactions. A simplified model, using only two dimensions of space and iso-space, is considered further; the non-linear meson field has solutions with particle character, and an indication is given of the way in which the particle field variables might be introduced as collective co-ordinates describing the dynamics of these particular solutions of the meson field equations, suggesting a unified theory based on the meson field alone. (author). 7 refs

  7. Theoretical & Experimental Research in Weak, Electromagnetic & Strong Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Nandi, Satyanarayan [Oklahoma State Univ., Stillwater, OK (United States); Babu, Kaladi [Oklahoma State Univ., Stillwater, OK (United States); Rizatdinova, Flera [Oklahoma State Univ., Stillwater, OK (United States); Khanov, Alexander [Oklahoma State Univ., Stillwater, OK (United States); Haley, Joseph [Oklahoma State Univ., Stillwater, OK (United States)

    2015-09-17

    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 and 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

  8. Effective Field Theories and Strong Interactions. Final Technical Report

    International Nuclear Information System (INIS)

    Fleming, Sean

    2011-01-01

    The framework of Effective Field Theories (EFTs) allows us to describe strong interactions in terms of degrees of freedom relevant to the energy regimes of interest, in the most general way consistent with the symmetries of QCD. Observables are expanded systematically in powers of M lo /M hi , where M lo (M hi ) denotes a low-(high-)energy scale. This organizational principle is referred to as 'power counting'. Terms of increasing powers in the expansion parameter are referred to as leading order (LO), next-to-leading order (NLO), etc. Details of the QCD dynamics not included explicitly are encoded in interaction parameters, or 'low-energy constants' (LECs), which can in principle be calculated from an explicit solution of QCD - for example via lattice simulations- but can also be determined directly from experimental data. QCD has an intrinsic scale M QCD ≅ 1 GeV, at which the QCD coupling constant α s (M QCD ) becomes large and the dynamics becomes non-perturbative. As a consequence M QCD sets the scale for the masses of most hadrons, such as the nucleon mass m N ≅ 940 MeV. EFTs can roughly be divided into two categories: those that can be matched onto QCD in perturbation theory, which we call high-energy EFTs, and those that cannot be matched perturbatively, which we call low-energy EFTs. In high-energy EFTs, M QCD typically sets the low-energy scale, and all the dynamics associated with this scale reside in matrix elements of EFT operators. These non-perturbative matrix elements are the LECs and are also referred to as long-distance contributions. Each matrix element is multiplied by a short-distance coefficient, which contains the dynamics from the high scale M hi . Since M hi >> M QCD , α s (M hi ) hi ∼ M Q , the heavy-quark mass, and in addition to M QCD there are low scales associated with the typical relative momentum ∼ M Q v and energy ∼ M Q v 2 of the heavy quarks. Depending on the sizes of M Q and the heavy-quark velocity v these scales can

  9. Phases of strongly-interacting matter with functional methods

    International Nuclear Information System (INIS)

    Mitter, M.

    2012-01-01

    Non-perturbative aspects of strongly-interacting matter, in particular at non-vanishing temperatures, are investigated with functional methods. The consequences of confinement in terms of a linearly rising static quark potential arising from an infrared singular quark 4-point function are studied. Such a singularity is only consistent for a specific color structure and implies the existence of similar singularities in special color structures of n-point functions with n>3. A simple explanation for Casimir scaling is found within this mechanism of confinement.The deconfinement transition of fundamentally charged scalar and quark matter is investigated in terms of center symmetry. Novel dual order parameters are introduced that can be obtained from the corresponding matter propagators. In the case of quark matter the new order parameter compares well with the dual chiral condensate, with the advantage that no regularization is necessary even at non-vanishing quark masses.The influence of the axial anomaly on the chiral transition is studied in terms of a 't Hooft determinant with quarks and mesons as effective degrees of freedom in the functional renormalization group. In the case of two quark flavors, the calculated temperature dependent determinant results in a decrease of the anomalous eta'-mass close to the chiral transition temperature. This is connected to a partial Z(2) restoration at the chiral transition instead of the restoration of full axial U(1). With 2+1 quark flavors and a temperature independent 't Hooft term, the chiral transition is found to be of second order with three dimensional O(4) critical exponents in the limit of vanishing up and down quark mass, whereas a first-order transition is seen without U(1) violation. (author) [de

  10. The colours of strong interaction; L`interaction forte sous toutes ses couleurs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The aim of this session is to draw a consistent framework about the different ways to consider strong interaction. A large part is dedicated to theoretical work and the latest experimental results obtained at the first electron collider HERA are discussed. (A.C.)

  11. The colours of strong interaction; L`interaction forte sous toutes ses couleurs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The aim of this session is to draw a consistent framework about the different ways to consider strong interaction. A large part is dedicated to theoretical work and the latest experimental results obtained at the first electron collider HERA are discussed. (A.C.)

  12. Les Houches Summer School : Strongly Interacting Quantum Systems out of Equilibrium

    CERN Document Server

    Millis, Andrew J; Parcollet, Olivier; Saleur, Hubert; Cugliandolo, Leticia F

    2016-01-01

    Over the last decade new experimental tools and theoretical concepts are providing new insights into collective nonequilibrium behavior of quantum systems. The exquisite control provided by laser trapping and cooling techniques allows us to observe the behavior of condensed bose and degenerate Fermi gases under nonequilibrium drive or after quenches' in which a Hamiltonian parameter is suddenly or slowly changed. On the solid state front, high intensity short-time pulses and fast (femtosecond) probes allow solids to be put into highly excited states and probed before relaxation and dissipation occur. Experimental developments are matched by progress in theoretical techniques ranging from exact solutions of strongly interacting nonequilibrium models to new approaches to nonequilibrium numerics. The summer school Strongly interacting quantum systems out of equilibrium' held at the Les Houches School of Physics as its XCIX session was designed to summarize this progress, lay out the open questions and define dir...

  13. Intensities and strong interaction attenuation of kaonic x-rays

    CERN Document Server

    Backenstoss, Gerhard; Koch, H; Povel, H P; Schwitter, A; Tauscher, Ludwig

    1974-01-01

    Relative intensities of numerous kaonic X-ray transitions have been measured for the elements C, P, S, and Cl, from which level widths due to the strong K-nucleus absorption have been determined. From these and earlier published data, optical potential parameters have been derived and possible consequences on the nuclear matter distribution are discussed. (10 refs).

  14. Interaction of neutral particles with strong laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Meuren, Sebastian; Keitel, Christoph H.; Di Piazza, Antonino [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

    2013-07-01

    Since the invention of the laser in the 1960s the experimentally available field strengths have continuously increased. The current peak intensity record is 2 x 10{sup 22} W/cm{sup 2} and next generation facilities such as ELI, HiPER and XCELS plan to reach even intensities of the order of 10{sup 24} W/cm{sup 2}. Thus, modern laser facilities are a clean source for very strong external electromagnetic fields and promise new and interesting high-energy physics experiments. In particular, strong laser fields could be used to test non-linear effects in quantum field theory. Earlier we have investigated how radiative corrections modify the coupling of a charged particle inside a strong plane-wave electromagnetic background field. However, a charged particle couples already at tree level to electromagnetic radiation. Therefore, we have now analyzed how the coupling between neutral particles and radiation is affected by a very strong plane-wave electromagnetic background field, when loop corrections are taken into account. In particular, the case of neutrinos is discussed.

  15. Low energy p anti p strong interactions: theoretical perspective

    International Nuclear Information System (INIS)

    Dover, C.B.

    1985-01-01

    Several of the frontier problems in low energy nucleon-antinucleon phenomenology are addressed. Spin observables and dynamical selection rules in N anti N annihilation are used as examples of phenomena which offer particularly strong constraints on theoretical models, formulated either in terms of meson and baryon exchange or as effective operators in a non-perturbative quark-gluon picture. 24 refs

  16. On the strong influence of molecular interactions over large distances

    Science.gov (United States)

    Pfennig, Andreas

    2018-03-01

    Molecular-dynamics simulations of liquid water show deterministic chaos, i.e. an intentionally introduced molecular position shift of an individual molecule increases exponentially by a factor of 10 in 0.23 ps. This is a Lyaponov instability. As soon as it reaches molecular scale, the direction of the resulting shift in molecular motions is unpredictable. The influence of any individual distant particle on an observed molecule will be minute, but the effect will quickly increase to molecular scale and beyond due to this exponential growth. Consequently, any individual particle in the universe will affect the behavior of any molecule within at most 33 ps after the interaction reaches it. A larger distance of the faraway particle does not decrease the influence on an observed molecule, but the effect reaches molecular scale only some ps later. Thus in evaluating the interactions, nearby and faraway molecules have to be equally accounted for. The consequences of this quickly reacting network of interactions on universal scale are fundamental. Even in a strictly deterministic view, molecular behavior is principally unpredictable, and thus has to be regarded random. Corresponding statements apply for any particles interacting. This result leads to a fundamental rethinking of the structure of interactions of molecules and particles as well as the behavior of reality.

  17. Strong-coupling interaction in high-Tc superconductors

    International Nuclear Information System (INIS)

    Ray, D.K.

    1991-01-01

    Extensive experimental and theoretical work have been done to understand the mechanisms of superconductivity. Until 1986 when Bednorz and Muller discovered superconductivity in the copper oxide perovskite, the principal mechanism was found to be electron-phonon interaction and the characteristics of superconductivity vary depending on the strength of the electron-phonon interaction and the electronic structure. The essential characteristic of these conventional superconductors could be divided into two groups: wide band metals with low density of states N(E F ) at the Fermi energy E F and a rather weak electron-phonon coupling V obeying the universal characteristics of the BCS theory and narrow d band metals, compounds, and alloys with high values of N(E F ), electron-phonon coupling V and non negligible Coulomb interaction between the electrons. In this paper a short summary and the important results of these theories are discussed. The inherent limitations of these theories based on electron-phonon interaction will be discussed. The authors indicate the major characteristics of the new superconductors. These characteristics are difficult to explain on the basis of either the conventional electron-phonon theory or theories based on magnetic interactions alone

  18. Magnetic dynamics of weakly and strongly interacting hematite nanoparticles

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Bender Koch, Christian; Mørup, Steen

    2000-01-01

    The magnetic dynamics of two differently treated samples of hematite nanoparticles from the same batch with a particle size of about 20 nm have been studied by Mossbauer spectroscopy. The dynamics of the first sample, in which the particles are coated and dispersed in water, is in accordance with...... down by interparticle interactions and a magnetically split spectrum is retained at room temperature. The temperature variation or the magnetic hyperfine field, corresponding to different quantiles in the hyperfine field distribution, can be consistently described by a mean field model...... for "superferromagnetism" in which the magnetic anisotropy is included. The coupling between the particles is due to exchange interactions and the interaction strength can be accounted for by just a few exchange bridges between surface atoms in neighboring crystallites....

  19. Magnetic interactions in strongly correlated systems: Spin and orbital contributions

    Energy Technology Data Exchange (ETDEWEB)

    Secchi, A., E-mail: a.secchi@science.ru.nl [Radboud University, Institute for Molecules and Materials, 6525 AJ Nijmegen (Netherlands); Lichtenstein, A.I. [Universitat Hamburg, Institut für Theoretische Physik, Jungiusstraße 9, D-20355 Hamburg (Germany); Katsnelson, M.I. [Radboud University, Institute for Molecules and Materials, 6525 AJ Nijmegen (Netherlands)

    2015-09-15

    We present a technique to map an electronic model with local interactions (a generalized multi-orbital Hubbard model) onto an effective model of interacting classical spins, by requiring that the thermodynamic potentials associated to spin rotations in the two systems are equivalent up to second order in the rotation angles, when the electronic system is in a symmetry-broken phase. This allows to determine the parameters of relativistic and non-relativistic magnetic interactions in the effective spin model in terms of equilibrium Green’s functions of the electronic model. The Hamiltonian of the electronic system includes, in addition to the non-relativistic part, relativistic single-particle terms such as the Zeeman coupling to an external magnetic field, spin–orbit coupling, and arbitrary magnetic anisotropies; the orbital degrees of freedom of the electrons are explicitly taken into account. We determine the complete relativistic exchange tensors, accounting for anisotropic exchange, Dzyaloshinskii–Moriya interactions, as well as additional non-diagonal symmetric terms (which may include dipole–dipole interaction). The expressions of all these magnetic interactions are determined in a unified framework, including previously disregarded features such as the vertices of two-particle Green’s functions and non-local self-energies. We do not assume any smallness in spin–orbit coupling, so our treatment is in this sense exact. Finally, we show how to distinguish and address separately the spin, orbital and spin–orbital contributions to magnetism, providing expressions that can be computed within a tight-binding Dynamical Mean Field Theory.

  20. Strongly-Interacting Fermi Gases in Reduced Dimensions

    Science.gov (United States)

    2015-11-16

    12 2012): 0. doi: 10.1103/PhysRevA.86.063625 Allan Adams , Lincoln D Carr, Thomas Schäfer, Peter Steinberg, John E Thomas. Strongly correlated quantum...Physics (NCSU, 2013) Received Book Chapter TOTAL: PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: Discipline Willie Ong 1.00 Chingyun Cheng 0.50...PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: NAME Total Number: NAME Total Number: Willie Ong 1 PERCENT_SUPPORTEDNAME FTE Equivalent: Total

  1. Coulomb plus strong interaction bound states - momentum space numerical solutions

    International Nuclear Information System (INIS)

    Heddle, D.P.; Tabakin, F.

    1985-01-01

    The levels and widths of hadronic atoms are calculated in momentum space using an inverse algorithm for the eigenvalue problem. The Coulomb singularity is handled by the Lande substraction method. Relativistic, nonlocal, complex hadron-nucleus interactions are incorporated as well as vacuum polarization and finite size effects. Coordinate space wavefunctions are obtained by employing a Fourier Bessel transformation. (orig.)

  2. Strong light-matter interaction in graphene - Invited talk

    DEFF Research Database (Denmark)

    Xiao, Sanshui

    Graphene has attracted lots of attention due to its remarkable electronic and optical properties, thus providing great promise in photonics and optoelectronics. However, the performance of these devices is generally limited by the weak light-matter interaction in graphene. The combination...

  3. Strongly anisotropic RKKY interaction in monolayer black phosphorus

    Science.gov (United States)

    Zare, Moslem; Parhizgar, Fariborz; Asgari, Reza

    2018-06-01

    We theoretically study the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in two-dimensional black phosphorus, phosphorene. The RKKY interaction enhances significantly for the low levels of hole doping owing to the nearly valence flat band. Remarkably, for the hole-doped phosphorene, the highest RKKY interaction occurs when two impurities located along the zigzag direction and it tends to a minimum value with changing the direction from the zigzag to the armchair direction. We show that the interaction is highly anisotropic and the magnetic ground-state of two magnetic adatoms can be tuned by changing the rotational configuration of impurities. Owing to the anisotropic band dispersion, the oscillatory behavior with respect to the angle of the rotation and the distance of two magnetic impurities, R is well-described by sin (2kF R) , where the Fermi wavelength kF changes in different directions. We also find that the tail of the RKKY oscillations falls off as 1 /R2 at large distances.

  4. Interaction of a strong vortex with decaying turbulence

    International Nuclear Information System (INIS)

    Terry, P.W.

    1988-01-01

    The evolution of a localized, axially symmetric vortex under the action of shear stresses associated with decaying two-dimensional turbulent vorticity which is inhomogeneous in the presence of the vortex is studied analytically. For a vortex which is sufficiently strong relative to the coefficient of turbulent eddy viscosity, it is shown that turbulent fluctuations in the vortex interior and diffusion of coherent vorticity by the turbulence localize to the vortex periphery. It is also found that the coefficient of diffusion is small compared to the coefficient of eddy viscosity. 8 refs

  5. The hard-sphere model of strongly interacting fermion systems

    OpenAIRE

    Mecca, Angela

    2016-01-01

    The formalism based on Correlated Basis Functions (CBF) and the cluster-expansion technique has been recently employed to derive an effective interaction from a realistic nuclear Hamiltonian. One of the main objectives of the work described in this Thesis is establishing the accuracy of this novel approach--that allows to combine the flexibility of perturbation theory in the basis of eigenstates of the noninteracting system with a realistic description of short-range correlations in coordinat...

  6. Bose-Einstein-condensed gases with arbitrary strong interactions

    International Nuclear Information System (INIS)

    Yukalov, V. I.; Yukalova, E. P.

    2006-01-01

    Bose-condensed gases are considered with an effective interaction strength varying in the whole range of the values between zero and infinity. The consideration is based on the usage of a representative statistical ensemble for Bose systems with broken global gauge symmetry. Practical calculations are illustrated for a uniform Bose gas at zero temperature, employing a self-consistent mean-field theory, which is both conserving and gapless

  7. Colliding winds: Interaction regions with strong heat conduction

    International Nuclear Information System (INIS)

    Imamura, J.N.; Chevalier, R.A.

    1984-01-01

    The interaction of fast stellar wind with a slower wind from previous mass loss gives rise to a region of hot, shocked gas. We obtain self-similar solutions for the interaction region under the assumptions of constant mass loss rate and wind velocity for the two winds, conversion of energy in the shock region, and either isothermal electrons and adiabatic ions or isothermal electrons ad ions in the shocked region. The isothermal assumption is intended to show the effects of strog heat conduction. The solutions have no heat conduction through the shock waves and assume that the electron and ion temperatures are equilibriated in the shock waves. The one-temperature isothermal solutions have nearly constant density through the shocked region, while the two-temperature solutions are intermediate between the one-temperature adiabatic and isothermal solutions. In the two-temperature solutions, the ion temperature goes to zero at the point where the gas comoves with the shocked region and the density peaks at this point. The solution may qualitatively describe the effects of heat conduction on interaction regions in the solar wind. It will be important to determine whether the assumption of no thermal waves outside the shocked region applies to shock waves in the solar wind

  8. Strongly-interacting mirror fermions at the LHC

    Directory of Open Access Journals (Sweden)

    Triantaphyllou George

    2017-01-01

    Full Text Available The introduction of mirror fermions corresponding to an interchange of leftwith right-handed fermion quantum numbers of the Standard Model can lead to a model according to which the BEH mechanism is just an effective manifestation of a more fundamental theory while the recently-discovered Higgs-like particle is composite. This is achieved by a non-abelian gauge symmetry encompassing three mirror-fermion families strongly coupled at energies near 1 TeV. The corresponding non-perturbative dynamics lead to dynamical mirror-fermion masses between 0.14 - 1.2 TeV. Furthermore, one expects the formation of composite states, i.e. “mirror mesons”, with masses between 0.1 and 3 TeV. The number and properties of the resulting new degrees of freedom lead to a rich and interesting phenomenology, part of which is analyzed in the present work.

  9. Interaction of Energetic Particles with Discontinuities Upstream of Strong Shocks

    Science.gov (United States)

    Malkov, Mikhail; Diamond, Patrick

    2008-11-01

    Acceleration of particles in strong astrophysical shocks is known to be accompanied and promoted by a number of instabilities which are driven by the particles themselves. One of them is an acoustic (also known as Drury's) instability driven by the pressure gradient of accelerated particles upstream. The generated sound waves naturally steepen into shocks thus forming a shocktrain. Similar magnetoacoustic or Alfven type structures may be driven by pick-up ions, for example. We consider the solutions of kinetic equation for accelerated particles within the shocktrain. The accelerated particles are assumed to be coupled to the flow by an intensive pitch-angle scattering on the self-generated Alfven waves. The implications for acceleration and confinement of cosmic rays in this shock environment will be discussed.

  10. Spin effects in strong-field laser-electron interactions

    International Nuclear Information System (INIS)

    Ahrens, S; Bauke, H; Müller, T-O; Villalba-Chávez, S; Müller, C

    2013-01-01

    The electron spin degree of freedom can play a significant role in relativistic scattering processes involving intense laser fields. In this contribution we discuss the influence of the electron spin on (i) Kapitza-Dirac scattering in an x-ray laser field of high intensity, (ii) photo-induced electron-positron pair production in a strong laser wave and (iii) multiphoton electron-positron pair production on an atomic nucleus. We show that in all cases under consideration the electron spin can have a characteristic impact on the process properties and their total probabilities. To this end, spin-resolved calculations based on the Dirac equation in the presence of an intense laser field are performed. The predictions from Dirac theory are also compared with the corresponding results from the Klein-Gordon equation.

  11. Strong delayed interactive effects of metal exposure and warming

    DEFF Research Database (Denmark)

    Debecker, Sara; Dinh, Khuong Van; Stoks, Robby

    2017-01-01

    ’ ranges could lead to an important underestimation of the risks. We addressed all three mechanisms by studying effects of larval exposure to zinc and warming before, during, and after metamorphosis in Ischnura elegans damselflies from high- and lowlatitude populations. By integrating these mechanisms...... into a single study, we could identify two novel patterns. First, during exposure zinc did not affect survival, whereas it induced mild to moderate postexposure mortality in the larval stage and at metamorphosis, and very strongly reduced adult lifespan. This severe delayed effect across metamorphosis...... was especially remarkable in high-latitude animals, as they appeared almost insensitive to zinc during the larval stage. Second, the well-known synergism between metals and warming was manifested not only during the larval stage but also after metamorphosis, yet notably only in low-latitude damselflies...

  12. Strong Constraints on Aerosol-Cloud Interactions from Volcanic Eruptions

    Science.gov (United States)

    Malavelle, Florent F.; Haywood, Jim M.; Jones, Andy; Gettelman, Andrew; Clarisse, Lieven; Bauduin, Sophie; Allan, Richard P.; Karset, Inger Helene H.; Kristjansson, Jon Egill; Oreopoulos, Lazaros; hide

    2017-01-01

    Aerosols have a potentially large effect on climate, particularly through their interactions with clouds, but the magnitude of this effect is highly uncertain. Large volcanic eruptions produce sulfur dioxide, which in turn produces aerosols; these eruptions thus represent a natural experiment through which to quantify aerosol-cloud interactions. Here we show that the massive 2014-2015 fissure eruption in Holuhraun, Iceland, reduced the size of liquid cloud droplets - consistent with expectations - but had no discernible effect on other cloud properties. The reduction in droplet size led to cloud brightening and global-mean radiative forcing of around minus 0.2 watts per square metre for September to October 2014. Changes in cloud amount or cloud liquid water path, however, were undetectable, indicating that these indirect effects, and cloud systems in general, are well buffered against aerosol changes. This result will reduce uncertainties in future climate projections, because we are now able to reject results from climate models with an excessive liquid-water-path response.

  13. Light and neutron scattering study of strongly interacting ionic micelles

    International Nuclear Information System (INIS)

    Degiorgio, V.; Corti, M.; Piazza, R.

    1989-01-01

    Dilute solutions of ionic micelles formed by biological glycolipids (gangliosides) have been investigated at various ionic strengths by static and dynamic light scaterring and by small-angle neutron scattering. The size and shape of the micelle is not appreciably affected by the added salt concentration in the range 0-100 mM NaCL. From the measured intensity of scattered light we derive the electric charge Z of the micelle by fitting the data to a theoretical calculation which uses a screened Coulomb potential for the intermicellar interaction, and the hypernetted chain approximation for the calculation of the radial distribution function. The correlation function derived from dynamic light scattering shows the long time contribution typical of concentrated polydisperse systems (author). 15 refs.; 6 figs

  14. Natural cold baryogenesis from strongly interacting electroweak symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Konstandin, Thomas; Servant, Géraldine, E-mail: tkonstan@cern.ch, E-mail: geraldine.servant@cern.ch [CERN Physics Department, Theory Division, CH-1211 Geneva 23 (Switzerland)

    2011-07-01

    The mechanism of ''cold electroweak baryogenesis'' has been so far unpopular because its proposal has relied on the ad-hoc assumption of a period of hybrid inflation at the electroweak scale with the Higgs acting as the waterfall field. We argue here that cold baryogenesis can be naturally realized without the need to introduce any slow-roll potential. Our point is that composite Higgs models where electroweak symmetry breaking arises via a strongly first-order phase transition provide a well-motivated framework for cold baryogenesis. In this case, reheating proceeds by bubble collisions and we argue that this can induce changes in Chern-Simons number, which in the presence of new sources of CP violation commonly lead to baryogenesis. We illustrate this mechanism using as a source of CP violation an effective dimension-six operator which is free from EDM constraints, another advantage of cold baryogenesis compared to the standard theory of electroweak baryogenesis. Our results are general as they do not rely on any particular UV completion but only on a stage of supercooling ended by a first-order phase transition in the evolution of the universe, which can be natural if there is nearly conformal dynamics at the TeV scale. Besides, baryon-number violation originates from the Standard Model only.

  15. Natural Cold Baryogenesis from Strongly Interacting Electroweak Symmetry Breaking

    CERN Document Server

    Konstandin, Thomas

    2011-01-01

    The mechanism of "cold electroweak baryogenesis" has been so far unpopular because its proposal has relied on the ad-hoc assumption of a period of hybrid inflation at the electroweak scale with the Higgs acting as the waterfall field. We argue here that cold baryogenesis can be naturally realized without the need to introduce any slow-roll potential. Our point is that composite Higgs models where electroweak symmetry breaking arises via a strongly first-order phase transition provide a well-motivated framework for cold baryogenesis. In this case, reheating proceeds by bubble collisions and we argue that this can induce changes in Chern-Simons number, which in the presence of new sources of CP violation commonly lead to baryogenesis. We illustrate this mechanism using as a source of CP violation an effective dimension-six operator which is free from EDM constraints, another advantage of cold baryogenesis compared to the standard theory of electroweak baryogenesis. Our results are general as they do not rely on...

  16. Natural cold baryogenesis from strongly interacting electroweak symmetry breaking

    International Nuclear Information System (INIS)

    Konstandin, Thomas; Servant, Géraldine

    2011-01-01

    The mechanism of ''cold electroweak baryogenesis'' has been so far unpopular because its proposal has relied on the ad-hoc assumption of a period of hybrid inflation at the electroweak scale with the Higgs acting as the waterfall field. We argue here that cold baryogenesis can be naturally realized without the need to introduce any slow-roll potential. Our point is that composite Higgs models where electroweak symmetry breaking arises via a strongly first-order phase transition provide a well-motivated framework for cold baryogenesis. In this case, reheating proceeds by bubble collisions and we argue that this can induce changes in Chern-Simons number, which in the presence of new sources of CP violation commonly lead to baryogenesis. We illustrate this mechanism using as a source of CP violation an effective dimension-six operator which is free from EDM constraints, another advantage of cold baryogenesis compared to the standard theory of electroweak baryogenesis. Our results are general as they do not rely on any particular UV completion but only on a stage of supercooling ended by a first-order phase transition in the evolution of the universe, which can be natural if there is nearly conformal dynamics at the TeV scale. Besides, baryon-number violation originates from the Standard Model only

  17. Strongly coupled semiclassical plasma: interaction model and some properties

    International Nuclear Information System (INIS)

    Baimbetov, N.F.; Bekenov, N.A.

    1999-01-01

    In the report a fully ionized strongly coupled hydrogen plasma is considered. The density number is considered within range n=n e =n i ≅(10 21 -2·10 25 )sm -3 , and the temperature domian is T≅(5·10 4 -10 6 ) K. The coupling parameter Γ is defined by Γ=e 2 /αk B T, where k B is the Boltzmann constant and e is electrical charge, α=(3/4πn) 1/3 is the average distance between the particles (Wigner-Seitz radius). The dimensionless density parameter r s =α/α B is given in terms of the Bohr radius α B =ℎ 2 /me 2 ∼0.529·10 - 8 sm. The degeneracy parameter for the electron was defined by the ratio between the thermal energy k B T and the Fermi energy E F :Θ=k B T/E F ∼0.54·r s /Γ. The intermediate temperature-density region, where Γ≥1; Θ≅1; T>13.6 eV is examined. A semiclassical effective potential which account for the short-range, quantum diffraction and symmetry effects of charge carriers screening

  18. Gray solitons in a strongly interacting superfluid Fermi gas

    International Nuclear Information System (INIS)

    Spuntarelli, Andrea; Pieri, Pierbiagio; Strinati, Giancarlo C; Carr, Lincoln D

    2011-01-01

    The Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate (BEC) crossover problem is solved for stationary gray solitons via the Boguliubov-de Gennes equations at zero temperature. These crossover solitons exhibit a localized notch in the gap and a characteristic phase difference across the notch for all interaction strengths, from BEC to BCS regimes. However, they do not follow the well-known Josephson-like sinusoidal relationship between velocity and phase difference except in the far BEC limit: at unitarity, the velocity has a nearly linear dependence on phase difference over an extended range. For a fixed phase difference, the soliton is of nearly constant depth from the BEC limit to unitarity and then grows progressively shallower into the BCS limit, and on the BCS side, Friedel oscillations are apparent in both gap amplitude and phase. The crossover soliton appears fundamentally in the gap; we show, however, that the density closely follows the gap, and the soliton is therefore observable. We develop an approximate power-law relationship to express this fact: the density of gray crossover solitons varies as the square of the gap amplitude in the BEC limit and as a power of about 1.5 at unitarity.

  19. Exact tensor network ansatz for strongly interacting systems

    Science.gov (United States)

    Zaletel, Michael P.

    It appears that the tensor network ansatz, while not quite complete, is an efficient coordinate system for the tiny subset of a many-body Hilbert space which can be realized as a low energy state of a local Hamiltonian. However, we don't fully understand precisely which phases are captured by the tensor network ansatz, how to compute their physical observables (even numerically), or how to compute a tensor network representation for a ground state given a microscopic Hamiltonian. These questions are algorithmic in nature, but their resolution is intimately related to understanding the nature of quantum entanglement in many-body systems. For this reason it is useful to compute the tensor network representation of various `model' wavefunctions representative of different phases of matter; this allows us to understand how the entanglement properties of each phase are expressed in the tensor network ansatz, and can serve as test cases for algorithm development. Condensed matter physics has many illuminating model wavefunctions, such as Laughlin's celebrated wave function for the fractional quantum Hall effect, the Bardeen-Cooper-Schrieffer wave function for superconductivity, and Anderson's resonating valence bond ansatz for spin liquids. This thesis presents some results on exact tensor network representations of these model wavefunctions. In addition, a tensor network representation is given for the time evolution operator of a long-range one-dimensional Hamiltonian, which allows one to numerically simulate the time evolution of power-law interacting spin chains as well as two-dimensional strips and cylinders.

  20. Light-matter interaction in the strong coupling regime: configurations, conditions, and applications.

    Science.gov (United States)

    Dovzhenko, D S; Ryabchuk, S V; Rakovich, Yu P; Nabiev, I R

    2018-02-22

    Resonance interaction between a molecular transition and a confined electromagnetic field can reach the coupling regime where coherent exchange of energy between light and matter becomes reversible. In this case, two new hybrid states separated in energy are formed instead of independent eigenstates, which is known as Rabi splitting. This modification of the energy spectra of the system offers new possibilities for controlled impact on various fundamental properties of coupled matter (such as the rate of chemical reactions and the conductivity of organic semiconductors). To date, the strong coupling regime has been demonstrated in many configurations under different ambient conditions. However, there is still no comprehensive approach to determining parameters for achieving the strong coupling regime for a wide range of practical applications. In this review, a detailed analysis of various systems and corresponding conditions for reaching strong coupling is carried out and their advantages and disadvantages, as well as the prospects for application, are considered. The review also summarizes recent experiments in which the strong coupling regime has led to new interesting results, such as the possibility of collective strong coupling between X-rays and matter excitation in a periodic array of Fe isotopes, which extends the applications of quantum optics; a strong amplification of the Raman scattering signal from a coupled system, which can be used in surface-enhanced and tip-enhanced Raman spectroscopy; and more efficient second-harmonic generation from the low polaritonic state, which is promising for nonlinear optics. The results reviewed demonstrate great potential for further practical applications of strong coupling in the fields of photonics (low-threshold lasers), quantum communications (switches), and biophysics (molecular fingerprinting).

  1. Lasing by driven atoms-cavity system in collective strong coupling regime.

    Science.gov (United States)

    Sawant, Rahul; Rangwala, S A

    2017-09-12

    The interaction of laser cooled atoms with resonant light is determined by the natural linewidth of the excited state. An optical cavity is another optically resonant system where the loss from the cavity determines the resonant optical response of the system. The near resonant combination of an optical Fabry-Pérot cavity with laser cooled and trapped atoms couples two distinct optical resonators via light and has great potential for precision measurements and the creation of versatile quantum optics systems. Here we show how driven magneto-optically trapped atoms in collective strong coupling regime with the cavity leads to lasing at a frequency red detuned from the atomic transition. Lasing is demonstrated experimentally by the observation of a lasing threshold accompanied by polarization and spatial mode purity, and line-narrowing in the outcoupled light. Spontaneous emission into the cavity mode by the driven atoms stimulates lasing action, which is capable of operating as a continuous wave laser in steady state, without a seed laser. The system is modeled theoretically, and qualitative agreement with experimentally observed lasing is seen. Our result opens up a range of new measurement possibilities with this system.

  2. Strong Selection Significantly Increases Epistatic Interactions in the Long-Term Evolution of a Protein.

    Directory of Open Access Journals (Sweden)

    Aditi Gupta

    2016-03-01

    Full Text Available Epistatic interactions between residues determine a protein's adaptability and shape its evolutionary trajectory. When a protein experiences a changed environment, it is under strong selection to find a peak in the new fitness landscape. It has been shown that strong selection increases epistatic interactions as well as the ruggedness of the fitness landscape, but little is known about how the epistatic interactions change under selection in the long-term evolution of a protein. Here we analyze the evolution of epistasis in the protease of the human immunodeficiency virus type 1 (HIV-1 using protease sequences collected for almost a decade from both treated and untreated patients, to understand how epistasis changes and how those changes impact the long-term evolvability of a protein. We use an information-theoretic proxy for epistasis that quantifies the co-variation between sites, and show that positive information is a necessary (but not sufficient condition that detects epistasis in most cases. We analyze the "fossils" of the evolutionary trajectories of the protein contained in the sequence data, and show that epistasis continues to enrich under strong selection, but not for proteins whose environment is unchanged. The increase in epistasis compensates for the information loss due to sequence variability brought about by treatment, and facilitates adaptation in the increasingly rugged fitness landscape of treatment. While epistasis is thought to enhance evolvability via valley-crossing early-on in adaptation, it can hinder adaptation later when the landscape has turned rugged. However, we find no evidence that the HIV-1 protease has reached its potential for evolution after 9 years of adapting to a drug environment that itself is constantly changing. We suggest that the mechanism of encoding new information into pairwise interactions is central to protein evolution not just in HIV-1 protease, but for any protein adapting to a changing

  3. Observation of Spin-Polarons in a strongly interacting Fermi liquid

    Science.gov (United States)

    Zwierlein, Martin

    2009-03-01

    We have observed spin-polarons in a highly imbalanced mixture of fermionic atoms using tomographic RF spectroscopy. Feshbach resonances allow to freely tune the interactions between the two spin states involved. A single spin down atom immersed in a Fermi sea of spin up atoms can do one of two things: For strong attraction, it can form a molecule with exactly one spin up partner, but for weaker interaction it will spread its attraction and surround itself with a collection of majority atoms. This spin down atom ``dressed'' with a spin up cloud constitutes the spin-polaron. We have observed a striking spectroscopic signature of this quasi-particle for various interaction strengths, a narrow peak in the spin down spectrum that emerges above a broad background. The narrow width signals a long lifetime of the spin-polaron, much longer than the collision rate with spin up atoms, as it must be for a proper quasi-particle. The peak position allows to directly measure the polaron energy. The broad pedestal at high energies reveals physics at short distances and is thus ``molecule-like'': It is exactly matched by the spin up spectra. The comparison with the area under the polaron peak allows to directly obtain the quasi-particle weight Z. We observe a smooth transition from polarons to molecules. At a critical interaction strength of 1/kFa = 0.7, the polaron peak vanishes and spin up and spin down spectra exactly match, signalling the formation of molecules. This is the same critical interaction strength found earlier to separate a normal Fermi mixture from a superfluid molecular Bose-Einstein condensate. The spin-polarons determine the low-temperature phase diagram of imbalanced Fermi mixtures. In principle, polarons can interact with each other and should, at low enough temperatures, form a superfluid of p-wave pairs. We will present a first indication for interactions between polarons.

  4. Investigation of the charge collection for strongly irradiated silicon strip detectors of the CMS ECAL Preshower

    International Nuclear Information System (INIS)

    Bloch, Ph.; Peisert, A.; Chang, Y.H.; Chen, A.E.; Hou, S.; Lin, W.T.; Cheremukhin, A.E.; Golutvin, I.A.; Urkinbaev, A.R.; Zamyatin, N.I.; Loukas, D.

    2001-01-01

    Strongly irradiated (2.3·10 14 n/cm 2 ) silicon strip detectors of different size, thickness and different design options were tested in a muon beam at CERN in 1999. A charge collection efficiency in excess of 85% and a signal-to-noise ratio of about 6 are obtained in all cases at high enough bias voltage. Details of the charge collection in the interstrip and the guard ring region and cross-talk between strips were also studied. We find that the charge collection efficiency and the cross-talk between strips depend on the interstrip distance

  5. Hyperspherical Treatment of Strongly-Interacting Few-Fermion Systems in One Dimension

    DEFF Research Database (Denmark)

    Volosniev, A. G.; Fedorov, D. V.; Jensen, A. S.

    2015-01-01

    We examine a one-dimensional two-component fermionic system in a trap, assuming that all particles have the same mass and interact through a strong repulsive zero-range force. First we show how a simple system of three strongly interacting particles in a harmonic trap can be treated using...

  6. Search for strongly interacting massive particles using semiconductor detectors on the ground

    International Nuclear Information System (INIS)

    Derbin, A.V.; Egorov, A.I.; Bakhlanov, S.V.; Muratova, V.N.

    1999-01-01

    Using signals from recoil nucleus in semiconductor detectors, search for strongly interacting massive particles, as a possible candidate for dark matter, is continued. Experimental installation and the experimental results are given. New limits on the possible masses and cross sections of strongly interacting massive particles are presented [ru

  7. Extension of lattice cluster theory to strongly interacting, self-assembling polymeric systems.

    Science.gov (United States)

    Freed, Karl F

    2009-02-14

    A new extension of the lattice cluster theory is developed to describe the influence of monomer structure and local correlations on the free energy of strongly interacting and self-assembling polymer systems. This extension combines a systematic high dimension (1/d) and high temperature expansion (that is appropriate for weakly interacting systems) with a direct treatment of strong interactions. The general theory is illustrated for a binary polymer blend whose two components contain "sticky" donor and acceptor groups, respectively. The free energy is determined as an explicit function of the donor-acceptor contact probabilities that depend, in turn, on the local structure and both the strong and weak interactions.

  8. Deducing T, C, and P invariance for strong interactions in topological particle theory

    International Nuclear Information System (INIS)

    Jones, C.E.

    1985-01-01

    It is shown here how the separate discrete invariances [time reversal (T), charge conjugation (C), and parity (P)] in strong interactions can be deduced as consequences of other S-matrix requirements in topological particle theory

  9. Effects of interaction imbalance in a strongly repulsive one-dimensional Bose gas

    DEFF Research Database (Denmark)

    Barfknecht, Rafael Emilio; Zinner, Nikolaj Thomas; Foerster, Angela

    2018-01-01

    We calculate the spatial distributions and the dynamics of a few-body two-component strongly interacting Bose gas confined to an effectively one-dimensional trapping potential. We describe the densities for each component in the trap for different interaction and population imbalances. We calculate...

  10. Relativistic stability of interacting Fermi gas in a strong magnetic field

    International Nuclear Information System (INIS)

    Wang Lilin; Tian Jincheng; Men Fudian; Zhang Yipeng

    2013-01-01

    By means of the single particle energy spectrum of weak interaction between fermions and Poisson formula, the thermodynamic potential function of relativistic Fermi gas in a strong magnetic field is derived. Based on this, we obtained the criterion of stability for the system. The results show that the mechanics stability of a Fermi gas with weak interacting is influenced by the interacting. While the magnetic field is able to regulate the influence and the relativistic effect has almost no effect on it. (authors)

  11. Effects of Interaction Imbalance in a Strongly Repulsive One-Dimensional Bose Gas

    Science.gov (United States)

    Barfknecht, R. E.; Foerster, A.; Zinner, N. T.

    2018-05-01

    We calculate the spatial distributions and the dynamics of a few-body two-component strongly interacting Bose gas confined to an effectively one-dimensional trapping potential. We describe the densities for each component in the trap for different interaction and population imbalances. We calculate the time evolution of the system and show that, for a certain ratio of interactions, the minority population travels through the system as an effective wave packet.

  12. Interacting collective modes in a laser cavity

    International Nuclear Information System (INIS)

    Graca, E.L.; Brito, A.L. de; Baseia, B.

    1985-01-01

    Collective operators are defined for the quantized radiation field in a one-dimensional laser cavity coupled to a semi-infinite outside region and the overlaps of neighbouring collective modes are considered to show how they modify, in the linear appoximation, the time evolution of the radiation field below threshold. The model and procedure work directly within a continuous spectrum of modes and allow us to get an improved insight on the prescription for the laser field in single-mode operation. (Author) [pt

  13. Collective interaction by design collective controllers for social navigation on digital photos

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Krogh, Peter; Mortensen, Morten Boye

    2010-01-01

    trial use serves to refine the collective interaction model and identify qualities and shortcommings of collective interaction applications. In this way we wish to point to a design space, which can lead to new interaction techniques and -designs supporting shared social experiences around digital...

  14. Gauge unification of basic forces particularly of gravitation with strong interactions

    International Nuclear Information System (INIS)

    Salam, A.

    1977-01-01

    Corresponding to the two known types of gauge theories, Yang-Mills with spin-one mediating particles and Einstein Weyl with spin-two mediating particles, it is speculated that two distinct gauge unifications of the basic forces appear to be taking place. One is the familiar Yang-Mills unification of weak and electromagnetic forces with the strong. The second is the less familiar gauge unification of gravitation with spin-two tensor-dominated aspects of strong interactions. It is proposed that there are strongly interacting spin-two strong gravitons obeying Einstein's equations, and their existence gives a clue to an understanding of the (partial) confinement of quarks, as well as of the concept of hadronic temperature, through the use of Schwarzschild de-Sitter-like partially confining solitonic solutions of the strong gravity Einstein equation

  15. Wave, particle-family duality and the conservation of discrete symmetries in strong interaction

    International Nuclear Information System (INIS)

    van der Spuy, E.

    1984-01-01

    This paper starts from a nonlinear fermion field equation of motion with a strongly coupled self-interaction. Nonperturbative quark solutions of the equation of motion are constructed in terms of a Reggeized infinite component free spinor field. Such a field carries a family of strongly interacting unstable compounds lying on a Regge locus in the analytically continued quark spin. Such a quark field is naturally confined and also possesses the property of asymptotic freedom. Furthermore, the particular field self-regularizes the interactions and naturally breaks the chiral invariance of the equation of motion. We show why and how the existence of such a strongly coupled solution and its particle-family, wave duality forces a change in the field equation of motion such that it conserves C,P,T, although its individual interaction terms are of V-A and thus C,P nonconserving type

  16. Strong coupling of two interacting excitons confined in a nanocavity-quantum dot system

    International Nuclear Information System (INIS)

    Cardenas, Paulo C; RodrIguez, Boris A; Quesada, Nicolas; Vinck-Posada, Herbert

    2011-01-01

    We present a study of the strong coupling between radiation and matter, considering a system of two quantum dots, which are in mutual interaction and interact with a single mode of light confined in a semiconductor nanocavity. We take into account dissipative mechanisms such as the escape of the cavity photons, decay of the quantum dot excitons by spontaneous emission, and independent exciton pumping. It is shown that the mutual interaction between the dots can be measured off-resonance only if the strong coupling condition is reached. Using the quantum regression theorem, a reasonable definition of the dynamical coupling regimes is introduced in terms of the complex Rabi frequency. Finally, the emission spectrum for relevant conditions is presented and compared with the above definition, demonstrating that the interaction between the excitons does not affect the strong coupling.

  17. arXiv Recent results from the strong interactions program of NA61/SHINE

    CERN Document Server

    Pulawski, Szymon

    2017-01-01

    The NA61/SHINE experiment studies hadron production in hadron+hadron, hadron+nucleus and nucleus+nucleus collisions. The strong interactions program has two main purposes: study the properties of the onset of deconfinement and search for the signatures of the critical point of strongly interacting matter. This aim is pursued by performing a two-dimensional scan of the phase diagram by varying the energy/momentum (13A-158A GeV/c) and the system size (p+p, Be+Be, Ar+Sc, Xe+La) of the collisions. This publication reviews recent results from p+p, Be+Be and Ar+Sc interactions. Measured particle spectra are discussed and compared to NA49 results from Pb+Pb collisions. The results illustrate the progress towards scanning the phase diagram of strongly interacting matter.

  18. ICLIC : interactive categorization of large image collections

    NARCIS (Netherlands)

    Van Der Corput, Paul; van Wijk, Jarke J.

    2016-01-01

    We present a new approach for the analysis of large image collections. We argue that categorization plays an important role in this process, not only to label images as end result, but also during exploration. Furthermore, to increase the effectiveness and efficiency of the categorization process we

  19. Experimental and numerical study of the strong interaction between wakes of cylindrical obstacles

    International Nuclear Information System (INIS)

    Brun, Ch.

    1998-01-01

    In the context of thermal-hydraulics of nuclear reactors, strong interaction between wakes is encountered in the bottom of reactor vessels where control and measurement rods of variable size and disposition interact with the overall wakes generated in these flow zones. This study deals with the strong interaction between two wakes developed downstream of two parallel cylinders with a small spacing. The analysis focusses on the effect of the Reynolds regime which controls the equilibrium between the inertia and viscosity forces of the fluid and influences the large scale behaviour of the flow with the development of hydrodynamic instabilities and turbulence. The document is organized as follows: the characteristic phenomena of wakes formation downstream of cylindrical obstacles are recalled in the first chapter (single cylinder, interaction between two tubes, case of a bundle of tubes perpendicular to the flow). The experimental setup (hydraulic loop, velocity and pressure measurement instrumentation) and the statistical procedures applied to the signals measured are detailed in chapters 2 and 3. Chapter 4 is devoted to the experimental study of the strong interaction between two tubes. Laser Doppler velocity measurements in the wakes close to cylinders and pressure measurements performed on tube walls are reported in this chapter. In chapter 5, a 2-D numerical simulation of two typical cases of interaction (Re = 1000 and Re = 5000) is performed. In the last chapter, a more complex application of strong interactions inside and downstream of a bunch of staggered tubes is analyzed experimentally for equivalent Reynolds regimes. (J.S.)

  20. Strong excitonic interactions in the oxygen K-edge of perovskite oxides

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Kota; Miyata, Tomohiro [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan); Olovsson, Weine [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden); Mizoguchi, Teruyasu, E-mail: teru@iis.u-tokyo.ac.jp [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan)

    2017-07-15

    Excitonic interactions of the oxygen K-edge electron energy-loss near-edge structure (ELNES) of perovskite oxides, CaTiO{sub 3}, SrTiO{sub 3}, and BaTiO{sub 3}, together with reference oxides, MgO, CaO, SrO, BaO, and TiO{sub 2}, were investigated using a first-principles Bethe–Salpeter equation calculation. Although the transition energy of oxygen K-edge is high, strong excitonic interactions were present in the oxygen K-edge ELNES of the perovskite oxides, whereas the excitonic interactions were negligible in the oxygen K-edge ELNES of the reference compounds. Detailed investigation of the electronic structure suggests that the strong excitonic interaction in the oxygen K-edge ELNES of the perovskite oxides is caused by the directionally confined, low-dimensional electronic structure at the Ti–O–Ti bonds. - Highlights: • Excitonic interaction in oxygen-K edge is investigated. • Strong excitonic interaction is found in the oxygen-K edge of perovskite oxides. • The strong excitonic interaction is ascribed to the low-dimensional and confined electronic structure.

  1. Quantum magnetism in strongly interacting one-dimensional spinor Bose systems

    DEFF Research Database (Denmark)

    Salami Dehkharghani, Amin; Volosniev, A. G.; Lindgren, E. J.

    2015-01-01

    -range inter-species interactions much larger than their intra-species interactions and show that they have novel energetic and magnetic properties. In the strongly interacting regime, these systems have energies that are fractions of the basic harmonic oscillator trap quantum and have spatially separated......Strongly interacting one-dimensional quantum systems often behave in a manner that is distinctly different from their higher-dimensional counterparts. When a particle attempts to move in a one-dimensional environment it will unavoidably have to interact and 'push' other particles in order...... ground states with manifestly ferromagnetic wave functions. Furthermore, we predict excited states that have perfect antiferromagnetic ordering. This holds for both balanced and imbalanced systems, and we show that it is a generic feature as one crosses from few- to many-body systems....

  2. The physics of collective neutrino-plasma interactions

    International Nuclear Information System (INIS)

    Shukla, P.K.; Silva, L.O.; Dawson, J.M.; Bethe, H.; Bingham, R.; Stenflo, L.; Mendonca, J.T.; Dalhed, S.

    1999-01-01

    A review of recent work on collective neutrino-plasma interactions is presented. The basic physical concepts of this new field as well as some possible astrophysical problems where the physics of collective neutrino-plasma interactions can have a radical impact, are discussed. (author)

  3. Spectral asymptotics of a strong δ′ interaction supported by a surface

    International Nuclear Information System (INIS)

    Exner, Pavel; Jex, Michal

    2014-01-01

    Highlights: • Attractive δ ′ interactions supported by a smooth surface are considered. • Surfaces can be either infinite and asymptotically planar, or compact and closed. • Spectral asymptotics is determined by the geometry of the interaction support. - Abstract: We derive asymptotic expansion for the spectrum of Hamiltonians with a strong attractive δ ′ interaction supported by a smooth surface in R 3 , either infinite and asymptotically planar, or compact and closed. Its second term is found to be determined by a Schrödinger type operator with an effective potential expressed in terms of the interaction support curvatures

  4. Wave, particle-family duality and the conservation of discrete symmetries in strong interaction

    International Nuclear Information System (INIS)

    Van der Spuy, E.

    1984-01-01

    This paper starts from a nonlinear fermion field equation of motion with a strongly coupled selfinteraction. Nonperturbative quark solutions of the equation of motion are constructed in terms of a Reggeized infinite component free spinor field. Such a field carries a family of strongly interacting unstable compounds lying on a Regge locus in the analytically continued quark spin. Such a quark field is naturally confined and also possesses the property of asymptotic freedom. Furthermore the particular field selfregularizes the interactions and naturally breaks the chiral invariance of the equation of motion. We show why and how the existence of such a strongly coupled solution and its particle-family, wave duality forces a change in the field equation of motion such that it conserves C, P, T although its individual interaction terms are of V - A and thus C, P nonconserving type

  5. Proceedings of the summer institute on particle physics: The strong interaction, from hadrons to partons

    International Nuclear Information System (INIS)

    Chan, J.; DePorcel, L.; Dixon, L.

    1997-06-01

    This conference explored the role of the strong interaction in the physics of hadrons and partons. The Institute attracted 239 physicists from 16 countries to hear lectures on the underlying theory of Quantum Chromodynamics, modern theoretical calculational techniques, and experimental investigation of the strong interaction as it appears in various phenomena. Different regimes in which one can calculate reliably in QCD were addressed in series of lectures on perturbation theory, lattice gauge theories, and heavy quark expansions. Studies of QCD in hadron-hadron collisions, electron-positron annihilation, and electron-proton collisions all give differing perspectives on the strong interaction--from low-x to high-Q 2 . Experimental understanding of the production and decay of heavy quarks as well as the lighter meson states has continued to evolve over the past years, and these topics were also covered at the School. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database

  6. Strong field QED in lepton colliders and electron/laser interactions

    Science.gov (United States)

    Hartin, Anthony

    2018-05-01

    The studies of strong field particle physics processes in electron/laser interactions and lepton collider interaction points (IPs) are reviewed. These processes are defined by the high intensity of the electromagnetic fields involved and the need to take them into account as fully as possible. Thus, the main theoretical framework considered is the Furry interaction picture within intense field quantum field theory. In this framework, the influence of a background electromagnetic field in the Lagrangian is calculated nonperturbatively, involving exact solutions for quantized charged particles in the background field. These “dressed” particles go on to interact perturbatively with other particles, enabling the background field to play both macroscopic and microscopic roles. Macroscopically, the background field starts to polarize the vacuum, in effect rendering it a dispersive medium. Particles encountering this dispersive vacuum obtain a lifetime, either radiating or decaying into pair particles at a rate dependent on the intensity of the background field. In fact, the intensity of the background field enters into the coupling constant of the strong field quantum electrodynamic Lagrangian, influencing all particle processes. A number of new phenomena occur. Particles gain an intensity-dependent rest mass shift that accounts for their presence in the dispersive vacuum. Multi-photon events involving more than one external field photon occur at each vertex. Higher order processes which exchange a virtual strong field particle resonate via the lifetimes of the unstable strong field states. Two main arenas of strong field physics are reviewed; those occurring in relativistic electron interactions with intense laser beams, and those occurring in the beam-beam physics at the interaction point of colliders. This review outlines the theory, describes its significant novel phenomenology and details the experimental schema required to detect strong field effects and the

  7. Computational strong-field quantum dynamics. Intense light-matter interactions

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Dieter (ed.) [Rostock Univ. (Germany). Inst. fuer Physik

    2017-09-01

    This graduate textbook introduces the computational techniques to study ultra-fast quantum dynamics of matter exposed to strong laser fields. Coverage includes methods to propagate wavefunctions according to the time dependent Schroedinger, Klein-Gordon or Dirac equation, the calculation of typical observables, time-dependent density functional theory, multi configurational time-dependent Hartree-Fock, time-dependent configuration interaction singles, the strong-field approximation, and the microscopic particle-in-cell approach.

  8. Strong coupling strategy for fluid-structure interaction problems in supersonic regime via fixed point iteration

    Science.gov (United States)

    Storti, Mario A.; Nigro, Norberto M.; Paz, Rodrigo R.; Dalcín, Lisandro D.

    2009-03-01

    In this paper some results on the convergence of the Gauss-Seidel iteration when solving fluid/structure interaction problems with strong coupling via fixed point iteration are presented. The flow-induced vibration of a flat plate aligned with the flow direction at supersonic Mach number is studied. The precision of different predictor schemes and the influence of the partitioned strong coupling on stability is discussed.

  9. Computational strong-field quantum dynamics. Intense light-matter interactions

    International Nuclear Information System (INIS)

    Bauer, Dieter

    2017-01-01

    This graduate textbook introduces the computational techniques to study ultra-fast quantum dynamics of matter exposed to strong laser fields. Coverage includes methods to propagate wavefunctions according to the time dependent Schroedinger, Klein-Gordon or Dirac equation, the calculation of typical observables, time-dependent density functional theory, multi configurational time-dependent Hartree-Fock, time-dependent configuration interaction singles, the strong-field approximation, and the microscopic particle-in-cell approach.

  10. Computational strong-field quantum dynamics intense light-matter interactions

    CERN Document Server

    2017-01-01

    This graduate textbook introduces the computational techniques to study ultra-fast quantum dynamics of matter exposed to strong laser fields. Coverage includes methods to propagate wavefunctions according to the time-dependent Schrödinger, Klein-Gordon or Dirac equation, the calculation of typical observables, time-dependent density functional theory, multi-configurational time-dependent Hartree-Fock, time-dependent configuration interaction singles, the strong-field approximation, and the microscopic particle-in-cell approach.

  11. Lagrangian formulation for a gauge theory of strong and electromagnetic interactions defined on a Cartan bundle

    International Nuclear Information System (INIS)

    Drechsler, W.

    1977-01-01

    A Lagrangian formalism invariant under the gauge group U 1 xUSpsub(2.2) is set up in terms of spinor fields defined on a fiber bundle with Cartan connexion. The fiber of the Cartan bundle over space-time associated with strong interactions is characterized by an elementary length parameter R related to the range of the strong forces, and the structural group USpsub(2.2) of the bundle (being the covering group of the SOsub(4.1) de Sitter group) implies a gauge description of strong interactions based on the noncompact gauge group USpsub(2.2). The U 1 factor in the total gauge group corresponds to the usual gauge formulation for the electromagnetic interactions. The positivity of the energy associated with stable extended one-particle states in this dualistic description of charged hadronic matter immersed in the fiber geometry (this dualism is called strong fiber dynamics (SFD)) requires hadrons to be assigned to representations of the compact subgroup SU 2 xSU 2 of the strong-interaction gauge group USpsub(2.2). A brief discussion of the point-particle limit R→O is given by linking the presented SFD formalism for extended hadrons to an idealized description in terms of operators in a local quantum field theory

  12. Understanding strong-field coherent control: Measuring single-atom versus collective dynamics

    International Nuclear Information System (INIS)

    Trallero-Herrero, Carlos; Weinacht, Thomas; Spanner, Michael

    2006-01-01

    We compare the results of two strong field coherent control experiments: one which optimizes multi-photon population transfer in atomic sodium (from the 3s to the 4s state, measured by spontaneous emission from the 3p-3s transition) with one that optimizes stimulated emission on the 3p-3s transition in an ensemble of sodium atoms. Both experiments make use of intense, shaped ultrafast laser pulses discovered by a Genetic Algorithm inside a learning control loop. Optimization leads to improvements in the spontaneous and stimulated emission yields of about 4 and 10 4 , respectively, over an unshaped pulse. We interpret these results by modeling both the single atom dynamics as well as the stimulated emission buildup through numerical integration of Schroedinger's and Maxwell's equations. Our interpretation leads to the conclusion that modest yields for controlling single quantum systems can lead to dramatic effects whenever an ensemble of such systems acts collectively following controlled impulsive excitation

  13. Collective strong coupling with homogeneous Rabi frequencies using a 3D lumped element microwave resonator

    International Nuclear Information System (INIS)

    Angerer, Andreas; Astner, Thomas; Wirtitsch, Daniel; Majer, Johannes; Sumiya, Hitoshi; Onoda, Shinobu; Isoya, Junichi; Putz, Stefan

    2016-01-01

    We design and implement 3D-lumped element microwave cavities that spatially focus magnetic fields to a small mode volume. They allow coherent and uniform coupling to electron spins hosted by nitrogen vacancy centers in diamond. We achieve large homogeneous single spin coupling rates, with an enhancement of more than one order of magnitude compared to standard 3D cavities with a fundamental resonance at 3 GHz. Finite element simulations confirm that the magnetic field distribution is homogeneous throughout the entire sample volume, with a root mean square deviation of 1.54%. With a sample containing 10"1"7 nitrogen vacancy electron spins, we achieve a collective coupling strength of Ω = 12 MHz, a cooperativity factor C = 27, and clearly enter the strong coupling regime. This allows to interface a macroscopic spin ensemble with microwave circuits, and the homogeneous Rabi frequency paves the way to manipulate the full ensemble population in a coherent way.

  14. The dust acoustic wave in a bounded dusty plasma with strong electrostatic interactions between dust grains

    International Nuclear Information System (INIS)

    Shukla, Nitin; Shukla, P.K.

    2011-01-01

    The dispersion relation for the dust acoustic wave (DAW) in an unmagnetized dusty plasma cylindrical waveguide is derived, accounting for strong electrostatic interactions between charged dust grains. It is found that the boundary effect limits the radial extent of the DAW. The present result should be helpful for understanding the frequency spectrum of the DAW in a dusty plasma waveguide with strongly coupled charged dust grains. - Highlights: → We study the dust acoustic wave (DAW) in a bounded plasma. → We account for interactions between dust grains. → The boundary effect limits the radial extent of the DAW.

  15. Proceedings of Summer Institute of Particle Physics, July 27-August 7, 1981: the strong interactions

    Energy Technology Data Exchange (ETDEWEB)

    Mosher, A. (ed.)

    1982-01-01

    The ninth SLAC Summer Institute on Particle Physics was held in the period July 27 to August 7, 1981. The central topic was the strong interactions with the first seven days spent in a pedagogic mode and the last three in a topical conference. In addition to the morning lectures on experimental and theoretical aspects of the strong interactions, three were lectures on machine physics; this year it was electron-positron colliding beam machines, both storage rings and linear colliders. Twenty-three individual items from the meeting were prepared separately for the data base. (GHT)

  16. Strong Ligand-Protein Interactions Derived from Diffuse Ligand Interactions with Loose Binding Sites.

    Science.gov (United States)

    Marsh, Lorraine

    2015-01-01

    Many systems in biology rely on binding of ligands to target proteins in a single high-affinity conformation with a favorable ΔG. Alternatively, interactions of ligands with protein regions that allow diffuse binding, distributed over multiple sites and conformations, can exhibit favorable ΔG because of their higher entropy. Diffuse binding may be biologically important for multidrug transporters and carrier proteins. A fine-grained computational method for numerical integration of total binding ΔG arising from diffuse regional interaction of a ligand in multiple conformations using a Markov Chain Monte Carlo (MCMC) approach is presented. This method yields a metric that quantifies the influence on overall ligand affinity of ligand binding to multiple, distinct sites within a protein binding region. This metric is essentially a measure of dispersion in equilibrium ligand binding and depends on both the number of potential sites of interaction and the distribution of their individual predicted affinities. Analysis of test cases indicates that, for some ligand/protein pairs involving transporters and carrier proteins, diffuse binding contributes greatly to total affinity, whereas in other cases the influence is modest. This approach may be useful for studying situations where "nonspecific" interactions contribute to biological function.

  17. Collective-field-corrected strong field approximation for laser-irradiated metal clusters

    International Nuclear Information System (INIS)

    Keil, Th; Bauer, D

    2014-01-01

    The strong field approximation (SFA) formulated in terms of so-called ‘quantum orbits’ led to much insight into intense-laser driven ionization dynamics. In plain SFA, the emitted electron is treated as a free electron in the laser field alone. However, with improving experimental techniques and more advanced numerical simulations, it becomes more and more obvious that the plain SFA misses interesting effects even on a qualitative level. Examples are holographic side lobes, the low-energy structure, radial patterns in photoelectron spectra at low kinetic energies and strongly rotated angular distributions. For this reason, increasing efforts have been recently devoted to Coulomb corrections of the SFA. In the current paper, we follow a similar line but consider ionization of metal clusters. It is known that photoelectrons from clusters can be much more energetic than those emitted from atoms or small molecules, especially if the Mie resonance of the expanding cluster is evoked. We develop a SFA that takes the collective field inside the cluster via the simple rigid-sphere model into account. Our approach is based on field-corrected quantum orbits so that the acceleration process (or any other spectral feature of interest) can be investigated in detail. (paper)

  18. Quasi-particles and effective mean field in strongly interacting matter

    International Nuclear Information System (INIS)

    Levai, P.; Ko, C.M.

    2010-01-01

    We introduce a quasi-particle model of strongly interacting quark-gluon matter and explore the possible connection to an effective field theoretical description consisting of a scalar σ field by introducing a dynamically generated mass, M(σ), and a self-consistently determined interaction term, B(σ). We display a possible connection between the two types of effective description, using the Friedberg-Lee model.

  19. Constraining strong baryon-dark-matter interactions with primordial nucleosynthesis and cosmic rays

    International Nuclear Information System (INIS)

    Cyburt, Richard H.; Fields, Brian D.; Pavlidou, Vasiliki; Wandelt, Benjamin

    2002-01-01

    Self-interacting dark matter (SIDM) was introduced by Spergel and Steinhardt to address possible discrepancies between collisionless dark matter simulations and observations on scales of less than 1 Mpc. We examine the case in which dark matter particles not only have strong self-interactions but also have strong interactions with baryons. The presence of such interactions will have direct implications for nuclear and particle astrophysics. Among these are a change in the predicted abundances from big bang nucleosynthesis (BBN) and the flux of γ rays produced by the decay of neutral pions which originate in collisions between dark matter and galactic cosmic rays (CR). From these effects we constrain the strength of the baryon-dark-matter interactions through the ratio of baryon-dark-matter interaction cross section to dark matter mass, s. We find that BBN places a weak upper limit on this ratio (less-or-similar sign)10 8 cm 2 g -1 . CR-SIDM interactions, however, limit the possible DM-baryon cross section to (less-or-similar sign)5x10 -3 cm 2 g -1 ; this rules out an energy-independent interaction, but not one which falls with center-of-mass velocity s∝1/v or steeper

  20. The universal sound velocity formula for the strongly interacting unitary Fermi gas

    International Nuclear Information System (INIS)

    Liu Ke; Chen Ji-Sheng

    2011-01-01

    Due to the scale invariance, the thermodynamic laws of strongly interacting limit unitary Fermi gas can be similar to those of non-interacting ideal gas. For example, the virial theorem between pressure and energy density of the ideal gas P = 2E/3V is still satisfied by the unitary Fermi gas. This paper analyses the sound velocity of unitary Fermi gases with the quasi-linear approximation. For comparison, the sound velocities for the ideal Boltzmann, Bose and Fermi gas are also given. Quite interestingly, the sound velocity formula for the ideal non-interacting gas is found to be satisfied by the unitary Fermi gas in different temperature regions. (general)

  1. Strong FANCA/FANCG but weak FANCA/FANCC interaction in the yeast 2-hybrid system.

    Science.gov (United States)

    Reuter, T; Herterich, S; Bernhard, O; Hoehn, H; Gross, H J

    2000-01-15

    Three of at least 8 Fanconi anemia (FA) genes have been cloned (FANCA, FANCC, FANCG), but their functions remain unknown. Using the yeast 2-hybrid system and full-length cDNA, the authors found a strong interaction between FANCA and FANCG proteins. They also obtained evidence for a weak interaction between FANCA and FANCC. Neither FANCA nor FANCC was found to interact with itself. These results support the notion of a functional association between the FA gene products. (Blood. 2000;95:719-720)

  2. Engineering the Dynamics of Effective Spin-Chain Models for Strongly Interacting Atomic Gases

    DEFF Research Database (Denmark)

    Volosniev, A. G.; Petrosyan, D.; Valiente, M.

    2015-01-01

    We consider a one-dimensional gas of cold atoms with strong contact interactions and construct an effective spin-chain Hamiltonian for a two-component system. The resulting Heisenberg spin model can be engineered by manipulating the shape of the external confining potential of the atomic gas. We...

  3. Superfluid quenching of the moment of inertia in a strongly interacting Fermi gas

    Science.gov (United States)

    Riedl, S.; Sánchez Guajardo, E. R.; Kohstall, C.; Hecker Denschlag, J.; Grimm, R.

    2011-03-01

    We report on the observation of a quenched moment of inertia resulting from superfluidity in a strongly interacting Fermi gas. Our method is based on setting the hydrodynamic gas in slow rotation and determining its angular momentum by detecting the precession of a radial quadrupole excitation. The measurements distinguish between the superfluid and collisional origins of hydrodynamic behavior, and show the phase transition.

  4. Interaction of a neutral composite particle with a strong Coulomb field

    International Nuclear Information System (INIS)

    Wong, Cheuk-Yin.

    1988-01-01

    The author discusses the interaction of the quasi-composite (e/sup /plus//e/sup /minus//) system with an external electromagnetic field. This problem addresses the question of the origin of strong positron lines in quasi-elastic heavy-ion reactions. 3 refs

  5. Goldberger-treiman relation and nucleon's mean square radius of strong interaction in the Skyrme model

    International Nuclear Information System (INIS)

    Li Bingan

    1988-01-01

    In this letter it is shown that even in m π ≠ 0 case the Goldberger-Treiman relation is still hold in the Skyrme model. The mean square radius of strong interaction of nucleon 2 > s 1/2 is computed in the Skyrme model

  6. Strong Coupling Asymptotics for a Singular Schrodinger Operator with an Interaction Supported by an Open Arc

    Czech Academy of Sciences Publication Activity Database

    Exner, Pavel; Pankrashkin, K.

    2014-01-01

    Roč. 39, č. 2 (2014), s. 193-212 ISSN 0360-5302 R&D Projects: GA ČR GAP203/11/0701 Institutional support: RVO:61389005 Keywords : Eigenvalue * Schrödinger operator * singular interaction * strong coupling * 35Q40 * 35P15 * 35J10 Subject RIV: BE - Theoretical Physics Impact factor: 1.013, year: 2014

  7. Spectral asymptotics of a strong delta ' interaction supported by a surface

    Czech Academy of Sciences Publication Activity Database

    Exner, Pavel; Jex, M.

    2014-01-01

    Roč. 378, 30-31 (2014), s. 2091-2095 ISSN 0375-9601 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : delta ' surface interaction * strong coupling expansion Subject RIV: BE - Theoretical Physics Impact factor: 1.683, year: 2014

  8. On eigenvalue asymptotics for strong delta-interactions supported by surfaces with boundaries

    Czech Academy of Sciences Publication Activity Database

    Dittrich, Jaroslav; Exner, Pavel; Kuhn, C.; Pankrashkin, K.

    2016-01-01

    Roč. 97, 1-2 (2016), s. 1-25 ISSN 0921-7134 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : singular Schrodinger operator * delta-interaction * strong coupling * eigenvalue Subject RIV: BE - Theoretical Physics Impact factor: 0.933, year: 2016

  9. The Continuum Limit of a Fermion System Involving Leptons and Quarks: Strong, Electroweak and Gravitational Interactions

    OpenAIRE

    Finster, Felix

    2014-01-01

    The causal action principle is analyzed for a system of relativistic fermions composed of massive Dirac particles and neutrinos. In the continuum limit, we obtain an effective interaction described by classical gravity as well as the strong and electroweak gauge fields of the standard model.

  10. The effect of strong intermolecular and chemical interactions on the compatibility of polymers

    International Nuclear Information System (INIS)

    Askadskii, Andrei A

    1999-01-01

    The data on compatibility and on the properties of polymer blends are generalised. The emphasis is placed on the formation of strong intermolecular interactions (dipole-dipole interaction and hydrogen bonding) between the components of blends, as well as on the chemical reactions between them. A criterion for the prediction of compatibility of polymers is described in detail. Different cases of compatibility are considered and the dependences of the glass transition temperatures on the composition of blends are analysed. The published data on the effect of strong intermolecular interactions between the blend components on the glass transition temperature are considered. The preparation of interpolymers is described whose macromolecules are composed of incompatible polymers, which leads to the so-called 'forced compatibility.' The bibliography includes 80 references.

  11. Strongly interacting fermion systems. Progress report, November 15, 1994--November 14, 1995

    International Nuclear Information System (INIS)

    1994-01-01

    This paper is the progress report for the period November 15, 1993 to November 14, 1994 for a program which relates to studies of strongly interacting fermion systems. The author has made significant progress in three areas, which are discussed in the report. These are: (1) optical properties in the open-quotes electronic structure program,close quotes calculating optical properties of quartz and urea; (2) quasi-one-dimensional systems, discussing the tuning of the large-density-wave or Peierls distortion in transition-metal linear chain compounds and the universal subgap optical absorptance of classes of quasi-one-dimensional compounds; and (3) other strongly interaction fermion systems, emphasizing the study of the effect of many-body interactions on the low-temperature properties of metals and superconductors

  12. Exact results relating spin-orbit interactions in two-dimensional strongly correlated systems

    Science.gov (United States)

    Kucska, Nóra; Gulácsi, Zsolt

    2018-06-01

    A 2D square, two-bands, strongly correlated and non-integrable system is analysed exactly in the presence of many-body spin-orbit interactions via the method of Positive Semidefinite Operators. The deduced exact ground states in the high concentration limit are strongly entangled, and given by the spin-orbit coupling are ferromagnetic and present an enhanced carrier mobility, which substantially differs for different spin projections. The described state emerges in a restricted parameter space region, which however is clearly accessible experimentally. The exact solutions are provided via the solution of a matching system of equations containing 74 coupled, non-linear and complex algebraic equations. In our knowledge, other exact results for 2D interacting systems with spin-orbit interactions are not present in the literature.

  13. Resonance tuning due to Coulomb interaction in strong near-field coupled metamaterials

    International Nuclear Information System (INIS)

    Roy Chowdhury, Dibakar; Xu, Ningning; Zhang, Weili; Singh, Ranjan

    2015-01-01

    Coulomb's law is one of the most fundamental laws of physics that describes the electrostatic interaction between two like or unlike point charges. Here, we experimentally observe a strong effect of Coulomb interaction in tightly coupled terahertz metamaterials where the split-ring resonator dimers in a unit cell are coupled through their near fields across the capacitive split gaps. Using a simple analytical model, we evaluated the Coulomb parameter that switched its sign from negative to positive values indicating the transition in the nature of Coulomb force from being repulsive to attractive depending upon the near field coupling between the split ring resonators. Apart from showing interesting effects in the strong coupling regime between meta-atoms, Coulomb interaction also allows an additional degree of freedom to achieve frequency tunable dynamic metamaterials

  14. The strong interaction in e{sup +}e{sup -} annihilation and deep inelastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, J

    1996-01-01

    Various aspects of strong interactions are considered. Correlation effects in the hadronization process in a string model are studied. A discrete approximation scheme to the perturbative QCD cascade in e{sup +}e{sup -} annihilation is formulated. The model, Discrete QCD, predicts a rather low phase space density of `effective gluons`. This is related to the properties of the running coupling constant. It provides us with a simple tool for studies of the strong interaction. It is shown that it reproduces well-known properties of parton cascades. A new formalism for the Deep Inelastic Scattering (DIS) process is developed. The model which is called the Linked Dipole Chain Model provides an interpolation between regions of high Q{sup 2} (DGLAP) and low x-moderate Q{sup 2} (BFKL). It gives a unified treatment of the different interaction channels an a DIS process. 17 figs.

  15. The strong interaction in e+e- annihilation and deep inelastic scattering

    International Nuclear Information System (INIS)

    Samuelsson, J.

    1996-01-01

    Various aspects of strong interactions are considered. Correlation effects in the hadronization process in a string model are studied. A discrete approximation scheme to the perturbative QCD cascade in e + e - annihilation is formulated. The model, Discrete QCD, predicts a rather low phase space density of 'effective gluons'. This is related to the properties of the running coupling constant. It provides us with a simple tool for studies of the strong interaction. It is shown that it reproduces well-known properties of parton cascades. A new formalism for the Deep Inelastic Scattering (DIS) process is developed. The model which is called the Linked Dipole Chain Model provides an interpolation between regions of high Q 2 (DGLAP) and low x-moderate Q 2 (BFKL). It gives a unified treatment of the different interaction channels an a DIS process. 17 figs

  16. Stimulated adiabatic passage in a dissipative ensemble of atoms with strong Rydberg-state interactions

    DEFF Research Database (Denmark)

    Petrosyan, David; Molmer, Klaus

    2013-01-01

    We study two-photon excitation of Rydberg states of atoms under stimulated adiabatic passage with delayed laser pulses. We find that the combination of strong interaction between the atoms in Rydberg state and the spontaneous decay of the intermediate exited atomic state leads to the Rydberg exci...... for deterministic creation and, possibly, extraction of Rydberg atoms or ions one at a time. The sympathetic monitoring via decay of ancilla particles may find wider applications for state preparation and probing of interactions in dissipative many-body systems.......We study two-photon excitation of Rydberg states of atoms under stimulated adiabatic passage with delayed laser pulses. We find that the combination of strong interaction between the atoms in Rydberg state and the spontaneous decay of the intermediate exited atomic state leads to the Rydberg...

  17. Elaboration of the recently proposed test of Pauli's principle under strong interactions

    International Nuclear Information System (INIS)

    Ktorides, C.N.; Myung, H.C.; Santilli, R.M.

    1980-01-01

    The primary objective of this paper is to stimulate the experimental verification of the validity or invalidity of Pauli's principle under strong interactions. We first outline the most relevant steps in the evolution of the notion of particle. The spin as well as other intrinsic characteristics of extended, massive, particles under electromagnetic interactions at large distances might be subjected to a mutation under additional strong interactions at distances smaller than their charge radius. These dynamical effects can apparently be conjectured to account for the nonpointlike nature of the particles, their necessary state of penetration to activate the strong interactions, and the consequential emergence of broader forces which imply the breaking of the SU(2)-spin symmetry. We study a characterization of the mutated value of the spin via the transition from the associative enveloping algebra of SU(2) to a nonassociative Lie-admissible form. The departure from the original associative product then becomes directly representative of the breaking of the SU(2)-spin symmetry, the presence of forces more general than those derivable from a potential, and the mutated value of the spin. In turn, such a departure of the spin from conventional quantum-mechanical values implies the inapplicability of Pauli's exclusion principle under strong interactions, because, according to this hypothesis, particles that are fermions under long-range electromagnetic interactions are no longer fermions under these broader, short-range, forces. In nuclear physics possible deviations from Pauli's exclusion principle can at most be very small. These experimental data establish that, for the nuclei considered, nucleons are in a partial state of penetration of their charge volumes although of small statistical character

  18. Interaction Technology for Collective and Psychomotor Training in Sports

    DEFF Research Database (Denmark)

    Fogtmann, Maiken Hillerup; Grønbæk, Kaj; Ludvigsen, Martin

    2011-01-01

    the kinesthetic empathic elements inherently present within open sports. To put focus on collective training, we draw inspiration from Kinesthetic Empathy Interaction in designing the collective training equipment, TacTowers. The TacTowers prototype is aimed at supporting athletes, particularly team handball...

  19. Heavy quark mass effects and improved tests of the flavor independence of strong interactions

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, P.N. [Univ. of Oxford (United Kingdom); SLD Collaboration

    1998-08-01

    A review is given of latest results on tests of the flavor independence of strong interactions. Heavy quark mass effects are evident in the data and are now taken into account at next-to-leading order in QCD perturbation theory. The strong-coupling ratios {alpha}{sub s}{sup b}/{alpha}{sub s}{sup uds} and {alpha}{sub s}{sup c}/{alpha}{sub s}{sup uds} are found to be consistent with unity. Determinations of the b-quark mass m{sub b} (M{sub Z}) are discussed.

  20. Semiclassical quantization of integrable systems of few interacting anyons in a strong magnetic field

    International Nuclear Information System (INIS)

    Sivan, N.; Levit, S.

    1992-01-01

    We present a semiclassical theory of charged interacting anyons in a strong magnetic field. We derive the appropriate generalization of the WKB quantization conditions and determine the corresponding wave functions for non separable integrable anyonic systems. This theory is applies to a system of two interacting anyons, two interacting anyons in the presence of an impurity and three interacting anyons. We calculate the dependence of the semiclassical energy levels on the statistical parameter and find regions in which dependence follows very different patterns. The semiclassical treatment allows to find the correlation between these patterns and the change in the character of the classical motion of the system. We also test the accuracy of the mean field approximation for low and high energy states of the three anyons. (author)

  1. Strong constraints on self-interacting dark matter with light mediators

    International Nuclear Information System (INIS)

    Bringmann, Torsten; Walia, Parampreet

    2017-04-01

    Coupling dark matter to light new particles is an attractive way to combine thermal production with strong velocity-dependent self-interactions. Here we point out that in such models the dark matter annihilation rate is generically enhanced by the Sommerfeld effect, and we derive the resulting constraints from the Cosmic Microwave Background and other indirect detection probes. For the frequently studied case of s-wave annihilation these constraints exclude the entire parameter space where the self-interactions are large enough to address the small-scale problems of structure formation.

  2. Nonlinear interaction of strong microwave beam with the ionosphere MINIX rocket experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, N.; Matsumoto, H.; Miyatake, S.; Kimura, I.; Nagatomo, M.; Obayashi, T.

    1986-01-01

    A rocket-borne experiment called MINIX was carried out to investigate the nonlinear interaction of a strong microwave energy beam with the ionosphere. The MINIX stands for Microwave-Ionosphere Nonlinear Interaction Experiment and was carried out on August 29, 1983. The objectives of the MINIX is to study possible impacts of the SPS microwave energy beam on the ionosphere such as the Ohmic heating and plasma wave excitation. The experiment showed that the microwave with f = 2.45 GHz nonlinearly excites various electrostatic plasma waves, though no Ohmic heating effects were detected. 4 figures.

  3. Nonlinear interaction of strong microwave beam with the ionosphere MINIX rocket experiment

    Science.gov (United States)

    Kaya, N.; Matsumoto, H.; Miyatake, S.; Kimura, I.; Nagatomo, M.

    A rocket-borne experiment called 'MINIX' was carried out to investigate the nonlinear interaction of a strong microwave energy beam with the ionosphere. The MINIX stands for Microwave-Ionosphere Nonlinear Interaction eXperiment and was carried out on August 29, 1983. The objective of the MINIX is to study possible impacts of the SPS microwave energy beam on the ionosphere, such as the ohmic heating and plasma wave excitation. The experiment showed that the microwave with f = 2.45 GHz nonlinearly excites various electrostatic plasma waves, though no ohmic heating effects were detected.

  4. Nonlinear interaction of strong microwave beam with the ionosphere MINIX rocket experiment

    International Nuclear Information System (INIS)

    Kaya, N.; Matsumoto, H.; Miyatake, S.; Kimura, I.; Nagatomo, M.; Obayashi, T.

    1986-01-01

    A rocket-borne experiment called MINIX was carried out to investigate the nonlinear interaction of a strong microwave energy beam with the ionosphere. The MINIX stands for Microwave-Ionosphere Nonlinear Interaction Experiment and was carried out on August 29, 1983. The objectives of the MINIX is to study possible impacts of the SPS microwave energy beam on the ionosphere such as the Ohmic heating and plasma wave excitation. The experiment showed that the microwave with f = 2.45 GHz nonlinearly excites various electrostatic plasma waves, though no Ohmic heating effects were detected. 4 figures

  5. Metastability and coherence of repulsive polarons in a strongly interacting Fermi mixture

    DEFF Research Database (Denmark)

    Kohstall, Cristoph; Zaccanti, Mattheo; Jag, Matthias

    2012-01-01

    show that a well-defined quasiparticle exists for strongly repulsive interactions. We measure the energy and the lifetime of this ‘repulsive polaron’9, 12, 13, and probe its coherence properties by measuring the quasiparticle residue. The results are well described by a theoretical approach that takes...... into account the finite effective range of the interaction in our system. We find that when the effective range is of the order of the interparticle spacing, there is a substantial increase in the lifetime of the quasiparticles. The existence of such a long-lived, metastable many-body state offers intriguing...

  6. Strong constraints on self-interacting dark matter with light mediators

    Energy Technology Data Exchange (ETDEWEB)

    Bringmann, Torsten; Walia, Parampreet [Oslo Univ. (Norway). Dept. of Physics; Kahlhoefer, Felix; Schmidt-Hoberg, Kai [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2017-04-15

    Coupling dark matter to light new particles is an attractive way to combine thermal production with strong velocity-dependent self-interactions. Here we point out that in such models the dark matter annihilation rate is generically enhanced by the Sommerfeld effect, and we derive the resulting constraints from the Cosmic Microwave Background and other indirect detection probes. For the frequently studied case of s-wave annihilation these constraints exclude the entire parameter space where the self-interactions are large enough to address the small-scale problems of structure formation.

  7. Universal Behavior of Pair Correlations in a Strongly Interacting Fermi Gas

    International Nuclear Information System (INIS)

    Kuhnle, E. D.; Hu, H.; Liu, X.-J.; Dyke, P.; Mark, M.; Drummond, P. D.; Hannaford, P.; Vale, C. J.

    2010-01-01

    We show that short-range pair correlations in a strongly interacting Fermi gas follow a simple universal law described by Tan's relations. This is achieved through measurements of the static structure factor which displays a universal scaling proportional to the ratio of Tan's contact to the momentum C/q. Bragg spectroscopy of ultracold 6 Li atoms from a periodic optical potential is used to measure the structure factor for a wide range of momenta and interaction strengths, providing broad confirmation of this universal law. We calibrate our Bragg spectra using the f-sum rule, which is found to improve the accuracy of the structure factor measurement.

  8. On the Frequency Distribution of Neutral Particles from Low-Energy Strong Interactions

    Directory of Open Access Journals (Sweden)

    Federico Colecchia

    2017-01-01

    Full Text Available The rejection of the contamination, or background, from low-energy strong interactions at hadron collider experiments is a topic that has received significant attention in the field of particle physics. This article builds on a particle-level view of collision events, in line with recently proposed subtraction methods. While conventional techniques in the field usually concentrate on probability distributions, our study is, to our knowledge, the first attempt at estimating the frequency distribution of background particles across the kinematic space inside individual collision events. In fact, while the probability distribution can generally be estimated given a model of low-energy strong interactions, the corresponding frequency distribution inside a single event typically deviates from the average and cannot be predicted a priori. We present preliminary results in this direction and establish a connection between our technique and the particle weighting methods that have been the subject of recent investigation at the Large Hadron Collider.

  9. Gauge unification of basic forces, particularly of gravitation with strong interactions

    International Nuclear Information System (INIS)

    Salam, A.

    1977-01-01

    An attempt is made to present a case for the use of both the Einstein--Weyl spin-two and the Yang--Mills spin-one gauge structures for describing strong interactions. By emphasizing both spin-one and -two aspects of this force, it is hoped that a unification of this force, on the one hand, with gravity theory and, on the other, with the electromagnetic and weak interactions can be achieved. A Puppi type of tetrahedral interralation of fundamental forces, with the strong force playing a pivotal role due to its mediation through both spin-one and -two quanta, is proposed. It is claimed that the gauge invariance of gravity theory permits the use of ambuguity-free nonpolynomial techniques and thereby the securing of relistic regularization in gravity-modified field theories with the Newtonian constant G/sub N/ providing a relistic cutoff. 37 references

  10. Anisotropy of the magnetoviscous effect in a cobalt ferrofluid with strong interparticle interaction

    Energy Technology Data Exchange (ETDEWEB)

    Linke, J.M., E-mail: julia.linke@tu-dresden.de; Odenbach, S.

    2015-12-15

    The anisotropy of the magnetoviscous effect (MVE) of a cobalt ferrofluid has been studied in a slit die viscometer for three orientations of the applied magnetic field: in the direction of the fluid flow (Δη{sub 1}), the velocity gradient (Δη{sub 2}), and the vorticity (Δη{sub 3}). The majority of the cobalt particles in the ferrofluid exhibit a strong dipole–dipole interaction, which corresponds to a weighted interaction parameter of λ{sub w}≈10.6. Thus the particles form extended microstructures inside the fluid which lead to enhanced MVE ratios Δη{sub 2}/Δη{sub 1}>3 and Δη{sub 3}/Δη{sub 1}>0.3 even for strong shearing and weak magnetic fields compared to fluids which contain non-interacting spherical particles with Δη{sub 2}/Δη{sub 1}≈1 and Δη{sub 3}/Δη{sub 1}=0. Furthermore, a non-monotonic increase has been observed in the shear thinning behavior of Δη{sub 2} for weak magnetic fields <10 kA/m, which cannot be explained solely by the magnetization of individual particles and the formation and disintegration of linear particle chains but indicates the presence of heterophase structures. - Highlights: • The magnetoviscous effect in a ferrofluid with strong interaction is anisotropic. • The strongest effects are found in a magnetic field parallel to the shear gradient. • In strong magnetic fields the microstructure of the fluid is stable against shearing. • In weak fields the fluid behavior indicates the presence of heterophase structures.

  11. Quasi-particle description of strongly interacting matter: Towards a foundation

    International Nuclear Information System (INIS)

    Bluhm, M.; Kaempfer, B.; Schulze, R.; Seipt, D.

    2007-01-01

    We confront our quasi-particle model for the equation of state of strongly interacting matter with recent first-principle QCD calculations. In particular, we test its applicability at finite baryon densities by comparing with Taylor expansion coefficients of the pressure for two quark flavours. We outline a chain of approximations starting from the Φ-functional approach to QCD which motivates the quasi-particle picture. (orig.)

  12. Limitations due to strong head-on beam-beam interactions (MD 1434)

    CERN Document Server

    Buffat, Xavier; Iadarola, Giovanni; Papadopoulou, Parthena Stefania; Papaphilippou, Yannis; Pellegrini, Dario; Pojer, Mirko; Crockford, Guy; Salvachua Ferrando, Belen Maria; Trad, Georges; Barranco Garcia, Javier; Pieloni, Tatiana; Tambasco, Claudia; CERN. Geneva. ATS Department

    2017-01-01

    The results of an experiment aiming at probing the limitations due to strong head on beam-beam interactions are reported. It is shown that the loss rates significantly increase when moving the working point up and down the diagonal, possibly due to effects of the 10th and/or 14th order resonances. Those limitations are tighter for bunches with larger beam-beam parameters, a maximum total beam-beam tune shift just below 0.02 could be reached.

  13. Fractional energy states of strongly-interacting bosons in one dimension

    DEFF Research Database (Denmark)

    Zinner, Nikolaj Thomas; G. Volosniev, A.; V. Fedorov, D.

    2014-01-01

    We study two-component bosonic systems with strong inter-species and vanishing intra-species interactions. A new class of exact eigenstates is found with energies that are {\\it not} sums of the single-particle energies with wave functions that have the characteristic feature that they vanish over...... than three particles. The states can be probed using the same techniques that have recently been used for fermionic few-body systems in quasi-1D.......We study two-component bosonic systems with strong inter-species and vanishing intra-species interactions. A new class of exact eigenstates is found with energies that are {\\it not} sums of the single-particle energies with wave functions that have the characteristic feature that they vanish over...... extended regions of coordinate space. This is demonstrated in an analytically solvable model for three equal mass particles, two of which are identical bosons, which is exact in the strongly-interacting limit. We numerically verify our results by presenting the first application of the stochastic...

  14. Strong excitonic interactions in the oxygen K-edge of perovskite oxides.

    Science.gov (United States)

    Tomita, Kota; Miyata, Tomohiro; Olovsson, Weine; Mizoguchi, Teruyasu

    2017-07-01

    Excitonic interactions of the oxygen K-edge electron energy-loss near-edge structure (ELNES) of perovskite oxides, CaTiO 3 , SrTiO 3 , and BaTiO 3 , together with reference oxides, MgO, CaO, SrO, BaO, and TiO 2 , were investigated using a first-principles Bethe-Salpeter equation calculation. Although the transition energy of oxygen K-edge is high, strong excitonic interactions were present in the oxygen K-edge ELNES of the perovskite oxides, whereas the excitonic interactions were negligible in the oxygen K-edge ELNES of the reference compounds. Detailed investigation of the electronic structure suggests that the strong excitonic interaction in the oxygen K-edge ELNES of the perovskite oxides is caused by the directionally confined, low-dimensional electronic structure at the Ti-O-Ti bonds. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. arXiv Recent results and future of the NA61/SHINE strong interactions program

    CERN Document Server

    Lysakowski, Bartosz

    2018-01-01

    NA61/SHINE is a fixed target experiment at the CERN Super-Proton- Synchrotron. The main goals of the experiment are to discover the critical point of strongly interacting matter and study the properties of the onset of deconfnement. In order to reach these goals the collaboration studies hadron production properties in nucleus-nucleus, proton-proton and proton-nucleus interactions. In this talk, recent results on particle production in p+p interactions, as well as Be+Be and Ar+Sc collisions in the SPS energy range are reviewed. The results are compared with available world data. The future of the NA61/SHINE scientifc program is also presented.

  16. Interacting Electrons and Holes in Quasi-2D Quantum Dots in Strong Magnetic Fields

    Science.gov (United States)

    Hawrylak, P.; Sheng, W.; Cheng, S.-J.

    2004-09-01

    Theory of optical properties of interacting electrons and holes in quasi-2D quantum dots in strong magnetic fields is discussed. In two dimensions and the lowest Landau level, hidden symmetries control the interaction of the interacting system with light. By confining electrons and holes into quantum dots hidden symmetries can be removed and the excitation spectrum of electrons and excitons can be observed. We discuss a theory electronic and of excitonic quantum Hall droplets at a filling factorν=2. For an excitonic quantum Hall droplet the characteristic emission spectra are predicted to be related to the total spin of electron and hole configurations. For the electronic droplet the excitation spectrum of the droplet can be mapped out by measuring the emission for increasing number of electrons.

  17. Interacting electrons and holes in quasi-2D quantum dots in strong magnetic fields

    International Nuclear Information System (INIS)

    Hawrylak, P.; Sheng, W.; Cheng, S.-J.

    2004-01-01

    Theory of optical properties of interacting electrons and holes in quasi-2D quantum dots in strong magnetic fields is discussed. In two dimensions and the lowest Landau level, hidden symmetries control the interaction of the interacting system with light. By confining electrons and holes into quantum dots hidden symmetries can be removed and the excitation spectrum of electrons and excitons can be observed. We discuss a theory electronic and excitonic quantum Hall droplets at a filling factor υ = 2. For an excitonic quantum Hall droplet the characteristic emission spectra are predicted to be related to the total spin of electron and hole configurations. For the electronic droplet the excitation spectrum of the droplet can be mapped out by measuring the emission for increasing number of electrons. (author)

  18. Strong late-time circumstellar interaction in the peculiar supernova iPTF14hls

    Science.gov (United States)

    Andrews, Jennifer E.; Smith, Nathan

    2018-06-01

    We present a moderate-resolution spectrum of the peculiar Type II supernova (SN) iPTF14hls taken on day 1153 after discovery. This spectrum reveals the clear signature of shock interaction with dense circumstellar material (CSM). We suggest that this CSM interaction may be an important clue for understanding the extremely unusual photometric and spectroscopic evolution seen over the first 600 d of iPTF14hls. The late-time spectrum shows a double-peaked intermediate-width H α line indicative of expansion speeds around 1000 km s-1, with the double-peaked shape hinting at a disc-like geometry in the CSM. If the CSM were highly asymmetric, perhaps in a disc or torus that was ejected from the star 3-6 yr prior to explosion, the CSM interaction could have been overrun and hidden below the SN ejecta photosphere from a wide range of viewing angles. In that case, CSM interaction luminosity would have been thermalized well below the photosphere, potentially sustaining the high luminosity without exhibiting the traditional observational signatures of strong CSM interaction (narrow H α emission and X-rays). Variations in density structure of the CSM could account for the multiple rebrightenings of the light curve. We propose that a canonical 1 × 1051 erg explosion energy with enveloped CSM interaction as seen in some recent SNe, rather than an entirely new explosion mechanism, may be adequate to explain the peculiar evolution of iPTF14hls.

  19. Magnetized Langmuir wave packets excited by a strong beam-plasma interaction

    International Nuclear Information System (INIS)

    Pelletier, G.; Sol, H.; Asseo, E.

    1988-01-01

    The physics of beam-plasma interaction, which has been investigated for a long time mostly in relation with solar bursts, is now more widely invoked in various astrophysical contexts such as pulsars, active galactic nuclei, close binaries, cataclysmic variables, γ bursters, and so on. In these situations the interaction is more likely in the spirit of strong Langmuir turbulence rather than in the spirit of quasilinear theory. Many investigations have been done for two opposite extremes, namely, in very weak and in very strong magnetic fields. Very few properties of the strong Langmuir turbulence are known in the most usual astrophysical situation where the magnetic field plays a significant role but is not strong enough to force the electrons into one-dimensional motion. For this case, we analyze the dynamics of Langmuir wave packets and provide new results about the stability of the solitons against transverse perturbations. It turns out that both the averaged Lagrangian method and the adiabatic perturbation method derived from the inverse scattering transform give exactly the same results (which is not obvious in soliton perturbation theory). In particular, they predict the stability of the solitons as long as the electron gyrofrequency is greater than the plasma frequency (strong magnetic field) and their instability against transverse self-modulation in the opposite case (weak magnetic field); moreover, they allow one to deduce the self-similar collapsing oblate cavitons in the latter case. The laws governing the collapse of the wave packets determine the relaxation of the beam in the surrounding medium and we derive a useful formula giving the power loss of the beam. We outline the astrophysical consequences of this investigation

  20. Strong coupling electrostatics for randomly charged surfaces: antifragility and effective interactions.

    Science.gov (United States)

    Ghodrat, Malihe; Naji, Ali; Komaie-Moghaddam, Haniyeh; Podgornik, Rudolf

    2015-05-07

    We study the effective interaction mediated by strongly coupled Coulomb fluids between dielectric surfaces carrying quenched, random monopolar charges with equal mean and variance, both when the Coulomb fluid consists only of mobile multivalent counterions and when it consists of an asymmetric ionic mixture containing multivalent and monovalent (salt) ions in equilibrium with an aqueous bulk reservoir. We analyze the consequences that follow from the interplay between surface charge disorder, dielectric and salt image effects, and the strong electrostatic coupling that results from multivalent counterions on the distribution of these ions and the effective interaction pressure they mediate between the surfaces. In a dielectrically homogeneous system, we show that the multivalent counterions are attracted towards the surfaces with a singular, disorder-induced potential that diverges logarithmically on approach to the surfaces, creating a singular but integrable counterion density profile that exhibits an algebraic divergence at the surfaces with an exponent that depends on the surface charge (disorder) variance. This effect drives the system towards a state of lower thermal 'disorder', one that can be described by a renormalized temperature, exhibiting thus a remarkable antifragility. In the presence of an interfacial dielectric discontinuity, the singular behavior of counterion density at the surfaces is removed but multivalent counterions are still accumulated much more strongly close to randomly charged surfaces as compared with uniformly charged ones. The interaction pressure acting on the surfaces displays in general a highly non-monotonic behavior as a function of the inter-surface separation with a prominent regime of attraction at small to intermediate separations. This attraction is caused directly by the combined effects from charge disorder and strong coupling electrostatics of multivalent counterions, which dominate the surface-surface repulsion due to

  1. Magnetism of one-dimensional strongly repulsive spin-1 bosons with antiferromagnetic spin-exchange interaction

    International Nuclear Information System (INIS)

    Lee, J. Y.; Guan, X. W.; Batchelor, M. T.; Lee, C.

    2009-01-01

    We investigate magnetism and quantum phase transitions in a one-dimensional system of integrable spin-1 bosons with strongly repulsive density-density interaction and antiferromagnetic spin-exchange interaction via the thermodynamic Bethe ansatz method. At zero temperature, the system exhibits three quantum phases: (i) a singlet phase of boson pairs when the external magnetic field H is less than the lower critical field H c1 ; (ii) a ferromagnetic phase of atoms in the hyperfine state |F=1, m F =1> when the external magnetic field exceeds the upper critical field H c2 ; and (iii) a mixed phase of singlet pairs and unpaired atoms in the intermediate region H c1 c2 . At finite temperatures, the spin fluctuations affect the thermodynamics of the model through coupling the spin bound states to the dressed energy for the unpaired m F =1 bosons. However, such spin dynamics is suppressed by a sufficiently strong external field at low temperatures. Thus the singlet pairs and unpaired bosons may form a two-component Luttinger liquid in the strong coupling regime.

  2. Electron gas interacting in a metal, submitted to a strong magnetic field

    International Nuclear Information System (INIS)

    Alcaraz, Francisco Castilho

    1977-01-01

    Using the propagator's technique in the grand ensemble developed by Montroll and Ward we investigate the magnetic properties of an interacting electron gas in a strong magnetic field. The free propagator properly constructed shows that the spin paramagnetism does not have a term with strong temperature dependence, contrary to the result of Isihara. Considering the electron density to be constant, the dHVA oscillations in the magnetic susceptibility and sound velocity, considering the effects of first exchange interactions, show only one phase in agreement with experimental result, while Ichimura and Isihara obtained two phases differing by π/2. The effects of first order exchange interactions in the dHVA oscillations of the magnetic susceptibility and sound velocity give rise to an exponential factor in the amplitudes of oscillator (Dingle factor), being the Dingle temperature linearly dependent of the Fermi velocity. The calculations of the ring diagram contribution to the grand partition function, show that the approximation used by Isihara for this calculations is not good and the dHVA oscillations of the contributions from the ring diagrams for the grand partition function have a phase differing by π/2 from that obtained by Isihara. (author)

  3. Quantum criticality of one-dimensional multicomponent Fermi gas with strongly attractive interaction

    International Nuclear Information System (INIS)

    He, Peng; Jiang, Yuzhu; Guan, Xiwen; He, Jinyu

    2015-01-01

    Quantum criticality of strongly attractive Fermi gas with SU(3) symmetry in one dimension is studied via the thermodynamic Bethe ansatz (TBA) equations. The phase transitions driven by the chemical potential μ, effective magnetic field H 1 , H 2 (chemical potential biases) are analyzed at the quantum criticality. The phase diagram and critical fields are analytically determined by the TBA equations in the zero temperature limit. High accurate equations of state, scaling functions are also obtained analytically for the strong interacting gases. The dynamic exponent z=2 and correlation length exponent ν=1/2 read off the universal scaling form. It turns out that the quantum criticality of the three-component gases involves a sudden change of density of states of one cluster state, two or three cluster states. In general, this method can be adapted to deal with the quantum criticality of multicomponent Fermi gases with SU(N) symmetry. (paper)

  4. Studies of the strong and electroweak interactions at the Z0 pole

    International Nuclear Information System (INIS)

    Hildreth, M.D.

    1995-03-01

    This thesis presents studies of the strong and electroweak forces, two of the fundamental interactions that govern the behavior of matter at high energies. The authors have used the hadronic decays of Z 0 bosons produced with the unique experimental apparatus of the e + e - Linear Collider at the Stanford Linear Accelerator Center (SLAC) and the SLAC Large Detector (SLD) for these measurements. Employing the precision tracking capabilities of the SLD, they isolated samples of Z 0 events containing primarily the decays of the Z 0 to a chosen quark type. With an inclusive selection technique, they have tested the flavor independence of the strong coupling, α s by measuring the rates of multi-jet production in isolated samples of light (uds), c, and b quark events. They find: α s uds /α s all 0.987 ± 0.027(stat) ± 0.022(syst) ± 0.022(theory), α s c /α s all = 1.012 ± 0.104(stat) ± 0.102(syst) ± 0.096(theory), α s b /α s all = 1.026 ± 0.041(stat) ± 0.030(theory), which implies that the strong interaction is independent of quark flavor within the present experimental sensitivity. They have also measured the extent of parity-violation in the Z 0 c bar c coupling, given by the parameter A c 0 , using a sample of fully and partially reconstructed D* and D + meson decays and the longitudinal polarization of the SLC electron beam. This sample of charm quark events was derived with selection techniques based on their kinematic properties and decay topologies. They find A c 0 = 0.73 ± 0.22(stat) ± 0.10(syst). This value is consistent with that expected in the electroweak standard model of particle interactions

  5. Collective properties of 2D magnetoexcitons interacting with plasmons

    International Nuclear Information System (INIS)

    Dumanov, Evghenij

    2009-01-01

    The dissertation is dedicated to the solution of two interdependent problems of the theory of high-density two-dimensional excitons and electron-hole pairs in a strong perpendicular magnetic field. One of them is the influence of the excited Landau levels (ELLs) on two ground states of these systems such as Bose-Einstein condensation of magnetoexcitons and another one is the metallic-type electron-hole liquid. The second problem is the determination of the energy spectrum of the collective elementary excitations arising in the presence of these two ground states, when the excitations of the quasiparticles take place in the frame of the lowest Landau levels (LLLs) and in the absence of their kinetic energy. In the present work a supplementary Hamiltonian of indirect interaction was calculated. It describes the additional indirect interaction between particles existing in the frame of the LLL, brought about by influence of ELL, under which two particles in the process of Coulomb interaction make virtual transitions from LLL to heteronymous and homonymous ELL and return back. The indirect supplementary e-e and h-h interaction gives rise to direct pairing terms and exchanges pairing terms. The first terms being negative increase the binding energy of magnetoexcitons and energy per pair in the EHL phase, whereas the second terms are repulsive. They diminish the influence of the direct pairing terms, but do not surpass them, so that the resulting influence of both terms remains attractive. The supplementary e-h attraction after the u-v transformation in the case of BEC of magnetoexcitons on the state with wave vector k gives rise to repulsive-type Bogoliubov self-energy terms. They stabilize the BEC in the small region of wave vectors . The energy per one e-h pair inside the EHD happens to be situated on the energy scale very close to the value of the chemical potential of the Bose-Einstein condensed magnetoexcitons with wave vector . These two phases can coexist. It was

  6. Thermodynamics of strongly interacting system from reparametrized Polyakov-Nambu-Jona-Lasinio model

    International Nuclear Information System (INIS)

    Bhattacharyya, Abhijit; Ghosh, Sanjay K.; Maity, Soumitra; Raha, Sibaji; Ray, Rajarshi; Saha, Kinkar; Upadhaya, Sudipa

    2017-01-01

    The Polyakov-Nambu-Jona-Lasinio model has been quite successful in describing various qualitative features of observables for strongly interacting matter, that are measurable in heavy-ion collision experiments. The question still remains on the quantitative uncertainties in the model results. Such an estimation is possible only by contrasting these results with those obtained from rst principles using the lattice QCD framework. Recently a variety of lattice QCD data were reported in the realistic continuum limit. Here we make a first attempt at reparametrizing the model so as to reproduce these lattice data

  7. Atomic wavefunctions probed through strong-field light-matter interaction

    Energy Technology Data Exchange (ETDEWEB)

    Mairesse, Y; Villeneuve, D M; Corkum, P B; Dudovich, N [Natl Res Council Canada, Ottawa, ON K1A 0R6 (Canada); Shafir, D; Dudovich, N [Weizmann Inst Sci, Dept Phys Complex Syst, IL-76100 Rehovot, (Israel); Mairesse, Y [Univ Bordeaux 1, CELIA, CNRS, UMR 5107, CEA, F-33405 Talence (France)

    2009-07-01

    Strong-field light-matter interactions can encode the spatial properties of the electronic wavefunctions that contribute to the process. In particular, the broadband harmonic spectra, measured for a series of molecular alignments, can be used to create a tomographic reconstruction of molecular orbitals. Here, we present an extension of the tomography approach to systems that cannot be naturally aligned. We demonstrate this ability by probing the two-dimensional properties of atomic wavefunctions. By manipulating an electron-ion re-collision process, we are able to resolve the symmetry of the atomic wavefunction with high contrast. (authors)

  8. Exotic Quantum Phases and Phase Transitions of Strongly Interacting Electrons in Low-Dimensional Systems

    Science.gov (United States)

    Mishmash, Ryan V.

    Experiments on strongly correlated quasi-two-dimensional electronic materials---for example, the high-temperature cuprate superconductors and the putative quantum spin liquids kappa-(BEDT-TTF)2Cu2(CN)3 and EtMe3Sb[Pd(dmit)2]2---routinely reveal highly mysterious quantum behavior which cannot be explained in terms of weakly interacting degrees of freedom. Theoretical progress thus requires the introduction of completely new concepts and machinery beyond the traditional framework of the band theory of solids and its interacting counterpart, Landau's Fermi liquid theory. In full two dimensions, controlled and reliable analytical approaches to such problems are severely lacking, as are numerical simulations of even the simplest of model Hamiltonians due to the infamous fermionic sign problem. Here, we attempt to circumvent some of these difficulties by studying analogous problems in quasi-one dimension. In this lower dimensional setting, theoretical and numerical tractability are on much stronger footing due to the methods of bosonization and the density matrix renormalization group, respectively. Using these techniques, we attack two problems: (1) the Mott transition between a Fermi liquid metal and a quantum spin liquid as potentially directly relevant to the organic compounds kappa-(BEDT-TTF)2Cu 2(CN)3 and EtMe3Sb[Pd(dmit)2] 2 and (2) non-Fermi liquid metals as strongly motivated by the strange metal phase observed in the cuprates. In both cases, we are able to realize highly exotic quantum phases as ground states of reasonable microscopic models. This lends strong credence to respective underlying slave-particle descriptions of the low-energy physics, which are inherently strongly interacting and also unconventional in comparison to weakly interacting alternatives. Finally, working in two dimensions directly, we propose a new slave-particle theory which explains in a universal way many of the intriguing experimental results of the triangular lattice organic spin

  9. Evidence for strong Breit interaction in dielectronic recombination of highly charged heavy ions.

    Science.gov (United States)

    Nakamura, Nobuyuki; Kavanagh, Anthony P; Watanabe, Hirofumi; Sakaue, Hiroyuki A; Li, Yueming; Kato, Daiji; Currell, Fred J; Ohtani, Shunsuke

    2008-02-22

    Resonant strengths have been measured for dielectronic recombination of Li-like iodine, holmium, and bismuth using an electron beam ion trap. By observing the atomic number dependence of the state-resolved resonant strength, clear experimental evidence has been obtained that the importance of the generalized Breit interaction (GBI) effect on dielectronic recombination increases as the atomic number increases. In particular, it has been shown that the GBI effect is exceptionally strong for the recombination through the resonant state [1s2s(2)2p(1/2)](1).

  10. Volkov basis for simulation of interaction of strong laser pulses and solids

    Science.gov (United States)

    Kidd, Daniel; Covington, Cody; Li, Yonghui; Varga, Kálmán

    2018-01-01

    An efficient and accurate basis comprised of Volkov states is implemented and tested for time-dependent simulations of interactions between strong laser pulses and crystalline solids. The Volkov states are eigenstates of the free electron Hamiltonian in an electromagnetic field and analytically represent the rapidly oscillating time-dependence of the orbitals, allowing significantly faster time propagation than conventional approaches. The Volkov approach can be readily implemented in plane-wave codes by multiplying the potential energy matrix elements with a simple time-dependent phase factor.

  11. Residual correlation in two-proton interferometry from Λ-proton strong interactions

    International Nuclear Information System (INIS)

    Wang, Fuqiang

    1999-01-01

    We investigate the residual effect of Λp strong interactions in pp correlations with one proton from Λ decays. It is found that the residual correlation is about 10% of the Λp correlation strength, and has a broad distribution centered around q≅40 MeV/c. The residual correlation cannot explain the observed structure on the tail of the recently measured pp correlation function in central Pb+Pb collisions by NA49 at the Super Proton Synchrotron. (c) 1999 The American Physical Society

  12. Partial widths of boson resonances in the quark-gluon model of strong interactions

    International Nuclear Information System (INIS)

    Kaidalov, A.B.; Volkovitsky, P.E.

    1981-01-01

    The quark-gluon model of strong interactions based on the topological expansion and the string model ib used for the calculation of the partial widths of boson resonances in the channels with two pseudoscalar mesons. The partial widths of mesons with arbitrary spins lying on the vector and tensor Regge trajectories are expressed in terms of the only rho-meson width. The violation of SU(3) symmetry increases with the growth of the spin of the resonance. The theoretical predictions are in a good agreement with experimental data [ru

  13. Multiphonon contribution to the polaron formation in cuprates with strong electron correlations and strong electron-phonon interaction

    Science.gov (United States)

    Ovchinnikov, Sergey G.; Makarov, Ilya A.; Kozlov, Peter A.

    2017-03-01

    In this work dependences of the electron band structure and spectral function in the HTSC cuprates on magnitude of electron-phonon interaction (EPI) and temperature are investigated. We use three-band p-d model with diagonal and offdiagonal EPI with breathing and buckling phonon mode in the frameworks of polaronic version of the generalized tight binding (GTB) method. The polaronic quasiparticle excitation in the system with EPI within this approach is formed by a hybridization of the local multiphonon Franck-Condon excitations with lower and upper Hubbard bands. Increasing EPI leads to transfer of spectral weight to high-energy multiphonon excitations and broadening of the spectral function. Temperature effects are taken into account by occupation numbers of local excited polaronic states and variations in the magnitude of spin-spin correlation functions. Increasing the temperature results in band structure reconstruction, spectral weight redistribution, broadening of the spectral function peak at the top of the valence band and the decreasing of the peak intensity. The effect of EPI with two phonon modes on the polaron spectral function is discussed.

  14. Mechanism for thermal relic dark matter of strongly interacting massive particles.

    Science.gov (United States)

    Hochberg, Yonit; Kuflik, Eric; Volansky, Tomer; Wacker, Jay G

    2014-10-24

    We present a new paradigm for achieving thermal relic dark matter. The mechanism arises when a nearly secluded dark sector is thermalized with the standard model after reheating. The freeze-out process is a number-changing 3→2 annihilation of strongly interacting massive particles (SIMPs) in the dark sector, and points to sub-GeV dark matter. The couplings to the visible sector, necessary for maintaining thermal equilibrium with the standard model, imply measurable signals that will allow coverage of a significant part of the parameter space with future indirect- and direct-detection experiments and via direct production of dark matter at colliders. Moreover, 3→2 annihilations typically predict sizable 2→2 self-interactions which naturally address the "core versus cusp" and "too-big-to-fail" small-scale structure formation problems.

  15. Introduction to unified theories of weak, electromagnetic and strong interactions - SU(5)

    International Nuclear Information System (INIS)

    Billoire, Alain; Morel, Andre.

    1980-11-01

    These notes correspond to a series of lectures given at Salay during winter 1979-1980. They are meant to be an introduction to the so-called grand unified theories of weak, electromagnetic and strong interactions. In a first part, we recall in a very elementary way the standard SU(2) model of electroweak interactions, putting the emphasis on the questions which are left open by this model and which unified theories help to answer. In part II, we explain in a systematic way how unified theories can be constructed, and develop the SU(5) model in great detail. Other models, like SO(10) and E 6 , are not presented, because SU(5) is the simplest one and has been subject to the deepest investigations up to now. Also it appears that most concepts and general results are not specific to any particular symmetry group [fr

  16. Questioning the quark model. Strong interaction, gravitation and time arrows. An approach to asymptotic freedom

    International Nuclear Information System (INIS)

    Basini, G.

    2003-01-01

    Asymptotic freedom, as a natural result of a theory based on a general approach, derived by a new interpretation of phenomena like the EPR paradox, the black-hole formation and the absence of primary cosmic antimatter is presented. In this approach, conservation laws are considered always and absolutely valid, leading to the possibility of topology changes, and recovering the mutual influence between fundamental forces. Moreover, a new consideration of time arrows leads to asymptotic freedom as a necessary consequence. In fact, asymptotic freedom of strong interactions seems to be a feature common also to gravitational interaction, if induced-gravity theories (t → ∞) are taken into account and a symmetric-time dynamics is recovered in the light of a general conservation principle. (authors)

  17. Questioning the quark model. Strong interaction, gravitation and time arrows. An approach to asymptotic freedom

    Energy Technology Data Exchange (ETDEWEB)

    Basini, G. [Istituto Nazionale di Fisica Nucleare, Frascati (Italy). Lab. Nazionale di Frascati; Capozziello, S. [E.R. Caianiello, Dipt. di Fisica, Roma (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Universita di Salerno, Boronissi, SA (Italy)

    2003-09-01

    Asymptotic freedom, as a natural result of a theory based on a general approach, derived by a new interpretation of phenomena like the EPR paradox, the black-hole formation and the absence of primary cosmic antimatter is presented. In this approach, conservation laws are considered always and absolutely valid, leading to the possibility of topology changes, and recovering the mutual influence between fundamental forces. Moreover, a new consideration of time arrows leads to asymptotic freedom as a necessary consequence. In fact, asymptotic freedom of strong interactions seems to be a feature common also to gravitational interaction, if induced-gravity theories (t {yields} {infinity}) are taken into account and a symmetric-time dynamics is recovered in the light of a general conservation principle. (authors)

  18. Quasiparticle Energy in a Strongly Interacting Homogeneous Bose-Einstein Condensate.

    Science.gov (United States)

    Lopes, Raphael; Eigen, Christoph; Barker, Adam; Viebahn, Konrad G H; Robert-de-Saint-Vincent, Martin; Navon, Nir; Hadzibabic, Zoran; Smith, Robert P

    2017-05-26

    Using two-photon Bragg spectroscopy, we study the energy of particlelike excitations in a strongly interacting homogeneous Bose-Einstein condensate, and observe dramatic deviations from Bogoliubov theory. In particular, at large scattering length a the shift of the excitation resonance from the free-particle energy changes sign from positive to negative. For an excitation with wave number q, this sign change occurs at a≈4/(πq), in agreement with the Feynman energy relation and the static structure factor expressed in terms of the two-body contact. For a≳3/q we also see a breakdown of this theory, and better agreement with calculations based on the Wilson operator product expansion. Neither theory explains our observations across all interaction regimes, inviting further theoretical efforts.

  19. Many-body Anderson localization of strongly interacting bosons in random lattices

    International Nuclear Information System (INIS)

    Katzer, Roman

    2015-05-01

    In the present work, we investigate the problem of many-body localization of strongly interacting bosons in random lattices within the disordered Bose-Hubbard model. This involves treating both the local Mott-Hubbard physics as well as the non-local quantum interference processes, which give rise to the phenomenon of Anderson localization, within the same theory. In order to determine the interaction induced transition to the Mott insulator phase, it is necessary to treat the local particle interaction exactly. Therefore, here we use a mean-field approach that approximates only the kinetic term of the Hamiltonian. This way, the full problem of interacting bosons on a random lattice is reduced to a local problem of a single site coupled to a particle bath, which has to be solved self-consistently. In accordance to previous works, we find that a finite disorder width leads to a reduced size of the Mott insulating regions. The transition from the superfluid phase to the Bose glass phase is driven by the non-local effect of Anderson localization. In order to describe this transition, one needs to work within a theory that is non-local as well. Therefore, here we introduce a new approach to the problem. Based on the results for the local excitation spectrum obtained within the mean-field theory, we reduce the full, interacting model to an effective, non-interacting model by applying a truncation scheme to the Hilbert space. Evaluating the long-ranged current density within this approximation, we identify the transition from the Bose glass to the superfluid phase with the Anderson transition of the effective model. Resolving this transition using the self-consistent theory of localization, we obtain the full phase diagram of the disordered Bose-Hubbard model in the regime of strong interaction and larger disorder. In accordance to the theorem of inclusions, we find that the Mott insulator and the superfluid phase are always separated by the compressible, but insulating

  20. Interaction and Collective Movement Processing : Report from Dagstuhl Seminar 14132

    NARCIS (Netherlands)

    2014-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 14132 “Interaction and Collective Movement Processing”. This seminar brought together a group of 30 scientists with varied backgrounds, but with a shared interest in computations involved in the processing of moving entity data,

  1. Effective model with strong Kitaev interactions for α -RuCl3

    Science.gov (United States)

    Suzuki, Takafumi; Suga, Sei-ichiro

    2018-04-01

    We use an exact numerical diagonalization method to calculate the dynamical spin structure factors of three ab initio models and one ab initio guided model for a honeycomb-lattice magnet α -RuCl3 . We also use thermal pure quantum states to calculate the temperature dependence of the heat capacity, the nearest-neighbor spin-spin correlation function, and the static spin structure factor. From the results obtained from these four effective models, we find that, even when the magnetic order is stabilized at low temperature, the intensity at the Γ point in the dynamical spin structure factors increases with increasing nearest-neighbor spin correlation. In addition, we find that the four models fail to explain heat-capacity measurements whereas two of the four models succeed in explaining inelastic-neutron-scattering experiments. In the four models, when temperature decreases, the heat capacity shows a prominent peak at a high temperature where the nearest-neighbor spin-spin correlation function increases. However, the peak temperature in heat capacity is too low in comparison with that observed experimentally. To address these discrepancies, we propose an effective model that includes strong ferromagnetic Kitaev coupling, and we show that this model quantitatively reproduces both inelastic-neutron-scattering experiments and heat-capacity measurements. To further examine the adequacy of the proposed model, we calculate the field dependence of the polarized terahertz spectra, which reproduces the experimental results: the spin-gapped excitation survives up to an onset field where the magnetic order disappears and the response in the high-field region is almost linear. Based on these numerical results, we argue that the low-energy magnetic excitation in α -RuCl3 is mainly characterized by interactions such as off-diagonal interactions and weak Heisenberg interactions between nearest-neighbor pairs, rather than by the strong Kitaev interactions.

  2. Simulation of Quantum Many-Body Dynamics for Generic Strongly-Interacting Systems

    Science.gov (United States)

    Meyer, Gregory; Machado, Francisco; Yao, Norman

    2017-04-01

    Recent experimental advances have enabled the bottom-up assembly of complex, strongly interacting quantum many-body systems from individual atoms, ions, molecules and photons. These advances open the door to studying dynamics in isolated quantum systems as well as the possibility of realizing novel out-of-equilibrium phases of matter. Numerical studies provide insight into these systems; however, computational time and memory usage limit common numerical methods such as exact diagonalization to relatively small Hilbert spaces of dimension 215 . Here we present progress toward a new software package for dynamical time evolution of large generic quantum systems on massively parallel computing architectures. By projecting large sparse Hamiltonians into a much smaller Krylov subspace, we are able to compute the evolution of strongly interacting systems with Hilbert space dimension nearing 230. We discuss and benchmark different design implementations, such as matrix-free methods and GPU based calculations, using both pre-thermal time crystals and the Sachdev-Ye-Kitaev model as examples. We also include a simple symbolic language to describe generic Hamiltonians, allowing simulation of diverse quantum systems without any modification of the underlying C and Fortran code.

  3. Possible Cosmological consequences of thermodynamics in a unified approach to gravitational and strong interactions

    International Nuclear Information System (INIS)

    Recami, E.; Tonin Zanchin, V.; Martinez, J.M.

    1986-01-01

    A unified geometrical approach to strong and gravitational interactions has been recently proposed, based on the classical methods of General Relativity. According to it, hadrons can be regarded as black-hole type solutions of new field equations describing two tensorial metric-field (the ordinary gravitational field, and the strong one). In this paper, we first seize the opportunity for an improved exposition of some elements of the theory relevant to our present scope. Secondly, by extending the Bekenstein-Hawking thermodynamics to the above mentioned strong black-holes (SBH), it is shown: 1) that SBH thermodynamics seems to require a new expansion of our cosmos after its Big Crunch (i.e. that a recontraction of our cosmos has to be followed by a new creation); 2) that a collapsing star with mass M approximately in the range 3 to 5 solar masses, once reached the neutron-star density, could re-explode tending to form a (radiating) object with a diameter of the order of 1 light-day: thus failing to create a gravitational black-hole

  4. Deterministic alternatives to the full configuration interaction quantum Monte Carlo method for strongly correlated systems

    Science.gov (United States)

    Tubman, Norm; Whaley, Birgitta

    The development of exponential scaling methods has seen great progress in tackling larger systems than previously thought possible. One such technique, full configuration interaction quantum Monte Carlo, allows exact diagonalization through stochastically sampling of determinants. The method derives its utility from the information in the matrix elements of the Hamiltonian, together with a stochastic projected wave function, which are used to explore the important parts of Hilbert space. However, a stochastic representation of the wave function is not required to search Hilbert space efficiently and new deterministic approaches have recently been shown to efficiently find the important parts of determinant space. We shall discuss the technique of Adaptive Sampling Configuration Interaction (ASCI) and the related heat-bath Configuration Interaction approach for ground state and excited state simulations. We will present several applications for strongly correlated Hamiltonians. This work was supported through the Scientific Discovery through Advanced Computing (SciDAC) program funded by the U.S. Department of Energy, Office of Science, Advanced Scientific Computing Research and Basic Energy Sciences.

  5. The proton-neutron interaction and nuclear collectivity

    International Nuclear Information System (INIS)

    Casten, R.F.

    1987-01-01

    A review is given of several aspects, and empirical consequences, of the p-n interaction as it relates to the structure, phase transitions and collectivity of medium and heavy nuclei. The N/sub p/N/sub n/ scheme is reviewed as background material while the emphasis centers on a discussion of a related quantity, the P factor, and on the relationship of the integrated strength of the p-n interaction to the empirically observed ''saturation'' of B(E2) values in the mid-shell regions of deformed nuclei. 19 refs., 13 figs

  6. The residual proton-neutron interaction and nuclear collectivity

    International Nuclear Information System (INIS)

    Casten, R.F.

    1990-01-01

    The essential role of the valence, residual p-n interaction in the development of collectivity, though long known in general terms, has recently become increasingly apparent. A brief review of the p-n interaction is given, including some very basic nuclear data that illustrate its effects and the phenomenological N p N n scheme and the P-factor. This is followed by a discussion of recent experimental extractions of p-n matrix elements throughout the periodic table and theoretical efforts to understand them, in terms of both Shell and Nilsson models. 20 refs., 13 figs

  7. Model of Collective Fish Behavior with Hydrodynamic Interactions

    Science.gov (United States)

    Filella, Audrey; Nadal, François; Sire, Clément; Kanso, Eva; Eloy, Christophe

    2018-05-01

    Fish schooling is often modeled with self-propelled particles subject to phenomenological behavioral rules. Although fish are known to sense and exploit flow features, these models usually neglect hydrodynamics. Here, we propose a novel model that couples behavioral rules with far-field hydrodynamic interactions. We show that (1) a new "collective turning" phase emerges, (2) on average, individuals swim faster thanks to the fluid, and (3) the flow enhances behavioral noise. The results of this model suggest that hydrodynamic effects should be considered to fully understand the collective dynamics of fish.

  8. Studies of the strong and electroweak interactions at the Z0 pole

    Energy Technology Data Exchange (ETDEWEB)

    Hildreth, Michael Douglas [Stanford Univ., CA (United States)

    1995-03-01

    This thesis presents studies of the strong and electroweak forces, two of the fundamental interactions that govern the behavior of matter at high energies. The authors have used the hadronic decays of Z0 bosons produced with the unique experimental apparatus of the e+e- Linear Collider at the Stanford Linear Accelerator Center (SLAC) and the SLAC Large Detector (SLD) for these measurements. Employing the precision tracking capabilities of the SLD, they isolated samples of Z0 events containing primarily the decays of the Z0 to a chosen quark type. With an inclusive selection technique, they have tested the flavor independence of the strong coupling, αs by measuring the rates of multi-jet production in isolated samples of light (uds), c, and b quark events. They find: α$s\\atop{uds}$/α$s\\atop{all}$ 0.987 ± 0.027(stat) ± 0.022(syst) ± 0.022(theory), α$c\\atop{s}$/α$all\\atop{s}$ = 1.012 ± 0.104(stat) ± 0.102(syst) ± 0.096(theory), α$b\\atop{s}$/α$all\\atop{s}$ = 1.026 {+-} 0.041(stat) ± 0.030(theory), which implies that the strong interaction is independent of quark flavor within the present experimental sensitivity. They have also measured the extent of parity-violation in the Z0 c$\\bar{c}$ coupling, given by the parameter A $0\\atop{c}$, using a sample of fully and partially reconstructed D* and D+ meson decays and the longitudinal polarization of the SLC electron beam. This sample of charm quark events was derived with selection techniques based on their kinematic properties and decay topologies. They find A$0\\atop{c}$ = 0.73 ± 0.22(stat) ± 0.10(syst). This value is consistent with that expected in the electroweak standard model of particle interactions.

  9. Effects of strong and electromagnetic correlations on neutrino interactions in dense matter

    International Nuclear Information System (INIS)

    Reddy, S.; Prakash, M.; Lattimer, J.M.; Reddy, S.; Pons, J.A.

    1999-01-01

    An extensive study of the effects of correlations on both charged and neutral current weak interaction rates in dense matter is performed. Both strong and electromagnetic correlations are considered. The propagation of particle-hole interactions in the medium plays an important role in determining the neutrino mean free paths. The effects due to Pauli blocking and density, spin, and isospin correlations in the medium significantly reduce the neutrino cross sections. As a result of the lack of experimental information at high density, these correlations are necessarily model dependent. For example, spin correlations in nonrelativistic models are found to lead to larger suppressions of neutrino cross sections compared to those of relativistic models. This is due to the tendency of the nonrelativistic models to develop spin instabilities. Notwithstanding the above caveats, and the differences between nonrelativistic and relativistic approaches such as the spin- and isospin-dependent interactions and the nucleon effective masses, suppressions of order 2 - 3, relative to the case in which correlations are ignored, are obtained. Neutrino interactions in dense matter are especially important for supernova and early neutron star evolution calculations. The effects of correlations for protoneutron star evolution are calculated. Large effects on the internal thermodynamic properties of protoneutron stars, such as the temperature, are found. These translate into significant early enhancements in the emitted neutrino energies and fluxes, especially after a few seconds. At late times, beyond about 10 s, the emitted neutrino fluxes decrease more rapidly compared to simulations without the effects of correlations, due to the more rapid onset of neutrino transparency in the protoneutron star. copyright 1999 The American Physical Society

  10. CONAN—The cruncher of local exchange coefficients for strongly interacting confined systems in one dimension

    DEFF Research Database (Denmark)

    Loft, Niels Jakob Søe; Kristensen, Lasse Bjørn; Thomsen, Anders

    2016-01-01

    We consider a one-dimensional system of particles with strong zero-range interactions. This system can be mapped onto a spin chain of the Heisenberg type with exchange coefficients that depend on the external trap. In this paper, we present an algorithm that can be used to compute these exchange...... coefficients. We introduce an open source code CONAN (Coefficients of One-dimensional N-Atom Networks) which is based on this algorithm. CONAN works with arbitrary external potentials and we have tested its reliability for system sizes up to around 35 particles. As illustrative examples, we consider a harmonic...... trap and a box trap with a superimposed asymmetric tilted potential. For these examples, the computation time typically scales with the number of particles as O(N3.5±0.4). Computation times are around 10 s for N=10 particles and less than 10 min for N=20 particles....

  11. Fluctuation instability of the Dirac Sea in quark models of strong interactions

    Science.gov (United States)

    Zinovjev, G. M.; Molodtsov, S. V.

    2016-03-01

    A number of exactly integrable (quark) models of quantum field theory that feature an infinite correlation length are considered. An instability of the standard vacuum quark ensemble, a Dirac sea (in spacetimes of dimension higher than three), is highlighted. It is due to a strong ground-state degeneracy, which, in turn, stems from a special character of the energy distribution. In the case where the momentumcutoff parameter tends to infinity, this distribution becomes infinitely narrow and leads to large (unlimited) fluctuations. A comparison of the results for various vacuum ensembles, including a Dirac sea, a neutral ensemble, a color superconductor, and a Bardeen-Cooper-Schrieffer (BCS) state, was performed. In the presence of color quark interaction, a BCS state is unambiguously chosen as the ground state of the quark ensemble.

  12. Fluctuation instability of the Dirac Sea in quark models of strong interactions

    International Nuclear Information System (INIS)

    Zinovjev, G. M.; Molodtsov, S. V.

    2016-01-01

    A number of exactly integrable (quark) models of quantum field theory that feature an infinite correlation length are considered. An instability of the standard vacuum quark ensemble, a Dirac sea (in spacetimes of dimension higher than three), is highlighted. It is due to a strong ground-state degeneracy, which, in turn, stems from a special character of the energy distribution. In the case where the momentumcutoff parameter tends to infinity, this distribution becomes infinitely narrow and leads to large (unlimited) fluctuations. A comparison of the results for various vacuum ensembles, including a Dirac sea, a neutral ensemble, a color superconductor, and a Bardeen–Cooper–Schrieffer (BCS) state, was performed. In the presence of color quark interaction, a BCS state is unambiguously chosen as the ground state of the quark ensemble.

  13. Fluctuation instability of the Dirac Sea in quark models of strong interactions

    Energy Technology Data Exchange (ETDEWEB)

    Zinovjev, G. M., E-mail: Gennady.Zinovjev@cern.ch [National Academy of Sciences of Ukraine, Bogolyubov Institute for Theoretical Physics (Ukraine); Molodtsov, S. V. [Joint Institute for Nuclear Research (Russian Federation)

    2016-03-15

    A number of exactly integrable (quark) models of quantum field theory that feature an infinite correlation length are considered. An instability of the standard vacuum quark ensemble, a Dirac sea (in spacetimes of dimension higher than three), is highlighted. It is due to a strong ground-state degeneracy, which, in turn, stems from a special character of the energy distribution. In the case where the momentumcutoff parameter tends to infinity, this distribution becomes infinitely narrow and leads to large (unlimited) fluctuations. A comparison of the results for various vacuum ensembles, including a Dirac sea, a neutral ensemble, a color superconductor, and a Bardeen–Cooper–Schrieffer (BCS) state, was performed. In the presence of color quark interaction, a BCS state is unambiguously chosen as the ground state of the quark ensemble.

  14. Electron-muon correlation as a new probe of strongly interacting quark-gluon plasma

    International Nuclear Information System (INIS)

    Akamatsu, Yukinao; Hatsuda, Tetsuo; Hirano, Tetsufumi

    2009-01-01

    As a new and clean probe to the strongly interacting quark-gluon plasma (sQGP), we propose an azimuthal correlation of an electron and a muon that originate from the semileptonic decay of charm and bottom quarks. By solving the Langevin equation for the heavy quarks under the hydrodynamic evolution of the hot plasma, we show that substantial quenching of the away-side peak in the electron-muon correlation can be seen if the sQGP drag force acting on heavy quarks is large enough as suggested from the gauge/gravity correspondence. The effect could be detected in high-energy heavy ion collisions at the Relativistic Heavy Ion Collider and the Large Hadron Collider.

  15. Thermal dark matter co-annihilating with a strongly interacting scalar

    Science.gov (United States)

    Biondini, S.; Laine, M.

    2018-04-01

    Recently many investigations have considered Majorana dark matter co-annihilating with bound states formed by a strongly interacting scalar field. However only the gluon radiation contribution to bound state formation and dissociation, which at high temperatures is subleading to soft 2 → 2 scatterings, has been included. Making use of a non-relativistic effective theory framework and solving a plasma-modified Schrödinger equation, we address the effect of soft 2 → 2 scatterings as well as the thermal dissociation of bound states. We argue that the mass splitting between the Majorana and scalar field has in general both a lower and an upper bound, and that the dark matter mass scale can be pushed at least up to 5…6TeV.

  16. Phase transitions, nonequilibrium dynamics, and critical behavior of strongly interacting systems

    International Nuclear Information System (INIS)

    Mottola, E.; Bhattacharya, T.; Cooper, F.

    1998-01-01

    This is the final report of a three-year, Laboratory Directed Research and Development project at Los Alamos National Laboratory. In this effort, large-scale simulations of strongly interacting systems were performed and a variety of approaches to the nonequilibrium dynamics of phase transitions and critical behavior were investigated. Focus areas included (1) the finite-temperature quantum chromodynamics phase transition and nonequilibrium dynamics of a new phase of matter (the quark-gluon plasma) above the critical temperature, (2) nonequilibrium dynamics of a quantum fields using mean field theory, and (3) stochastic classical field theoretic models with applications to spinodal decomposition and structural phase transitions in a variety of systems, such as spin chains and shape memory alloys

  17. Phase transitions, nonequilibrium dynamics, and critical behavior of strongly interacting systems

    Energy Technology Data Exchange (ETDEWEB)

    Mottola, E.; Bhattacharya, T.; Cooper, F. [and others

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development project at Los Alamos National Laboratory. In this effort, large-scale simulations of strongly interacting systems were performed and a variety of approaches to the nonequilibrium dynamics of phase transitions and critical behavior were investigated. Focus areas included (1) the finite-temperature quantum chromodynamics phase transition and nonequilibrium dynamics of a new phase of matter (the quark-gluon plasma) above the critical temperature, (2) nonequilibrium dynamics of a quantum fields using mean field theory, and (3) stochastic classical field theoretic models with applications to spinodal decomposition and structural phase transitions in a variety of systems, such as spin chains and shape memory alloys.

  18. Baryon femtoscopy considering residual correlations as a tool to extract strong interaction potentials

    Directory of Open Access Journals (Sweden)

    Szymański Maciej

    2015-01-01

    Full Text Available In this article, the analysis of baryon-antibaryon femtoscopic correlations is presented. In particular, it is shown that taking into account residual correlations is crucial for the description of pΛ¯$\\bar \\Lambda $ and p̄Λ correlation functions measured by the STAR experiment in Au–Au collisions at the centre-of-mass energy per nucleon pair √sNN = 200 GeV. This approach enables to obtain pΛ¯$\\bar \\Lambda $ (p̄Λ source size consistent with the sizes extracted from correlations in pΛ (p̄Λ¯$\\bar \\Lambda $ and lighter pair systems as well as with model predictions. Moreover, with this analysis it is possible to derive the unknown parameters of the strong interaction potential for baryon-antibaryon pairs under several assumptions.

  19. Particle-Hole Character of the Higgs and Goldstone Modes in Strongly Interacting Lattice Bosons

    Science.gov (United States)

    Di Liberto, M.; Recati, A.; Trivedi, N.; Carusotto, I.; Menotti, C.

    2018-02-01

    We study the low-energy excitations of the Bose-Hubbard model in the strongly interacting superfluid phase using a Gutzwiller approach. We extract the single-particle and single-hole excitation amplitudes for each mode and report emergent mode-dependent particle-hole symmetry on specific arc-shaped lines in the phase diagram connecting the well-known Lorentz-invariant limits of the Bose-Hubbard model. By tracking the in-phase particle-hole symmetric oscillations of the order parameter, we provide an answer to the long-standing question about the fate of the pure amplitude Higgs mode away from the integer-density critical point. Furthermore, we point out that out-of-phase symmetric oscillations in the gapless Goldstone mode are responsible for a full suppression of the condensate density oscillations. Possible detection protocols are also discussed.

  20. New precision era of experiments on strong interaction with strangeness at DAFNE/LNF-INFN

    Directory of Open Access Journals (Sweden)

    Ishiwatari T.

    2014-03-01

    Full Text Available The strong-interaction shifts and widths of kaonic hydrogen, deuterium, 3He, and 4He were measured in the SIDDHARTA experiment. The most precise values of the shift and width of the kaonic hydrogen 1s state were determined to be ϵ1s = −283 ± 36(stat±6(syst eV and Γ1s = 541±89(stat±22(syst eV. The upper limit of the kaonic deuterium Kα yield was found to be ≤ 0.39%. In addition, the shifts and widths of the kaonic 3He and 4He 2p states were determined to be ϵ2p(3He = −2 ± 2(stat ± 4(syst eV and Γ2p(3He = 6 ± 6(stat ± 7(syst eV; ϵ2p(4He = +5 ± 3(stat ± 4(syst eV and Γ2p(4He = 14 ± 8(stat ± 5(syst eV. These values are important for the constraints of the low-energy K¯N$\\bar KN$ interaction in theoretical approaches.

  1. Strong Delayed Interactive Effects of Metal Exposure and Warming: Latitude-Dependent Synergisms Persist Across Metamorphosis.

    Science.gov (United States)

    Debecker, Sara; Dinh, Khuong V; Stoks, Robby

    2017-02-21

    As contaminants are often more toxic at higher temperatures, predicting their impact under global warming remains a key challenge for ecological risk assessment. Ignoring delayed effects, synergistic interactions between contaminants and warming, and differences in sensitivity across species' ranges could lead to an important underestimation of the risks. We addressed all three mechanisms by studying effects of larval exposure to zinc and warming before, during, and after metamorphosis in Ischnura elegans damselflies from high- and low-latitude populations. By integrating these mechanisms into a single study, we could identify two novel patterns. First, during exposure zinc did not affect survival, whereas it induced mild to moderate postexposure mortality in the larval stage and at metamorphosis, and very strongly reduced adult lifespan. This severe delayed effect across metamorphosis was especially remarkable in high-latitude animals, as they appeared almost insensitive to zinc during the larval stage. Second, the well-known synergism between metals and warming was manifested not only during the larval stage but also after metamorphosis, yet notably only in low-latitude damselflies. These results highlight that a more complete life-cycle approach that incorporates the possibility of delayed interactions between contaminants and warming in a geographical context is crucial for a more realistic risk assessment in a warming world.

  2. Numerical simulation of wave-current interaction under strong wind conditions

    Science.gov (United States)

    Larrañaga, Marco; Osuna, Pedro; Ocampo-Torres, Francisco Javier

    2017-04-01

    Although ocean surface waves are known to play an important role in the momentum and other scalar transfer between the atmosphere and the ocean, most operational numerical models do not explicitly include the terms of wave-current interaction. In this work, a numerical analysis about the relative importance of the processes associated with the wave-current interaction under strong off-shore wind conditions in Gulf of Tehuantepec (the southern Mexican Pacific) was carried out. The numerical system includes the spectral wave model WAM and the 3D hydrodynamic model POLCOMS, with the vertical turbulent mixing parametrized by the kappa-epsilon closure model. The coupling methodology is based on the vortex-force formalism. The hydrodynamic model was forced at the open boundaries using the HYCOM database and the wave model was forced at the open boundaries by remote waves from the southern Pacific. The atmospheric forcing for both models was provided by a local implementation of the WRF model, forced at the open boundaries using the CFSR database. The preliminary analysis of the model results indicates an effect of currents on the propagation of the swell throughout the study area. The Stokes-Coriolis term have an impact on the transient Ekman transport by modifying the Ekman spiral, while the Stokes drift has an effect on the momentum advection and the production of TKE, where the later induces a deepening of the mixing layer. This study is carried out in the framework of the project CONACYT CB-2015-01 255377 and RugDiSMar Project (CONACYT 155793).

  3. Neutron star equilibrium configurations within a fully relativistic theory with strong, weak, electromagnetic, and gravitational interactions

    International Nuclear Information System (INIS)

    Belvedere, Riccardo; Pugliese, Daniela; Rueda, Jorge A.; Ruffini, Remo; Xue, She-Sheng

    2012-01-01

    We formulate the equations of equilibrium of neutron stars taking into account strong, weak, electromagnetic, and gravitational interactions within the framework of general relativity. The nuclear interactions are described by the exchange of the σ, ω, and ρ virtual mesons. The equilibrium conditions are given by our recently developed theoretical framework based on the Einstein–Maxwell–Thomas–Fermi equations along with the constancy of the general relativistic Fermi energies of particles, the “Klein potentials”, throughout the configuration. The equations are solved numerically in the case of zero temperatures and for selected parameterizations of the nuclear models. The solutions lead to a new structure of the star: a positively charged core at supranuclear densities surrounded by an electronic distribution of thickness ∼ℏ/(m e c)∼10 2 ℏ/(m π c) of opposite charge, as well as a neutral crust at lower densities. Inside the core there is a Coulomb potential well of depth ∼m π c 2 /e. The constancy of the Klein potentials in the transition from the core to the crust, imposes the presence of an overcritical electric field ∼(m π /m e ) 2 E c , the critical field being E c =m e 2 c 3 /(eℏ). The electron chemical potential and the density decrease, in the boundary interface, until values μ e crust e core and ρ crust core . For each central density, an entire family of core–crust interface boundaries and, correspondingly, an entire family of crusts with different mass and thickness, exist. The configuration with ρ crust =ρ drip ∼4.3×10 11 gcm −3 separates neutron stars with and without inner crust. We present here the novel neutron star mass–radius for the especial case ρ crust =ρ drip and compare and contrast it with the one obtained from the traditional Tolman–Oppenheimer–Volkoff treatment.

  4. Quadrupole collective dynamics from energy density functionals: Collective Hamiltonian and the interacting boson model

    International Nuclear Information System (INIS)

    Nomura, K.; Vretenar, D.; Niksic, T.; Otsuka, T.; Shimizu, N.

    2011-01-01

    Microscopic energy density functionals have become a standard tool for nuclear structure calculations, providing an accurate global description of nuclear ground states and collective excitations. For spectroscopic applications, this framework has to be extended to account for collective correlations related to restoration of symmetries broken by the static mean field, and for fluctuations of collective variables. In this paper, we compare two approaches to five-dimensional quadrupole dynamics: the collective Hamiltonian for quadrupole vibrations and rotations and the interacting boson model (IBM). The two models are compared in a study of the evolution of nonaxial shapes in Pt isotopes. Starting from the binding energy surfaces of 192,194,196 Pt, calculated with a microscopic energy density functional, we analyze the resulting low-energy collective spectra obtained from the collective Hamiltonian, and the corresponding IBM Hamiltonian. The calculated excitation spectra and transition probabilities for the ground-state bands and the γ-vibration bands are compared to the corresponding sequences of experimental states.

  5. Introduction to gauge theories of the strong, weak, and electromagnetic interactions

    International Nuclear Information System (INIS)

    Quigg, C.

    1980-07-01

    The plan of these notes is as follows. Chapter 1 is devoted to a brief evocative review of current beliefs and prejudices that form the context for the discussion to follow. The idea of Gauge Invariance is introduced in Chapter 2, and the connection between conservation laws and symmetries of the Lagrangian is recalled. Non-Abelian gauge field theories are constructed in Chapter 3, by analogy with the familiar case of electromagnetism. The Yang-Mills theory based upon isospin symmetry is constructed explicitly, and the generalization is made to other gauge groups. Chapter 4 is concerned with spontaneous symmetry breaking and the phenomena that occur in the presence or absence of local gauge symmetries. The existence of massless scalar fields (Goldstone particles) and their metamorphosis by means of the Higgs mechanism are illustrated by simple examples. The Weinberg-Salam model is presented in Chapter 5, and a brief resume of applications to experiment is given. Quantum Chromodynamics, the gauge theory of colored quarks and gluons, is developed in Chapter 6. Asymptotic freedom is derived schematically, and a few simple applications of perturbative QCD ae exhibited. Details of the conjectured confinement mechanism are omitted. The strategy of grand unified theories of the strong, weak, and electromagnetic interactions is laid out in Chapter 7. Some properties and consequences of the minimal unifying group SU(5) are presented, and the gauge hierarchy problem is introduced in passing. The final chapter contains an essay on the current outlook: aspirations, unanswered questions, and bold scenarios

  6. Strong interactions between learned helplessness and risky decision-making in a rat gambling model.

    Science.gov (United States)

    Nobrega, José N; Hedayatmofidi, Parisa S; Lobo, Daniela S

    2016-11-18

    Risky decision-making is characteristic of depression and of addictive disorders, including pathological gambling. However it is not clear whether a propensity to risky choices predisposes to depressive symptoms or whether the converse is the case. Here we tested the hypothesis that rats showing risky decision-making in a rat gambling task (rGT) would be more prone to depressive-like behaviour in the learned helplessness (LH) model. Results showed that baseline rGT choice behaviour did not predict escape deficits in the LH protocol. In contrast, exposure to the LH protocol resulted in a significant increase in risky rGT choices on retest. Unexpectedly, control rats subjected only to escapable stress in the LH protocol showed a subsequent decrease in riskier rGT choices. Further analyses indicated that the LH protocol affected primarily rats with high baseline levels of risky choices and that among these it had opposite effects in rats exposed to LH-inducing stress compared to rats exposed only to the escape trials. Together these findings suggest that while baseline risky decision making may not predict LH behaviour it interacts strongly with LH conditions in modulating subsequent decision-making behaviour. The suggested possibility that stress controllability may be a key factor should be further investigated.

  7. Inhomogeneous chiral symmetry breaking in isospin-asymmetric strong-interaction matter

    Energy Technology Data Exchange (ETDEWEB)

    Nowakowski, Daniel

    2017-07-01

    In this thesis we investigate the effects of an isospin asymmetry on inhomogeneous chiral symmetry breaking phases, which are characterized by spatially modulated quarkantiquark condensates. In order to determine the relevance of such phases for the phase diagram of strong-interaction matter, a two-flavor Nambu-Jona-Lasinio model is used to study the properties of the ground state of the system. Confirming the presence of inhomogeneous chiral symmetry breaking in isospin-asymmetric matter for a simple Chiral Density Wave, we generalize the modulation of the quark-antiquark pairs to more complicated shapes and study the effects of different degrees of flavor-mixing on the inhomogeneous phase at non-zero isospin asymmetry. Then, we investigate the occurrence of crystalline chiral symmetry breaking phases in charge-neutral matter, from which we determine the influence of crystalline phases on a quark star by calculating mass-radius sequences. Finally, our model is extended through color-superconducting phases and we study the interplay of these phases with inhomogeneous chiral-symmetry breaking at non-vanishing isospin asymmetry, before we discuss our findings.

  8. Electron-photon and electron-electron interactions in the presence of strong electromagnetic fields

    International Nuclear Information System (INIS)

    Surzhykov, A.; Fritzsche, S.; Stoehlker, Th.

    2010-01-01

    During the last decade, photon emission from highly-charged, heavy ions has been in the focus of intense studies at the GSI accelerator and storage ring facility in Darmstadt. These studies have revealed unique information about the electron-electron and electron-photon interactions in the presence of extremely strong nuclear fields. Apart from the radiative electron capture processes, characteristic photon emission following collisional excitation of projectile ions has also attracted much interest. In this contribution, we summarize the recent theoretical studies on the production of excited ionic states and their subsequent radiative decay. We will pay special attention to the angular and polarization properties of Kα emission from helium-like ions produced by means of dielectronic recombination. The results obtained for this (resonant) capture process will be compared with the theoretical predictions for the characteristic X-rays following Coulomb excitation and radiative recombination of few-electron, heavy ions. Work is supported by Helmholtz Association and GSl under the project VH-NG--421. (author)

  9. Compact X-ray sources. Simulating the electron/strong laser interaction

    Energy Technology Data Exchange (ETDEWEB)

    Hartin, Anthony [DESY, CFEL, Hamburg (Germany)

    2016-07-01

    The collision of an intense laser with an electron bunch can be used to produce X-rays via the inverse Compton scattering (ICS) mechanism. The ICS can be simulated via either a classical theory in which electrons and photons are treated in terms of classical electromagnetic waves - or a quantum theory in which charged particles interact with strong electromagnetic fields. The laser intensity used in a practical ICS collision is likely to be at such a level that quantum effects may be significant and the use of quantum theory may become a necessity. A simulation study is presented here comparing the classical and quantum approaches to the ICS. A custom particle-in-cell (PIC) software code, with photon generation by monte carlo of the exact quantum transition probability is used to simulate the quantum treatment. Peak resonant energies and the angular distribution of the X-rays are obtained and compared with those predicted by the classical theory. The conditions under which significant differences between the two theories emerges is obtained.

  10. Lattice QCD results on soft and hard probes of strongly interacting matter

    Science.gov (United States)

    Kaczmarek, Olaf

    2017-11-01

    We present recent results from lattice QCD relevant for the study of strongly interacting matter as it is produced in heavy ion collision experiments. The equation of state at non-vanishing density from a Taylor expansion up to 6th order will be discussed for a strangeness neutral system and using the expansion coefficients of the series limits on the critical point are estimated. Chemical freeze-out temperatures from the STAR and ALICE Collaborations will be compared to lines of constant physics calculated from the Taylor expansion of QCD bulk thermodynamic quantities. We show that qualitative features of the √{sNN} dependence of skewness and kurtosis ratios of net proton-number fluctuations measured by the STAR Collaboration can be understood from QCD results for cumulants of conserved baryon-number fluctuations. As an example for recent progress towards the determination of spectral and transport properties of the QGP from lattice QCD, we will present constraints on the thermal photon rate determined from a spectral reconstruction of continuum extrapolated lattice correlation functions in combination with input from most recent perturbative calculations.

  11. Parametric analysis of the thermodynamic properties for a medium with strong interaction between particles

    International Nuclear Information System (INIS)

    Dubovitskii, V.A.; Pavlov, G.A.; Krasnikov, Yu.G.

    1996-01-01

    Thermodynamic analysis of media with strong interparticle (Coulomb) interaction is presented. A method for constructing isotherms is proposed for a medium described by a closed multicomponent thermodynamic model. The method is based on choosing an appropriate nondegenerate frame of reference in the extended space of thermodynamic variables and provides efficient thermodynamic calculations in a wide range of parameters, for an investigation of phase transitions of the first kind, and for determining both the number of phases and coexistence curves. A number of approximate thermodynamic models of hydrogen plasma are discussed. The approximation corresponding to the n5/2 law, in which the effects of particle attraction and repulsion are taken into account qualitatively, is studied. This approximation allows studies of thermodynamic properties of a substance for a wide range of parameters. In this approximation, for hydrogen at a constant temperature, various properties of the degree of ionization are revealed. In addition, the parameters of the second critical point are found under conditions corresponding to the Jovian interior

  12. Theory and phenomenology of strong and weak interaction high energy physics: Progress report, May 1, 1987-April 30, 1988

    International Nuclear Information System (INIS)

    Carruthers, P.; Thews, R.L.

    1988-01-01

    This paper contains progress information on the following topics in High Energy Physics: strong, electromagnetic, and weak interactions; aspects of quark-gluon models for hadronic interactions, decays, and structure; the dynamical generation of a mass gap and the role and truthfulness of perturbation theory; statistical and dynamical aspects of hadronic multiparticle production; and realization of chiral symmetry and temperature effects in supersymmetric theories

  13. Comparison of fully internally and strongly contracted multireference configuration interaction procedures

    Science.gov (United States)

    Sivalingam, Kantharuban; Krupicka, Martin; Auer, Alexander A.; Neese, Frank

    2016-08-01

    Multireference (MR) methods occupy an important class of approaches in quantum chemistry. In many instances, for example, in studying complex magnetic properties of transition metal complexes, they are actually the only physically satisfactory choice. In traditional MR approaches, single and double excitations are performed with respect to all reference configurations (or configuration state functions, CSFs), which leads to an explosive increase of computational cost for larger reference spaces. This can be avoided by the internal contraction scheme proposed by Meyer and Siegbahn, which effectively reduces the number of wavefunction parameters to their single-reference counterpart. The "fully internally contracted" scheme (FIC) is well known from the popular CASPT2 approach. An even shorter expansion of the wavefunction is possible with the "strong contraction" (SC) scheme proposed by Angeli and Malrieu in their NEVPT2 approach. Promising multireference configuration interaction formulations (MRCI) employing internal contraction and strong contraction have been reported by several authors. In this work, we report on the implementation of the FIC-MRCI and SC-MRCI methodologies, using a computer assisted implementation strategy. The methods are benchmarked against the traditional uncontracted MRCI approach for ground and excited states of small molecules (N2, O2, CO, CO+, OH, CH, and CN). For ground states, the comparison includes the "partially internally contracted" MRCI based on the Celani-Werner ansatz (PC-MRCI). For the three contraction schemes, the average errors range from 2% to 6% of the uncontracted MRCI correlation energies. Excitation energies are reproduced with ˜0.2 eV accuracy. In most cases, the agreement is better than 0.2 eV, even in cases with very large differential correlation contributions as exemplified for the d-d and ligand-to-metal charge transfer transitions of a Cu [NH 3 ] 4 2 + model complex. The benchmark is supplemented with the

  14. Rapid plasma heating by collective interactions, using strong turbulence and relativistic electron beams

    International Nuclear Information System (INIS)

    Wharton, C.B.

    1977-01-01

    A multi-kilovolt, moderate density plasma was generated in a magnetic mirror confinement system by two methods: turbulent heating and relativistic electron beam. Extensive diagnostic development permitted the measurement of important plasma characteristics, leading to interesting and novel conclusions regarding heating and loss mechanisms. Electron and ion heating mechanisms were categorized, and parameter studies made to establish ranges of importance. Nonthermal ion and electron energy distributions were measured. Beam propagation and energy deposition studies yielded the spatial dependence of plasma heating

  15. Monitoring interaction and collective text production through text mining

    Directory of Open Access Journals (Sweden)

    Macedo, Alexandra Lorandi

    2014-04-01

    Full Text Available This article presents the Concepts Network tool, developed using text mining technology. The main objective of this tool is to extract and relate terms of greatest incidence from a text and exhibit the results in the form of a graph. The Network was implemented in the Collective Text Editor (CTE which is an online tool that allows the production of texts in synchronized or non-synchronized forms. This article describes the application of the Network both in texts produced collectively and texts produced in a forum. The purpose of the tool is to offer support to the teacher in managing the high volume of data generated in the process of interaction amongst students and in the construction of the text. Specifically, the aim is to facilitate the teacher’s job by allowing him/her to process data in a shorter time than is currently demanded. The results suggest that the Concepts Network can aid the teacher, as it provides indicators of the quality of the text produced. Moreover, messages posted in forums can be analyzed without their content necessarily having to be pre-read.

  16. Coupling of tt̄ and γγ with a strongly interacting Electroweak Symmetry Breaking Sector

    Directory of Open Access Journals (Sweden)

    Delgado Rafael L.

    2017-01-01

    Full Text Available We report the coupling of an external γγ or tt̄ state to a strongly interacting EWSBS satisfying unitarity. We exploit perturbation theory for those coupling of the external state, whereas the EWSBS is taken as strongly interacting. We use a modified version of the IAM unitarization procedure to model such a strongly interacting regime. The matrix elements VLVL → VLVL, VLVL ↔ hh, hh → hh, VLVL ↔ {γγ, tt̄}, hh ↔ {γγ, tt̄} are all computed to NLO in perturbation theory with the Nonlinear Effective Field Theory of the EWSBS, within the Equivalence Theorem. This allows us to describe resonances of the electroweak sector that may be found at the LHC and their effect on other channels such as γγ or tt̄ where they may be discovered.

  17. Proceedings of the 24. SLAC summer institute on particle physics: The strong interaction, from hadrons to partons

    Energy Technology Data Exchange (ETDEWEB)

    Chan, J.; DePorcel, L.; Dixon, L. [eds.

    1997-06-01

    This conference explored the role of the strong interaction in the physics of hadrons and partons. The Institute attracted 239 physicists from 16 countries to hear lectures on the underlying theory of Quantum Chromodynamics, modern theoretical calculational techniques, and experimental investigation of the strong interaction as it appears in various phenomena. Different regimes in which one can calculate reliably in QCD were addressed in series of lectures on perturbation theory, lattice gauge theories, and heavy quark expansions. Studies of QCD in hadron-hadron collisions, electron-positron annihilation, and electron-proton collisions all give differing perspectives on the strong interaction--from low-x to high-Q{sup 2}. Experimental understanding of the production and decay of heavy quarks as well as the lighter meson states has continued to evolve over the past years, and these topics were also covered at the School. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  18. The significance of a new correspondence principle for electromagnetic interaction in strong optical field ionisation

    International Nuclear Information System (INIS)

    Boreham, B. W.; Hora, H.

    1997-01-01

    We have recently developed a correspondence principle for electromagnetic interaction. When applied to laser interactions with electrons this correspondence principle identifies a critical laser intensity I*. This critical intensity is a transition intensity separating classical mechanical and quantum mechanical interaction regimes. In this paper we discuss the further application of I* to the interaction of bound electrons in atoms. By comparing I* with the ionisation threshold intensities as calculated from a cycle-averaged simple-atom model we conclude that I* can be usefully interpreted as a lower bound to the classical regime in studies of ionisation of gas atoms by intense laser beams

  19. Pionic 4f→3d transition in 181Ta, natural Re, and 209Bi and the strong interaction level shift and the strong interaction level shift and width of the pionic 3d state

    International Nuclear Information System (INIS)

    Konijn, J.; Panman, J.K.; Koch, J.H.; Doesburg, W. van; Ewan, G.T.; Johansson, T.; Tibell, G.; Fransson, K.; Tauscher, L.

    1979-01-01

    Owing to a powerful Compton-suppression technique it was possible to observe for the first time the pionic 4f→3d X-ray transition in elements heavier than A=150. The strong interaction monopole shifts epsilon 0 and widths GAMMA 0 as well as the quadrupole splitting of the 3d levels have been measured in Ta, Re and Bi. Thus in addition to the strongly shifted and broadened 5g→4f transitions, a second, strongly affected line is available for these elements. For the pionic 4f levels, standard optical potentials fit the strong interaction shifts and broadenings quite well. The now observed, deeper-lying 3d states in Ta, Re and Bi have shifts and widths that differ by a factor of 2 or more from the standard optical potential predictions. From the observed relative X-ray intensities of the pionic cascade the strong interaction widths of the 5g and 4f levels are also extracted. (Auth.)

  20. Search for pair production of strongly interacting particles decaying to pairs of jets in pp collisions at √s=1.96 TeV.

    Science.gov (United States)

    Aaltonen, T; Albin, E; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Bae, T; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brigliadori, L; Bromberg, C; Brucken, E; Budagov, J; Budd, H S; Burkett, K; Busetto, G; Bussey, P; Butti, P; Buzatu, A; Calamba, A; Camarda, S; Campanelli, M; Canelli, F; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Cho, K; Chokheli, D; Ciocci, M A; Clark, A; Clarke, C; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Cremonesi, M; Cruz, D; Cuevas, J; Culbertson, R; d'Ascenzo, N; Datta, M; De Barbaro, P; Demortier, L; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dorigo, M; Driutti, A; Ebina, K; Edgar, R; Elagin, A; Erbacher, R; Errede, S; Esham, B; Eusebi, R; Farrington, S; Fernández Ramos, J P; Field, R; Flanagan, G; Forrest, R; Franklin, M; Freeman, J C; Frisch, H; Funakoshi, Y; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González López, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gramellini, E; Grinstein, S; Grosso-Pilcher, C; Group, R C; Guimaraes da Costa, J; Hahn, S R; Han, J Y; Happacher, F; Hara, K; Hare, M; Harr, R F; Harrington-Taber, T; Hatakeyama, K; Hays, C; Heinrich, J; Herndon, M; Hocker, A; Hong, Z; Hopkins, W; Hou, S; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kambeitz, M; Kamon, T; Karchin, P E; Kasmi, A; Kato, Y; Ketchum, W; Keung, J; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kim, Y J; Kimura, N; Kirby, M; Knoepfel, K; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Kruse, M; Kuhr, T; Kurata, M; Laasanen, A T; Lammel, S; Lancaster, M; Lannon, K; Latino, G; Lee, H S; Lee, J S; Leo, S; Leone, S; Lewis, J D; Limosani, A; Lipeles, E; Liu, H; Liu, Q; Liu, T; Lockwitz, S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maestro, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, P; Martínez, M; Matera, K; Mattson, M E; Mazzacane, A; Mazzanti, P; McNulty, R; Mehta, A; Mehtala, P; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M J; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Nigmanov, T; Nodulman, L; Noh, S Y; Norniella, O; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagliarone, C; Palencia, E; Palni, P; Papadimitriou, V; Parker, W; Pauletta, G; Paulini, M; Paus, C; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Poprocki, S; Potamianos, K; Prokoshin, F; Pranko, A; Ptohos, F; Punzi, G; Ranjan, N; Redondo Fernández, I; Renton, P; Rescigno, M; Riddick, T; Rimondi, F; Ristori, L; Robson, A; Rodriguez, T; Rolli, S; Ronzani, M; Roser, R; Rosner, J L; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Sakurai, Y; Santi, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, E E; Schwarz, T; Scodellaro, L; Scuri, F; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shochet, M; Shreyber-Tecker, I; Simonenko, A; Sinervo, P; Sliwa, K; Smith, J R; Snider, F D; Sorin, V; Song, H; Stancari, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thomson, E; Thukral, V; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Ukegawa, F; Uozumi, S; Vázquez, F; Velev, G; Vellidis, C; Vernieri, C; Vidal, M; Vilar, R; Vizán, J; Vogel, M; Volpi, G; Wagner, P; Wallny, R; Wang, S M; Warburton, A; Waters, D; Wester, W C; Whiteson, D; Wicklund, A B; Wilbur, S; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamato, D; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Zanetti, A M; Zeng, Y; Zhou, C; Zucchelli, S

    2013-07-19

    We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant production via an intermediate gluon as well as resonant production via a distinct nonstandard-model intermediate strongly interacting particle. We use data collected by the CDF experiment in proton-antiproton collisions at √[s]=1.96 TeV corresponding to an integrated luminosity of 6.6 fb(-1). We find the data to be consistent with nonresonant production. We report limits on σ(pp[over ¯]→jjjj) as a function of the masses of the hypothetical intermediate particles. Upper limits on the production cross sections for nonstandard-model particles in several resonant and nonresonant processes are also derived.

  1. The Quantum-to-Classical Transition in Strongly Interacting Nanoscale Systems

    Science.gov (United States)

    Benatov, Latchezar Latchezarov

    This thesis comprises two separate but related studies, dealing with two strongly interacting nanoscale systems on the border between the quantum and classical domains. In Part 1, we use a Born-Markov approximated master equation approach to study the symmetrized-in-frequency current noise spectrum and the oscillator steady state of a nanoelectromechanical system where a nanoscale resonator is coupled linearly via its momentum to a quantum point contact (QPC). Our current noise spectra exhibit clear signatures of the quantum correlations between the QPC current and the back-action force on the oscillator at a value of the relative tunneling phase where such correlations are expected to be maximized. We also show that the steady state of the oscillator obeys a classical Fokker-Planck equation, but can experience thermomechanical noise squeezing in the presence of a momentum-coupled detector bath and a position-coupled environmental bath. Besides, the full master equation clearly shows that half of the detector back-action is correlated with electron tunneling, indicating a departure from the model of the detector as an effective bath and suggesting that a future calculation valid at lower bias voltage, stronger tunneling and/or stronger coupling might reveal interesting quantum effects in the oscillator dynamics. In the second part of the thesis, we study the subsystem dynamics and thermalization of an oscillator-spin star model, where a nanomechanical resonator is coupled to a few two-level systems (TLS's). We use a fourth-order Runge-Kutta numerical algorithm to integrate the Schrodinger equation for the system and obtain our results. We find that the oscillator reaches a Boltzmann steady state when the TLS bath is initially in a thermal state at a temperature higher than the oscillator phonon energy. This occurs in both chaotic and integrable systems, and despite the small number of spins (only six) and the lack of couplings between them. At the same time, pure

  2. Radiation-induced structural transitions in composite materials with strong interaction of polymer components

    International Nuclear Information System (INIS)

    Zaikin, Yu.A.; Koztaeva, U.P.

    2002-01-01

    In earlier papers the internal friction (IF) method was applied to studies of structural relaxation in different types of polymer-based composite materials (glass-cloth, paper-based and foiled laminates impregnated by epoxy and phenolic resins) irradiated by 2 MeV electrons in the dose range of 0.1-50.0 MGy. Selectivity and high sensibility of the internal friction method allowed to distinguish glassy transitions in different structural components of the composites. The relaxation processes observed were identified and attributed to structural alterations in the polymer filler, the binder and the boundary layers. It was shown that changes in the parameters of relaxation maximums during irradiation can be considered as quantitative characteristics for the degree of radiation-induced degradation or cross-linking of polymer molecules. This paper deals with specific features of IF spectra in paper-based laminates where both the filler fibers and the binder are strongly interacting polymers. Anisotropy of viscous and elastic properties is very weak for this kind of materials, so that IF measurements give nearly the same result independently on the filler fiber orientation in the sample. The main reasons for it are the rigid chain structure of fillers (polyethylene-terephthalate and cellulose) and the good adhesion strengthened by diffusion of the epoxy or phenolic binder to defect regions of the filler.The IF temperature dependence observed in paper-based laminates is represented by superposition of two very broad relaxation maximums associated with transitions from glassy to high-elastic state in structural components, each based on one of the polymers. The inflection points characteristic for IF temperature dependence in paper-based laminates give a reason to treat them as a superposition of α-peaks associated with transitions from glassy to high-elastic state in structural components of a composite based on the binder and the filler, respectively. Another

  3. Collective excitations of strongly coupled bilayer charged Bose liquids in the third-frequency-moment sum rule

    International Nuclear Information System (INIS)

    Tas, Murat; Tanatar, B.

    2008-01-01

    We calculate the collective excitation modes of strongly coupled bilayer charged Bose systems. We employ the dielectric matrix formulation to study the correlation effects within the random-phase approximation (RPA), the self consistent field approximation Singwi, Tosi, Land, and Sjoelander (STLS), and the quasilocalized charge approximation (QLCA), which satisfies the third-frequency-moment ( 3 >) sum rule. We find that the QLCA predicts a long-wavelength correlation-induced energy gap in the out-of-phase plasmon mode, similar to the situation in electronic bilayer systems. The energy gap and the plasmon density of states are studied as a function of interlayer separation and coupling parameter r s . The results should be helpful for experimental investigations

  4. Construction of exchange-correlation functionals through interpolation between the non-interacting and the strong-correlation limit

    International Nuclear Information System (INIS)

    Zhou, Yongxi; Ernzerhof, Matthias; Bahmann, Hilke

    2015-01-01

    Drawing on the adiabatic connection of density functional theory, exchange-correlation functionals of Kohn-Sham density functional theory are constructed which interpolate between the extreme limits of the electron-electron interaction strength. The first limit is the non-interacting one, where there is only exchange. The second limit is the strong correlated one, characterized as the minimum of the electron-electron repulsion energy. The exchange-correlation energy in the strong-correlation limit is approximated through a model for the exchange-correlation hole that is referred to as nonlocal-radius model [L. O. Wagner and P. Gori-Giorgi, Phys. Rev. A 90, 052512 (2014)]. Using the non-interacting and strong-correlated extremes, various interpolation schemes are presented that yield new approximations to the adiabatic connection and thus to the exchange-correlation energy. Some of them rely on empiricism while others do not. Several of the proposed approximations yield the exact exchange-correlation energy for one-electron systems where local and semi-local approximations often fail badly. Other proposed approximations generalize existing global hybrids by using a fraction of the exchange-correlation energy in the strong-correlation limit to replace an equal fraction of the semi-local approximation to the exchange-correlation energy in the strong-correlation limit. The performance of the proposed approximations is evaluated for molecular atomization energies, total atomic energies, and ionization potentials

  5. Field-matter interaction in atomic and plasma physics, from fluctuations to the strongly nonlinear regime

    International Nuclear Information System (INIS)

    Benisti, D.

    2011-01-01

    This manuscript provides a theoretical description, sometimes illustrated by experimental results, of several examples of field-matter interaction in various domains of physics, showing how the same basic concepts and theoretical methods may be used in very different physics situations. The issues addressed here are nonlinear field-matter interaction in plasma physics within the framework of classical mechanics (with a particular emphasis on wave-particle interaction), the linear analysis of beam-plasma instabilities in the relativistic regime, and the quantum description of laser-atom interaction, including quantum electrodynamics. Novel methods are systematically introduced in order to solve some very old problems, like the nonlinear counterpart of the Landau damping rate in plasma physics, for example. Moreover, our results directly apply to inertial confinement fusion, laser propagation in an atomic vapor, ion acceleration in a magnetized plasma and the physics of the Reversed Field Pinch for magnetic fusion. (author)

  6. A new model for the collective beam-beam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, J.A.; Sobol, A.V. [New Mexico Univ., Albuquerque, NM (United States); Vogt, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2006-09-15

    The Collective Beam-Beam interaction is studied in the framework of maps with a ''kick-lattice'' model in 4-D phase space. A novel approach to the classical method of averaging is used to derive an approximate map which is equivalent to a flow within the averaging approximation. The flow equation is a continuous-time Vlasov equation which we call the averaged Vlasov equation, the new model of this paper. The power of this approach is evidenced by the fact that the averaged Vlasov equation has exact equilibria and the associated lineralized equations have uncoupled azimuthal Fourier modes. The equation for the Fourier modes leads to a Fredholm integral equation of the third kind and the setting is ready-made for the development of a weakly nonlinear theory to study the coupling of the {pi} and {sigma} modes. The {pi} and {sigma} modes are calculated from the third kind integral equation and results are compared with the kick-lattice model. (orig.)

  7. A new model for the collective beam-beam interaction

    International Nuclear Information System (INIS)

    Ellison, J.A.; Sobol, A.V.; Vogt, M.

    2006-09-01

    The Collective Beam-Beam interaction is studied in the framework of maps with a ''kick-lattice'' model in 4-D phase space. A novel approach to the classical method of averaging is used to derive an approximate map which is equivalent to a flow within the averaging approximation. The flow equation is a continuous-time Vlasov equation which we call the averaged Vlasov equation, the new model of this paper. The power of this approach is evidenced by the fact that the averaged Vlasov equation has exact equilibria and the associated lineralized equations have uncoupled azimuthal Fourier modes. The equation for the Fourier modes leads to a Fredholm integral equation of the third kind and the setting is ready-made for the development of a weakly nonlinear theory to study the coupling of the π and σ modes. The π and σ modes are calculated from the third kind integral equation and results are compared with the kick-lattice model. (orig.)

  8. Measurement and optimization of the light collection uniformity in strongly tapered PWO crystals of the PANDA detector

    Science.gov (United States)

    Diehl, Stefan; Bremer, Daniel; Brinkmann, Kai-Thomas; Dormenev, Valery; Eissner, Tobias; Novotny, Rainer W.; Rosenbaum, Christoph; Zaunick, Hans-Georg; PANDA Collaboration

    2017-06-01

    The uniformity of the light collection is a crucial parameter for detectors based on inorganic scintillation crystals to guarantee a response proportional to the deposited energy. Especially in case of tapered crystals, like they are widely used to realize a 4π geometry of electromagnetic calorimeters (EMC) in high energy physics experiments, a strong non-uniformity is introduced by an additional focusing of the scintillation light due to the tapered geometry. The paper will discuss the determination and the reduction of the non-uniformity in strongly tapered lead tungstate crystals as used for the construction of the electromagnetic calorimeter of the PANDA detector at the future Facility for Antiproton and Ion Research (FAIR). Among different concepts for an uniformization a single de-polished lateral side face provided the optimum result with a remaining non-uniformity below 5% in good agreement with similar studies for the CMS ECAL at LHC. The impact on the achievable energy resolution in the energy regime of photons below 800 MeV is discussed in detail in comparison to GEANT4 simulations. The comparison of the response of two arrays with polished and de-polished crystals, respectively, shows in the latter case a significant improvement of the constant term of the parametrization of the energy resolution down to 0.5% accompanied by only very slight increase of the statistical term.

  9. Measurement and optimization of the light collection uniformity in strongly tapered PWO crystals of the PANDA detector

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Stefan; Bremer, Daniel; Brinkmann, Kai-Thomas; Dormenev, Valery; Eissner, Tobias; Novotny, Rainer W.; Rosenbaum, Christoph; Zaunick, Hans-Georg

    2017-06-11

    The uniformity of the light collection is a crucial parameter for detectors based on inorganic scintillation crystals to guarantee a response proportional to the deposited energy. Especially in case of tapered crystals, like they are widely used to realize a 4π geometry of electromagnetic calorimeters (EMC) in high energy physics experiments, a strong non-uniformity is introduced by an additional focusing of the scintillation light due to the tapered geometry. The paper will discuss the determination and the reduction of the non-uniformity in strongly tapered lead tungstate crystals as used for the construction of the electromagnetic calorimeter of the PANDA detector at the future Facility for Antiproton and Ion Research (FAIR). Among different concepts for an uniformization a single de-polished lateral side face provided the optimum result with a remaining non-uniformity below 5% in good agreement with similar studies for the CMS ECAL at LHC. The impact on the achievable energy resolution in the energy regime of photons below 800 MeV is discussed in detail in comparison to GEANT4 simulations. The comparison of the response of two arrays with polished and de-polished crystals, respectively, shows in the latter case a significant improvement of the constant term of the parametrization of the energy resolution down to 0.5% accompanied by only very slight increase of the statistical term.

  10. Evidence for a strong sulfur-aromatic interaction derived from crystallographic data.

    Science.gov (United States)

    Zauhar, R J; Colbert, C L; Morgan, R S; Welsh, W J

    2000-03-01

    We have uncovered new evidence for a significant interaction between divalent sulfur atoms and aromatic rings. Our study involves a statistical analysis of interatomic distances and other geometric descriptors derived from entries in the Cambridge Crystallographic Database (F. H. Allen and O. Kennard, Chem. Design Auto. News, 1993, Vol. 8, pp. 1 and 31-37). A set of descriptors was defined sufficient in number and type so as to elucidate completely the preferred geometry of interaction between six-membered aromatic carbon rings and divalent sulfurs for all crystal structures of nonmetal-bearing organic compounds present in the database. In order to test statistical significance, analogous probability distributions for the interaction of the moiety X-CH(2)-X with aromatic rings were computed, and taken a priori to correspond to the null hypothesis of no significant interaction. Tests of significance were carried our pairwise between probability distributions of sulfur-aromatic interaction descriptors and their CH(2)-aromatic analogues using the Smirnov-Kolmogorov nonparametric test (W. W. Daniel, Applied Nonparametric Statistics, Houghton-Mifflin: Boston, New York, 1978, pp. 276-286), and in all cases significance at the 99% confidence level or better was observed. Local maxima of the probability distributions were used to define a preferred geometry of interaction between the divalent sulfur moiety and the aromatic ring. Molecular mechanics studies were performed in an effort to better understand the physical basis of the interaction. This study confirms observations based on statistics of interaction of amino acids in protein crystal structures (R. S. Morgan, C. E. Tatsch, R. H. Gushard, J. M. McAdon, and P. K. Warme, International Journal of Peptide Protein Research, 1978, Vol. 11, pp. 209-217; R. S. Morgan and J. M. McAdon, International Journal of Peptide Protein Research, 1980, Vol. 15, pp. 177-180; K. S. C. Reid, P. F. Lindley, and J. M. Thornton, FEBS

  11. Asymptotic freedom in the theory of the strong interaction. Comment on the nobel prize in physics 2004

    International Nuclear Information System (INIS)

    Zhang Zhaoxi

    2005-01-01

    The 2004 Nobel Prize in Physics was awarded to David J. Gross, Frank Wilczek and H. David Politzer for their decisive contributions to the theory of the asymptotic freedom of the strong interaction (a fundamental interaction). The fundamental elements of quantum chromodynamics (QCD) and the theory of the strong interaction are briefly reviewed in their historical context. How to achieve asymptotic freedom is introduced and its physical meaning explained. The latest experimental tests of asymptotic freedom are presented, and it is shown that the theoretical prediction agrees excellently with the experimental measurements. Perturbative QCD which is based on the asymptotic freedom is outlined. It is pointed out that the theoretical discovery and experimental proof of the asymptotic freedom are crucial for QCD to be the correct theory of strong interaction. Certain frontier research areas of QCD, such as 'color confinement', are mentioned. The discovery and confirmation of asymptotic freedom has indeed deeply affected particle physics, and has led to QCD becoming a main content of the standard model, and to further development of the so-called grand unification theories of interactions. (author)

  12. Systematics of interaction and strong absorption radii determined from heavy-ion elastic scattering

    International Nuclear Information System (INIS)

    Birkelund, J.R.; Huizenga, J.R.

    1977-01-01

    Various methods for determining the strong absorption radius for light and intermediate mass nuclei are discussed. It is found that this determination in terms of the half-density radii of the target and projectile is more accurate over the whole range of available data than the other simple parametrizations. 62 references

  13. Communication and Collective Consensus Making in Animal Groups via Mechanical Interactions

    Science.gov (United States)

    Várkonyi, Péter L.

    2011-06-01

    Mechanical constraints have a strong influence on the dynamics and structure of granular aggregations. The contact forces within dense suspensions of active particles may give rise to intriguing phenomena, including anomalous density fluctuations, long-range orientational ordering, and spontaneous pattern formation. Various authors have proposed that these physical phenomena contribute to the ability of animal groups to move coherently. Our systematic numerical simulations confirm that spontaneous interactions of elongated individuals can trigger oriented motion in small groups. They are, however, insufficient in larger ones, despite their significant imprint on the group's internal structure. It is also demonstrated that preferred directions of motion of a minority of group members can be communicated to others solely by mechanical interactions. These findings strengthen the link between pattern formation in active nematics and the collective decision making of social animals.

  14. Does interaction matter? Testing whether a confidence heuristic can replace interaction in collective decision-making.

    Science.gov (United States)

    Bang, Dan; Fusaroli, Riccardo; Tylén, Kristian; Olsen, Karsten; Latham, Peter E; Lau, Jennifer Y F; Roepstorff, Andreas; Rees, Geraint; Frith, Chris D; Bahrami, Bahador

    2014-05-01

    In a range of contexts, individuals arrive at collective decisions by sharing confidence in their judgements. This tendency to evaluate the reliability of information by the confidence with which it is expressed has been termed the 'confidence heuristic'. We tested two ways of implementing the confidence heuristic in the context of a collective perceptual decision-making task: either directly, by opting for the judgement made with higher confidence, or indirectly, by opting for the faster judgement, exploiting an inverse correlation between confidence and reaction time. We found that the success of these heuristics depends on how similar individuals are in terms of the reliability of their judgements and, more importantly, that for dissimilar individuals such heuristics are dramatically inferior to interaction. Interaction allows individuals to alleviate, but not fully resolve, differences in the reliability of their judgements. We discuss the implications of these findings for models of confidence and collective decision-making. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Strong CH/O interactions between polycyclic aromatic hydrocarbons and water: Influence of aromatic system size.

    Science.gov (United States)

    Veljković, Dušan Ž

    2018-03-01

    Energies of CH/O interactions between water molecule and polycyclic aromatic hydrocarbons with a different number of aromatic rings were calculated using ab initio calculations at MP2/cc-PVTZ level. Results show that an additional aromatic ring in structure of polycyclic aromatic hydrocarbons significantly strengthens CH/O interactions. Calculated interaction energies in optimized structures of the most stable tetracene/water complex is -2.27 kcal/mol, anthracene/water is -2.13 kcal/mol and naphthalene/water is -1.97 kcal/mol. These interactions are stronger than CH/O contacts in benzene/water complex (-1.44 kcal/mol) while CH/O contacts in tetracene/water complex are even stronger than CH/O contacts in pyridine/water complexes (-2.21 kcal/mol). Electrostatic potential maps for different polycyclic aromatic hydrocarbons were calculated and used to explain trends in the energies of interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. A model-independent description of few-body system with strong interaction

    International Nuclear Information System (INIS)

    Simenog, I.V.

    1985-01-01

    In this contribution, the authors discuss the formulation of equations that provide model-independent description of systems of three and more nucleons irrespective of the details of the interaction, substantiate the approach, estimate the correction terms with respect to the force range, and give basic qualitative results obtained by means of the model-independent procedure. They consider three nucleons in the doublet state (spin S=I/2) taking into account only S-interaction. The elastic nd-scattering amplitude may be found from the model-independent equations that follow from the Faddeev equations in the short-range-force limit. They note that the solutions of several model-independent equations and basic results obtained with the use of this approach may serve both as a standard solution and starting point in the discussion of various conceptions concerning the details of nuclear interactions

  17. Motion of Rydberg atoms with strong permanent-electric-dipole interactions

    International Nuclear Information System (INIS)

    Gonçalves, Luís Felipe; Thaicharoen, Nithiwadee; Raithel, Georg

    2016-01-01

    Using classical trajectories simulations, we investigate the dynamics of a cold sample of Rydberg atoms with high permanent electric dipole moments. The dipolar state can be created using an adiabatic passage through an avoided crossing between an S-like state and a linear Stark state. The simulations yield the pair-correlation functions (PCF) of the atom samples, which allow us to extract the motion of Rydberg-atom pairs in the many-body system. The results reveal the strength and the anisotropic character of the underlying interaction. The simulation is employed to test the suitability of experimental methods designed to derive interaction parameters from PCF. Insight is obtained about the stability of the method against variation of experimentally relevant parameters. Transient correlations due to interaction-induced heating are observed. (paper)

  18. Potential of future seismogenesis in Hebei Province (NE China) due to stress interactions between strong earthquakes

    Science.gov (United States)

    Karakostas, Vassilios; Papadimitriou, Eleftheria; Jin, Xueshen; Liu, Zhihui; Paradisopoulou, Parthena; He, Zhang

    2013-10-01

    Northeast China, a densely populated area, is affected by intense seismic activity, which includes large events that caused extensive disaster and tremendous loss of life. For contributing to the continuous efforts for seismic hazard assessment, the earthquake potential from the active faults near the cities of Zhangjiakou and Langfang in Hebei Province is examined. We estimate the effect of the coseismic stress changes of strong (M ⩾ 5.0) earthquakes on the major regional active faults, and mapped Coulomb stress change onto these target faults. More importantly our calculations reveal that positive stress changes caused by the largest events of the 1976 Tangshan sequence make the Xiadian and part of Daxing fault, thus considered the most likely sites of the next strong earthquake in the study area. The accumulated static stress changes that reached a value of up to 0.4 bar onto these faults, were subsequently incorporated in earthquake probability estimates for the next 30 years.

  19. RAMAN LIGHT SCATTERING IN PSEUDOSPIN-ELECTRON MODEL AT STRONG PSEUDOSPIN-ELECTRON INTERACTION

    Directory of Open Access Journals (Sweden)

    T.S.Mysakovych

    2004-01-01

    Full Text Available Anharmonic phonon contributions to Raman scattering in locally anharmonic crystal systems in the framework of the pseudospin-electron model with tunneling splitting of levels are investigated. The case of strong pseudospin-electron coupling is considered. Pseudospin and electron contributions to scattering are taken into account. Frequency dependences of Raman scattering intensity for different values of model parameters and for different polarization of scattering and incident light are investigated.

  20. Spectral asymptotics of a strong delta ' interaction on a planar loop

    Czech Academy of Sciences Publication Activity Database

    Exner, Pavel; Jex, M.

    2013-01-01

    Roč. 46, č. 34 (2013), s. 345201 ISSN 1751-8113 R&D Projects: GA ČR GAP203/11/0701 Institutional support: RVO:61389005 Keywords : Schrodinger operators * strong coupling asymptotics Subject RIV: BE - Theoretical Physics Impact factor: 1.687, year: 2013 http://iopscience.iop.org/1751-8121/46/34/345201/pdf/1751-8121_46_34_345201.pdf

  1. Periodicity and chaos in strongly perturbed classical orbitals for Coulomb interactions

    Energy Technology Data Exchange (ETDEWEB)

    Klar, H

    1986-01-01

    Within the framework of classical mechanics two prototypes of strongly perturbed orbitals, the diamagnetism in hydrogen and electronic double excitation, are analyzed near critical phase space points (fixed points). The motion of the hydrogen electron under the joint influence of the Coulomb field and the magnetic field is periodic for any field strengths. For a two-electron atom however the author finds a chaotic time evolution of the electron pair correlation, causing presumably irregular spectral patterns. (Auth.).

  2. Numerical investigation into strong axis bending shear interaction in rolled I-shaped steel sections

    NARCIS (Netherlands)

    Dekker, R.W.A.; Snijder, B.H.; Maljaars, J.

    2016-01-01

    Clause 6.2.8 of EN 1993-1-1 covers the design rules on bending-shear resistance, taking presence of shear into account by a reduced yield stress for the shear area. Numerical research on bending-shear interaction by means of the Abaqus Finite Element modelling soft-ware is presented. The numerical

  3. Numerical investigation into strong axis bending-shear interaction in rolled I-shaped steel sections

    NARCIS (Netherlands)

    Dekker, R.W.A.; Snijder, H.H.; Maljaars, J.; Dubina, Dan; Ungureanu, Viorel

    2016-01-01

    Clause 6.2.8 of EN 1993-1-1 covers the design rules on bending-shear resistance, taking presence of shear into account by a reduced yield stress for the shear area. Numerical research on bending-shear interaction by means of the Abaqus Finite Element modelling software is presented. The numerical

  4. Interaction of N-hydroxyurea with strong proton donors: HCl and HF

    International Nuclear Information System (INIS)

    Sałdyka, Magdalena

    2014-01-01

    Highlights: • 1:1 and 1:2 N-hydroxyurea complexes with HCl and HF are trapped in argon matrices. • The complexes are stabilized by strong X–H⋯O bond. • Hydrogen bonds in the cyclic 1:2 complexes show strong cooperativity. • The C=O group is the strongest proton acceptor centre in the N-hydroxyurea molecule. - Abstract: An infrared spectroscopic and MP2/6-311++G(2d,2p) study of strong hydrogen bonded complexes of N-hydroxyurea (NH 2 CONHOH) with hydrogen halides (HCl and HF) trapped in solid argon matrices is reported. 1:1 and 1:2 complexes between N-hydroxyurea and hydrogen chloride, hydrogen fluoride have been identified in the NH 2 CONHOH/HCl/Ar, NH 2 CONHOH/HF/Ar matrices, respectively; their structures were determined by comparison of the spectra with the results of calculations. In the 1:1 complexes, identified for both hydrogen halide molecules, the cyclic structure stabilized by the X–H⋯O and N–H⋯X bonds is present; for the NH 2 CONHOH⋯HF system another isomeric 1:1 complex is also observed. Two 1:2 complexes were identified for the N-hydroxyurea–hydrogen chloride system characterised by the Cl–H⋯O and N–H⋯Cl bonds. The results of the study evidence that N-hydroxyurea is an oxygen base in the gas-phase with the carbonyl group as the strongest proton acceptor centre in the molecule

  5. Interaction of N-hydroxyurea with strong proton donors: HCl and HF

    Energy Technology Data Exchange (ETDEWEB)

    Sałdyka, Magdalena, E-mail: magdalena.saldyka@chem.uni.wroc.pl

    2014-11-24

    Highlights: • 1:1 and 1:2 N-hydroxyurea complexes with HCl and HF are trapped in argon matrices. • The complexes are stabilized by strong X–H⋯O bond. • Hydrogen bonds in the cyclic 1:2 complexes show strong cooperativity. • The C=O group is the strongest proton acceptor centre in the N-hydroxyurea molecule. - Abstract: An infrared spectroscopic and MP2/6-311++G(2d,2p) study of strong hydrogen bonded complexes of N-hydroxyurea (NH{sub 2}CONHOH) with hydrogen halides (HCl and HF) trapped in solid argon matrices is reported. 1:1 and 1:2 complexes between N-hydroxyurea and hydrogen chloride, hydrogen fluoride have been identified in the NH{sub 2}CONHOH/HCl/Ar, NH{sub 2}CONHOH/HF/Ar matrices, respectively; their structures were determined by comparison of the spectra with the results of calculations. In the 1:1 complexes, identified for both hydrogen halide molecules, the cyclic structure stabilized by the X–H⋯O and N–H⋯X bonds is present; for the NH{sub 2}CONHOH⋯HF system another isomeric 1:1 complex is also observed. Two 1:2 complexes were identified for the N-hydroxyurea–hydrogen chloride system characterised by the Cl–H⋯O and N–H⋯Cl bonds. The results of the study evidence that N-hydroxyurea is an oxygen base in the gas-phase with the carbonyl group as the strongest proton acceptor centre in the molecule.

  6. Strong electron-phonon interaction in the high-Tc superconductors: Evidence from the infrared

    International Nuclear Information System (INIS)

    Timusk, T.; Porter, C.D.; Tanner, D.B.

    1991-01-01

    We show that low-frequency structure in the infrared reflectance of the high-temperature superconductor YBa 2 Cu 3 O 7 results from the electron-phonon interaction. Characteristic antiresonant line shapes are seen in the phonon region of the spectrum and the frequency-dependent scattering rate of the mid-infrared electronic continuum has peaks at 150 cm -1 (19 meV) and at 360 cm -1 (45 meV) in good agreement with phonon density-of-states peaks in neutron time-of-flight spectra that develop in superconducting samples. The interaction between the phonons and the charge carriers can be understood in terms of a charged-phonon model

  7. Exchange interaction of strongly anisotropic tripodal erbium single-ion magnets with metallic surfaces

    DEFF Research Database (Denmark)

    Dreiser, Jan; Wäckerlin, Christian; Ali, Md. Ehesan

    2014-01-01

    We present a comprehensive study of Er(trensal) single-ion magnets deposited in ultrahigh vacuum onto metallic surfaces. X-ray photoelectron spectroscopy reveals that the molecular structure is preserved after sublimation, and that the molecules are physisorbed on Au(111) while they are chemisorbed...... on a Ni thin film on Cu(100) single-crystalline surfaces. X-ray magnetic circular dichroism (XMCD) measurements performed on Au(111) samples covered with molecular monolayers held at temperatures down to 4 K suggest that the easy axes of the strongly anisotropic molecules are randomly oriented...... pathways toward optical addressing of surface-deposited single-ion magnets....

  8. CLEO-c and CESR-c: A new frontier in strong and weak interactions

    Energy Technology Data Exchange (ETDEWEB)

    Richichi, Stephen J

    2003-06-01

    We report on the physics potential of a charm and QCD factory, based on a proposal for the conversion of the existing CESR machine and CLEO detector: ''CESR-c and OLEO-c''. Such a facility will make major contributions to the field of quark flavor physics in this decade. It may also provide the best chance for understanding non-perturbative QCD, which is essential to understanding the strongly-coupled sectors of the new physics that lies beyond the Standard Model.

  9. CLEO-c and CESR-c: A new frontier in strong and weak interactions

    Science.gov (United States)

    Richichi, Stephen J.

    2003-06-01

    We report on the physics potential of a charm and QCD factory, based on a proposal for the conversion of the existing CESR machine and CLEO detector: "CESR-c and OLEO-c". Such a facility will make major contributions to the field of quark flavor physics in this decade. It may also provide the best chance for understanding non-perturbative QCD, which is essential to understanding the strongly-coupled sectors of the new physics that lies beyond the Standard Model.

  10. CLEO-c and CESR-c: A new frontier in strong and weak interactions

    International Nuclear Information System (INIS)

    Richichi, Stephen J.

    2003-01-01

    We report on the physics potential of a charm and QCD factory, based on a proposal for the conversion of the existing CESR machine and CLEO detector: ''CESR-c and OLEO-c''. Such a facility will make major contributions to the field of quark flavor physics in this decade. It may also provide the best chance for understanding non-perturbative QCD, which is essential to understanding the strongly-coupled sectors of the new physics that lies beyond the Standard Model

  11. Two-Fluid Description of Wave-Particle Interactions in Strong Buneman Turbulence

    OpenAIRE

    Che, H.

    2014-01-01

    To understand the nature of anomalous resistivity in magnetic reconnection, we investigate turbulence-induced momentum transport and energy dissipation while a plasma is unstable to the Buneman instability in force-free current sheets. Using 3D particle-in-cell simulations, we find that the macroscopic effects generated by wave-particle interactions in Buneman instability can be approximately described by a set of electron fluid equations. We show that both energy dissipation and momentum tra...

  12. Second sound in a two-dimensional Bose gas: From the weakly to the strongly interacting regime

    Science.gov (United States)

    Ota, Miki; Stringari, Sandro

    2018-03-01

    Using Landau's theory of two-fluid hydrodynamics, we investigate first and second sounds propagating in a two-dimensional (2D) Bose gas. We study the temperature and interaction dependence of both sound modes and show that their behavior exhibits a deep qualitative change as the gas evolves from the weakly interacting to the strongly interacting regime. Special emphasis is placed on the jump of both sounds at the Berezinskii-Kosterlitz-Thouless transition, caused by the discontinuity of the superfluid density. We find that the excitation of second sound through a density perturbation becomes weaker and weaker as the interaction strength increases as a consequence of the decrease in the thermal expansion coefficient. Our results could be relevant for future experiments on the propagation of sound on the Bose-Einstein condensate (BEC) side of the BCS-BEC crossover of a 2D superfluid Fermi gas.

  13. Final Report - Composite Fermion Approach to Strongly Interacting Quasi Two Dimensional Electron Gas Systems

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, John

    2009-11-30

    Work related to this project introduced the idea of an effective monopole strength Q* that acted as the effective angular momentum of the lowest shell of composite Fermions (CF). This allowed us to predict the angular momentum of the lowest band of energy states for any value of the applied magnetic field simply by determining N{sub QP} the number of quasielectrons (QE) or quasiholes (QH) in a partially filled CF shell and adding angular momenta of the N{sub QP} Fermions excitations. The approach reported treated the filled CF level as a vacuum state which could support QE and QH excitations. Numerical diagonalization of small systems allowed us to determine the angular momenta, the energy, and the pair interaction energies of these elementary excitations. The spectra of low energy states could then be evaluated in a Fermi liquid-like picture, treating the much smaller number of quasiparticles and their interactions instead of the larger system of N electrons with Coulomb interactions.

  14. Aspects of the flipped unification of strong, weak and electromagnetic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, J.; Hagelin, J.S.; Kelley, S.; Nanopoulos, D.V.

    1988-12-19

    We explore phenomenological aspects of a recently proposed flipped SU(5) x U(1) supersymmetric GUT which incorporates an economical and natural mechanism for splitting Higgs doublets and triplets, and can be derived from string theory. Using experimental values of sin/sup 2/theta/sub W/ and the strong QCD coupling, we estimate the grand unification scale M/sub G/, where the strong and weak coupling strengths are equal, and the superunification scale M/sub SU/, where all couplings are equal. We find typical values of M/sub G/ approx. = 10/sup 15/ to 10/sup 17/ GeV, with M/sub SU/ somewhat higher and close to the value suggested by string models. We discuss different mechanisms for baryon decay, finding that the dominant one is gauge-boson exchange giving rise to p -> e/sup +/ /sup 0/, anti /sup +/ and n -> e/sup +/ /sup -/, anti /sup 0/ with partial lifetimes approx. = 10/sup 35+-2/ y. We show that a large GUT symmetry-breaking scale M/sub G/ is naturally generated by radiative corrections to the effective potential if a small amount approx. = m/sub W/ of soft supersymmetry breaking is generated dynamically at a large scale. We analyze the low-energy effective theory obtained using the renormalization group equations, demonstrating that electroweak symmetry breaking is obtained if m/sub t/ approx. = 60 to 90 GeV. We analyze the spectrum of sparticles, with particular attention to neutralinos.

  15. Dynamics of bleomycin interaction with a strongly bound hairpin DNA substrate, and implications for cleavage of the bound DNA.

    Science.gov (United States)

    Bozeman, Trevor C; Nanjunda, Rupesh; Tang, Chenhong; Liu, Yang; Segerman, Zachary J; Zaleski, Paul A; Wilson, W David; Hecht, Sidney M

    2012-10-31

    Recent studies involving DNAs bound strongly by bleomycins have documented that such DNAs are degraded by the antitumor antibiotic with characteristics different from those observed when studying the cleavage of randomly chosen DNAs in the presence of excess Fe·BLM. In the present study, surface plasmon resonance has been used to characterize the dynamics of BLM B(2) binding to a strongly bound hairpin DNA, to define the effects of Fe(3+), salt, and temperature on BLM-DNA interaction. One strong primary DNA binding site, and at least one much weaker site, were documented. In contrast, more than one strong cleavage site was found, an observation also made for two other hairpin DNAs. Evidence is presented for BLM equilibration between the stronger and weaker binding sites in a way that renders BLM unavailable to other, less strongly bound DNAs. Thus, enhanced binding to a given site does not necessarily result in increased DNA degradation at that site; i.e., for strongly bound DNAs, the facility of DNA cleavage must involve other parameters in addition to the intrinsic rate of C-4' H atom abstraction from DNA sugars.

  16. Metastability and avalanche dynamics in strongly correlated gases with long-range interactions

    Science.gov (United States)

    Hruby, Lorenz; Dogra, Nishant; Landini, Manuele; Donner, Tobias; Esslinger, Tilman

    2018-03-01

    We experimentally study the stability of a bosonic Mott insulator against the formation of a density wave induced by long-range interactions and characterize the intrinsic dynamics between these two states. The Mott insulator is created in a quantum degenerate gas of 87-Rubidium atoms, trapped in a 3D optical lattice. The gas is located inside and globally coupled to an optical cavity. This causes interactions of global range, mediated by photons dispersively scattered between a transverse lattice and the cavity. The scattering comes with an atomic density modulation, which is measured by the photon flux leaking from the cavity. We initialize the system in a Mott-insulating state and then rapidly increase the global coupling strength. We observe that the system falls into either of two distinct final states. One is characterized by a low photon flux, signaling a Mott insulator, and the other is characterized by a high photon flux, which we associate with a density wave. Ramping the global coupling slowly, we observe a hysteresis loop between the two states—a further signature of metastability. A comparison with a theoretical model confirms that the metastability originates in the competition between short- and global-range interactions. From the increasing photon flux monitored during the switching process, we find that several thousand atoms tunnel to a neighboring site on the timescale of the single-particle dynamics. We argue that a density modulation, initially forming in the compressible surface of the trapped gas, triggers an avalanche tunneling process in the Mott-insulating region.

  17. Gravity as a dynamical consequence of the strong, weak, and electromagnetic interactions

    International Nuclear Information System (INIS)

    Zee, A.

    1981-12-01

    A coherent and reasonable account of gravitational physics is shown to be possible. The three non-gravitational interactions are described by a scale and conformal invariant and asymptotically free Yang-Mills theory with massless fermions. Conformal invariance is required so that the gravitational sector of the theory is given by the Weyl action. The theory is renormalizable and has a unitary S-matrix. Possible breakdown of causality is observable only at the Planck length. In this theory, Einstein's theory of gravity is induced as an effective long-distance theory. An R 2 term is also induced with a finite and physically desired sign

  18. Probing non nucleonic degrees of freedom with strong and electromagnetic interactions

    International Nuclear Information System (INIS)

    Frois, B.

    1985-10-01

    In this talk, I would like to examine our present view on non-nucleonic degrees of freedom with a few typical experimental results obtained recently both with hadronic and electromagnetic probes at intermediate energies. It is the first generation of experimental data which has probed mesonic degrees of freedom with a spatial resolution of the order of 0.5 fm. This has made possible for example the measurement of the size of the pion-nucleon interaction region. This is very stimulating progress and we begin to have a coherent overview on the various reaction mechanisms which are induced by hadronic and electromagnetic probes

  19. Stability condition of a strongly interacting boson-fermion mixture across an interspecies Feshbach resonance

    International Nuclear Information System (INIS)

    Yu Zengqiang; Zhai Hui; Zhang Shizhong

    2011-01-01

    We study the properties of dilute bosons immersed in a single-component Fermi sea across a broad boson-fermion Feshbach resonance. The stability of the mixture requires that the bare interaction between bosons exceeds a critical value, which is a universal function of the boson-fermion scattering length, and exhibits a maximum in the unitary region. We calculate the quantum depletion, momentum distribution, and the boson contact parameter across the resonance. The transition from condensate to molecular Fermi gas is also discussed.

  20. Communication: An adaptive configuration interaction approach for strongly correlated electrons with tunable accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Schriber, Jeffrey B.; Evangelista, Francesco A. [Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322 (United States)

    2016-04-28

    We introduce a new procedure for iterative selection of determinant spaces capable of describing highly correlated systems. This adaptive configuration interaction (ACI) determines an optimal basis by an iterative procedure in which the determinant space is expanded and coarse grained until self-consistency. Two importance criteria control the selection process and tune the ACI to a user-defined level of accuracy. The ACI is shown to yield potential energy curves of N{sub 2} with nearly constant errors, and it predicts singlet-triplet splittings of acenes up to decacene that are in good agreement with the density matrix renormalization group.

  1. Divalent Ion Parameterization Strongly Affects Conformation and Interactions of an Anionic Biomimetic Polymer

    Energy Technology Data Exchange (ETDEWEB)

    Daily, Michael D.; Baer, Marcel D.; Mundy, Christopher J.

    2016-03-10

    The description of peptides and the use of molecular dynamics simulations to refine structures and investigate the dynamics on an atomistic scale are well developed. Through a consensus in this community over multiple decades, parameters were developed for molecular interactions that only require the sequence of amino-acids and an initial guess for the three-dimensional structure. The recent discovery of peptoids will require a retooling of the currently available interaction potentials in order to have the same level of confidence in the predicted structures and pathways as there is presently in the peptide counterparts. Here we present modeling of peptoids using a combination of ab initio molecular dynamics (AIMD) and atomistic resolution classical forcefield (FF) to span the relevant time and length scales. To properly account for the dominant forces that stabilize ordered structures of peptoids, namely steric-, electrostatic, and hydrophobic interactions mediated through sidechain-sidechain interactions in the FF model, those have to be first mapped out using high fidelity atomistic representations. A key feature here is not only to use gas phase quantum chemistry tools, but also account for solvation effects in the condensed phase through AIMD. One major challenge is to elucidate ion binding to charged or polar regions of the peptoid and its concomitant role in the creation of local order. Here, similar to proteins, a specific ion effect is observed suggesting that both the net charge and the precise chemical nature of the ion will need to be described. MDD was supported by MS3 (Materials Synthesis and Simulation Across Scales) Initiative at Pacific Northwest National Laboratory. Research was funded by the Laboratory Directed Research and Development program at Pacific Northwest National Laboratory. MDB acknowledges support from US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Material & Engineering. CJM acknowledges

  2. Use of Synergistic Interactions to Fabricate Strong, Tough, and Conductive Artificial Nacre Based on Graphene Oxide and Chitosan.

    Science.gov (United States)

    Wan, Sijie; Peng, Jingsong; Li, Yuchen; Hu, Han; Jiang, Lei; Cheng, Qunfeng

    2015-10-27

    Graphene is the strongest and stiffest material, leading to the development of promising applications in many fields. However, the assembly of graphene nanosheets into macrosized nanocomposites for practical applications remains a challenge. Nacre in its natural form sets the "gold standard" for toughness and strength, which serves as a guide to the assembly of graphene nanosheets into high-performance nanocomposites. Here we show the strong, tough, conductive artificial nacre based on graphene oxide through synergistic interactions of hydrogen and covalent bonding. Tensile strength and toughness was 4 and 10 times higher, respectively, than that of natural nacre. The exceptional integrated strong and tough artificial nacre has promising applications in aerospace, artificial muscle, and tissue engineering, especially for flexible supercapacitor electrodes due to its high electrical conductivity. The use of synergistic interactions is a strategy for the development of high-performance nanocomposites.

  3. Equilibration of a strongly interacting plasma: holographic analysis of local and nonlocal probes

    Directory of Open Access Journals (Sweden)

    Bellantuono Loredana

    2016-01-01

    Full Text Available The relaxation of a strongly coupled plasma towards the hydrodynamic regime is studied by analyzing the evolution of local and nonlocal observables in the holographic approach. The system is driven in an initial anisotropic and far-from equilibrium state through an impulsive time-dependent deformation (quench of the boundary spacetime geometry. Effective temperature and entropy density are related to the position and area of a black hole horizon, which has formed as a consequence of the distortion. The behavior of stress-energy tensor, equal-time correlation functions and Wilson loops of different shapes is examined, and a hierarchy among their thermalization times emerges: probes involving shorter length scales thermalize faster.

  4. Nonlinear interaction of charged particles with strong laser pulses in a gaseous media

    Directory of Open Access Journals (Sweden)

    H. K. Avetissian

    2007-07-01

    Full Text Available The charged particles nonlinear dynamics in the field of a strong electromagnetic wave pulse of finite duration and certain form of the envelope, in the refractive medium with a constant and variable refraction indexes, is investigated by means of numerical integration of the classical relativistic equations of motion. The particle energy dependence on the pulse intensity manifests the nonlinear threshold phenomenon of a particle reflection and capture by actual laser pulses in dielectric-gaseous media that takes place for a plane electromagnetic wave in the induced Cherenkov process. Laser acceleration of the particles in the result of the reflection from the pulse envelope and in the capture regime with the variable refraction index along the pulse propagation direction is investigated.

  5. Electromagnetic soliton production during interaction of relativistically strong laser pulses with plasma

    International Nuclear Information System (INIS)

    Bulanov, S.V.; Esirkepov, T.Zh.; Kamenets, F.F.; Naumova, N.M.

    1995-01-01

    The paper presents the results of a numeric modelling of the propagation of ultra short relativistically strong laser pulses in a rarefied plasma by the 'particle in cell'. Primary attention is paid to the process of the formation of electromagnetic solitons which can not be described in the approximation of envelopes. It is found that under certain conditions a significant portion of pulse energy can transform is solitons. The soliton excitation mechanism is related to a decrease of local frequency of electromagnetic radiation due to the generation of wave plasma waves. From one soliton to a stub of solitons can be generated in the wake of a relatively long pulse depending on the parameters of laser pulse in plasma. Particles are effectively accelerated forwards radiation propagation in the electric field of wake plasma waves. 22 refs., 7 figs

  6. Strongly coupled interaction between a ridge of fluid and an inviscid airflow

    KAUST Repository

    Paterson, C.

    2015-07-01

    © 2015 AIP Publishing LLC. The behaviour of a steady thin sessile or pendent ridge of fluid on an inclined planar substrate which is strongly coupled to the external pressure gradient arising from an inviscid airflow parallel to the substrate far from the ridge is described. When the substrate is nearly horizontal, a very wide ridge can be supported against gravity by capillary and/or external pressure forces; otherwise, only a narrower (but still wide) ridge can be supported. Classical thin-aerofoil theory is adapted to obtain the governing singular integro-differential equation for the profile of the ridge in each case. Attention is focused mainly on the case of a very wide sessile ridge. The effect of strengthening the airflow is to push a pinned ridge down near to its edges and to pull it up near to its middle. At a critical airflow strength, the upslope contact angle reaches the receding contact angle at which the upslope contact line de-pins, and continuing to increase the airflow strength beyond this critical value results in the de-pinned ridge becoming narrower, thicker, and closer to being symmetric in the limit of a strong airflow. The effect of tilting the substrate is to skew a pinned ridge in the downslope direction. Depending on the values of the advancing and receding contact angles, the ridge may first de-pin at either the upslope or the downslope contact line but, in general, eventually both contact lines de-pin. The special cases in which only one of the contact lines de-pins are also considered. It is also shown that the behaviour of a very wide pendent ridge is qualitatively similar to that of a very wide sessile ridge, while the important qualitative difference between the behaviour of a very wide ridge and a narrower ridge is that, in general, for the latter one or both of the contact lines may never de-pin.

  7. Electron-Ion Beam Coupling Through Collective Interactions

    National Research Council Canada - National Science Library

    Wheelock, Adrian; Cooke, David L; Gatsonis, Nikolaos A

    2006-01-01

    .... It is shown that Coulomb collisions, which can act to match velocities through strong ion-electron collisions between particles with low relative velocities, are far too slow to explain the phenomenon...

  8. Tunable self-assembled spin chains of strongly interacting cold atoms for demonstration of reliable quantum state transfer

    DEFF Research Database (Denmark)

    Loft, N. J. S.; Marchukov, O. V.; Petrosyan, D.

    2016-01-01

    We have developed an efficient computational method to treat long, one-dimensional systems of strongly-interacting atoms forming self-assembled spin chains. Such systems can be used to realize many spin chain model Hamiltonians tunable by the external confining potential. As a concrete...... demonstration, we consider quantum state transfer in a Heisenberg spin chain and we show how to determine the confining potential in order to obtain nearly-perfect state transfer....

  9. Effective collision frequency method in the theory of the conductivity of Coulomb systems. II. Strong interion interaction and plasma structure

    International Nuclear Information System (INIS)

    Bobrov, V.B.; Triger, S.A.

    1994-01-01

    The effective collision frequency method developed earlier by the authors for Coulomb systems characterized by strong interion interaction is developed further. An explicit expression is obtained for the effective electron collision frequency on the basis of the exact diagram representation obtained in Part I and the use of the model of a one-component plasma as initial approximation. The description of plasma structure in the corresponding approximation is considered. 25 refs

  10. Electrical Control of Structural and Physical Properties via Strong Spin-Orbit Interactions in Sr2IrO4

    Science.gov (United States)

    Cao, G.; Terzic, J.; Zhao, H. D.; Zheng, H.; De Long, L. E.; Riseborough, Peter S.

    2018-01-01

    Electrical control of structural and physical properties is a long-sought, but elusive goal of contemporary science and technology. We demonstrate that a combination of strong spin-orbit interactions (SOI) and a canted antiferromagnetic Mott state is sufficient to attain that goal. The antiferromagnetic insulator Sr2IrO4 provides a model system in which strong SOI lock canted Ir magnetic moments to IrO6 octahedra, causing them to rigidly rotate together. A novel coupling between an applied electrical current and the canting angle reduces the Néel temperature and drives a large, nonlinear lattice expansion that closely tracks the magnetization, increases the electron mobility, and precipitates a unique resistive switching effect. Our observations open new avenues for understanding fundamental physics driven by strong SOI in condensed matter, and provide a new paradigm for functional materials and devices.

  11. The quadrupole moment and strong interaction parameters from muonic and pionic X-ray studies of 237Np

    International Nuclear Information System (INIS)

    Laat, C.T.A.M. de; Taal, A.; Duinker, W.; Konijn, J.; Petitjean, C.; Reist, H.W.; Mueller, W.; Commission of the European Communities, Geel

    1987-01-01

    The X-ray spectrum of muonic and pionic 237 Np has been investigated with muons and pions stopped in a NpO 2 target. The nuclear spectroscopic quadrupole moment was determined to be Q=3.886±0.006 b from the splittings of the muonic 5g→4f hyperfine complexes. The B(E2)↓-values for the first and second excited states were evaluated as 3.17±0.08 and 2.77±0.10 e 2 b 2 , respectively. A comparison between the muonic and pionic 5g→4f hyperfine complexes yields the strong interaction parameter for the pionic 4f state. For the first time a change of sign as function of Z for the strong interaction quadrupole shift ε 2 (4f) has been observed. The standard optical model predictions agree reasonably well with the measured strong interaction monopole shift, ε 0 (4f), and width, Γ 0 (4f), while they disagree with the experimental value for ε 2 . A stronger s-wave repulsion in the optical potential could explain this effect. (orig.)

  12. Inclusion of the strong interaction in low-energy hydrogen-antihydrogen scattering using a complex potential

    International Nuclear Information System (INIS)

    Armour, E A G; Liu, Y; Vigier, A

    2005-01-01

    The aim of experimentalists currently working on the preparation of antihydrogen is to trap it at very low temperatures so that its properties can be studied. Any process that can lead to loss of antihydrogen is thus of great concern to them. In view of this, we have carried out a calculation of the antiproton annihilation cross section in very low-energy hydrogen-antihydrogen scattering using a complex potential to represent the strong interaction that brings about the annihilation. The potential takes into account the isotopic spin state of the proton and the antiproton and the possibility that they may be in either a singlet or a triplet spin state. The results for the annihilation cross section and the percentage change in the elastic cross section due to the inclusion of the strong interaction are similar to those obtained in a recent calculation (Jonsell et al 2004 J. Phys. B: At. Mol. Opt. Phys. 37 1195), using an effective range expansion. They are smaller by a factor of 2 and 3, respectively, than those obtained in an earlier calculation (Voronin and Carbonell 2001 Nucl. Phys. A 689 529c), using a coupled channel method and a complex strong interaction potential. (letter to the editor)

  13. Explaining the large numbers by a hierarchy of ''universes'': a unified theory of strong and gravitational interactions

    International Nuclear Information System (INIS)

    Caldirola, P.; Recami, E.

    1978-01-01

    By assuming covariance of physical laws under (discrete) dilatations, strong and gravitational interactions have been described in a unified way. In terms of the (additional, discrete) ''dilatational'' degree of freedom, our cosmos as well as hadrons can be considered as different states of the same system, or rather as similar systems. Moreover, a discrete hierarchy can be defined of ''universes'' which are governed by force fields with strengths inversely proportional to the ''universe'' radii. Inside each ''universe'' an equivalence principle holds, so that its characteristic field can be geometrized there. It is thus easy to derive a whole ''numerology'', i.e. relations among numbers analogous to the so-called Weyl-Eddington-Dirac ''large numbers''. For instance, the ''Planck mass'' happens to be nothing but the (average) magnitude of the strong charge of the hadron quarks. However, our ''numerology'' connects the (gravitational) macrocosmos with the (strong) microcosmos, rather than with the electromagnetic ones (as, e.g., in Dirac's version). Einstein-type scaled equations (with ''cosmological'' term) are suggested for the hadron interior, which - incidentally - yield a (classical) quark confinement in a very natural way and are compatible with the ''asymptotic freedom''. At last, within a ''bi-scale'' theory, further equations are proposed that provide a priori a classical field theory of strong interactions (between different hadrons). The relevant sections are 5.2, 7 and 8. (author)

  14. On a low energy, strong interaction model, unifying mesons and baryons

    International Nuclear Information System (INIS)

    Kalafatis, D.

    1993-03-01

    This thesis is concerned with the study of a unified theory of mesons and baryons. An effective Lagrangian with the low mass mesons, generalizing the Skyrme model, is constructed. The vector meson fields are introduced as gauge fields in the linear sigma model instead of the non linear sigma model. Topological soliton solutions of the model are examined and the nucleon-nucleon interaction in the product approximation is investigated. The leading correction to the classical skyrmion mass, the Casimir energy, is evaluated. The problem of the stability of topological solitons when vector fields enter the chiral Lagrangian is also studied. It is shown that the soliton is stable in very much the same way as with the ωmeson and that peculiar classical doublet solutions do not exist

  15. RADIO AND X-RAY OBSERVATIONS OF SN 2006jd: ANOTHER STRONGLY INTERACTING TYPE IIn SUPERNOVA

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, Poonam [Department of Physics, Royal Military College of Canada, Kingston, ON K7K 7B4 (Canada); Chevalier, Roger A.; Irwin, Christopher M. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Chugai, Nikolai [Institute of Astronomy of Russian Academy of Sciences, Pyatnitskaya Street 48, 109017 Moscow (Russian Federation); Fransson, Claes [Department of Astronomy, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Soderberg, Alicia M. [Smithsonian Astrophysical Observatory, 60 Garden Street, MS-20, Cambridge, MA 02138 (United States); Chakraborti, Sayan [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Colaba, Mumbai 400005 (India); Immler, Stefan, E-mail: Poonam.Chandra@rmc.ca [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2012-08-20

    We report four years of radio and X-ray monitoring of the Type IIn supernova SN 2006jd at radio wavelengths with the Very Large Array, Giant Metrewave Radio Telescope, and Expanded Very Large Array; at X-ray wavelengths with Chandra, XMM-Newton, and Swift-XRT. We assume that the radio and X-ray emitting particles are produced by shock interaction with a dense circumstellar medium. The radio emission shows an initial rise that can be attributed to free-free absorption by cool gas mixed into the nonthermal emitting region; external free-free absorption is disfavored because of the shape of the rising light curves and the low gas column density inferred along the line of sight to the emission region. The X-ray luminosity implies a preshock circumstellar density {approx}10{sup 6} cm{sup -3} at a radius r {approx} 2 Multiplication-Sign 10{sup 16} cm, but the column density inferred from the photoabsorption of X-rays along the line of sight suggests a significantly lower density. The implication may be an asymmetry in the interaction. The X-ray spectrum shows Fe line emission at 6.9 keV that is stronger than is expected for the conditions in the X-ray emitting gas. We suggest that cool gas mixed into the hot gas plays a role in the line emission. Our radio and X-ray data both suggest the density profile is flatter than r{sup -2} because of the slow evolution of the unabsorbed emission.

  16. Interaction of N-hydroxyurea with strong proton donors: HCl and HF

    Science.gov (United States)

    Sałdyka, Magdalena

    2014-11-01

    An infrared spectroscopic and MP2/6-311++G(2d,2p) study of strong hydrogen bonded complexes of N-hydroxyurea (NH2CONHOH) with hydrogen halides (HCl and HF) trapped in solid argon matrices is reported. 1:1 and 1:2 complexes between N-hydroxyurea and hydrogen chloride, hydrogen fluoride have been identified in the NH2CONHOH/HCl/Ar, NH2CONHOH/HF/Ar matrices, respectively; their structures were determined by comparison of the spectra with the results of calculations. In the 1:1 complexes, identified for both hydrogen halide molecules, the cyclic structure stabilized by the X-H⋯O and N-H⋯X bonds is present; for the NH2CONHOH⋯HF system another isomeric 1:1 complex is also observed. Two 1:2 complexes were identified for the N-hydroxyurea-hydrogen chloride system characterised by the Cl-H⋯O and N-H⋯Cl bonds. The results of the study evidence that N-hydroxyurea is an oxygen base in the gas-phase with the carbonyl group as the strongest proton acceptor centre in the molecule.

  17. Inelastic strong interactions at high energies. Annual progress report, June 1, 1979-May 1, 1980

    International Nuclear Information System (INIS)

    Suranyi, P.

    1980-02-01

    Investigations in the area of Grand Unified Field Theories were begun. Various ways of breaking the SU(5) symmetric theory of Georgi and Glashow were studied. As usual, an approx. 24 of Higgs breaks the symmetry from SU(5) to SU(3)/sub c/xSU(2)xU(1). It was found that an approx. 45 of Higgs is acceptable for breaking the symmetry from SU(3)/sub c/xSU(2)xU(1) to SU(3)/sub c/xU(1)/sub em/. In addition phenomenologically correct quark-lepton mass ratios are obtained by use of renormalization-group techniques if there are 6 generations of particles in the theory. Efforts directed at the development of approximate methods for extracting information from quantum field theories were continued. The quantum mechanics of polynomial potentials as a model for quantum field theories was investigated. A perturbation expansion for the energy levels and wave functions was constructed and has been proven to be convergent for arbitrary values of the coupling constants, in contrast to ordinary perturbation expansions that have a zero radius of convergence. The physical significance of the new perturbation expansions was explored both in the weak and strong coupling limits

  18. Polysaccharide fraction from higher plants which strongly interacts with the cytosolic phosphorylase isozyme. I. Isolation and characterization

    International Nuclear Information System (INIS)

    Yang, Yi; Steup, M.

    1990-01-01

    From leaves of Spinacia oleracea L. or from Pisum sativum L. and from cotyledons of germinating pea seeds a high molecular weight polysaccharide fraction was isolated. The apparent size of the fraction, as determined by gel filtration, was similar to that of dextran blue. Following acid hydrolysis the monomer content of the polysaccharide preparation was studied using high pressure liquid and thin layer chromatography. Glucose, galactose, arabinose, and ribose were the main monosaccharide compounds. The native polysaccharide preparation interacted strongly with the cytosolic isozyme of phosphorylase (EC 2.4.1.1). Interaction with the plastidic phosphorylase isozyme(s) was by far weaker. Interaction with the cytosolic isozyme was demonstrated by affinity electrophoresis, kinetic measurements, and by 14 C-labeling experiments in which the glucosyl transfer from [ 14 C]glucose 1-phosphate to the polysaccharide preparation was monitored

  19. Strong-coupling superconductivity in the two-dimensional t-J model supplemented by a hole-phonon interaction

    International Nuclear Information System (INIS)

    Sherman, A.; Schreiber, M.

    1995-01-01

    We use the Eliashberg formalism for calculating T c in a model of cuprate perovskites with pairing mediated by both magnons and apex-oxygen vibrations. The influence of strong correlations on the energy spectrum is taken into account in the spin-wave approximation. It is shown that the hole-magnon interaction alone cannot yield high T c . But together with a moderate hole-phonon interaction it does lead to d-wave superconductivity at temperatures and hole concentrations observed in cuprates. High T c are connected with a large density of states due to extended Van Hove singularities, a conformity of the two interactions for the d symmetry, and high phonon frequencies

  20. Flutter-by Interactive Butterfly Using interactivity to excite and educate children about butterflies and the National Museum of Play at The Strong's Dancing Wings Butterfly Garden

    Science.gov (United States)

    Powers, Lydia

    The National Museum of Play at The Strong's Dancing Wings Butterfly Garden is a tropical rainforest that allows visitors to step into the world of butterflies, but lacks a more comprehensive educational element to teach visitors additional information about butterflies. Flutter-by Interactive Butterfly is a thesis project designed to enhance younger visitors' experience of the Dancing Wings Butterfly Garden with an interactive educational application that aligns with The Strong's mission of encouraging learning, creativity, and discovery. This was accomplished through a series of fun and educational games and animations, designed for use as a kiosk outside the garden and as a part of The Strong's website. Content, planning, and organization of this project has been completed through research and observation of the garden in the following areas: its visitors, butterflies, best usability practices for children, and game elements that educate and engage children. Flutter-by Interactive Butterfly teaches users about the butterfly's life cycle, anatomy, and characteristics as well as their life in the Dancing Wings Butterfly Garden. Through the use of the design programs Adobe Illustrator, Flash, and After Effects; the programming language ActionScript3.0; a child-friendly user interface and design; audio elements and user takeaways, Flutter-by Interactive Butterfly appeals to children of all ages, interests, and learning styles. The project can be viewed at lydiapowers.com/Thesis/FlutterByButterfly.html

  1. managing hiv as a chronic disease: using interactive data collection ...

    African Journals Online (AJOL)

    Enrique

    2004-11-02

    Nov 2, 2004 ... Clinical Director, Reproductive Health Research Unit, University of the Witwatersrand, Johannesburg ... In the Chronic Care Model described by Ed Wagner,11 this interaction can be ... pharmacists re-enter demographic.

  2. Exploring effects of strong interactions in enhancing masses of dynamical origin

    International Nuclear Information System (INIS)

    Cabo Montes de Oca, Alejandro

    2011-01-01

    A previous study of the dynamical generation of masses in massless QCD is considered from another viewpoint. The quark mass is assumed to have a dynamical origin and is substituted for by a scalar field without self-interaction. The potential for the new field background is evaluated up to two loops. Expressing the running coupling in terms of the scale parameter μ, the potential minimum is chosen to fix m top =175 GeV when μ 0 =498 MeV. The second derivative of the potential predicts a scalar field mass of 126.76 GeV. This number is close to the value 114 GeV, which preliminary data taken at CERN suggested to be associated with the Higgs particle. However, the simplifying assumptions limit the validity of the calculations done, as indicated by the large value of α=(g 2 )/(4π)=1.077 obtained. However, supporting statements about the possibility of improving the scheme come from the necessary inclusion of weak and scalar field couplings and mass counterterms in the renormalization procedure, in common with the seemingly needed consideration of the massive W and Z fields, if the real conditions of the SM model are intended to be approached. (orig.)

  3. Some issues linked to the description of systems in strong interaction

    International Nuclear Information System (INIS)

    Theussl, L.

    2001-06-01

    In the first part of this work we have dealt with some issues that are relevant in the area of nucleonic resonances within different constituent quark models. In this context we have concentrated on the theoretical description of Pi and Nu decays for N and Delta resonances. The results obtained point to the necessity of a more microscopic description of the dynamics which is at the same time responsible for the binding of quarks inside baryons and the decay of the latter ones. In the second part we have contributed to the study of crossed two-boson exchanges in the Bethe-Salpeter equation as well as to the investigation of different three-dimensional approaches that follow from the Bethe-Salpeter equation in a certain non-relativistic reduction scheme. These one include in particular an equation whose interaction depends on the total energy of the system. It was shown that such an equation is able to account for a certain number of properties of Bethe-Salpeter equation, in particular, that there also arise abnormal solutions in such an approach. (author)

  4. Electron Fluid Description of Wave-Particle Interactions in Strong Buneman Turbulence

    Science.gov (United States)

    Che, Haihong

    2013-10-01

    To understand the nature of anomalous resistivity in magnetic reconnection, we investigate turbulence-induced momentum transport and energy dissipation associated with electron heating in Buneman instability. Using 3D particle-in-cell simulations, we find that the macroscopic effects generated by wave-particle interactions can be described by a set of electron fluid equations. These equations show that the energy dissipation and momentum transports in Buneman instability are locally quasi-static but globally non-static and irreversible. Turbulence drag dissipates both the bulk energy of electron streams and the associated magnetic energy. The decrease of magnetic field maintains an inductive electric field that re-accelerates electrons. The net loss of streaming energy is converted into electron heat and increases the electron Boltzmann entropy. The growth of self-sustained Buneman waves satisfies a Bernoulli-like equation which relates the turbulence-induced convective momentum transport and thermal momentum transport. Electron trapping and de-trapping drives local momentum transports, while phase mixing converts convective momentum into thermal momentum.These two local momentum transports sustain the Buneman waves and act as the micro-macro link in the anomalous heating process. This research is supported by the NASA Postdoctoral Program at NASA/GSFC administered by Oak Ridge Associated Universities through a contract with NASA.

  5. Two-fluid description of wave-particle interactions in strong Buneman turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Che, H. [NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

    2014-06-15

    To understand the nature of anomalous resistivity in magnetic reconnection, we investigate turbulence-induced momentum transport and energy dissipation while a plasma is unstable to the Buneman instability in force-free current sheets. Using 3D particle-in-cell simulations, we find that the macroscopic effects generated by wave-particle interactions in Buneman instability can be approximately described by a set of electron fluid equations. We show that both energy dissipation and momentum transport along electric current in the current layer are locally quasi-static, but globally dynamic and irreversible. Turbulent drag dissipates both the streaming energy of the current sheet and the associated magnetic energy. The net loss of streaming energy is converted into the electron component heat conduction parallel to the magnetic field and increases the electron Boltzmann entropy. The growth of self-sustained Buneman waves satisfies a Bernoulli-like equation that relates the turbulence-induced convective momentum transport and thermal momentum transport. Electron trapping and de-trapping drive local momentum transports, while phase mixing converts convective momentum into thermal momentum. The drag acts like a micro-macro link in the anomalous heating processes. The decrease of magnetic field maintains an inductive electric field that re-accelerates electrons, but most of the magnetic energy is dissipated and converted into the component heat of electrons perpendicular to the magnetic field. This heating process is decoupled from the heating of Buneman instability in the current sheets. Ion heating is weak but ions play an important role in assisting energy exchanges between waves and electrons. Cold ion fluid equations together with our electron fluid equations form a complete set of equations that describes the occurrence, growth, saturation and decay of the Buneman instability.

  6. Two-fluid description of wave-particle interactions in strong Buneman turbulence

    Science.gov (United States)

    Che, H.

    2014-06-01

    To understand the nature of anomalous resistivity in magnetic reconnection, we investigate turbulence-induced momentum transport and energy dissipation while a plasma is unstable to the Buneman instability in force-free current sheets. Using 3D particle-in-cell simulations, we find that the macroscopic effects generated by wave-particle interactions in Buneman instability can be approximately described by a set of electron fluid equations. We show that both energy dissipation and momentum transport along electric current in the current layer are locally quasi-static, but globally dynamic and irreversible. Turbulent drag dissipates both the streaming energy of the current sheet and the associated magnetic energy. The net loss of streaming energy is converted into the electron component heat conduction parallel to the magnetic field and increases the electron Boltzmann entropy. The growth of self-sustained Buneman waves satisfies a Bernoulli-like equation that relates the turbulence-induced convective momentum transport and thermal momentum transport. Electron trapping and de-trapping drive local momentum transports, while phase mixing converts convective momentum into thermal momentum. The drag acts like a micro-macro link in the anomalous heating processes. The decrease of magnetic field maintains an inductive electric field that re-accelerates electrons, but most of the magnetic energy is dissipated and converted into the component heat of electrons perpendicular to the magnetic field. This heating process is decoupled from the heating of Buneman instability in the current sheets. Ion heating is weak but ions play an important role in assisting energy exchanges between waves and electrons. Cold ion fluid equations together with our electron fluid equations form a complete set of equations that describes the occurrence, growth, saturation and decay of the Buneman instability.

  7. Two-fluid description of wave-particle interactions in strong Buneman turbulence

    International Nuclear Information System (INIS)

    Che, H.

    2014-01-01

    To understand the nature of anomalous resistivity in magnetic reconnection, we investigate turbulence-induced momentum transport and energy dissipation while a plasma is unstable to the Buneman instability in force-free current sheets. Using 3D particle-in-cell simulations, we find that the macroscopic effects generated by wave-particle interactions in Buneman instability can be approximately described by a set of electron fluid equations. We show that both energy dissipation and momentum transport along electric current in the current layer are locally quasi-static, but globally dynamic and irreversible. Turbulent drag dissipates both the streaming energy of the current sheet and the associated magnetic energy. The net loss of streaming energy is converted into the electron component heat conduction parallel to the magnetic field and increases the electron Boltzmann entropy. The growth of self-sustained Buneman waves satisfies a Bernoulli-like equation that relates the turbulence-induced convective momentum transport and thermal momentum transport. Electron trapping and de-trapping drive local momentum transports, while phase mixing converts convective momentum into thermal momentum. The drag acts like a micro-macro link in the anomalous heating processes. The decrease of magnetic field maintains an inductive electric field that re-accelerates electrons, but most of the magnetic energy is dissipated and converted into the component heat of electrons perpendicular to the magnetic field. This heating process is decoupled from the heating of Buneman instability in the current sheets. Ion heating is weak but ions play an important role in assisting energy exchanges between waves and electrons. Cold ion fluid equations together with our electron fluid equations form a complete set of equations that describes the occurrence, growth, saturation and decay of the Buneman instability

  8. Investigating Conversational Dynamics: Interactive Alignment, Interpersonal Synergy, and Collective Task Performance

    Science.gov (United States)

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, "interactive alignment" and "interpersonal synergy", and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between interlocutors, the synergy…

  9. Perturbative analysis of the influence of π+π- strong interaction on the relation between A2π creation probabilities in ns-states

    International Nuclear Information System (INIS)

    Voskresenskaya, O.O.

    2002-01-01

    It is shown that the relations between probabilities of A 2π -atoms creation in ns-states, derived with neglecting of the strong interaction between pions, hold practically unchanged if the strong interaction is taken into account in the first order of the perturbation theory. The formulation of Deser equation for the energy levels shift of the hadronic atoms (HA) is given in terms of the effective range of the strong interaction and relative correction to the Coulomb wave function of HA at origin, caused by the strong interaction. (author)

  10. Cirhin up-regulates a canonical NF-{kappa}B element through strong interaction with Cirip/HIVEP1

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Bin; Mitchell, Grant A. [Genetique Medicale, Centre de Recherche CHU Sainte-Justine, Departement de Pediatrie, Universite de Montreal, Montreal, QC (Canada); Richter, Andrea, E-mail: andrea.richter@umontreal.ca [Genetique Medicale, Centre de Recherche CHU Sainte-Justine, Departement de Pediatrie, Universite de Montreal, Montreal, QC (Canada)

    2009-11-01

    North American Indian childhood cirrhosis (NAIC/CIRH1A) is a severe autosomal recessive intrahepatic cholestasis. All NAIC patients have a homozygous mutation in CIRH1A that changes conserved Arg565 to Trp (R565W) in Cirhin, a nucleolar protein of unknown function. Subcellular localization is unaffected by the mutation. Yeast two-hybrid screening identified Cirip (Cirhin interaction protein) and found that interaction between Cirip and R565W-Cirhin was weakened. Co-immunoprecipitation of the two proteins from nuclear extracts of HeLa cells strongly supports the yeast two hybrid results. Cirip has essentially the same sequence as the C-terminal of HIVEP1, a regulator of a canonical NF-{kappa}B sequence. Since Cirip has the zinc fingers required for this interaction, we developed an in vitro assay based on this element in mammalian cells to demonstrate functional Cirhin-Cirip interaction. The strong positive effect of Cirip on the NF-{kappa}B sequence was further increased by both Cirhin and R565W-Cirhin. Importantly, the effect of R565W-Cirhin was weaker than that of the wild type protein. We observed increased levels of Cirhin-Cirip complex in nuclear extracts in the presence of this NF-{kappa}B sequence. Our hypothesis is that Cirhin is a transcriptional regulatory factor of this NF-{kappa}B sequence and could be a participant in the regulation of other genes with NF-{kappa}B responsive elements. Since the activities of genes regulated through NF-{kappa}B responsive elements are especially important during development, this interaction may be a key to explain the perinatal appearance of NAIC.

  11. Cirhin up-regulates a canonical NF-κB element through strong interaction with Cirip/HIVEP1

    International Nuclear Information System (INIS)

    Yu, Bin; Mitchell, Grant A.; Richter, Andrea

    2009-01-01

    North American Indian childhood cirrhosis (NAIC/CIRH1A) is a severe autosomal recessive intrahepatic cholestasis. All NAIC patients have a homozygous mutation in CIRH1A that changes conserved Arg565 to Trp (R565W) in Cirhin, a nucleolar protein of unknown function. Subcellular localization is unaffected by the mutation. Yeast two-hybrid screening identified Cirip (Cirhin interaction protein) and found that interaction between Cirip and R565W-Cirhin was weakened. Co-immunoprecipitation of the two proteins from nuclear extracts of HeLa cells strongly supports the yeast two hybrid results. Cirip has essentially the same sequence as the C-terminal of HIVEP1, a regulator of a canonical NF-κB sequence. Since Cirip has the zinc fingers required for this interaction, we developed an in vitro assay based on this element in mammalian cells to demonstrate functional Cirhin-Cirip interaction. The strong positive effect of Cirip on the NF-κB sequence was further increased by both Cirhin and R565W-Cirhin. Importantly, the effect of R565W-Cirhin was weaker than that of the wild type protein. We observed increased levels of Cirhin-Cirip complex in nuclear extracts in the presence of this NF-κB sequence. Our hypothesis is that Cirhin is a transcriptional regulatory factor of this NF-κB sequence and could be a participant in the regulation of other genes with NF-κB responsive elements. Since the activities of genes regulated through NF-κB responsive elements are especially important during development, this interaction may be a key to explain the perinatal appearance of NAIC.

  12. Osteoclast formation is strongly reduced both in vivo and in vitro in the absence of CD47/SIRPα-interaction

    International Nuclear Information System (INIS)

    Lundberg, Pernilla; Koskinen, Cecilia; Baldock, Paul A.; Loethgren, Hanna; Stenberg, Asa; Lerner, Ulf H.; Oldenborg, Per-Arne

    2007-01-01

    Physical interaction between the cell surface receptors CD47 and signal regulatory protein alpha (SIRPα) was reported to regulate cell migration, phagocytosis, cytokine production, and macrophage fusion. However, it is unclear if the CD47/SIRPα-interaction can also regulate macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor (NF)-κB ligand (RANKL)-stimulated formation of osteoclasts. Here, we show that functional blocking antibodies to either CD47 or SIRPα strongly reduced formation of multinucleated tartrate-resistant acid phosphatase (TRAP) + osteoclasts in cultures of murine hematopoietic cells, stimulated in vitro by M-CSF and RANKL. In addition, the numbers of osteoclasts formed in M-CSF/RANKL-stimulated bone marrow macrophage cultures from CD47 -/- mice were strongly reduced, and bones of CD47 -/- mice exhibited significantly reduced osteoclast numbers, as compared with wild-type controls. We conclude that the CD47/SIRPα interaction is important for M-CSF/RANKL-stimulated osteoclast formation both in vivo and in vitro, and that absence of CD47 results in decreased numbers of osteoclasts in CD47 -/- mice

  13. Probing different regimes of strong field light-matter interaction with semiconductor quantum dots and few cavity photons

    Science.gov (United States)

    Hargart, F.; Roy-Choudhury, K.; John, T.; Portalupi, S. L.; Schneider, C.; Höfling, S.; Kamp, M.; Hughes, S.; Michler, P.

    2016-12-01

    In this work we present an extensive experimental and theoretical investigation of different regimes of strong field light-matter interaction for cavity-driven quantum dot (QD) cavity systems. The electric field enhancement inside a high-Q micropillar cavity facilitates exceptionally strong interaction with few cavity photons, enabling the simultaneous investigation for a wide range of QD-laser detuning. In case of a resonant drive, the formation of dressed states and a Mollow triplet sideband splitting of up to 45 μeV is measured for a mean cavity photon number ≤slant 1. In the asymptotic limit of the linear AC Stark effect we systematically investigate the power and detuning dependence of more than 400 QDs. Some QD-cavity systems exhibit an unexpected anomalous Stark shift, which can be explained by an extended dressed 4-level QD model. We provide a detailed analysis of the QD-cavity systems properties enabling this novel effect. The experimental results are successfully reproduced using a polaron master equation approach for the QD-cavity system, which includes the driving laser field, exciton-cavity and exciton-phonon interactions.

  14. MediaTable : interactive categorization of multimedia collections

    NARCIS (Netherlands)

    Rooij, de O.; Wijk, van J.J.; Worring, M.

    2010-01-01

    Many multimedia collections include only metadata such as date created and file size and remain largely unannotated. So, browsing them is cumbersome. Automatic content-analysis techniques yield metadata in the form of high-level content-based descriptors. However, these techniques' accuracy is

  15. Next-to-leading order strong interaction corrections to the ΔF = 2 effective Hamiltonian in the MSSM

    International Nuclear Information System (INIS)

    Ciuchini, Marco; Franco, E.; Guadagnoli, D.; Lubicz, Vittorio; Porretti, V.; Silvestrini, L.

    2006-01-01

    We compute the next-to-leading order strong interaction corrections to gluino-mediated ΔF = 2 box diagrams in the Minimal Supersymmetric Standard Model. These corrections are given by two loop diagrams which we have calculated in three different regularization schemes in the mass insertion approximation. We obtain the next-to-leading order Wilson coefficients of the ΔF = 2 effective Hamiltonian relevant for neutral meson mixings. We find that the matching scale uncertainty is largely reduced at the next-to-leading order, typically from about 10-15% to few percent

  16. Evolution of the Normal State of a Strongly Interacting Fermi Gas from a Pseudogap Phase to a Molecular Bose Gas

    International Nuclear Information System (INIS)

    Perali, A.; Palestini, F.; Pieri, P.; Strinati, G. C.; Stewart, J. T.; Gaebler, J. P.; Drake, T. E.; Jin, D. S.

    2011-01-01

    Wave-vector resolved radio frequency spectroscopy data for an ultracold trapped Fermi gas are reported for several couplings at T c , and extensively analyzed in terms of a pairing-fluctuation theory. We map the evolution of a strongly interacting Fermi gas from the pseudogap phase into a fully gapped molecular Bose gas as a function of the interaction strength, which is marked by a rapid disappearance of a remnant Fermi surface in the single-particle dispersion. We also show that our theory of a pseudogap phase is consistent with a recent experimental observation as well as with quantum Monte Carlo data of thermodynamic quantities of a unitary Fermi gas above T c .

  17. Using X-ray spectroheliograph technique for investigations of laser-produced plasma under interaction with strong magnetic field

    International Nuclear Information System (INIS)

    Faenov, A.; Dyakin, V.; Magunov, A.; Pikuz, T.; Skobelev, I.; Pikuz, S.; Pisarczyk, T.; Wolowski, J.; Zielinska, E.

    1996-01-01

    A dense jet of a plasma consisting of multiply charged ions was generated in the interaction of a laser plasma with a strong external axial magnetic field. It is shown that using the high-luminosity X-ray spectroheliograph technique allows to measure plasma emission spectra with 2-dimensional spatial resolution even in the cases when these spectra have small intensities. The X-ray spectroscopy and interferometry methods are used to measure plasma parameter distributions. The dependencies of N e (z) and T e (z) measured in this paper can be used to calculate the evolution of plasma ionization state during plasma expansion. The quasihomogeneous laser jet, which appears when a laser plasma interacts with an external magnetic field can be used not only to form an active medium of a short wavelength laser, but probably also to tackle the urgent problem of transport in a laser ion injector. (orig.)

  18. Using X-ray spectroheliograph technique for investigations of laser-produced plasma under interaction with strong magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Faenov, A. [MISDC of VNIIFTRI, Mendeleevo (Russian Federation); Dyakin, V. [MISDC of VNIIFTRI, Mendeleevo (Russian Federation); Magunov, A. [MISDC of VNIIFTRI, Mendeleevo (Russian Federation); Pikuz, T. [MISDC of VNIIFTRI, Mendeleevo (Russian Federation); Skobelev, I. [MISDC of VNIIFTRI, Mendeleevo (Russian Federation); Pikuz, S. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Fizicheskij Inst.; Kasperczyk, A. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Pisarczyk, T. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Wolowski, J. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Zielinska, E. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland)

    1996-08-01

    A dense jet of a plasma consisting of multiply charged ions was generated in the interaction of a laser plasma with a strong external axial magnetic field. It is shown that using the high-luminosity X-ray spectroheliograph technique allows to measure plasma emission spectra with 2-dimensional spatial resolution even in the cases when these spectra have small intensities. The X-ray spectroscopy and interferometry methods are used to measure plasma parameter distributions. The dependencies of N{sub e}(z) and T{sub e}(z) measured in this paper can be used to calculate the evolution of plasma ionization state during plasma expansion. The quasihomogeneous laser jet, which appears when a laser plasma interacts with an external magnetic field can be used not only to form an active medium of a short wavelength laser, but probably also to tackle the urgent problem of transport in a laser ion injector. (orig.).

  19. Resolution-of-identity stochastic time-dependent configuration interaction for dissipative electron dynamics in strong fields.

    Science.gov (United States)

    Klinkusch, Stefan; Tremblay, Jean Christophe

    2016-05-14

    In this contribution, we introduce a method for simulating dissipative, ultrafast many-electron dynamics in intense laser fields. The method is based on the norm-conserving stochastic unraveling of the dissipative Liouville-von Neumann equation in its Lindblad form. The N-electron wave functions sampling the density matrix are represented in the basis of singly excited configuration state functions. The interaction with an external laser field is treated variationally and the response of the electronic density is included to all orders in this basis. The coupling to an external environment is included via relaxation operators inducing transition between the configuration state functions. Single electron ionization is represented by irreversible transition operators from the ionizing states to an auxiliary continuum state. The method finds its efficiency in the representation of the operators in the interaction picture, where the resolution-of-identity is used to reduce the size of the Hamiltonian eigenstate basis. The zeroth-order eigenstates can be obtained either at the configuration interaction singles level or from a time-dependent density functional theory reference calculation. The latter offers an alternative to explicitly time-dependent density functional theory which has the advantage of remaining strictly valid for strong field excitations while improving the description of the correlation as compared to configuration interaction singles. The method is tested on a well-characterized toy system, the excitation of the low-lying charge transfer state in LiCN.

  20. Resolution-of-identity stochastic time-dependent configuration interaction for dissipative electron dynamics in strong fields

    Energy Technology Data Exchange (ETDEWEB)

    Klinkusch, Stefan; Tremblay, Jean Christophe [Institute for Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin (Germany)

    2016-05-14

    In this contribution, we introduce a method for simulating dissipative, ultrafast many-electron dynamics in intense laser fields. The method is based on the norm-conserving stochastic unraveling of the dissipative Liouville-von Neumann equation in its Lindblad form. The N-electron wave functions sampling the density matrix are represented in the basis of singly excited configuration state functions. The interaction with an external laser field is treated variationally and the response of the electronic density is included to all orders in this basis. The coupling to an external environment is included via relaxation operators inducing transition between the configuration state functions. Single electron ionization is represented by irreversible transition operators from the ionizing states to an auxiliary continuum state. The method finds its efficiency in the representation of the operators in the interaction picture, where the resolution-of-identity is used to reduce the size of the Hamiltonian eigenstate basis. The zeroth-order eigenstates can be obtained either at the configuration interaction singles level or from a time-dependent density functional theory reference calculation. The latter offers an alternative to explicitly time-dependent density functional theory which has the advantage of remaining strictly valid for strong field excitations while improving the description of the correlation as compared to configuration interaction singles. The method is tested on a well-characterized toy system, the excitation of the low-lying charge transfer state in LiCN.

  1. Strong interactions - quark models

    International Nuclear Information System (INIS)

    Goto, M.; Ferreira, P.L.

    1979-01-01

    The variational method is used for the PSI and upsilon family spectra reproduction from the quark model, through several phenomenological potentials, viz.: linear, linear plus coulomb term and logarithmic. (L.C.) [pt

  2. Strong quadrupole interaction in electron paramagnetic resonance. Study of the indium hexacyanide (III) in KCl irradiated with electrons

    International Nuclear Information System (INIS)

    Vugman, N.V.

    1973-08-01

    The radiation effects in ]Ir III (CN) 6 ] 3- diamagnetic complexe inserted in the KCl lattice and irradiated with electrons of 2MeV by electron spin resonance (ESR) are analysed. Formulas for g and A tensors in the ligand field approximation, are derivated to calculate non coupling electron density in the metal. The X polarization field of inner shells is positive, indicating a 6s function mixture in the non coupling electron molecular orbital. The observed hyperfine structure is assigned to 4 equivalent nitrogen and one non equivalent nitrogen. This hypothesis is verified by experience of isotope substitution with 15 N. The s and p spin density in ligands are calculated and discussed in terms of molecular obitals. The effects of strong quadrupole interaction into the EPR spectra of ]Ir II (CN) 5 ] 3- complex are analysed by MAGNSPEC computer program to diagonalize the Spin Hamiltonian of the system. Empiric rules for EPR espectrum interpretation with strong quadrupole interaction. A review of EPR technique and a review of main concepts of crystal-field and ligand field theories, are also presented. (M.C.K.) [pt

  3. Optical pulling and pushing forces exerted on silicon nanospheres with strong coherent interaction between electric and magnetic resonances.

    Science.gov (United States)

    Liu, Hongfeng; Panmai, Mingcheng; Peng, Yuanyuan; Lan, Sheng

    2017-05-29

    We investigated theoretically and numerically the optical pulling and pushing forces acting on silicon (Si) nanospheres (NSs) with strong coherent interaction between electric and magnetic resonances. We examined the optical pulling and pushing forces exerted on Si NSs by two interfering waves and revealed the underlying physical mechanism from the viewpoint of electric- and magnetic-dipole manipulation. As compared with a polystyrene (PS) NS, it was found that the optical pulling force for a Si NS with the same size is enlarged by nearly two orders of magnitude. In addition to the optical pulling force appearing at the long-wavelength side of the magnetic dipole resonance, very large optical pushing force is observed at the magnetic quadrupole resonance. The correlation between the optical pulling/pushing force and the directional scattering characterized by the ratio of the forward to backward scattering was revealed. More interestingly, it was found that the high-order electric and magnetic resonances in large Si NSs play an important role in producing optical pulling force which can be generated by not only s-polarized wave but also p-polarized one. Our finding indicates that the strong coherent interaction between the electric and magnetic resonances existing in nanoparticles with large refractive indices can be exploited to manipulate the optical force acting on them and the correlation between the optical force and the directional scattering can be used as guidance. The engineering and manipulation of optical forces will find potential applications in the trapping, transport and sorting of nanoparticles.

  4. Quantum centipedes: collective dynamics of interacting quantum walkers

    International Nuclear Information System (INIS)

    Krapivsky, P L; Luck, J M; Mallick, K

    2016-01-01

    We consider the quantum centipede made of N fermionic quantum walkers on the one-dimensional lattice interacting by means of the simplest of all hard-bound constraints: the distance between two consecutive fermions is either one or two lattice spacings. This composite quantum walker spreads ballistically, just as the simple quantum walk. However, because of the interactions between the internal degrees of freedom, the distribution of its center-of-mass velocity displays numerous ballistic fronts in the long-time limit, corresponding to singularities in the empirical velocity distribution. The spectrum of the centipede and the corresponding group velocities are analyzed by direct means for the first few values of N . Some analytical results are obtained for arbitrary N by exploiting an exact mapping of the problem onto a free-fermion system. We thus derive the maximal velocity describing the ballistic spreading of the two extremal fronts of the centipede wavefunction, including its non-trivial value in the large- N limit. (paper)

  5. Eight supramolecular assemblies constructed from bis(benzimidazole) and organic acids through strong classical hydrogen bonding and weak noncovalent interactions

    Science.gov (United States)

    Jin, Shouwen; Wang, Daqi

    2014-05-01

    Eight crystalline organic acid-base adducts derived from alkane bridged bis(N-benzimidazole) and organic acids (2,4,6-trinitrophenol, p-nitrobenzoic acid, m-nitrobenzoic acid, 3,5-dinitrobenzoic acid, 5-sulfosalicylic acid and oxalic acid) were prepared and characterized by X-ray diffraction analysis, IR, mp, and elemental analysis. Of the eight compounds five are organic salts (1, 4, 6, 7 and 8) and the other three (2, 3, and 5) are cocrystals. In all of the adducts except 1 and 8, the ratio of the acid and the base is 2:1. All eight supramolecular assemblies involve extensive intermolecular classical hydrogen bonds as well as other noncovalent interactions. The role of weak and strong noncovalent interactions in the crystal packing is ascertained. These weak interactions combined, all the complexes displayed 3D framework structure. The results presented herein indicate that the strength and directionality of the classical N+-H⋯O-, O-H⋯O, and O-H⋯N hydrogen bonds (ionic or neutral) and other nonbonding associations between acids and ditopic benzimidazoles are sufficient to bring about the formation of cocrystals or organic salts.

  6. Interactive comparison and remediation of collections of macromolecular structures.

    Science.gov (United States)

    Moriarty, Nigel W; Liebschner, Dorothee; Klei, Herbert E; Echols, Nathaniel; Afonine, Pavel V; Headd, Jeffrey J; Poon, Billy K; Adams, Paul D

    2018-01-01

    Often similar structures need to be compared to reveal local differences throughout the entire model or between related copies within the model. Therefore, a program to compare multiple structures and enable correction any differences not supported by the density map was written within the Phenix framework (Adams et al., Acta Cryst 2010; D66:213-221). This program, called Structure Comparison, can also be used for structures with multiple copies of the same protein chain in the asymmetric unit, that is, as a result of non-crystallographic symmetry (NCS). Structure Comparison was designed to interface with Coot(Emsley et al., Acta Cryst 2010; D66:486-501) and PyMOL(DeLano, PyMOL 0.99; 2002) to facilitate comparison of large numbers of related structures. Structure Comparison analyzes collections of protein structures using several metrics, such as the rotamer conformation of equivalent residues, displays the results in tabular form and allows superimposed protein chains and density maps to be quickly inspected and edited (via the tools in Coot) for consistency, completeness and correctness. © 2017 The Protein Society.

  7. Measurement of the quadrupole moments of the strongly deformed nuclei 18173Ta108 and 18375Re108 by hyperfine interaction in metals

    International Nuclear Information System (INIS)

    Netz, G.

    1974-01-01

    The quadrupole moments of two single particle proton states were measured in the strongly deformed nuclei region. Both measurements are independent of model because the field gradient is known in a rhenium lattice as well as at the nucleus site of a rhenium atom and also at the nucleus site of an incorporated tantalum atom. The quadrupole moments could thus be directly extracted from the quadrupole interaction frequency, the product of quadrupole moment and field gradient. For the 482 keV state (I = 5/2 + ) in 181 73 Ta 108 one obtains a quadrupole moment of: Q (5/2) = 2.5 +- 0.2 barn. For the 496 keV state (I = 9/2 - ) in 183 75 Re 108 , a quadrupole moment of: Q (0/2) = 3.6 +- 0.4 barn is found. This value agrees well with other experimental data within the framework of the collective model. (orig./LH) [de

  8. Field-substance interaction and collective oscillation of nuclei

    International Nuclear Information System (INIS)

    Shermatov, E.N.; Choriev, M.

    2004-01-01

    Full text: In this work a mechanism of formation of collective excitation in a set of particles, including atomic nuclei, is proposed. According to [1] the energy density of cosmic vacuum significantly exceeds the energy density of an atomic nucleus. In [2] the process of formation of the physical vacuum in surrounding cosmic space was considered. We considered the behavior of a system of particles, which possesses transversal and longitudinal oscillation with frequency ω 0 in the physical or cosmic vacuum. The oscillating influence on the physical vacuum and surrounding particles on a single particle leads to inducing the spins with various directions and magnitudes. This process leads to the formation of oscillating response wave function (RWF) of particles. As a result of a phase coherency among RWF of particles an oscillating self-coordinated field in a set of particles is formed. As a result of realization of the phase coherency among harmonics of RWF of particles there occurs a deformation of the character of distribution of the energy structure of the self-coordinated field, which, finally, transforms into a resonant line. At this occurs a collapse of the RWF of particles there. In terms of these ideas we explained the observed regularities in the self-coordinated field in a set of particles, including the atomic nuclei. It was shown that the giant resonance in spectra of atomic nuclei is a result of manifestation of the self-coordinated field of atomic nuclei. As a result of realization of the phase coherency among harmonics of RWF of atomic nuclei there occurs a collapse of the RWF of particles, and the energy structure of the self-coordinated field of nuclei gains a resonant form, and it is manifested as the giant resonance. In deformable nuclei the RWF of particles possesses two oscillation modes, and that is why in the energy spectrum of the self-coordinated field of nuclei they are manifested as two maximum

  9. Study of thermodynamic and transport properties of strongly interacting matter in a color string percolation model at RHIC

    International Nuclear Information System (INIS)

    Sahoo, Pragati; Tiwari, Swatantra Kumar; De, Sudipan; Sahoo, Raghunath

    2017-01-01

    The main perspectives of Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory are to study the properties of the strongly interacting matter and to explore the conjectured Quantum Chromodynamics (QCD) phase diagram. Lattice QCD (lQCD) predicts a smooth crossover at vanishing baryon chemical potential (μ B ) and other QCD based theoretical models predicts first order phase transition at large μB. Searching of the Critical Point in the QCD phase diagram, finding the evidence and nature of phase transition, studying the properties of the matter formed in nuclear collisions as a function of √sNN are the main goals of RHIC. To investigate the nature of the matter produced at heavy-ion collisions, the thermodynamical and transport quantities like: energy density, shear viscosity etc. are studied. It is expected that the ratio of shear viscosity (η) to entropy density (s) would exhibit a minimum value near the QCD critical point

  10. Separating electroweak and strong interactions in Drell-Yan processes at LHC: leptons angular distributions and reference frames

    International Nuclear Information System (INIS)

    Richter-Was, E.; Was, Z.

    2016-01-01

    Among the physics goals of LHC experiments, precision tests of the Standard Model in the Strong and Electroweak sectors play an important role. Because of nature of the proton-proton processes, observables based on the measurement of the direction and energy of leptons provide the most precise signatures. In the present paper, we concentrate on the angular distribution of Drell-Yan process leptons, in the lepton-pair rest-frame. The vector nature of the intermediate state imposes that distributions are to a good precision described by spherical polynomials of at most second order. We show that with the proper choice of the coordinate frames, only one coefficient in this polynomial decomposition remains sizable, even in the presence of one or two high p T jets. The necessary stochastic choice of the frames relies on probabilities independent from any coupling constants. This remains true when one or two partons accompany the lepton pairs. In this way electroweak effects can be better separated from strong interaction ones for the benefit of the interpretation of the measurements. Our study exploits properties of single gluon emission matrix elements which are clearly visible if a conveniently chosen form of their representation is used. We rely also on distributions obtained from matrix element based Monte Carlo generated samples of events with two leptons and up to two additional partons in test samples. Incoming colliding protons' partons are distributed accordingly to PDFs and are strictly collinear to the corresponding beams. (orig.)

  11. Moiré superlattice-level stick-slip instability originated from geometrically corrugated graphene on a strongly interacting substrate

    Science.gov (United States)

    Shi, Ruoyu; Gao, Lei; Lu, Hongliang; Li, Qunyang; Ma, Tian-Bao; Guo, Hui; Du, Shixuan; Feng, Xi-Qiao; Zhang, Shuai; Liu, Yanmin; Cheng, Peng; Hu, Yuan-Zhong; Gao, Hong-Jun; Luo, Jianbin

    2017-06-01

    Two dimensional (2D) materials often exhibit novel properties due to various coupling effects with their supporting substrates. Here, using friction force microscopy (FFM), we report an unusual moiré superlattice-level stick-slip instability on monolayer graphene epitaxially grown on Ru(0 0 0 1) substrate. Instead of smooth friction modulation, a significant long-range stick-slip sawtooth modulation emerges with a period coinciding with the moiré superlattice structure, which is robust against high external loads and leads to an additional channel of energy dissipation. In contrast, the long-range stick-slip instability reduces to smooth friction modulation on graphene/Ir(1 1 1) substrate. The moiré superlattice-level slip instability could be attributed to the large sliding energy barrier, which arises from the morphological corrugation of graphene on Ru(0 0 0 1) surface as indicated by density functional theory (DFT) calculations. The locally steep humps acting as obstacles opposing the tip sliding, originates from the strong interfacial electronic interaction between graphene and Ru(0 0 0 1). This study opens an avenue for modulating friction by tuning the interfacial atomic interaction between 2D materials and their substrates.

  12. Effects of strong interactions between Ti and ceria on the structures of Ti/CeO2.

    Science.gov (United States)

    Yao, Xiao-Dan; Zhu, Kong-Jie; Teng, Bo-Tao; Yu, Cao-Ming; Zhang, Yun-Lei; Liu, Ya; Fan, Maohong; Wen, Xiao-Dong

    2016-11-30

    The effects of strong interactions between Ti and ceria on the structures of Ti/CeO 2 (111) are systematically investigated by density functional theory calculation. To our best knowledge, the adsorption energy of a Ti atom at the hollow site of CeO 2 is the highest value (-7.99 eV) reported in the literature compared with those of Au (-0.88--1.26 eV), Ag (-1.42 eV), Cu (-2.69 eV), Pd (-1.75 eV), Pt (-2.62 eV) and Sn (-3.68 eV). It is very interesting to find that Ti adatoms disperse at the hollow site of CeO 2 (111) to form surface TiO x species, instead of aggregating to form Ti metal clusters for the Ti-CeO 2 interactions that are much stronger than those of Ti-Ti ones. Ti adatoms are completely oxidized to Ti 4+ ions if they are monatomically dispersed on the next near hollow sites of CeO 2 (111) (xTi-NN-hollow); while Ti 3+ ions are observed when they locate at the near hollow sites (xTi-N-hollow). Due to the electronic repulsive effects among Ti 3+ ions, the adsorption energies of xTi-N-hollow are slightly weaker than those of xTi-NN-hollow. Simultaneously, the existence of unstable Ti 3+ ions on xTi-N-hollow also leads to the restructuring of xTi-N-hollow by surface O atoms of ceria transferring to the top of Ti 3+ ions, or oxidation by O 2 adsorption and dissociation. Both processes improve the stability of the xTi/CeO 2 system by Ti 3+ oxidation. Correspondingly, surface TiO 2 -like species form. This work sheds light into the structures of metal/CeO 2 catalysts with strong interactions between the metal and the ceria support.

  13. Preparation of a novel dual-function strong cation exchange/hydrophobic interaction chromatography stationary phase for protein separation.

    Science.gov (United States)

    Zhao, Kailou; Yang, Li; Wang, Xuejiao; Bai, Quan; Yang, Fan; Wang, Fei

    2012-08-30

    We have explored a novel dual-function stationary phase which combines both strong cation exchange (SCX) and hydrophobic interaction chromatography (HIC) characteristics. The novel dual-function stationary phase is based on porous and spherical silica gel functionalized with ligand containing sulfonic and benzyl groups capable of electrostatic and hydrophobic interaction functionalities, which displays HIC character in a high salt concentration, and IEC character in a low salt concentration in mobile phase employed. As a result, it can be employed to separate proteins with SCX and HIC modes, respectively. The resolution and selectivity of the dual-function stationary phase were evaluated under both HIC and SCX modes with standard proteins and can be comparable to that of conventional IEC and HIC columns. More than 96% of mass and bioactivity recoveries of proteins can be achieved in both HIC and SCX modes, respectively. The results indicated that the novel dual-function column could replace two individual SCX and HIC columns for protein separation. Mixed retention mechanism of proteins on this dual-function column based on stoichiometric displacement theory (SDT) in LC was investigated to find the optimal balance of the magnitude of electrostatic and hydrophobic interactions between protein and the ligand on the silica surface in order to obtain high resolution and selectivity for protein separation. In addition, the effects of the hydrophobicity of the ligand of the dual-function packings and pH of the mobile phase used on protein separation were also investigated in detail. The results show that the ligand with suitable hydrophobicity to match the electrostatic interaction is very important to prepare the dual-function stationary phase, and a better resolution and selectivity can be obtained at pH 6.5 in SCX mode. Therefore, the dual-function column can replace two individual SCX and HIC columns for protein separation and be used to set up two-dimensional liquid

  14. Cloud-Resolving Model Simulations of Aerosol-Cloud Interactions Triggered by Strong Aerosol Emissions in the Arctic

    Science.gov (United States)

    Wang, H.; Kravitz, B.; Rasch, P. J.; Morrison, H.; Solomon, A.

    2014-12-01

    Previous process-oriented modeling studies have highlighted the dependence of effectiveness of cloud brightening by aerosols on cloud regimes in warm marine boundary layer. Cloud microphysical processes in clouds that contain ice, and hence the mechanisms that drive aerosol-cloud interactions, are more complicated than in warm clouds. Interactions between ice particles and liquid drops add additional levels of complexity to aerosol effects. A cloud-resolving model is used to study aerosol-cloud interactions in the Arctic triggered by strong aerosol emissions, through either geoengineering injection or concentrated sources such as shipping and fires. An updated cloud microphysical scheme with prognostic aerosol and cloud particle numbers is employed. Model simulations are performed in pure super-cooled liquid and mixed-phase clouds, separately, with or without an injection of aerosols into either a clean or a more polluted Arctic boundary layer. Vertical mixing and cloud scavenging of particles injected from the surface is still quite efficient in the less turbulent cold environment. Overall, the injection of aerosols into the Arctic boundary layer can delay the collapse of the boundary layer and increase low-cloud albedo. The pure liquid clouds are more susceptible to the increase in aerosol number concentration than the mixed-phase clouds. Rain production processes are more effectively suppressed by aerosol injection, whereas ice precipitation (snow) is affected less; thus the effectiveness of brightening mixed-phase clouds is lower than for liquid-only clouds. Aerosol injection into a clean boundary layer results in a greater cloud albedo increase than injection into a polluted one, consistent with current knowledge about aerosol-cloud interactions. Unlike previous studies investigating warm clouds, the impact of dynamical feedback due to precipitation changes is small. According to these results, which are dependent upon the representation of ice nucleation

  15. 78 FR 27243 - Proposed Collection; 60-Day Comment Request: Interactive Informed Consent for Pediatric Clinical...

    Science.gov (United States)

    2013-05-09

    ... consent or the interactive computer-based program, will be assessed by face-to-face interview. In addition... Comment Request: Interactive Informed Consent for Pediatric Clinical Trials SUMMARY: In compliance with... other technological collection techniques or other forms of information technology. To Submit Comments...

  16. The empirical residual proton-neutron interaction and the onset of collectivity in nuclei

    International Nuclear Information System (INIS)

    Casten, R.F.

    1991-01-01

    The critical role of the residual valence p-n interaction in the development and evolution of collectivity, and the onset of shape/phase transitions, is discussed from the standpoint of phenomenological approaches, and empirical extraction of individual p-n interaction strengths, and simple model calculation of them. 22 refs., 18 figs

  17. Rare sugar D-allose strongly induces thioredoxin-interacting protein and inhibits osteoclast differentiation in Raw264 cells.

    Science.gov (United States)

    Yamada, Kana; Noguchi, Chisato; Kamitori, Kazuyo; Dong, Youyi; Hirata, Yuko; Hossain, Mohammad A; Tsukamoto, Ikuko; Tokuda, Masaaki; Yamaguchi, Fuminori

    2012-02-01

    Oxidative stress modulates the osteoclast differentiation via redox systems, and thioredoxin 1 (Trx) promotes the osteoclast formation by regulating the activity of transcription factors. The function of Trx is known to be regulated by its binding partner, thioredoxin-interacting protein (TXNIP). We previously reported that the expression of TXNIP gene is strongly induced by a rare sugar D-allose. In this study, we tested the hypothesis that D-allose could inhibit the osteoclast differentiation by regulating the Trx function. We used a murine Raw264 cell line that differentiates to the osteoclast by the receptor activator of nuclear factor-κB ligand (RANKL) treatment. The effect of sugars was evaluated by tartrate-resistant acid phosphatase staining. The expression and localization of TXNIP and Trx protein were examined by Western blotting and immunohistochemisty. The activity of the nuclear factor-κB, nuclear factor of activated T cells, and activator protein 1 transcription factors was measured by the luciferase reporter assay. The addition of D-allose (25 mmol/L) inhibited the osteoclast differentiation down to 9.53% ± 1.27% of a receptor activator of nuclear factor-κB ligand-only treatment. During the osteoclast differentiation, a significant increase of TNXIP was observed by D-allose treatment. The immunohistochemical analysis showed that both Trx and TXNIP existed in the nucleus in preosteoclasts and osteoclasts. Overexpression of TXNIP by plasmid transfection also inhibited the osteoclast formation, indicating the functional importance of TXNIP for the osteoclast differentiation. Transcriptional activity of the activator protein 1, nuclear factor-κB, and nuclear factor of activated T cells, known to be modulated by Trx, were inhibited by D-allose. In conclusion, our data indicate that D-allose is a strong inhibitor of the osteoclast differentiation, and this effect could be caused by TXNIP induction and a resulting inhibition of the Trx function

  18. High-angle scattering events strongly affect light collection in clinically relevant measurement geometries for light transport through tissue

    International Nuclear Information System (INIS)

    Canpolat, M.; Mourant, J.R.

    2000-01-01

    Measurement of light transport in tissue has the potential to be an inexpensive and practical tool for non-invasive tissue diagnosis in medical applications because it can provide information on both morphological and biochemical properties. To capitalize on the potential of light transport as a diagnostic tool, an understanding of what information can be gleaned from light transport measurements is needed. We present data concerning the sensitivity of light transport measurements, made in clinically relevant geometries, to scattering properties. The intensity of the backscattered light at small source-detector separations is shown to be sensitive to the phase function, and furthermore the collected light intensity is found to be correlated with the amount of high-angle scattering in the medium. (author)

  19. A versatile setup for ultrafast broadband optical spectroscopy of coherent collective modes in strongly correlated quantum systems

    Directory of Open Access Journals (Sweden)

    Edoardo Baldini

    2016-11-01

    Full Text Available A femtosecond pump-probe setup is described that is optimised for broadband transient reflectivity experiments on solid samples over a wide temperature range. By combining high temporal resolution and a broad detection window, this apparatus can investigate the interplay between coherent collective modes and high-energy electronic excitations, which is a distinctive characteristic of correlated electron systems. Using a single-shot readout array detector at frame rates of 10 kHz allows resolving coherent oscillations with amplitudes <10−4. We demonstrate its operation on the charge-transfer insulator La2CuO4, revealing coherent phonons with frequencies up to 13 THz and providing access into their Raman matrix elements.

  20. Evidence for carbon flux shortage and strong carbon/nitrogen interactions in pea nodules at early stages of water stress.

    Science.gov (United States)

    Gálvez, Loli; González, Esther M; Arrese-Igor, Cesar

    2005-09-01

    Symbiotic N2 fixation in legume nodules declines under a wide range of environmental stresses. A high correlation between N2 fixation decline and sucrose synthase (SS; EC 2.4.1.13) activity down-regulation has been reported, although it has still to be elucidated whether a causal relationship between SS activity down-regulation and N2 fixation decline can be established. In order to study the likely C/N interactions within nodules and the effects on N2 fixation, pea plants (Pisum sativum L. cv. Sugar snap) were subjected to progressive water stress by withholding irrigation. Under these conditions, nodule SS activity declined concomitantly with apparent nitrogenase activity. The levels of UDP-glucose, glucose-1-phosphate, glucose-6-phosphate, and fructose-6-phosphate decreased in water-stressed nodules compared with unstressed nodules. Drought also had a marked effect on nodule concentrations of malate, succinate, and alpha-ketoglutarate. Moreover, a general decline in nodule adenylate content was detected. NADP+-dependent isocitrate dehydrogenase (ICDH; EC 1.1.1.42) was the only enzyme whose activity increased as a result of water deficit, compensating for a possible C/N imbalance and/or supplying NADPH in circumstances that the pentose phosphate pathway was impaired, as suggested by the decline in glucose-6-phosphate dehydrogenase (G6PDH; EC 1.1.1.49) activity. The overall results show the occurrence of strong C/N interactions in nodules subjected to water stress and support a likely limitation of carbon flux that might be involved in the decline of N2 fixation under drought.

  1. Search for single top-quark production via FCNC in strong interaction in $\\sqrt{s}=8\\,\\,\\mathrm{TeV}$ ATLAS data

    CERN Document Server

    The ATLAS collaboration

    2013-01-01

    Results with 2012 data on the search for single top-quark production via flavour changing neutral currents (FCNCs) in strong interactions are presented. Data collected with the ATLAS detector in 2012 at a centre-of-mass energy of $\\sqrt{s}=8\\,\\,\\mathrm{TeV}$ and corresponding to an integrated luminosity of $\\mathcal{L}_{\\mathrm{int}} =14.2\\,\\,\\mathrm{fb^{-1}}$ is used. It is searched for FCNC events in which a light quark ($u$ or $c$) interacts with a gluon to produce a single top-quark, either with or without the associated production of another light quark or gluon. Candidate events of top quarks decaying into leptons and jets are selected and classified into signal- and background-like events using a neural network. As no signal is observed in the neural network output distributions, a new upper limit on the production cross-sections multiplied by the $t \\rightarrow Wb$ branching fraction is set. The observed 95% C.L. limit is found at $\\sigma_{qg\\to t} \\times {\\cal B} (t \\to bW)<2.5\\,\\,\\mathrm{pb}$ can...

  2. The Relationship between Searches Performed in Online Databases and the Number of Full-Text Articles Accessed: Measuring the Interaction between Database and E-Journal Collections

    Science.gov (United States)

    Lamothe, Alain R.

    2011-01-01

    The purpose of this paper is to report the results of a quantitative analysis exploring the interaction and relationship between the online database and electronic journal collections at the J. N. Desmarais Library of Laurentian University. A very strong relationship exists between the number of searches and the size of the online database…

  3. The Global Burden of Journal Peer Review in the Biomedical Literature: Strong Imbalance in the Collective Enterprise.

    Science.gov (United States)

    Kovanis, Michail; Porcher, Raphaël; Ravaud, Philippe; Trinquart, Ludovic

    2016-01-01

    The growth in scientific production may threaten the capacity for the scientific community to handle the ever-increasing demand for peer review of scientific publications. There is little evidence regarding the sustainability of the peer-review system and how the scientific community copes with the burden it poses. We used mathematical modeling to estimate the overall quantitative annual demand for peer review and the supply in biomedical research. The modeling was informed by empirical data from various sources in the biomedical domain, including all articles indexed at MEDLINE. We found that for 2015, across a range of scenarios, the supply exceeded by 15% to 249% the demand for reviewers and reviews. However, 20% of the researchers performed 69% to 94% of the reviews. Among researchers actually contributing to peer review, 70% dedicated 1% or less of their research work-time to peer review while 5% dedicated 13% or more of it. An estimated 63.4 million hours were devoted to peer review in 2015, among which 18.9 million hours were provided by the top 5% contributing reviewers. Our results support that the system is sustainable in terms of volume but emphasizes a considerable imbalance in the distribution of the peer-review effort across the scientific community. Finally, various individual interactions between authors, editors and reviewers may reduce to some extent the number of reviewers who are available to editors at any point.

  4. Stability of strong species interactions resist the synergistic effects of local and global pollution in kelp forests.

    Directory of Open Access Journals (Sweden)

    Laura J Falkenberg

    Full Text Available Foundation species, such as kelp, exert disproportionately strong community effects and persist, in part, by dominating taxa that inhibit their regeneration. Human activities which benefit their competitors, however, may reduce stability of communities, increasing the probability of phase-shifts. We tested whether a foundation species (kelp would continue to inhibit a key competitor (turf-forming algae under moderately increased local (nutrient and near-future forecasted global pollution (CO(2. Our results reveal that in the absence of kelp, local and global pollutants combined to cause the greatest cover and mass of turfs, a synergistic response whereby turfs increased more than would be predicted by adding the independent effects of treatments (kelp absence, elevated nutrients, forecasted CO(2. The positive effects of nutrient and CO(2 enrichment on turfs were, however, inhibited by the presence of kelp, indicating the competitive effect of kelp was stronger than synergistic effects of moderate enrichment of local and global pollutants. Quantification of physicochemical parameters within experimental mesocosms suggests turf inhibition was likely due to an effect of kelp on physical (i.e. shading rather than chemical conditions. Such results indicate that while forecasted climates may increase the probability of phase-shifts, maintenance of intact populations of foundation species could enable the continued strength of interactions and persistence of communities.

  5. Measurement of the strong interaction coupling constant αs by jet study in the H1 experiment

    International Nuclear Information System (INIS)

    Squinabol, F.

    1997-01-01

    The H1 experiment allows to study hadronic jets produced in deep inelastic lepton (27.5 GeV) scattering off protons (820 GeV). The coupling constant of the strong interaction α s can be extracted from the measurement of the 2-jets rate in the final state. The use of the JADE algorithm is optimal for events with high energy transfer (100-4,000 GeV 2 ), corresponding to the 1994 and 1995 data. The error on α s (M Z 0 2 ) is dominated by the uncertainty from the hadronic energy measurement and the experimental resolution effects on jets. The theoretical error is dominated by the renormalization scale dependence. The final result is (M Z 0 2 ) 0.118 -0.008 +0.008 . This analysis is extended to smaller momentum transfers (25-100 GeV 2 ) using the factorizable K t algorithm, taking the transferred momentum as energy scale of the particle re-clustering. The result α s (M Z 0 2 ) 0.117 -0.008 +0.009 is compatible with the previous one. The precision of the measurement performed in this thesis is 7%. A precision of 4% could be achieved after progresses in the theoretical framework and/or after a significant increase of the luminosity. (author)

  6. Proceedings of RIKEN BNL Research Center Workshop: The Approach to Equilibrium in Strongly Interacting Matter. Volume 118

    Energy Technology Data Exchange (ETDEWEB)

    Liao, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Venugopalan, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berges, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaizot, J. -P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gelis, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-04-09

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory*. It is funded by the ''Rikagaku Kenkyusho'' (RIKEN, The Institute of Physical and Chemical Research) of Japan and the U. S. Department of Energy’s Office of Science. The RBRC is dedicated to the study of strong interactions, including spin physics, lattice QCD, and RHIC physics through the nurturing of a new generation of young physicists. The RBRC has theory, lattice gauge computing and experimental components. It is presently exploring the possibility of an astrophysics component being added to the program. The purpose of this Workshop is to critically review the recent progress on the theory and phenomenology of early time dynamics in relativistic heavy ion collisions from RHIC to LHC energies, to examine the various approaches on thermalization and existing issues, and to formulate new research efforts for the future. Topics slated to be covered include Experimental evidence for equilibration/isotropization, comparison of various approaches, dependence on the initial conditions and couplings, and turbulent cascades and Bose-Einstein condensation.

  7. Aacsfi-PSC. Advanced accelerator concepts for strong field interaction simulated with the Plasma-Simulation-Code

    Energy Technology Data Exchange (ETDEWEB)

    Ruhl, Hartmut [Munich Univ. (Germany). Chair for Computational and Plasma Physics

    2016-11-01

    Since the installation of SuperMUC phase 2 the 9216 nodes of phase 1 are more easily available for large scale runs allowing for the thin foil and AWAKE simulations. Besides phase 2 could be used in parallel for high throughput of the ion acceleration simulations. Challenging to our project were the full-volume checkpoints required by PIC that strained the I/O-subsystem of SuperMUC to its limits. New approaches considered for the next generation system, like burst buffers could overcome this bottleneck. Additionally, as the FDTD solver in PIC is strongly bandwidth bound, PSC will benefit profoundly from high-bandwidth memory (HBM) that most likely will be available in future HPC machines. This will be of great advantage as in 2018 phase II of AWAKE should begin, with a longer plasma channel further increasing the need for additional computing resources. Last but not least, it is expected that our methods used in plasma physics (many body interaction with radiation) will be more and more adapted for medical diagnostics and treatments. For this research field we expect centimeter sized volumes with necessary resolutions of tens of micro meters resulting in boxes of >10{sup 12} voxels (100-200 TB) on a regular basis. In consequence the demand for computing time and especially for data storage and data handling capacities will also increase significantly.

  8. Spin-flip configuration interaction singles with exact spin-projection: Theory and applications to strongly correlated systems.

    Science.gov (United States)

    Tsuchimochi, Takashi

    2015-10-14

    Spin-flip approaches capture static correlation with the same computational scaling as the ordinary single reference methods. Here, we extend spin-flip configuration interaction singles (SFCIS) by projecting out intrinsic spin-contamination to make it spin-complete, rather than by explicitly complementing it with spin-coupled configurations. We give a general formalism of spin-projection for SFCIS, applicable to any spin states. The proposed method is viewed as a natural unification of SFCIS and spin-projected CIS to achieve a better qualitative accuracy at a low computational cost. While our wave function ansatz is more compact than previously proposed spin-complete SF approaches, it successfully offers more general static correlation beyond biradicals without sacrificing good quantum numbers. It is also shown that our method is invariant with respect to open-shell orbital rotations, due to the uniqueness of spin-projection. We will report benchmark calculations to demonstrate its qualitative performance on strongly correlated systems, including conical intersections that appear both in ground-excited and excited-excited degeneracies.

  9. The tumor suppressor homolog in fission yeast, myh1+, displays a strong interaction with the checkpoint gene rad1+

    International Nuclear Information System (INIS)

    Jansson, Kristina; Warringer, Jonas; Farewell, Anne; Park, Han-Oh; Hoe, Kwang-Lae; Kim, Dong-Uk; Hayles, Jacqueline; Sunnerhagen, Per

    2008-01-01

    The DNA glycosylase MutY is strongly conserved in evolution, and homologs are found in most eukaryotes and prokaryotes examined. This protein is implicated in repair of oxidative DNA damage, in particular adenine mispaired opposite 7,8-dihydro-8-oxoguanine. Previous investigations in Escherichia coli, fission yeast, and mammalian cells show an association of mutations in MutY homologs with a mutator phenotype and carcinogenesis. Eukaryotic MutY homologs physically associate with several proteins with a role in replication, DNA repair, and checkpoint signaling, specifically the trimeric 9-1-1 complex. In a genetic investigation of the fission yeast MutY homolog, myh1 + , we show that the myh1 mutation confers a moderately increased UV sensitivity alone and in combination with mutations in several DNA repair genes. The myh1 rad1, and to a lesser degree myh1 rad9, double mutants display a synthetic interaction resulting in enhanced sensitivity to DNA damaging agents and hydroxyurea. UV irradiation of myh1 rad1 double mutants results in severe chromosome segregation defects and visible DNA fragmentation, and a failure to activate the checkpoint. Additionally, myh1 rad1 double mutants exhibit morphological defects in the absence of DNA damaging agents. We also found a moderate suppression of the slow growth and UV sensitivity of rhp51 mutants by the myh1 mutation. Our results implicate fission yeast Myh1 in repair of a wider range of DNA damage than previously thought, and functionally link it to the checkpoint pathway

  10. Model-free inference of direct network interactions from nonlinear collective dynamics.

    Science.gov (United States)

    Casadiego, Jose; Nitzan, Mor; Hallerberg, Sarah; Timme, Marc

    2017-12-19

    The topology of interactions in network dynamical systems fundamentally underlies their function. Accelerating technological progress creates massively available data about collective nonlinear dynamics in physical, biological, and technological systems. Detecting direct interaction patterns from those dynamics still constitutes a major open problem. In particular, current nonlinear dynamics approaches mostly require to know a priori a model of the (often high dimensional) system dynamics. Here we develop a model-independent framework for inferring direct interactions solely from recording the nonlinear collective dynamics generated. Introducing an explicit dependency matrix in combination with a block-orthogonal regression algorithm, the approach works reliably across many dynamical regimes, including transient dynamics toward steady states, periodic and non-periodic dynamics, and chaos. Together with its capabilities to reveal network (two point) as well as hypernetwork (e.g., three point) interactions, this framework may thus open up nonlinear dynamics options of inferring direct interaction patterns across systems where no model is known.

  11. Anisotropy and Strong-Coupling Effects on the Collective Mode Spectrum of Chiral Superconductors: Application to Sr2RuO4

    Directory of Open Access Journals (Sweden)

    James Avery Sauls

    2015-06-01

    Full Text Available Recent theories of Sr2RuO4 based on the interplay of strong interactions, spin-orbit coupling and multi-band anisotropy predict chiral or helical ground states with strong anisotropy of the pairing states, with deep minima in the excitation gap, as well as strong phase anisotropy for the chiral ground state. We develop time-dependent mean field theory to calculate the Bosonic spectrum for the class of 2D chiral superconductors spanning 3He-A to chiral superconductors with strong anisotropy. Chiral superconductors support a pair of massive Bosonic excitations of the time-reversed pairs labeled by their parity under charge conjugation. These modes are degenerate for 2D 3He-A. Crystal field anisotropy lifts the degeneracy. Strong anisotropy also leads to low-lying Fermions, and thus to channels for the decay of the Bosonic modes. Selection rules and phase space considerations lead to large asymmetries in the lifetimes and hybridization of the Bosonic modes with the continuum of un-bound Fermion pairs. We also highlight results for the excitation of the Bosonic modes by microwave radiation that provide clear signatures of the Bosonic modes of an anisotropic chiral ground state.

  12. Production Cross-Section Estimates for Strongly-Interacting Electroweak-Symmetry Breaking Sector Resonances at Particle Colliders

    Science.gov (United States)

    Dobado, Antonio; Guo, Feng-Kun; Llanes-Estrada, Felipe J.

    2015-12-01

    We are exploring a generic strongly-interacting Electroweak Symmetry Breaking Sector (EWSBS) with the low-energy effective field theory for the four experimentally known particles (W±L, ZL, h) and its dispersion-relation based unitary extension. In this contribution we provide simple estimates for the production cross-section of pairs of the EWSBS bosons and their resonances at proton-proton colliders as well as in a future e-e+ (or potentially a μ-μ+) collider with a typical few-TeV energy. We examine the simplest production mechanisms, tree-level production through a W (dominant when quantum numbers allow) and the simple effective boson approximation (in which the electroweak bosons are considered as collinear partons of the colliding fermions). We exemplify with custodial isovector and isotensor resonances at 2 TeV, the energy currently being discussed because of a slight excess in the ATLAS 2-jet data. We find it hard, though not unthinkable, to ascribe this excess to one of these WLWL rescattering resonances. An isovector resonance could be produced at a rate smaller than, but close to earlier CMS exclusion bounds, depending on the parameters of the effective theory. The ZZ excess is then problematic and requires additional physics (such as an additional scalar resonance). The isotensor one (that would describe all charge combinations) has smaller cross-section. Supported by the Spanish Excellence Network on Hadronic Physics FIS2014-57026-REDT, by Spanish Grants Universidad Complutense UCM:910309 and Ministerio de Economia y Competitividad MINECO:FPA2011-27853-C02-01, MINECO:FPA2014-53375-C2-1-P, by the Deutsche Forschungsgemeinschaft and National Natural Science Foundation of China through Funds Provided to the Sino-German CRC 110 “Symmetries and the Emergence of Structure in QCD” (NSFC Grant No. 11261130311) and by NSFC (Grant No. 11165005)

  13. Investigating conversational dynamics: Interactive alignment, Interpersonal synergy, and collective task performance

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, interactive alignment and interpersonal synergy, and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between...... and their impact on collective performance in a corpus of task-oriented conversations. The results show statistical presence of patterns relevant for both approaches. However, synergetic aspects of dialog provide the best statistical predictors of collective performance and adding aspects of the alignment approach...... does not improve the model. This suggests that structural organization at the level of the interaction plays a crucial role in task-oriented conversations, possibly constraining and integrating processes related to alignment....

  14. SN 2011A: A Low-luminosity Interacting Transient with a Double Plateau and Strong Sodium Absorption

    Science.gov (United States)

    de Jaeger, T.; Anderson, J. P.; Pignata, G.; Hamuy, M.; Kankare, E.; Stritzinger, M. D.; Benetti, S.; Bufano, F.; Elias-Rosa, N.; Folatelli, G.; Förster, F.; González-Gaitán, S.; Gutiérrez, C. P.; Inserra, C.; Kotak, R.; Lira, P.; Morrell, N.; Taddia, F.; Tomasella, L.

    2015-07-01

    We present optical photometry and spectroscopy of the optical transient SN 2011A. Our data span 140 days after discovery including {BVRI} u\\prime g\\prime r\\prime i\\prime z\\prime photometry and 11 epochs of optical spectroscopy. Originally classified as a type IIn supernova (SN IIn) due to the presence of narrow Hα emission, this object shows exceptional characteristics. First, the light curve shows a double plateau, a property only observed before in the impostor SN 1997bs. Second, SN 2011A has a very low luminosity ({M}V=-15.72), placing it between normal luminous SNe IIn and SN impostors. Third, SN 2011A shows low velocity and high equivalent width absorption close to the sodium doublet, which increases with time and is most likely of circumstellar origin. This evolution is also accompanied by a change in line profile; when the absorption becomes stronger, a P Cygni profile appears. We discuss SN 2011A in the context of interacting SNe IIn and SN impostors, which appears to confirm the uniqueness of this transient. While we favor an impostor origin for SN 2011A, we highlight the difficulty in differentiating between terminal and non-terminal interacting transients. This paper includes data obtained with the 6.5 m Magellan Telescopes and du Pont telescope; the Gemini-North Telescope, Mauna Kea, USA (Gemini Program GN-2010B-Q67, PI: Stritzinger); the PROMPT telescopes at Cerro Tololo Inter-American Observatory in Chile; with the Liverpool Telescope operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council; based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias; the NTT from ESO Science Archive

  15. Mathematical Analysis for Non-reciprocal-interaction-based Model of Collective Behavior

    Science.gov (United States)

    Kano, Takeshi; Osuka, Koichi; Kawakatsu, Toshihiro; Ishiguro, Akio

    2017-12-01

    In many natural and social systems, collective behaviors emerge as a consequence of non-reciprocal interaction between their constituents. As a first step towards understanding the core principle that underlies these phenomena, we previously proposed a minimal model of collective behavior based on non-reciprocal interactions by drawing inspiration from friendship formation in human society, and demonstrated via simulations that various non-trivial patterns emerge by changing parameters. In this study, a mathematical analysis of the proposed model wherein the system size is small is performed. Through the analysis, the mechanism of the transition between several patterns is elucidated.

  16. The dynamics of meaningful social interactions and the emergence of collective knowledge

    Science.gov (United States)

    Dankulov, Marija Mitrović; Melnik, Roderick; Tadić, Bosiljka

    2015-07-01

    Collective knowledge as a social value may arise in cooperation among actors whose individual expertise is limited. The process of knowledge creation requires meaningful, logically coordinated interactions, which represents a challenging problem to physics and social dynamics modeling. By combining two-scale dynamics model with empirical data analysis from a well-known Questions & Answers system Mathematics, we show that this process occurs as a collective phenomenon in an enlarged network (of actors and their artifacts) where the cognitive recognition interactions are properly encoded. The emergent behavior is quantified by the information divergence and innovation advancing of knowledge over time and the signatures of self-organization and knowledge sharing communities. These measures elucidate the impact of each cognitive element and the individual actor’s expertise in the collective dynamics. The results are relevant to stochastic processes involving smart components and to collaborative social endeavors, for instance, crowdsourcing scientific knowledge production with online games.

  17. Collective excitations with chiral NN+3N interactions from coupled-cluster and in-medium SRG

    International Nuclear Information System (INIS)

    Trippel, Richard

    2016-01-01

    A broad variety of many-body methods exists for the investigation of ground-state properties, ranging from sophisticated ab initio approaches to traditional, phenomenological models. The description of low-lying excited states of medium-mass nuclei with ab initio methods has also become possible through recent progress in many-body theory. For collective modes at higher energies, however, these methods usually cannot be applied. Therefore, when describing collective excitations either completely phenomenological, macroscopic models are employed or microscopic models using phenomenological interactions. One of the microscopic models well suited for the calculation of collective properties is the random-phase approximation (RPA). In the past, the use of phenomenological interactions for RPA has shown promising results. However, the application of chiral NN interactions yielded transitions at significantly too high energies, far from agreement with experimental data. This thesis focuses on the description of collective modes using both RPA and its second-order extension, SRPA. In contrast to previous research endeavors, we employ chiral NN+3N interactions. The use of chiral interactions is an important first step for describing ground-state, excitation and collective properties on an equal foundation. We find that the inclusion of 3N terms is crucial for RPA calculations and the prediction for collective modes is drastically improved through the 3N terms. For SRPA we show first-ever results with chiral interactions, again leading to an improvement in the predictions. For a successful ab initio description of ground-state properties the inclusion of correlations is of paramount importance. Past RPA calculations have been performed using the quasi-boson approximation, effectively neglecting ground-state correlations. Using RPA, the next step along the path towards an ab initio description of collective properties will, therefore, be the inclusion of correlations. To

  18. Collective excitations with chiral NN+3N interactions from coupled-cluster and in-medium SRG

    Energy Technology Data Exchange (ETDEWEB)

    Trippel, Richard

    2016-12-19

    A broad variety of many-body methods exists for the investigation of ground-state properties, ranging from sophisticated ab initio approaches to traditional, phenomenological models. The description of low-lying excited states of medium-mass nuclei with ab initio methods has also become possible through recent progress in many-body theory. For collective modes at higher energies, however, these methods usually cannot be applied. Therefore, when describing collective excitations either completely phenomenological, macroscopic models are employed or microscopic models using phenomenological interactions. One of the microscopic models well suited for the calculation of collective properties is the random-phase approximation (RPA). In the past, the use of phenomenological interactions for RPA has shown promising results. However, the application of chiral NN interactions yielded transitions at significantly too high energies, far from agreement with experimental data. This thesis focuses on the description of collective modes using both RPA and its second-order extension, SRPA. In contrast to previous research endeavors, we employ chiral NN+3N interactions. The use of chiral interactions is an important first step for describing ground-state, excitation and collective properties on an equal foundation. We find that the inclusion of 3N terms is crucial for RPA calculations and the prediction for collective modes is drastically improved through the 3N terms. For SRPA we show first-ever results with chiral interactions, again leading to an improvement in the predictions. For a successful ab initio description of ground-state properties the inclusion of correlations is of paramount importance. Past RPA calculations have been performed using the quasi-boson approximation, effectively neglecting ground-state correlations. Using RPA, the next step along the path towards an ab initio description of collective properties will, therefore, be the inclusion of correlations. To

  19. Interaction networks, ecological stability, and collective antibiotic tolerance in polymicrobial infections

    Science.gov (United States)

    de Vos, Marjon G. J.; Bollenbach, Tobias

    2017-01-01

    Polymicrobial infections constitute small ecosystems that accommodate several bacterial species. Commonly, these bacteria are investigated in isolation. However, it is unknown to what extent the isolates interact and whether their interactions alter bacterial growth and ecosystem resilience in the presence and absence of antibiotics. We quantified the complete ecological interaction network for 72 bacterial isolates collected from 23 individuals diagnosed with polymicrobial urinary tract infections and found that most interactions cluster based on evolutionary relatedness. Statistical network analysis revealed that competitive and cooperative reciprocal interactions are enriched in the global network, while cooperative interactions are depleted in the individual host community networks. A population dynamics model parameterized by our measurements suggests that interactions restrict community stability, explaining the observed species diversity of these communities. We further show that the clinical isolates frequently protect each other from clinically relevant antibiotics. Together, these results highlight that ecological interactions are crucial for the growth and survival of bacteria in polymicrobial infection communities and affect their assembly and resilience. PMID:28923953

  20. Antenatal interpersonal sensitivity is more strongly associated than perinatal depressive symptoms with postnatal mother-infant interaction quality.

    Science.gov (United States)

    Raine, Karen; Cockshaw, Wendell; Boyce, Philip; Thorpe, Karen

    2016-10-01

    Maternal mental health has enduring effects on children's life chances and is a substantial cost driver for child health, education and social services. A key linking mechanism is the quality of mother-infant interaction. A body of work associates maternal depressive symptoms across the antenatal and postnatal (perinatal) period with less-than-optimal mother-infant interaction. Our study aims to build on previous research in the field through exploring the association of a maternal personality trait, interpersonal sensitivity, measured in early pregnancy, with subsequent mother-infant interaction quality. We analysed data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to examine the association between antenatal interpersonal sensitivity and postnatal mother-infant interaction quality in the context of perinatal depressive symptoms. Interpersonal sensitivity was measured during early pregnancy and depressive symptoms in the antenatal year and across the first 21 months of the postnatal period. In a subsample of the ALSPAC, mother-infant interaction was measured at 12 months postnatal through a standard observation. For the subsample that had complete data at all time points (n = 706), hierarchical regression examined the contribution of interpersonal sensitivity to variance in mother-infant interaction quality. Perinatal depressive symptoms predicted little variance in mother-infant interaction. Antenatal interpersonal sensitivity explained a greater proportion of variance in mother-infant interaction quality. The personality trait, interpersonal sensitivity, measured in early pregnancy, is a more robust indicator of subsequent mother-infant-interaction quality than perinatal depressive symptoms, thus affording enhanced opportunity to identify vulnerable mother-infant relationships for targeted early intervention.

  1. Correlations and symmetry of interactions influence collective dynamics of molecular motors

    International Nuclear Information System (INIS)

    Celis-Garza, Daniel; Teimouri, Hamid; Kolomeisky, Anatoly B

    2015-01-01

    Enzymatic molecules that actively support many cellular processes, including transport, cell division and cell motility, are known as motor proteins or molecular motors. Experimental studies indicate that they interact with each other and they frequently work together in large groups. To understand the mechanisms of collective behavior of motor proteins we study the effect of interactions in the transport of molecular motors along linear filaments. It is done by analyzing a recently introduced class of totally asymmetric exclusion processes that takes into account the intermolecular interactions via thermodynamically consistent approach. We develop a new theoretical method that allows us to compute analytically all dynamic properties of the system. Our analysis shows that correlations play important role in dynamics of interacting molecular motors. Surprisingly, we find that the correlations for repulsive interactions are weaker and more short-range than the correlations for the attractive interactions. In addition, it is shown that symmetry of interactions affect dynamic properties of molecular motors. The implications of these findings for motor proteins transport are discussed. Our theoretical predictions are tested by extensive Monte Carlo computer simulations. (paper)

  2. A Comprehensive Analysis of Jet Quenching via a Hybrid Strong/Weak Coupling Model for Jet-Medium Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Casalderrey-Solana, Jorge [Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Gulhan, Doga Can [Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Milhano, José Guilherme [CENTRA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Physics Department, Theory Unit, CERN, CH-1211 Genève 23 (Switzerland); Pablos, Daniel [Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Rajagopal, Krishna [Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2016-12-15

    Within a hybrid strong/weak coupling model for jets in strongly coupled plasma, we explore jet modifications in ultra-relativistic heavy ion collisions. Our approach merges the perturbative dynamics of hard jet evolution with the strongly coupled dynamics which dominates the soft exchanges between the fast partons in the jet shower and the strongly coupled plasma itself. We implement this approach in a Monte Carlo, which supplements the DGLAP shower with the energy loss dynamics as dictated by holographic computations, up to a single free parameter that we fit to data. We then augment the model by incorporating the transverse momentum picked up by each parton in the shower as it propagates through the medium, at the expense of adding a second free parameter. We use this model to discuss the influence of the transverse broadening of the partons in a jet on intra-jet observables. In addition, we explore the sensitivity of such observables to the back-reaction of the plasma to the passage of the jet.

  3. Spontaneous emission spectra and quantum light-matter interactions from a strongly coupled quantum dot metal-nanoparticle system

    DEFF Research Database (Denmark)

    Van Vlack, C.; Kristensen, Philip Trøst; Hughes, S.

    2012-01-01

    the dot to the detector, we demonstrate that the strong-coupling regime should be observable in the far-field spontaneous emission spectrum, even at room temperature. The vacuum-induced emission spectra show that the usual vacuum Rabi doublet becomes a rich spectral triplet or quartet with two of the four...

  4. Collective multipole excitations based on correlated realistic nucleon-nucleon interactions

    International Nuclear Information System (INIS)

    Paar, N.; Papakonstantinou, P.; Hergert, H.; Roth, R.

    2006-01-01

    We investigate collective multipole excitations for closed shell nuclei from 16 O to 208 Pb using correlated realistic nucleon-nucleon interactions in the framework of the random phase approximation (RPA). The dominant short-range central and tensor correlations a re treated explicitly within the Unitary Correlation Operator Method (UCOM), which provides a phase-shift equivalent correlated interaction VUCOM adapted to simple uncorrelated Hilbert spaces. The same unitary transformation that defines the correlated interaction is used to derive correlated transition operators. Using VUCOM we solve the Hartree-Fock problem and employ the single-particle states as starting point for the RPA. By construction, the UCOM-RPA is fully self-consistent, i.e. the same correlated nucleon-nucleon interact ion is used in calculations of the HF ground state and in the residual RPA interaction. Consequently, the spurious state associated with the center-of-mass motion is properly removed and the sum-rules are exhausted within ±3%. The UCOM-RPA scheme results in a collective character of giant monopole, dipole, and quadrupole resonances in closed-shell nuclei across the nuclear chart. For the isoscalar giant monopole resonance, the resonance energies are in agreement with experiment hinting at a reasonable compressibility. However, in the 1 - and 2 + channels the resonance energies are overestimated due to missing long-range correlations and three-body contributions. (orig.)

  5. Pesticide interactions with soil affected by olive mill wastewater (OMW): how strong and long-lasting is the OMW effect?

    Science.gov (United States)

    Keren, Yonatan; Borisover, Mikhail; Schaumann, Gabriele E.; Diehl, Dörte; Tamimi, Nisreen; Bukhanovsky, Nadezhda

    2017-04-01

    Sorption interactions with soils are well known to control the environmental fate of multiple organic compounds including pesticides. Pesticide-soil interactions may be affected by organic amendments or organic matter (OM)-containing wastewater brought to the field. Specifically, land spreading of olive mill wastewater (OMW), occurring intentionally or not, may also influence pesticide-soil interactions. The effects of the OMW disposed in the field on soil properties, including their ability to interact with pesticides, become of great interest due to the increasing demand for olive oil and a constant growth of world oil production. This paper summarizes some recent findings related to the effect of prior OMW land application on the ability of soils to interact with the organic compounds including pesticides, diuron and simazine. The major findings are as following: (1) bringing OMW to the field increases the potential of soils to sorb non-ionized pesticides; (2) this sorption increase may not be related solely to the increase in soil organic carbon content but it can reflect also the changes in the soil sorption mechanisms; (3) increased pesticide interactions with OMW-affected soils may become irreversible, due, assumedly, to the swelling of some components of the OMW-treated soil; (4) enhanced pesticide-soil interactions mitigate with the time passed after the OMW application, however, in the case of diuron, the remaining effect could be envisioned at least 600 days after the normal OMW application; (5) the enhancement effect of OMW application on soil sorption may increase with soil depth, in the 0-10 cm interval; (6) at higher pesticide (diuron) concentrations, larger extents of sorption enhancement, following the prior OMW-soil interactions, may be expected; (7) disposal of OMW in the field may be seasonal-dependent, and, in the case studied, it led to more distinct impacts on sorption when carried out in spring and winter, as compared with summer. It appears

  6. Perturbative correction to the ground-state properties of one-dimensional strongly interacting bosons in a harmonic trap

    International Nuclear Information System (INIS)

    Paraan, Francis N. C.; Korepin, Vladimir E.

    2010-01-01

    We calculate the first-order perturbation correction to the ground-state energy and chemical potential of a harmonically trapped boson gas with contact interactions about the infinite repulsion Tonks-Girardeau limit. With c denoting the interaction strength, we find that, for a large number of particles N, the 1/c correction to the ground-state energy increases as N 5/2 , in contrast to the unperturbed Tonks-Girardeau value that is proportional to N 2 . We describe a thermodynamic scaling limit for the trapping frequency that yields an extensive ground-state energy and reproduces the zero temperature thermodynamics obtained by a local-density approximation.

  7. Experimental and numerical study of the strong interaction between wakes of cylindrical obstacles; Etude experimentale et numerique de l'interaction forte entre sillages d'obstacles cylindriques

    Energy Technology Data Exchange (ETDEWEB)

    Brun, Ch

    1998-04-02

    In the context of thermal-hydraulics of nuclear reactors, strong interaction between wakes is encountered in the bottom of reactor vessels where control and measurement rods of variable size and disposition interact with the overall wakes generated in these flow zones. This study deals with the strong interaction between two wakes developed downstream of two parallel cylinders with a small spacing. The analysis focusses on the effect of the Reynolds regime which controls the equilibrium between the inertia and viscosity forces of the fluid and influences the large scale behaviour of the flow with the development of hydrodynamic instabilities and turbulence. The document is organized as follows: the characteristic phenomena of wakes formation downstream of cylindrical obstacles are recalled in the first chapter (single cylinder, interaction between two tubes, case of a bundle of tubes perpendicular to the flow). The experimental setup (hydraulic loop, velocity and pressure measurement instrumentation) and the statistical procedures applied to the signals measured are detailed in chapters 2 and 3. Chapter 4 is devoted to the experimental study of the strong interaction between two tubes. Laser Doppler velocity measurements in the wakes close to cylinders and pressure measurements performed on tube walls are reported in this chapter. In chapter 5, a 2-D numerical simulation of two typical cases of interaction (Re = 1000 and Re = 5000) is performed. In the last chapter, a more complex application of strong interactions inside and downstream of a bunch of staggered tubes is analyzed experimentally for equivalent Reynolds regimes. (J.S.)

  8. Potential Drug-Drug Interactions among Patients prescriptions collected from Medicine Out-patient Setting.

    Science.gov (United States)

    Farooqui, Riffat; Hoor, Talea; Karim, Nasim; Muneer, Mehtab

    2018-01-01

    To identify and evaluate the frequency, severity, mechanism and common pairs of drug-drug interactions (DDIs) in prescriptions by consultants in medicine outpatient department. This cross sectional descriptive study was done by Pharmacology department of Bahria University Medical & Dental College (BUMDC) in medicine outpatient department (OPD) of a private hospital in Karachi from December 2015 to January 2016. A total of 220 prescriptions written by consultants were collected. Medications given with patient's diagnosis were recorded. Drugs were analyzed for interactions by utilizing Medscape drug interaction checker, drugs.com checker and stockley`s drug interactions index. Two hundred eleven prescriptions were selected while remaining were excluded from the study because of unavailability of the prescribed drugs in the drug interaction checkers. In 211 prescriptions, two common diagnoses were diabetes mellitus (28.43%) and hypertension (27.96%). A total of 978 medications were given. Mean number of medications per prescription was 4.6. A total of 369 drug-drug interactions were identified in 211 prescriptions (175%). They were serious 4.33%, significant 66.12% and minor 29.53%. Pharmacokinetic and pharmacodynamic interactions were 37.94% and 51.21% respectively while 10.84% had unknown mechanism. Number wise common pairs of DDIs were Omeprazole-Losartan (S), Gabapentine- Acetaminophen (M), Losartan-Diclofenac (S). The frequency of DDIs is found to be too high in prescriptions of consultants from medicine OPD of a private hospital in Karachi. Significant drug-drug interactions were more and mostly caused by Pharmacodynamic mechanism. Number wise evaluation showed three common pairs of drugs involved in interactions.

  9. INTERACTION OF LASER RADIATION WITH MATTER. LASER PLASMA: Self-pumped passive ring mirror in crystals with strong fanning

    Science.gov (United States)

    Bogodaev, N. V.; Zozulya, A. A.; Ivleva, Lyudmila I.; Korshunov, A. S.; Mamaev, A. V.; Polozkov, N. M.

    1992-05-01

    Most photorefractive crystals suitable for four-wave systems of phase self-conjugation and mutual conjugation have a fairly high level of light-induced scattering (fanning). This may imply that the nonlinearity of a crystal is too strong for optimal operation and a reduction in this nonlinearity would improve the characteristics. This statement is illustrated theoretically and experimentally using the geometry of a loop parametric oscillator as an example.

  10. Limits on cosmological variation of strong interaction and quark masses from big bang nucleosynthesis, cosmic, laboratory and Oklo data

    International Nuclear Information System (INIS)

    Flambaum, V.V.; Shuryak, E.V.

    2002-01-01

    Recent data on the cosmological variation of the electromagnetic fine structure constant from distant quasar (QSO) absorption spectra have inspired a more general discussion of the possible variation of other constants. We discuss the variation of strong scale and quark masses. We derive limits on their relative change from (i) primordial big bang nucleosynthesis, (ii) the Oklo natural nuclear reactor, (iii) quasar absorption spectra, and (iv) laboratory measurements of hyperfine intervals

  11. Fragility of the spin-glass-like collective state to a magnetic field in an interacting Fe-C nanoparticle system

    DEFF Research Database (Denmark)

    Jönsson, P. E.; Felton, S.; Svedlindh, P.

    2001-01-01

    The effect of applied magnetic fields on the collective nonequilibrium dynamics of a strongly interacting Fe-C nanoparticle system has been investigated. It is experimentally shown that the magnetic aging diminishes to finally disappear for fields of moderate strength. The field needed to remove ...... the observable aging behavior increases with decreasing temperature. The same qualitative behavior is observed in an amorphous metallic spin glass (Fe0.15Ni0.85)(75)P16B6Al3....

  12. A double-mutant collection targeting MAP kinase related genes in Arabidopsis for studying genetic interactions.

    Science.gov (United States)

    Su, Shih-Heng; Krysan, Patrick J

    2016-12-01

    Mitogen-activated protein kinase cascades are conserved in all eukaryotes. In Arabidopsis thaliana there are approximately 80 genes encoding MAP kinase kinase kinases (MAP3K), 10 genes encoding MAP kinase kinases (MAP2K), and 20 genes encoding MAP kinases (MAPK). Reverse genetic analysis has failed to reveal abnormal phenotypes for a majority of these genes. One strategy for uncovering gene function when single-mutant lines do not produce an informative phenotype is to perform a systematic genetic interaction screen whereby double-mutants are created from a large library of single-mutant lines. Here we describe a new collection of 275 double-mutant lines derived from a library of single-mutants targeting genes related to MAP kinase signaling. To facilitate this study, we developed a high-throughput double-mutant generating pipeline using a system for growing Arabidopsis seedlings in 96-well plates. A quantitative root growth assay was used to screen for evidence of genetic interactions in this double-mutant collection. Our screen revealed four genetic interactions, all of which caused synthetic enhancement of the root growth defects observed in a MAP kinase 4 (MPK4) single-mutant line. Seeds for this double-mutant collection are publicly available through the Arabidopsis Biological Resource Center. Scientists interested in diverse biological processes can now screen this double-mutant collection under a wide range of growth conditions in order to search for additional genetic interactions that may provide new insights into MAP kinase signaling. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  13. Calculation of anomalous dimension of single-particle Green function in scalar field theory with strong nonlinear interaction

    International Nuclear Information System (INIS)

    Kolesnichenko, A.V.

    1980-01-01

    An expression for the anomalous dimension of the single-particle Green function is derived in the scalar theory with the interaction Hamiltonian Hsub(int)=g(phisup(n)/n) in the limit n→infinity. It is simultaneously shown that in this model the range of essential distances is of order of nsup(-1/2)

  14. A global analysis of bidirectional interactions in alpine plant communities shows facilitators experiencing strong reciprocal fitness costs.

    Science.gov (United States)

    Schöb, Christian; Michalet, Richard; Cavieres, Lohengrin A; Pugnaire, Francisco I; Brooker, Rob W; Butterfield, Bradley J; Cook, Bradley J; Kikvidze, Zaal; Lortie, Christopher J; Xiao, Sa; Al Hayek, Patrick; Anthelme, Fabien; Cranston, Brittany H; García, Mary-Carolina; Le Bagousse-Pinguet, Yoann; Reid, Anya M; le Roux, Peter C; Lingua, Emanuele; Nyakatya, Mawethu J; Touzard, Blaise; Zhao, Liang; Callaway, Ragan M

    2014-04-01

    Facilitative interactions are defined as positive effects of one species on another, but bidirectional feedbacks may be positive, neutral, or negative. Understanding the bidirectional nature of these interactions is a fundamental prerequisite for the assessment of the potential evolutionary consequences of facilitation. In a global study combining observational and experimental approaches, we quantified the impact of the cover and richness of species associated with alpine cushion plants on reproductive traits of the benefactor cushions. We found a decline in cushion seed production with increasing cover of cushion-associated species, indicating that being a benefactor came at an overall cost. The effect of cushion-associated species was negative for flower density and seed set of cushions, but not for fruit set and seed quality. Richness of cushion-associated species had positive effects on seed density and modulated the effects of their abundance on flower density and fruit set, indicating that the costs and benefits of harboring associated species depend on the composition of the plant assemblage. Our study demonstrates 'parasitic' interactions among plants over a wide range of species and environments in alpine systems, and we consider their implications for the possible selective effects of interactions between benefactor and beneficiary species. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  15. Investigation of the source size and strong interaction with the femtoscopic correlations of baryons and antibaryons in heavy-ion collisions registered by ALICE

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00508100

    The strong interaction is one of the four fundamental forces of nature. It binds together quarks inside protons and neutrons (which are example of baryons - particles composed of three quarks) and assures the stability of the atomic nucleus. Parameters describing the strong potential are also crucial for the neutron stars models used in astrophysics. What is more, a precise study of strongly interacting particles may help to better understand the process of baryon annihilation. The current knowledge of the strong interactions between baryons other than nucle- ons is limited - there exist only a few measurements of the cross sections for pairs of (anti)baryons. The reason is that in many cases it is not possible to perform scattering experiments with beams of particles and antiparticles, as the exotic matter (such as Λ, Ξ or Σ baryons) is very shot-living. This issue can be solved thanks to the recent particle colliders like the Large Hadron Collider and experiments dedicated to study the heavy-ion collisio...

  16. Effect of exotic long-lived sub-strongly interacting massive particles in big bang nucleosynthesis and a new solution to the Li problem

    Directory of Open Access Journals (Sweden)

    Kawasaki Masahiro

    2012-02-01

    Full Text Available The plateau of 7Li abundance as a function of the iron abundance by spectroscopic observations of metal-poor halo stars (MPHSs indicates its primordial origin. The observed abundance levels are about a factor of three smaller than the primordial 7Li abundance predicted in the standard Big Bang Nucleosynthesis (BBN model. This discrepancy might originate from exotic particle and nuclear processes operating in BBN epoch. Some particle models include heavy (m >> 1 GeV long-lived colored particles which would be confined inside exotic heavy hadrons, i.e., strongly interacting massive particles (SIMPs. We have found reactions which destroy 7Be and 7Li during BBN in the scenario of BBN catalyzed by a long-lived sub-strongly interacting massive particle (sub-SIMP, X. The reactions are non radiative X captures of 7 Be and 7Li which can be operative if the X particle interacts with nuclei strongly enough to drive 7 Be destruction but not strongly enough to form a bound state with 4 He of relative angular momentum L = 1. We suggest that 7Li problem can be solved as a result of a new process beyond the standard model through which the observable signature was left on the primordial Li abundance.

  17. The Independent Gradient Model: A New Approach for Probing Strong and Weak Interactions in Molecules from Wave Function Calculations.

    Science.gov (United States)

    Lefebvre, Corentin; Khartabil, Hassan; Boisson, Jean-Charles; Contreras-García, Julia; Piquemal, Jean-Philip; Hénon, Eric

    2018-03-19

    Extraction of the chemical interaction signature from local descriptors based on electron density (ED) is still a fruitful field of development in chemical interpretation. In a previous work that used promolecular ED (frozen ED), the new descriptor, δg , was defined. It represents the difference between a virtual upper limit of the ED gradient (∇ρIGM , IGM=independent gradient model) that represents a noninteracting system and the true ED gradient (∇ρ ). It can be seen as a measure of electron sharing brought by ED contragradience. A compelling feature of this model is to provide an automatic workflow that extracts the signature of interactions between selected groups of atoms. As with the noncovalent interaction (NCI) approach, it provides chemists with a visual understanding of the interactions present in chemical systems. ∇ρIGM is achieved simply by using absolute values upon summing the individual gradient contributions that make up the total ED gradient. Hereby, we extend this model to relaxed ED calculated from a wave function. To this end, we formulated gradient-based partitioning (GBP) to assess the contribution of each orbital to the total ED gradient. We highlight these new possibilities across two prototypical examples of organic chemistry: the unconventional hexamethylbenzene dication, with a hexa-coordinated carbon atom, and β-thioaminoacrolein. It will be shown how a bond-by-bond picture can be obtained from a wave function, which opens the way to monitor specific interactions along reaction paths. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Average and extreme multi-atom Van der Waals interactions: Strong coupling of multi-atom Van der Waals interactions with covalent bonding

    Directory of Open Access Journals (Sweden)

    Finkelstein Alexei V

    2007-07-01

    Full Text Available Abstract Background The prediction of ligand binding or protein structure requires very accurate force field potentials – even small errors in force field potentials can make a 'wrong' structure (from the billions possible more stable than the single, 'correct' one. However, despite huge efforts to optimize them, currently-used all-atom force fields are still not able, in a vast majority of cases, even to keep a protein molecule in its native conformation in the course of molecular dynamics simulations or to bring an approximate, homology-based model of protein structure closer to its native conformation. Results A strict analysis shows that a specific coupling of multi-atom Van der Waals interactions with covalent bonding can, in extreme cases, increase (or decrease the interaction energy by about 20–40% at certain angles between the direction of interaction and the covalent bond. It is also shown that on average multi-body effects decrease the total Van der Waals energy in proportion to the square root of the electronic component of dielectric permittivity corresponding to dipole-dipole interactions at small distances, where Van der Waals interactions take place. Conclusion The study shows that currently-ignored multi-atom Van der Waals interactions can, in certain instances, lead to significant energy effects, comparable to those caused by the replacement of atoms (for instance, C by N in conventional pairwise Van der Waals interactions.

  19. YBa{sub 2}Cu{sub 3}O{sub 7} microwave resonators for strong collective coupling with spin ensembles

    Energy Technology Data Exchange (ETDEWEB)

    Ghirri, A., E-mail: alberto.ghirri@nano.cnr.it [Istituto Nanoscienze - CNR, Centro S3, via Campi 213/a, 41125 Modena (Italy); Bonizzoni, C.; Affronte, M. [Dipartimento Fisica, Informatica e Matematica, Università di Modena e Reggio Emilia and Istituto Nanoscienze - CNR, Centro S3, via Campi 213/a, 41125 Modena (Italy); Gerace, D.; Sanna, S. [Dipartimento di Fisica, Università di Pavia, via Bassi 6, 27100 Pavia (Italy); Cassinese, A. [CNR-SPIN and Dipartimento di Fisica, Università di Napoli Federico II, 80138 Napoli (Italy)

    2015-05-04

    Coplanar microwave resonators made of 330 nm-thick superconducting YBa{sub 2}Cu{sub 3}O{sub 7} have been realized and characterized in a wide temperature (T, 2–100 K) and magnetic field (B, 0–7 T) range. The quality factor (Q{sub L}) exceeds 10{sup 4} below 55 K and it slightly decreases for increasing fields, remaining 90% of Q{sub L}(B=0) for B = 7 T and T = 2 K. These features allow the coherent coupling of resonant photons with a spin ensemble at finite temperature and magnetic field. To demonstrate this, collective strong coupling was achieved by using di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium organic radical placed at the magnetic antinode of the fundamental mode: the in-plane magnetic field is used to tune the spin frequency gap splitting across the single-mode cavity resonance at 7.75 GHz, where clear anticrossings are observed with a splitting as large as ∼82 MHz at T = 2 K. The spin-cavity collective coupling rate is shown to scale as the square root of the number of active spins in the ensemble.

  20. Collective Dynamics and Strong Pinning near the Onset of Charge Order in La1.48Nd0.4Sr0.12CuO4

    Science.gov (United States)

    Baity, P. G.; Sasagawa, T.; Popović, Dragana

    2018-04-01

    The dynamics of charge-ordered states is one of the key issues in underdoped cuprate high-temperature superconductors, but static short-range charge-order (CO) domains have been detected in almost all cuprates. We probe the dynamics across the CO (and structural) transition in La1.48Nd0.4Sr0.12CuO4 by measuring nonequilibrium charge transport, or resistance R as the system responds to a change in temperature and to an applied magnetic field. We find evidence for metastable states, collective behavior, and criticality. The collective dynamics in the critical regime indicates strong pinning by disorder. Surprisingly, nonequilibrium effects, such as avalanches in R , are revealed only when the critical region is approached from the charge-ordered phase. Our results on La1.48Nd0.4Sr0.12CuO4 provide the long-sought evidence for the fluctuating order across the CO transition, and also set important constraints on theories of dynamic stripes.

  1. A new scalar resonance at 750 GeV: towards a proof of concept in favor of strongly interacting theories

    International Nuclear Information System (INIS)

    Son, Minho; Urbano, Alfredo

    2016-01-01

    We interpret the recently observed excess in the diphoton invariant mass as a new spin-0 resonant particle. On theoretical grounds, an interesting question is whether this new scalar resonance belongs to a strongly coupled sector or a well-defined weakly coupled theory. A possible UV-completion that has been widely considered in literature is based on the existence of new vector-like fermions whose loop contributions — Yukawa-coupled to the new resonance — explain the observed signal rate. The large total width preliminarily suggested by data seems to favor a large Yukawa coupling, at the border of a healthy perturbative definition. This potential problem can be fixed by introducing multiple vector-like fermions or large electric charges, bringing back the theory to a weakly coupled regime. However, this solution risks to be only a low-energy mirage: large multiplicity or electric charge can dangerously reintroduce the strong regime by modifying the renormalization group running of the dimensionless couplings. This issue is also tightly related to the (in)stability of the scalar potential. First, we study — in the theoretical setup described above — the parametric behavior of the diphoton signal rate, total width, and one-loop β functions. Then, we numerically solve the renormalization group equations, taking into account the observed diphoton signal rate and total width, to investigate the fate of the weakly coupled theory. We find that — with the only exception of few fine-tuned directions — weakly coupled interpretations of the excess are brought back to a strongly coupled regime if the running is taken into account.

  2. Theoretical Insights into Monometallofullerene Th@C76: Strong Covalent Interaction between Thorium and the Carbon Cage.

    Science.gov (United States)

    Zhao, Pei; Zhao, Xiang; Ehara, Masahiro

    2018-03-19

    Th@C 76 has been studied by density functional theory combined with statistical mechanics calculations. The results reveal that Th@ T d (19151)-C 76 satisfying the isolated pentagon rule possesses the lowest energy. Nevertheless, considering the enthalpy-entropy interplay, Th@ C 1 (17418)-C 76 with one pair of adjacent pentagons is thermodynamically favorable at elevated temperatures, which is reported for the first time. The bonding critical points in both isomers were analyzed to disclose covalent interactions between the inner Th and cages. In addition, the Wiberg bond orders of M-C bonding in different endohedral metallofullerenes (EMFs) were investigated to prove stronger covalent interactions of Th-C in Th-based EMFs.

  3. Micellar solubilization in strongly interacting binary surfactant systems. [Binary surfactant systems of: dodecyltrimethylammonium chloride + sodium dodecyl sulfate; benzyldimethyltetradecylammonium chloride + tetradecyltrimethylammonium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Treiner, C. (Universite Pierre et Marie Curie, Paris (France)); Nortz, M.; Vaution, C. (Faculte de Pharmacie de Paris-sud, Chatenay-Malabry (France))

    1990-07-01

    The apparent partition coefficient P of barbituric acids between micelles and water has been determined in mixed binary surfactant solutions from solubility measurements in the whole micellar composition range. The binary systems chosen ranged from the strongly interacting system dodecyltrimethylammonium chloride + sodium dodecyl sulfate to weakly interacting systems such as benzyldimethyltetradecylammonium chloride + tetradecyltrimethyammonium chloride. In all cases studied, mixed micelle formation is unfavorable to micellar solubilization. A correlation is found between the unlike surfactants interaction energy, as measured by the regular solution parameter {beta} and the solute partition coefficient change upon surfactant mixing. By use of literature data on micellar solubilization in binary surfactant solutions, it is shown that the change of P for solutes which are solubilized by surface adsorption is generally governed by the sign and amplitude of the interaction parameter {beta}.

  4. Origin of the Strong Interaction between Polar Molecules and Copper(II) Paddle-Wheels in Metal Organic Frameworks.

    Science.gov (United States)

    Ongari, Daniele; Tiana, Davide; Stoneburner, Samuel J; Gagliardi, Laura; Smit, Berend

    2017-07-20

    The copper paddle-wheel is the building unit of many metal organic frameworks. Because of the ability of the copper cations to attract polar molecules, copper paddle-wheels are promising for carbon dioxide adsorption and separation. They have therefore been studied extensively, both experimentally and computationally. In this work we investigate the copper-CO 2 interaction in HKUST-1 and in two different cluster models of HKUST-1: monocopper Cu(formate) 2 and dicopper Cu 2 (formate) 4 . We show that density functional theory methods severely underestimate the interaction energy between copper paddle-wheels and CO 2 , even including corrections for the dispersion forces. In contrast, a multireference wave function followed by perturbation theory to second order using the CASPT2 method correctly describes this interaction. The restricted open-shell Møller-Plesset 2 method (ROS-MP2, equivalent to (2,2) CASPT2) was also found to be adequate in describing the system and used to develop a novel force field. Our parametrization is able to predict the experimental CO 2 adsorption isotherms in HKUST-1, and it is shown to be transferable to other copper paddle-wheel systems.

  5. The Evolution of the Collective Forms of Interaction between Foreign Business and Government in Russia

    Directory of Open Access Journals (Sweden)

    Andrei A. Yakovlev

    2017-12-01

    Full Text Available The paper uses the evidence from Russia to analyze the arrangements for interaction between foreign firms and key national partners in the countries of their operations. We identify the main stages and factors that were driving the evolution of the two main channels of collective action for foreign firms in Russia over the last 25 years – the Foreign Investment Advisory Council under the Office of the Russian Prime Minister and foreign business associations. We also provide the comparative analysis of the effectiveness of these two main channels, as well as highlight the factors contributing to higher effectiveness of individual foreign business associations under the current Russia’s circumstances. We show that political rather than economic or institutional factors play a more significant role in explaining the changes in the effectiveness of collective efforts of foreign firms. Russia’s experience suggests that the mechanisms of interaction between foreign business and the authorities can work effectively only if there is mutual interest in such interaction. In Russia since the mid-2000s there have been relatively favorable political conditions for the dialogue between the Government and foreign firms, and the respective interaction mechanisms produced some positive effects regarding e.g. attraction of additional foreign investment inflows and modernization of the regulatory framework. However, with worsening the political situation in 2013, political priorities of the Russian Government became markedly more important than the economic ones, and thus, the effectiveness of the existing instruments for collective action of foreign firms significantly decreased. One consequence of this has been the greater willingness of foreign business associations to cooperate with Russian business in order to promote jointly a pragmatic reform agenda.

  6. Unexpected alignment patterns in high-j intruder bands evidence for a strong residual neutron proton interaction?

    International Nuclear Information System (INIS)

    Wyss, R.; Johnson, A.; Royal Inst. of Tech., Stockholm

    1990-01-01

    The alignment of h 11/12 protons in νi 13/2 intruder bands in mass A = 130 region is investigated. The lack of a clear h 11/12 band crossing is compared with the alignment pattern of i 13/2 neutrons in πi 13/2 intruder bands in mass A = 180 region. The very smooth rise in angular momentum in the intruder bands is related to a possible neutron proton interaction between the single intruder orbital and the aligned two-quasiparticle configuration. 36 refs., 3 figs

  7. Quantum ring with the Rashba spin-orbit interaction in the regime of strong light-matter coupling

    Science.gov (United States)

    Kozin, V. K.; Iorsh, I. V.; Kibis, O. V.; Shelykh, I. A.

    2018-04-01

    We developed the theory of electronic properties of semiconductor quantum rings with the Rashba spin-orbit interaction irradiated by an off-resonant high-frequency electromagnetic field (dressing field). Within the Floquet theory of periodically driven quantum systems, it is demonstrated that the dressing field drastically modifies all electronic characteristics of the rings, including spin-orbit coupling, effective electron mass, and optical response. In particular, the present effect paves the way to controlling the spin polarization of electrons with light in prospective ring-shaped spintronic devices.

  8. “Weak direct” and “Strong indirect” interactions are the mode of action of food factors

    Directory of Open Access Journals (Sweden)

    Tetsuya Konishi

    2014-06-01

    Full Text Available Age-dependent and lifestyle related diseases such as metabolic syndromes have become a social problem worldwide. Since these disorders are closely related to dietary lifestyle, the old saying “foods are medicine” is now being re-evaluated. Thus, dietary protection against these diseases is attracting much attention. As research into functional foods advances, a book of knowledge is being accumulated on the active ingredients, termed “food factors”, present in food resources. Identifying such molecules usually follows the conventional methodology used for finding drug candidates from natural resources. The question has arisen as to whether the mode of action of food factors as molecules is the same as that of drugs. In this article, the functional properties of food factors and drugs are comparatively reviewed and the characteristic features of food factor function is discussed, based on the idea of “weak direct” and “strong indirect” actions of food factors to their receptors

  9. Experimental characterization of a strongly coupled solid density plasma generated in a short-pulse laser target interaction

    International Nuclear Information System (INIS)

    Gregori, G.; Hansen, S.B.; Key, M.H.; King, J.; Mackinnon, A.J.; Park, H.; Patel, P.K.; Shepard, R.; Snavely, R.A.; Wilks, S.C.; Glenzer, S.H.

    2005-01-01

    We have measured high resolution copper Kα spectra from a picosecond high intensity laser produced plasma. By fitting the shape of the experimental spectra with a self-consistent-field model which includes all the relevant line shifts from multiply ionized atoms, we are able to infer time and spatially averaged electron temperatures (T e ) and ionization state (Z) in the foil. Our results show increasing values for T e and Z when the overall mass of the target is reduced. In particular, we measure temperatures in excess of 200 eV with Z ∼ 13-14. For these conditions the ion-ion coupling constant is Λ ii ∼ 8-9, thus suggesting the achievement of a strongly coupled plasma regime

  10. A Test of the Flavor Independence of Strong Interactions in e+e- Annihilation at the Z0 Pole

    Energy Technology Data Exchange (ETDEWEB)

    Muller, David

    1999-09-03

    This thesis presents a comparison of the strong coupling of the gluons to light (ql = u + d + s), c, and b quarks, determined from multijet rates in flavor-tagged samples of approximately 150,000 hadronic Z0 decays recorded with the SLC Large Detector at the SLAC Linear Collider between 1993 and 1995. Flavor separation among primary ql {anti ql} , c{anti c} and b {anti b} final states was made on the basis of the reconstructed mass of long-lived heavy-hadron decay vertices, yielding tags with high purity and low bias against {>=} 3-jet final states. The data obtained imply no flavor dependence within our sensitivity.

  11. Experimental characterization of a strongly coupled solid density plasma generated in a short-pulse laser target interaction

    Energy Technology Data Exchange (ETDEWEB)

    Gregori, G; Hansen, S B; Key, M H; King, J; Mackinnon, A J; Park, H; Patel, P K; Shepard, R; Snavely, R A; Wilks, S C; Glenzer, S H

    2005-03-17

    We have measured high resolution copper K{alpha} spectra from a picosecond high intensity laser produced plasma. By fitting the shape of the experimental spectra with a self-consistent-field model which includes all the relevant line shifts from multiply ionized atoms, we are able to infer time and spatially averaged electron temperatures (T{sub e}) and ionization state (Z) in the foil. Our results show increasing values for T{sub e} and Z when the overall mass of the target is reduced. In particular, we measure temperatures in excess of 200 eV with Z {approx} 13-14. For these conditions the ion-ion coupling constant is {Lambda}{sub ii} {approx} 8-9, thus suggesting the achievement of a strongly coupled plasma regime.

  12. Electric quadrupole moments and strong interaction effects in pionic atoms of 165Ho, 175Lu, 176Lu, 179Hf and 181Ta

    International Nuclear Information System (INIS)

    Olaniyi, B.; Shor, A.; Cheng, S.C.; Dugan, G.; Wu, C.S.

    1981-05-01

    The effective quadrupole moments Q sub(eff) of the nuclei of 165 Ho, 175 Lu, 176 Lu, 179 Hf and 181 Ta were accurately measured by detecting the pionic atom 5g-4f x-rays of the elements. The spectroscopic quadrupole moments, Q sub(spec), were obtained by correcting Q sub(eff) for nuclear finite size effect, distortion of the pion wave function by the pion-nucleus strong interaction, and contribution to the energy level splittings by the strong interaction. The intrinsic quadrupole moments, Q 0 , were obtained by projecting Q sub(spec) into the frame of reference fixed on the nucleus. The shift, epsilon 0 , and broadening, GAMMA 0 , of the 4f energy level due to the strong interactions between the pion and the nucleons for all the elements were also measured. Theoretical values of epsilon 0 and GAMMA 0 were calculated and compared to the experimental values. The measured values of Q 0 were compared with the existing results in muonic and pionic atoms. The measured values of epsilon 0 and GAMMA 0 were also compared with existing values. (auth)

  13. LATTICE SIMULATIONS OF THE THERMODYNAMICS OF STRONGLY INTERACTING ELEMENTARY PARTICLES AND THE EXPLORATION OF NEW PHASES OF MATTER IN RELATIVISTIC HEAVY ION COLLISIONS

    International Nuclear Information System (INIS)

    KARSCH, F.

    2006-01-01

    At high temperatures or densities matter formed by strongly interacting elementary particles (hadronic matter) is expected to undergo a transition to a new form of matter--the quark gluon plasma--in which elementary particles (quarks and gluons) are no longer confined inside hadrons but are free to propagate in a thermal medium much larger in extent than the typical size of a hadron. The transition to this new form of matter as well as properties of the plasma phase are studied in large scale numerical calculations based on the theory of strong interactions--Quantum Chromo Dynamics (QCD). Experimentally properties of hot and dense elementary particle matter are studied in relativistic heavy ion collisions such as those currently performed at the relativistic heavy ion collider (RHIC) at BNL. We review here recent results from studies of thermodynamic properties of strongly interacting elementary particle matter performed on Teraflops-Computer. We present results on the QCD equation of state and discuss the status of studies of the phase diagram at non-vanishing baryon number density

  14. Effects of the residual proton-neutron interaction in the development of collectivity in nuclei

    International Nuclear Information System (INIS)

    Casten, R.F.

    1990-01-01

    The widespread effects of the residual T=0 proton-neutron (p-n) interaction in the evolution of nuclear structure are discussed. Although these effects in inducing single nucleon configuration mixing, and hence in the development of non-spherical nuclear shapes, collectivity, and the associated shape and phase transitions have been known for four decades, it is only in recent years that their deep ramifications have become more fully appreciated. This had led to a unified phenomenological understanding of the role of the p-n interaction in nuclear collectivity and to, for example, the proposal of the N p N n scheme and the associated concept of the P factor, which is a normalized value of N p N n reflecting the average number of p-n interactions per valence nucleon. Simultaneously, experimentally-determined p-n matrix elements for many nuclei have been extracted: they disclose striking anomalies for N=Z nuclei, and intriguing microstructure. These developments and empirical results will be discussed along with microscopic calculations that can be used to interpret them. 18 refs., 13 figs

  15. Cell-cell interactions mediate cytoskeleton organization and collective endothelial cell chemotaxis.

    Science.gov (United States)

    Shamloo, Amir

    2014-09-01

    This study investigates the role of cell-cell and cell-ligand interactions in cytoskeleton organization of endothelial cells (ECs) and their directional migration within a microfluidic device. The migration of ECs in response to a biochemical factor was studied. Mathematical analysis of the cell migration pathways and cellular cytoskeleton revealed that directional migration, migration persistence length, migration speed, and cytoskeletal stress fiber alignment can be mediated by the level of cell contacts as well as the presence or absence of a biochemical polarizing factor. It was shown that in the presence of a biochemical polarizing factor, higher cell density and more frequent cell contacts has a reinforcing effect on collective cell chemotaxis. In contrast, in the absence of a polarizing factor, high cell density can decrease or suppress the ability of the cells to migrate. Also, the correlation of actin stress fiber organization and alignment with directional migration of ECs was investigated. It was shown that in the presence of a biochemical polarizing factor, stress fibers within the cytoskeleton of ECs can be significantly aligned parallel to the gradient direction when the cells have higher level of contacts. The results also show that the organization and alignment of actin stress fibers is mediated by cell adhesion junctions during collective cell migration and introduce cell-cell interactions as a key factor during collective cell chemotaxis. © 2014 Wiley Periodicals, Inc.

  16. Transcriptome analysis in oak uncovers a strong impact of endogenous rhythmic growth on the interaction with plant-parasitic nematodes.

    Science.gov (United States)

    Maboreke, Hazel R; Feldhahn, Lasse; Bönn, Markus; Tarkka, Mika T; Buscot, Francois; Herrmann, Sylvie; Menzel, Ralph; Ruess, Liliane

    2016-08-12

    Pedunculate oak (Quercus robur L.), an important forest tree in temperate ecosystems, displays an endogenous rhythmic growth pattern, characterized by alternating shoot and root growth flushes paralleled by oscillations in carbon allocation to below- and aboveground tissues. However, these common plant traits so far have largely been neglected as a determining factor for the outcome of plant biotic interactions. This study investigates the response of oak to migratory root-parasitic nematodes in relation to rhythmic growth, and how this plant-nematode interaction is modulated by an ectomycorrhizal symbiont. Oaks roots were inoculated with the nematode Pratylenchus penetrans solely and in combination with the fungus Piloderma croceum, and the systemic impact on oak plants was assessed by RNA transcriptomic profiles in leaves. The response of oaks to the plant-parasitic nematode was strongest during shoot flush, with a 16-fold increase in the number of differentially expressed genes as compared to root flush. Multi-layered defence mechanisms were induced at shoot flush, comprising upregulation of reactive oxygen species formation, hormone signalling (e.g. jasmonic acid synthesis), and proteins involved in the shikimate pathway. In contrast during root flush production of glycerolipids involved in signalling cascades was repressed, suggesting that P. penetrans actively suppressed host defence. With the presence of the mycorrhizal symbiont, the gene expression pattern was vice versa with a distinctly stronger effect of P. penetrans at root flush, including attenuated defence, cell and carbon metabolism, likely a response to the enhanced carbon sink strength in roots induced by the presence of both, nematode and fungus. Meanwhile at shoot flush, when nutrients are retained in aboveground tissue, oak defence reactions, such as altered photosynthesis and sugar pathways, diminished. The results highlight that gene response patterns of plants to biotic interactions, both

  17. Distortion of He(2l2l') Fano lineshapes by strong post-collision interaction in H+-He collisions

    International Nuclear Information System (INIS)

    Moretto-Capelle, P.; Benhenni, M.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A.

    1996-01-01

    The three-body post-collisional interaction (PCI) between the scattered proton, recoil target ion and emitted electron has been investigated by electron spectrometry near the 2l2l' helium resonances, in the 20-100 keV energy range (V p 0.9-2 au). Particular attention has been paid to the PCI deformations of the Fano lineshapes when V-vector'' p ≅ V-vector e (2l2l'). Their angle and collision velocity dependences have been studied for the first time experimentally. A large variety of lineshapes have been observed, all of them successfully described by a single formula. At the lowest proton velocities the rescattering effect (also called Coulomb two-path scattering) is seen. (Author)

  18. Spontaneous breaking of time-reversal symmetry in strongly interacting two-dimensional electron layers in silicon and germanium.

    Science.gov (United States)

    Shamim, S; Mahapatra, S; Scappucci, G; Klesse, W M; Simmons, M Y; Ghosh, A

    2014-06-13

    We report experimental evidence of a remarkable spontaneous time-reversal symmetry breaking in two-dimensional electron systems formed by atomically confined doping of phosphorus (P) atoms inside bulk crystalline silicon (Si) and germanium (Ge). Weak localization corrections to the conductivity and the universal conductance fluctuations were both found to decrease rapidly with decreasing doping in the Si:P and Ge:P delta layers, suggesting an effect driven by Coulomb interactions. In-plane magnetotransport measurements indicate the presence of intrinsic local spin fluctuations at low doping, providing a microscopic mechanism for spontaneous lifting of the time-reversal symmetry. Our experiments suggest the emergence of a new many-body quantum state when two-dimensional electrons are confined to narrow half-filled impurity bands.

  19. The unprecedented metamorphosis of SN2014C: from a H-stripped explosion to a strongly interacting supernova

    Science.gov (United States)

    Margutti, Raffaella

    2015-09-01

    Mass loss in massive stars is one of the least understood yet fundamental aspects of stellar evolution. HOW and WHEN do massive stars lose their H-envelopes? This central question motivates this proposal. We request a modest investment of Chandra time over 3 years to map the unique situation of the interaction of a H-stripped SN2014C with a H-rich shell ejected by its progenitor star, as part of our extensive radio-to-gamma-ray follow-up. Our goal is to constrain the density profile and proximity of the ejected material, and hence the mass-loss history of the progenitor star. Unlike all other H-stripped SNe, the radio and X-ray emission of SN14C is still increasing at 400 days, giving us the unprecedented opportunity to constrain the epoch ejection of H-rich material in fine detail.

  20. Disentangling weak and strong interactions in B → K*(→ Kπ)π Dalitz-plot analyses

    Energy Technology Data Exchange (ETDEWEB)

    Charles, Jerome [CNRS, Aix-Marseille Univ., Universite de Toulon, CPT UMR 7332, Marseille (France); Descotes-Genon, Sebastien [CNRS, Univ. Paris-Sud, Universite Paris-Saclay, Laboratoire de Physique Theorique (UMR 8627), Orsay (France); Ocariz, Jose [Sorbonne Universites, UPMC Univ. Paris 06, UMR 7585, LPNHE, Paris (France); Universite Paris Diderot, LPNHE UMR 7585, Sorbonne Paris Cite, Paris (France); Perez Perez, Alejandro [Universite de Strasbourg, CNRS, IPHC UMR 7178, Strasbourg (France); Collaboration: For the CKMfitter Group

    2017-08-15

    Dalitz-plot analyses of B → Kππ decays provide direct access to decay amplitudes, and thereby weak and strong phases can be disentangled by resolving the interference patterns in phase space between intermediate resonant states. A phenomenological isospin analysis of B → K*(→ Kπ)π decay amplitudes is presented exploiting available amplitude analyses performed at the BaBar, Belle and LHCb experiments. A first application consists in constraining the CKM parameters thanks to an external hadronic input. A method, proposed some time ago by two different groups and relying on a bound on the electroweak penguin contribution, is shown to lack the desired robustness and accuracy, and we propose a more alluring alternative using a bound on the annihilation contribution. A second application consists in extracting information on hadronic amplitudes assuming the values of the CKM parameters from a global fit to quark flavour data. The current data yields several solutions, which do not fully support the hierarchy of hadronic amplitudes usually expected from theoretical arguments (colour suppression, suppression of electroweak penguins), as illustrated from computations within QCD factorisation. Some prospects concerning the impact of future measurements at LHCb and Belle II are also presented. Results are obtained with the CKMfitter analysis package, featuring the frequentist statistical approach and using the Rfit scheme to handle theoretical uncertainties. (orig.)

  1. Stabilization effect of a strong HF electrical field on beam-plasma interaction in a relativistic plasma waveguide

    International Nuclear Information System (INIS)

    El-Shorbagy, K.H.

    2000-07-01

    The influence effect of a strong HF electrical field on the excitation of surface waves by an electron beam under the development of instability of low-density electron beam passing through plane relativistic plasma is investigated. Starting from the two fluid plasma model we separate the problem into two parts. The 'temporal' (dynamical) part enables us to find the frequencies and growth rates of unstable waves. This part within the redefinition of natural (eigen) frequencies coincide with the system describing HF suppression of the Buneman instability in a uniform unbounded plasma. Natural frequencies of oscillations and spatial distribution of the amplitude of the self-consistent electrical field are obtained by solving a boundary value problem ('spatial' part) considering a specific spatial distribution of plasma density. Plasma electrons are considered to have a relativistic velocity. It is shown that a HF electric field has no essential influence on dispersion characteristics of unstable surface waves excited in a relativistic plasma waveguide by a low-density electron beam. The region of instability only slightly narrowing and the growth rate decreases by a small parameter and this result has been reduced compared to nonrelativistic plasma. Also, it is found that the plasma electrons have not affected the solution of the space part of the problem. (author)

  2. Probing strongly interacting electroweak dynamics through W+W-/ZZ ratios at future e+e- colliders

    International Nuclear Information System (INIS)

    Barger, V.; Cheung, K.; Han, T.; Phillips, R.J.N.

    1995-01-01

    We point out that the ratio of W + W - →W + W - and W + W - →ZZ cross sections is a sensitive probe of the dynamics of electroweak symmetry breaking, in the c.m. energy region √s WW approx-gt 1 TeV where vector boson scattering may well become strong. We suggest ways in which this ratio can be extracted at a 1.5 TeV e + e - linear collider, using W ± ,Z→jj hadronic decays and relying on dijet mass resolution to provid statistical discrimination between W ± and Z. WW fusion processes studied here are unique for exploring scalar resonances of mass of about 1 TeV and are complementary to studies via the direct channel e + e - →W + W - for the vector and nonresonant cases. With an integrated luminosity of 200 fb -1 , the signals obtained are statistically significant. A comparision with a study of the e - e - →ννW - W - process is made. Enhancements of the signal rate from using a polarized electron beam, or at a 2 TeV e + e - linear colider and possible higher energy μ + μ - colliders, are also presented

  3. Probing strongly-interacting electroweak dynamics through W+W-/ZZ ratios at future e+e- colliders

    International Nuclear Information System (INIS)

    Barger, V.

    1995-01-01

    The authors point out that the ratio of W + W - → W + W - and W + W - → ZZ cross sections is a sensitive probe of the dynamics of electroweak symmetry breaking, in the CM energy region √s ww approx-gt 1 TeV where vector boson scattering may well become strong. They suggest ways in which this ratio can be extracted at a 1.5 TeV e + e - linear collider, using W ± , Z → jj hadronic decays and relying on dijet mass resolution to provide statistical discrimination between W ± and Z. WW fusion processes studied here are unique for exploring scalar resonances of mass about 1 TeV and are complementary to studies via the direct channel e + e - → W + W - for the vector and non-resonant cases. With an integrated luminosity of 200 fb -1 , the signals obtained are statistically significant. Comparison with a study of e - e - → ννW - W - process is made. Enhancements of the signal rate from using a polarized electron beam, or at a 2 TeV e + e - linear collider and possible higher energy μ + μ - colliders, are also presented

  4. Collective Phenomena Emerging from the Interactions between Dynamical Processes in Multiplex Networks.

    Science.gov (United States)

    Nicosia, Vincenzo; Skardal, Per Sebastian; Arenas, Alex; Latora, Vito

    2017-03-31

    We introduce a framework to intertwine dynamical processes of different nature, each with its own distinct network topology, using a multilayer network approach. As an example of collective phenomena emerging from the interactions of multiple dynamical processes, we study a model where neural dynamics and nutrient transport are bidirectionally coupled in such a way that the allocation of the transport process at one layer depends on the degree of synchronization at the other layer, and vice versa. We show numerically, and we prove analytically, that the multilayer coupling induces a spontaneous explosive synchronization and a heterogeneous distribution of allocations, otherwise not present in the two systems considered separately. Our framework can find application to other cases where two or more dynamical processes such as synchronization, opinion formation, information diffusion, or disease spreading, are interacting with each other.

  5. Collective Phenomena Emerging from the Interactions between Dynamical Processes in Multiplex Networks

    Science.gov (United States)

    Nicosia, Vincenzo; Skardal, Per Sebastian; Arenas, Alex; Latora, Vito

    2017-03-01

    We introduce a framework to intertwine dynamical processes of different nature, each with its own distinct network topology, using a multilayer network approach. As an example of collective phenomena emerging from the interactions of multiple dynamical processes, we study a model where neural dynamics and nutrient transport are bidirectionally coupled in such a way that the allocation of the transport process at one layer depends on the degree of synchronization at the other layer, and vice versa. We show numerically, and we prove analytically, that the multilayer coupling induces a spontaneous explosive synchronization and a heterogeneous distribution of allocations, otherwise not present in the two systems considered separately. Our framework can find application to other cases where two or more dynamical processes such as synchronization, opinion formation, information diffusion, or disease spreading, are interacting with each other.

  6. Interacting sp-boson model with isospin: an unified description of giant multipole resonances and other collective motions

    International Nuclear Information System (INIS)

    Chen, C.H.-T.

    1980-10-01

    A unified description of the following classes of nuclear collective states in terms of an interacting sp-boson model is proposed: (i) Low-lying collective states in the light nuclei, both odd-odd and even-even; (ii) Giant multipole resonances (GMR), and (iii) pairing collective motions. (Author) [pt

  7. Interaction and collective effects in classical-equations-of-motion calculations

    International Nuclear Information System (INIS)

    Bodmer, A.R.

    1981-01-01

    We discuss results obtained with the classical-equations-of-motion (CEOM) approach, with particular reference to interaction (potential energy) and collective effects in central collisions of equal mass nuclei. The essence of the CEOM approach is the classical calculation of all A = A/sub P/ + A/sub T/ trajectories using a 2-body potential V between all pairs of nucleons; V = V/sub short/ + V/sub long/ has a short range repulsion and a longer range attractive tail. In contrast to hydrodynamics, the CEOM approach is microscopic and includes transparency and nonequilibrium effects

  8. Spectroscopy of collective excitations in interacting low-dimensional many-body systems using quench dynamics.

    Science.gov (United States)

    Gritsev, Vladimir; Demler, Eugene; Lukin, Mikhail; Polkovnikov, Anatoli

    2007-11-16

    We study the problem of rapid change of the interaction parameter (quench) in a many-body low-dimensional system. It is shown that, measuring the correlation functions after the quench, the information about a spectrum of collective excitations in a system can be obtained. This observation is supported by analysis of several integrable models and we argue that it is valid for nonintegrable models as well. Our conclusions are supplemented by performing exact numerical simulations on finite systems. We propose that measuring the power spectrum in a dynamically split 1D Bose-Einsten condensate into two coupled condensates can be used as an experimental test of our predictions.

  9. Unitary Dynamics of Strongly Interacting Bose Gases with the Time-Dependent Variational Monte Carlo Method in Continuous Space

    Science.gov (United States)

    Carleo, Giuseppe; Cevolani, Lorenzo; Sanchez-Palencia, Laurent; Holzmann, Markus

    2017-07-01

    We introduce the time-dependent variational Monte Carlo method for continuous-space Bose gases. Our approach is based on the systematic expansion of the many-body wave function in terms of multibody correlations and is essentially exact up to adaptive truncation. The method is benchmarked by comparison to an exact Bethe ansatz or existing numerical results for the integrable Lieb-Liniger model. We first show that the many-body wave function achieves high precision for ground-state properties, including energy and first-order as well as second-order correlation functions. Then, we study the out-of-equilibrium, unitary dynamics induced by a quantum quench in the interaction strength. Our time-dependent variational Monte Carlo results are benchmarked by comparison to exact Bethe ansatz results available for a small number of particles, and are also compared to quench action results available for noninteracting initial states. Moreover, our approach allows us to study large particle numbers and general quench protocols, previously inaccessible beyond the mean-field level. Our results suggest that it is possible to find correlated initial states for which the long-term dynamics of local density fluctuations is close to the predictions of a simple Boltzmann ensemble.

  10. Strong Metal Support Interaction of Pt and Ru Nanoparticles Deposited on HOPG Probed by the H-D Exchange Reaction

    DEFF Research Database (Denmark)

    Fiordaliso, Elisabetta M.; Dahl, Søren; Chorkendorff, Ib

    2012-01-01

    The interaction between metals and support is investigated in the case of 50 Å Pt and 50 Å Ru films deposited on a HOPG substrate. The films are prepared by electron beam physical vapor deposition and annealed in UHV to temperatures up to 700 °C. The equilibrium hydrogen exchange rate between...... adsorbed and gas phase at 1 bar is measured before and after annealing. The rate is measured in the temperature range of 40–200 °C at 1 bar, by utilization of the H-D exchange reaction. Experiments are performed on fresh cleaved and sputtered HOPG, which give similar results. We find that annealing...... the films from 150 up to 700 °C increases the amount of carbon present in the films up to 95%, as derived by surface analysis, indicating the formation of a carbon layer on top of the metal films. The exchange rate decreases dramatically with increasing carbon content on the films for both metals, pointing...

  11. Onset of deconfinement and search for the critical point of strongly interacting matter at CERN SPS energies

    CERN Document Server

    Rybczyński, Maciej

    2014-01-01

    The exploration of the QCD phase diagram particularly the search for a phase transition from hadronic to partonic degrees of freedom and possibly a critical endpoint, is one of the most challenging tasks in present heavy-ion physics. As observed by the NA49 experiment, several hadronic observables in central Pb+Pb collisions at the CERN SPS show qualitative changes in their energy dependence. These features are not observed in elementary interactions and indi- cate the onset of a phase transition in the SPS energy range. The existence of a critical point is expected to result in the increase of event-by-event fluctuations of various hadronic observables provided that the freeze-out of the measured hadrons occurs close to its location in the phase di- agram and the evolution of the final hadron phase does not erase the fluctuations signals. Further information about the existence and nature of a phase transition in the SPS energy range can be gained from the studies of event-by-event fluctuations of final stat...

  12. irGPU.proton.Net: Irregular strong charge interaction networks of protonatable groups in protein molecules--a GPU solver using the fast multipole method and statistical thermodynamics.

    Science.gov (United States)

    Kantardjiev, Alexander A

    2015-04-05

    A cluster of strongly interacting ionization groups in protein molecules with irregular ionization behavior is suggestive for specific structure-function relationship. However, their computational treatment is unconventional (e.g., lack of convergence in naive self-consistent iterative algorithm). The stringent evaluation requires evaluation of Boltzmann averaged statistical mechanics sums and electrostatic energy estimation for each microstate. irGPU: Irregular strong interactions in proteins--a GPU solver is novel solution to a versatile problem in protein biophysics--atypical protonation behavior of coupled groups. The computational severity of the problem is alleviated by parallelization (via GPU kernels) which is applied for the electrostatic interaction evaluation (including explicit electrostatics via the fast multipole method) as well as statistical mechanics sums (partition function) estimation. Special attention is given to the ease of the service and encapsulation of theoretical details without sacrificing rigor of computational procedures. irGPU is not just a solution-in-principle but a promising practical application with potential to entice community into deeper understanding of principles governing biomolecule mechanisms. © 2015 Wiley Periodicals, Inc.

  13. Electron gas interacting in a metal, submitted to a strong magnetic field; Gas de eletrons interagentes num metal, sujeito a um campo magnetico forte

    Energy Technology Data Exchange (ETDEWEB)

    Alcaraz, Francisco Castilho

    1977-07-01

    Using the propagator's technique in the grand ensemble developed by Montroll and Ward we investigate the magnetic properties of an interacting electron gas in a strong magnetic field. The free propagator properly constructed shows that the spin paramagnetism does not have a term with strong temperature dependence, contrary to the result of Isihara. Considering the electron density to be constant, the dHVA oscillations in the magnetic susceptibility and sound velocity, considering the effects of first exchange interactions, show only one phase in agreement with experimental result, while Ichimura and Isihara obtained two phases differing by {pi}/2. The effects of first order exchange interactions in the dHVA oscillations of the magnetic susceptibility and sound velocity give rise to an exponential factor in the amplitudes of oscillator (Dingle factor), being the Dingle temperature linearly dependent of the Fermi velocity. The calculations of the ring diagram contribution to the grand partition function, show that the approximation used by Isihara for this calculations is not good and the dHVA oscillations of the contributions from the ring diagrams for the grand partition function have a phase differing by {pi}/2 from that obtained by Isihara. (author)

  14. Electron gas interacting in a metal, submitted to a strong magnetic field; Gas de eletrons interagentes num metal, sujeito a um campo magnetico forte

    Energy Technology Data Exchange (ETDEWEB)

    Alcaraz, Francisco Castilho

    1977-07-01

    Using the propagator's technique in the grand ensemble developed by Montroll and Ward we investigate the magnetic properties of an interacting electron gas in a strong magnetic field. The free propagator properly constructed shows that the spin paramagnetism does not have a term with strong temperature dependence, contrary to the result of Isihara. Considering the electron density to be constant, the dHVA oscillations in the magnetic susceptibility and sound velocity, considering the effects of first exchange interactions, show only one phase in agreement with experimental result, while Ichimura and Isihara obtained two phases differing by {pi}/2. The effects of first order exchange interactions in the dHVA oscillations of the magnetic susceptibility and sound velocity give rise to an exponential factor in the amplitudes of oscillator (Dingle factor), being the Dingle temperature linearly dependent of the Fermi velocity. The calculations of the ring diagram contribution to the grand partition function, show that the approximation used by Isihara for this calculations is not good and the dHVA oscillations of the contributions from the ring diagrams for the grand partition function have a phase differing by {pi}/2 from that obtained by Isihara. (author)

  15. Application of the interacting boson model to collective states in medium heavy nuclei

    International Nuclear Information System (INIS)

    Kaup, U.

    1983-01-01

    In the framework of the interacting boson model a systematic description of even-even isotopes of the medium heavy elements selenium, krypton, and strontium is given. The number of the free parameters could be kept very small by the determination of the physically relevant terms of the general model Hamiltonian. The variation of the collectivity from spherical to deformed, γ-soft nuclei could be mainly derived from the influence of the number of valence nucleons. All model parameters vary smoothly as function of the valence particle number and in qualitative agreement with predictions of a simplified microscopical model. Odd nuclei were studied in the framework of the interacting boson-fermion model. Beside the phenomenological description of odd-even rubidium, technetium, and silver isotope this part of the thesis is occupied mainly by the microscopical theory of the boson-fermion model. The effect of the antisymmetrization of the last, odd particle with the core nucleons is discussed. The microscopic theory is supplemented by the derivation of the so called Pauli term from the interaction of identical nucleons. (orig./HSI) [de

  16. PERSEUS-HUB: Interactive and Collective Exploration of Large-Scale Graphs

    Directory of Open Access Journals (Sweden)

    Di Jin

    2017-07-01

    Full Text Available Graphs emerge naturally in many domains, such as social science, neuroscience, transportation engineering, and more. In many cases, such graphs have millions or billions of nodes and edges, and their sizes increase daily at a fast pace. How can researchers from various domains explore large graphs interactively and efficiently to find out what is ‘important’? How can multiple researchers explore a new graph dataset collectively and “help” each other with their findings? In this article, we present Perseus-Hub, a large-scale graph mining tool that computes a set of graph properties in a distributed manner, performs ensemble, multi-view anomaly detection to highlight regions that are worth investigating, and provides users with uncluttered visualization and easy interaction with complex graph statistics. Perseus-Hub uses a Spark cluster to calculate various statistics of large-scale graphs efficiently, and aggregates the results in a summary on the master node to support interactive user exploration. In Perseus-Hub, the visualized distributions of graph statistics provide preliminary analysis to understand a graph. To perform a deeper analysis, users with little prior knowledge can leverage patterns (e.g., spikes in the power-law degree distribution marked by other users or experts. Moreover, Perseus-Hub guides users to regions of interest by highlighting anomalous nodes and helps users establish a more comprehensive understanding about the graph at hand. We demonstrate our system through the case study on real, large-scale networks.

  17. On the relation between the interacting boson model of Arima and Iachello and the collective model of Bohr and Mottelson

    International Nuclear Information System (INIS)

    Assenbaum, H.J.; Weiguny, A.

    1982-01-01

    The generator coordinate method is used to relate the interacting boson model of Arima and Iachello and the collective model of Bohr and Mottelson through an isometric transformation. It associates complex parameters to the original boson operators whereas the ultimate collective variables are real. The absolute squares of the collective wave functions can be given a direct probability interpretation. The lowest order Bohr-Mottelson hamiltonian is obtained in the harmonic approximation to the interacting boson model; unharmonic coupling terms render the collective potential to be velocity-dependent. (orig.)

  18. The Organic Secondary Building Unit: Strong Intermolecular π Interactions Define Topology in MIT-25, a Mesoporous MOF with Proton-Replete Channels.

    Science.gov (United States)

    Park, Sarah S; Hendon, Christopher H; Fielding, Alistair J; Walsh, Aron; O'Keeffe, Michael; Dincă, Mircea

    2017-03-15

    The structure-directing role of the inorganic secondary building unit (SBU) is key for determining the topology of metal-organic frameworks (MOFs). Here we show that organic building units relying on strong π interactions that are energetically competitive with the formation of common inorganic SBUs can also play a role in defining the topology. We demonstrate the importance of the organic SBU in the formation of Mg 2 H 6 (H 3 O)(TTFTB) 3 (MIT-25), a mesoporous MOF with the new ssp topology. A delocalized electronic hole is critical in the stabilization of the TTF triad organic SBUs and exemplifies a design principle for future MOF synthesis.

  19. $K^{0} \\leftrightharpoons \\overline{K}^0$ transitions monitored by strong interactions a new determination of the $K_{L} - K_{S}$ mass difference

    CERN Document Server

    Angelopoulos, Angelos; Backenstoss, Gerhard; Bargassa, P; Behnke, O; Benelli, A; Bertin, V; Blanc, F; Bloch, P; Carlson, P J; Carroll, M; Cawley, E; Chertok, M B; Danielsson, M; Dejardin, M; Derré, J; Ealet, A; Eleftheriadis, C; Fetscher, W; Fidecaro, Maria; Filipcic, A; Francis, D; Fry, J; Gabathuler, Erwin; Gamet, R; Gerber, H J; Go, A; Haselden, A; Haymen, P J; Henry-Coüannier, F; Hollander, R W; Jon-And, K; Kettle, P R; Kokkas, P; Kreuger, R; Le Gac, R; Leimgruber, F; Mandic, I; Manthos, N; Marel, Gérard; Mikuz, M; Miller, J; Montanet, François; Müller, A; Nakada, Tatsuya; Pagels, B; Papadopoulos, I M; Pavlopoulos, P; Polivka, G; Rickenbach, R; Roberts, B L; Ruf, T; Sakelliou, L; Schäfer, M; Schaller, L A; Schietinger, T; Schopper, A; Tauscher, Ludwig; Thibault, C; Touchard, F; Touramanis, C; van Eijk, C W E; Vlachos, S; Weber, P; Wigger, O; Wolter, M; Zavrtanik, D; Zimmerman, D

    2001-01-01

    The CPLEAR set-up (modified) has been used to determine the K/sub L/- K/sub S/ mass difference by a method where neutral-kaon strangeness oscillations are monitored through kaon strong interactions, rather than semileptonic decays, thus requiring no assumptions on CPT invariance for the decay amplitudes. The result, Delta m= (0.5343+or-0.0063/sub stat/+or-0.0025/sub syst/)*10/sup 10/ h(cross) /s, provides a valuable input for CPT tests. (22 refs).

  20. The differences in hadronic cross-sections and the residues of secondary reggeons in the quark-gluon model for strong interactions

    International Nuclear Information System (INIS)

    Kaidalov, A.B.; Volkovitsky, P.E.

    1981-01-01

    In the framework of the quark-gluon picture for strong interactions based on the topological expansion and the string model, the relations between t differences of hadronic cross- section are obtained. The system of equations for the contribution of secondary reggeons (rho, ω, f, A 2 and phi and f' poles) to the elastic scattering amplitudes for arbitrary hadrons is derived. It is shown that this system has a factorized solution and the secondary reggeon residues for all hadrons are expressed in terms of the universal function g(t). The model predictions are in a good agreement with experimental data [ru

  1. Electrodynamical forbiddance of a strong quadrupole interaction in surface enhanced optical processes. Experimental confirmation of the existence in fullerene C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Polubotko, A. M., E-mail: alex.marina@mail.ioffe.ru [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Chelibanov, V. P., E-mail: Chelibanov@gmail.com [State University of Information Technologies, Mechanics and Optics (Russian Federation)

    2017-02-15

    It is demonstrated that in the SERS and SEIRA spectra of the fullerene C{sub 60}, the lines, which are forbidden in usual Raman and IR spectra and allowed in SERS and SEIRA, are absent. In addition the enhancement SERS coefficient in a single molecule detection regime is ~10{sup 8} instead of the value 10{sup 14}–10{sup 15}, characteristic for this phenomenon. These results are explained by the existence of so-called electrodynamical forbiddance of a strong quadrupole light-molecule interaction, which arises because of belonging of C{sup 60} to the icosahedral symmetry group and due to the electrodynamical law divE = 0.

  2. Extreme enhancement of blocking temperature by strong magnetic dipoles interaction of α-Fe nanoparticle-based high-density agglomerate

    International Nuclear Information System (INIS)

    Kura, H; Takahashi, M; Ogawa, T

    2011-01-01

    High-volume fraction α-Fe nanoparticle (NP) agglomerates were prepared using chemically synthesized NPs. In the agglomerate, NPs are separated by surfactant and NP superlattice with a hexagonal close-packed structure is locally realized. Volume fractions of NPs at 20% and 42% were obtained in agglomerates consisting of 2.9 nm and 8.2 nm diameter NPs, respectively. The high saturation magnetization of α-Fe NPs and high volume fraction of NPs in the agglomerate provide strong magnetic dipole-dipole interaction. The interaction energy of the agglomerate became much larger than the anisotropic energy of individual NPs. As a result, the blocking temperature of the 8.2 nm NP agglomerate was significantly enhanced from 52.2 K to around 500 K. (fast track communication)

  3. Lattice fields and strong interactions

    International Nuclear Information System (INIS)

    Creutz, M.

    1989-06-01

    I review the lattice formulation of gauge theories and the use of numerical methods to investigate nonperturbative phenomena. These methods are directly applicable to studying hadronic matter at high temperatures. Considerable recent progress has been made in numerical algorithms for including dynamical fermions in such calculations. Dealing with a nonvanishing baryon density adds new unsolved challenges. 33 refs

  4. Strong interaction at finite temperature

    Indian Academy of Sciences (India)

    Quantum chromodynamics; finite temperature; chiral perturbation theory; QCD sum rules. PACS Nos 11.10. ..... at finite temperature. The self-energy diagrams of figure 2 modify it to ..... method of determination at present. Acknowledgement.

  5. Strong interaction at finite temperature

    Indian Academy of Sciences (India)

    The first one is the general method of chiral perturbation theory, which may be readily applied to this problem. The other is the method of thermal QCD sum rules. We show that, when the spectral sides of the sum rules are calculated correctly, they do not lead to any new results, but reproduce those of the vacuum sum rules.

  6. Design of a master Fastbus for the data acquisition of the DELPHI external detector. Measurement of the strong interaction coupling constant in the Z neutral boson hadronic decay

    International Nuclear Information System (INIS)

    Chorowicz, V.

    1990-05-01

    The thesis was prepared at the Delphi experiment. The work, performed in the LPNHE-Paris group, consists of two steps: the data acquisition at the Delphi External Detector and the analysis of the hadronic data, in order to extract the coupling constant of the strong interactions at √s = 91 GeV. In the first part of the thesis, the constraints relating to the data acquisition and the Delphi output are discussed. The data acquisition system of the External Detector and the implementation of the AM29000 on the main Fastbus are described. The AM29000 is a RISC type processor, which can support the high frequencies expected from the beam luminosity increase at LEP. This module will replace front end freeing monitor which is presently controlled by a 68020 microprocessor. In the second part of the thesis, the data acquired at Delphi from September to December 1989 is analyzed. The investigation is focused on the hadronic events in order to obtain the Standard Model basic parameter: the Λ QCD , which determines the energy dependence of the strong interactions coupling constant. A method based on the measurement of the energy-energy correlations in the hadronic jets is used and the results are discussed. The Λ QCD value is obtained by fitting the theoretical expected value to the distribution of the energy-energy correlations asymmetry [fr

  7. Electron-positron pairs creation in the field of two strong counterpropagating laser beams and the nonlocality of the photon-photon interaction

    International Nuclear Information System (INIS)

    Gainutdinov, R.Kh.; Khamadeev, M.A.; Mutygullina, A.A.

    2010-01-01

    Complete text of publication follows. We discuss various approaches to problem of the electron-positron pair creation in the strong external field. Special interest presents the circuit, in which the interaction of two strong counterpropagating laser beams in vacuum is considered. For the calculation of the probability of the creation the following formula is usually applied: W = 2Im(L (E-H) (ρ L )) = 2m 4 /(2π) 3 ρ L 2 Σ n=1 -∞ 1/n 2 e -nπ /ρ L where ρ L = E L / E cr and E cr = m 2 /e = 1.3 x 10 16 V/cm is the Schwinger field limit. However this expression was obtained even in pioneer works dedicated to vacuum nonlinearity and it based on some approximations. Attempt of the strict analysis has been made in work by introducing the nonlocal form-factor into the Lagrangian. But, as it is well known, such procedure leads to the loss of Lorenz invariance or unitarity. We show that the formalism of generalized quantum dynamic (GQD) opens new opportunities to solve such problems. We show also how it can be made proceeding from nonlocal interaction operator obtained earlier within the framework of the formalism of GQD. Acknowledgements. This work was supported by the Grant of Federal Agency on Education, Russia (Contract number 02.740.11.0428) and by the Grant of Russian President No. NSh 2965.2008.2.

  8. Two- and four-quasiparticle states in the interacting boson model: Strong-coupling and decoupled band patterns in the SU(3) limit

    International Nuclear Information System (INIS)

    Vretenar, D.; Paar, V.; Bonsignori, G.; Savoia, M.

    1990-01-01

    An extension of the interacting boson approximation model is proposed by allowing for two- and four-quasiparticle excitations out of the boson space. The formation of band patterns based on two- and four-quasiparticle states is investigated in the SU(3) limit of the model. For hole-type (particle-type) fermions coupled to the SU(3) prolate (oblate) core, it is shown that the algebraic K-representation basis, which is the analog of the strong-coupling basis of the geometrical model, provides an appropriate description of the low-lying two-quasiparticle bands. In the case of particle-type (hole-type) fermions coupled to the SU(3) prolate (oblate) core, a new algebraic decoupling basis is derived that is equivalent in the geometrical limit to Stephens' rotation-aligned basis. Comparing the wave functions that are obtained by diagonalization of the model Hamiltonian to the decoupling basis, several low-lying two-quasiparticle bands are identified. The effects of an interaction that conserves only the total nucleon number, mixing states with different number of fermions, are investigated in both the strong-coupling and decoupling limits. All calculations are performed for an SU(3) boson core and the h11/2 fermion orbital

  9. Phonon linewidth due to electron-phonon interactions with strong forward scattering in FeSe thin films on oxide substrates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yan [Univ. of Tennessee, Knoxville, TN (United States); Rademaker, Louk [Univ. of California, Santa Barbara, CA (United States); Dagotto, Elbio R. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnston, Steven [Univ. of Tennessee, Knoxville, TN (United States)

    2017-08-18

    Here, the discovery of an enhanced superconducting transition temperature Tc in monolayers of FeSe grown on several oxide substrates has opened a new route to high-Tc superconductivity through interface engineering. One proposal for the origin of the observed enhancement is an electronphonon (e-ph) interaction across the interface that peaked at small momentum transfers. In this paper, we examine the implications of such a coupling on the phononic properties of the system. We show that a strong forward scattering leads to a sizable broadening of phonon lineshape, which may result in charge instabilities at long-wavelengths. However, we further find that the inclusion of Coulombic screening significantly reduces the phonon broadening. Our results show that one might not expect anomalously broad phonon linewidths in the FeSe interface systems, despite the fact that the e-ph interaction has a strong peak in the forward scattering (small \\bfq ) direction.

  10. 76 FR 13647 - Proposed Collection; Comment Request-Interactive Diet and Activity Tracking in AARP (iDATA...

    Science.gov (United States)

    2011-03-14

    ... Request--Interactive Diet and Activity Tracking in AARP (iDATA): Biomarker Based Validation Study Summary... Collection: Title: Interactive Diet and Activity Tracking in AARP (iDATA): Biomarker Based Validation Study... Food Record 742 2 60/60 (1.0) 1,485 (Attachment 17). Diet History 742 2 45/60 (.75) 1,114 Questionnaire...

  11. Collective motion of groups of self-propelled particles following interacting leaders

    Science.gov (United States)

    Ferdinandy, B.; Ozogány, K.; Vicsek, T.

    2017-08-01

    In order to keep their cohesiveness during locomotion gregarious animals must make collective decisions. Many species boast complex societies with multiple levels of communities. A common case is when two dominant levels exist, one corresponding to leaders and the other consisting of followers. In this paper we study the collective motion of such two-level assemblies of self-propelled particles. We present a model adapted from one originally proposed to describe the movement of cells resulting in a smoothly varying coherent motion. We shall use the terminology corresponding to large groups of some mammals where leaders and followers form a group called a harem. We study the emergence (self-organization) of sub-groups within a herd during locomotion by computer simulations. The resulting processes are compared with our prior observations of a Przewalski horse herd (Hortobágy, Hungary) which we use as results from a published case study. We find that the model reproduces key features of a herd composed of harems moving on open ground, including fights for followers between leaders and bachelor groups (group of leaders without followers). One of our findings, however, does not agree with the observations. While in our model the emerging group size distribution is normal, the group size distribution of the observed herd based on historical data have been found to follow lognormal distribution. We argue that this indicates that the formation (and the size) of the harems must involve a more complex social topology than simple spatial-distance based interactions.

  12. Effect of dipole interaction on collective modes in 3He-A

    International Nuclear Information System (INIS)

    Tewordt, L.; Schopohl, N.; Vollhardt, D.

    1977-01-01

    A general theory for the correlation functions of superfluid 3 He which takes into account rigorously the magnetic dipole interaction is developed. The resulting equations are solved for the Anderson--Brinkman--Morel (ABM) state and for wave vectors q oriented parallel to the energy gap axis. Then the dispersion relations of low-frequency modes, including Fermi liquid corrections and damping due to pair breaking, are calculated in the zero-temperature and zero-field limit. There are two real frequency modes arising from each of the longitudinal and transverse spin density correlation functions: a spin wave and an orbit wave, both exhibiting a frequency gap where that of the spin wave is somewhat modified in comparison to the unperturbed longitudinal nuclear magnetic resonance frequency Ω/sup ABM//sub L/. The orbit wave is damped much more strongly than the spin wave. Further, there are two real frequency modes arising from the density correlation function: the sound wave, having a frequency gap of the order Ω/sup ABM//sub L/, and an orbit wave, exhibiting a gap in wave number of order Ω/sup ABM//sub L//v/sub F/.: The NMR frequency undergoes a small splitting, which is the result of the splitting of the energy gap due to the dipole interaction. One of the two gaps still has nodes.: In addition to these low-frequency modes our equations yield resonances at frequencies of the order of the gap frequency Δ 0 /h, i.e., at ω=1.22Δ 0 /h and at ω=1.58 Δ 0 /h. The damping and the oscillator strengths of these resonances are calculated

  13. Strong Langmuir turbulence

    International Nuclear Information System (INIS)

    Goldman, M.V.

    1984-01-01

    After a brief discussion of beam-excited Langmuir turbulence in the solar wind, we explain the criteria for wave-particle, three-wave and strong turbulence interactions. We then present the results of a numerical integration of the Zakharov equations, which describe the strong turbulence saturation of a weak (low-density) high energy, bump-on-tail beam instability. (author)

  14. Collective Behaviors in Spatially Extended Systems with Local Interactions and Synchronous Updating

    Science.gov (United States)

    ChatÉ, H.; Manneville, P.

    1992-01-01

    Assessing the extent to which dynamical systems with many degrees of freedom can be described within a thermodynamics formalism is a problem that currently attracts much attention. In this context, synchronously updated regular lattices of identical, chaotic elements with local interactions are promising models for which statistical mechanics may be hoped to provide some insights. This article presents a large class of cellular automata rules and coupled map lattices of the above type in space dimensions d = 2 to 6.Such simple models can be approached by a mean-field approximation which usually reduces the dynamics to that of a map governing the evolution of some extensive density. While this approximation is exact in the d = infty limit, where macroscopic variables must display the time-dependent behavior of the mean-field map, basic intuition from equilibrium statistical mechanics rules out any such behavior in a low-dimensional systems, since it would involve the collective motion of locally disordered elements.The models studied are chosen to be as close as possible to mean-field conditions, i.e., rather high space dimension, large connectivity, and equal-weight coupling between sites. While the mean-field evolution is never observed, a new type of non-trivial collective behavior is found, at odds with the predictions of equilibrium statistical mechanics. Both in the cellular automata models and in the coupled map lattices, macroscopic variables frequently display a non-transient, time-dependent, low-dimensional dynamics emerging out of local disorder. Striking examples are period 3 cycles in two-state cellular automata and a Hopf bifurcation for a d = 5 lattice of coupled logistic maps. An extensive account of the phenomenology is given, including a catalog of behaviors, classification tables for the celular automata rules, and bifurcation diagrams for the coupled map lattices.The observed underlying dynamics is accompanied by an intrinsic quasi-Gaussian noise

  15. Chromatin compaction by condensin I, intra-kinetochore stretch and tension, and anaphase onset, in collective spindle assembly checkpoint interaction

    International Nuclear Information System (INIS)

    Matsson, Leif

    2014-01-01

    The control mechanism in mitosis and meiosis by which cells decide to inhibit or allow segregation, the so-called spindle assembly checkpoint (SAC), increases the fidelity of chromosome segregation. It acts like a clockwork mechanism which measures time in units of stable attachments of microtubules (MTs) to kinetochores (the order parameter). Stable MT–kinetochore attachments mediate poleward forces and ‘unstable’ attachments, acting alone or together with motor proteins on kinetochores via chromosomes, antipoleward forces. Stable and unstable attachments could be separated, and the non-equilibrium integrated MT mediated force acting on stably attached kinetochores was derived in a collective interaction (Matsson 2009 J. Phys.: Condens. Matter 21 502101), in which kinetochores were treated as rigid protein complexes. As forces and tension in that model became equally distributed in all bioriented sister chromatid (SC) pairs, segregation was inhibited without need of a ‘wait-anaphase’ signal. In this generalization, the kinetochore is divided into an inner chromatin proximal complex and an outer MT proximal complex, and the integrated MT mediated force is divided into an integrated poleward and an integrated antipoleward force. The model also describes the collective interaction of condensin I with chromatin, which together with the MT mediated dynamics yields the putative in vivo tension in kinetochores and centromeric and pericentromeric chromatin, as a non-linear function of the order parameter. Supported by the compaction force and an increased stiffness in chromatin towards the end of metaphase, the two opposing integrated MT mediated poleward forces, together with metaphase oscillations, induce a swift and synchronized anaphase onset by first increasing the intra-kinetochore stretch. This increase lowers the SAC energy threshold, making a cleavage by separase of all cohesin tethering SC pairs in anaphase energetically possible, thereby reducing the

  16. Second-order Monte Carlo wave-function approach to the relaxation effects on ringing revivals in a molecular system interacting with a strongly squeezed coherent field

    International Nuclear Information System (INIS)

    Nakano, Masayoshi; Kishi, Ryohei; Nitta, Tomoshige; Yamaguchi, Kizashi

    2004-01-01

    We investigate the relaxation effects on the quantum dynamics in a two-state molecular system interacting with a single-mode strongly amplitude-squeezed coherent field using the second-order Monte Carlo wave-function method. The molecular population inversion (collapse-revival behavior of Rabi oscillations) is known to show the echoes after each revival, which are referred to as ringing revivals, in the case of strongly squeezed coherent fields with oscillatory photon-number distributions due to the phase-space interference effect. Two types of relaxation effects, i.e., cavity relaxation (the dissipation of an internal single mode to outer mode) and molecular coherent (phase) relaxation caused by nuclear vibrations on ringing revivals are investigated from the viewpoint of the quantum-phase dynamics using the quasiprobability (Q function) distribution of a single-mode field and the off-diagonal molecular density matrix ρ elec1,2 (t). It turns out that the molecular phase relaxation attenuates both the entire revival-collapse behavior and the increase in ρ elec1,2 (t) during the quiescent region, whereas a very slight cavity relaxation particularly suppresses the echoes in ringing revivals more significantly than the first revival but hardly changes a primary variation in envelope of ρ elec1,2 (t) in the nonrelaxation case

  17. Feasibility of automated speech sample collection with stuttering children using interactive voice response (IVR) technology.

    Science.gov (United States)

    Vogel, Adam P; Block, Susan; Kefalianos, Elaina; Onslow, Mark; Eadie, Patricia; Barth, Ben; Conway, Laura; Mundt, James C; Reilly, Sheena

    2015-04-01

    To investigate the feasibility of adopting automated interactive voice response (IVR) technology for remotely capturing standardized speech samples from stuttering children. Participants were 10 6-year-old stuttering children. Their parents called a toll-free number from their homes and were prompted to elicit speech from their children using a standard protocol involving conversation, picture description and games. The automated IVR system was implemented using an off-the-shelf telephony software program and delivered by a standard desktop computer. The software infrastructure utilizes voice over internet protocol. Speech samples were automatically recorded during the calls. Video recordings were simultaneously acquired in the home at the time of the call to evaluate the fidelity of the telephone collected samples. Key outcome measures included syllables spoken, percentage of syllables stuttered and an overall rating of stuttering severity using a 10-point scale. Data revealed a high level of relative reliability in terms of intra-class correlation between the video and telephone acquired samples on all outcome measures during the conversation task. Findings were less consistent for speech samples during picture description and games. Results suggest that IVR technology can be used successfully to automate remote capture of child speech samples.

  18. Interaction of a weak and a strong shock in reacting high enthalpy flow; Wechselwirkung einer starken und einer schwachen Stosswelle in reagierender Hochenthalpiestroemung

    Energy Technology Data Exchange (ETDEWEB)

    Schnieder, M.

    1998-11-01

    In the free piston driven shock tunnel HEG the interaction of shock waves in front of a blunt body is studied in reacting high enthalpy flow. The influence of high temperature effects is of interest. The so called type IV interaction produces a free jet that impinges onto the body and creates high pressure and heat loads on the body surface. A cylinder wedge model is used. At the cylinder surface pressure and heat flux are measured. Holographic interferometry and schlieren optic are applied to visualize the flow. The measured loads show unsteady behaviour. At higher Reynolds numbers the upper bow shock shows a strong disturbance. It is assumed that this disturbance is caused by an unstable shear layer if the convective Mach number (i.e. the Mach number of the flow relative to a frame of reference moving with the shear layer structures) is larger than one. A study of the influence of dissociation on the convective Mach number shows, that the convective Mach number increases. Numerical calculations and an analytical model, which is based on the ideal dissociating gas model and the Fay Riddell solution to stagnation point flows are discussed in comparison with the experiments. (orig.)

  19. Self-consistent field theory of tethered polymers: one dimensional, three dimensional, strong stretching theories and the effects of excluded-volume-only interactions.

    Science.gov (United States)

    Suo, Tongchuan; Whitmore, Mark D

    2014-11-28

    We examine end-tethered polymers in good solvents, using one- and three-dimensional self-consistent field theory, and strong stretching theories. We also discuss different tethering scenarios, namely, mobile tethers, fixed but random ones, and fixed but ordered ones, and the effects and important limitations of including only binary interactions (excluded volume terms). We find that there is a "mushroom" regime in which the layer thickness is independent of the tethering density, σ, for systems with ordered tethers, but we argue that there is no such plateau for mobile or disordered anchors, nor is there one in the 1D theory. In the other limit of brushes, all approaches predict that the layer thickness scales linearly with N. However, the σ(1/3) scaling is a result of keeping only excluded volume interactions: when the full potential is included, the dependence is faster and more complicated than σ(1/3). In fact, there does not appear to be any regime in which the layer thickness scales in the combination Nσ(1/3). We also compare the results for two different solvents with each other, and with earlier Θ solvent results.

  20. Self-consistent field theory of tethered polymers: One dimensional, three dimensional, strong stretching theories and the effects of excluded-volume-only interactions

    International Nuclear Information System (INIS)

    Suo, Tongchuan; Whitmore, Mark D.

    2014-01-01

    We examine end-tethered polymers in good solvents, using one- and three-dimensional self-consistent field theory, and strong stretching theories. We also discuss different tethering scenarios, namely, mobile tethers, fixed but random ones, and fixed but ordered ones, and the effects and important limitations of including only binary interactions (excluded volume terms). We find that there is a “mushroom” regime in which the layer thickness is independent of the tethering density, σ, for systems with ordered tethers, but we argue that there is no such plateau for mobile or disordered anchors, nor is there one in the 1D theory. In the other limit of brushes, all approaches predict that the layer thickness scales linearly with N. However, the σ 1/3 scaling is a result of keeping only excluded volume interactions: when the full potential is included, the dependence is faster and more complicated than σ 1/3 . In fact, there does not appear to be any regime in which the layer thickness scales in the combination Nσ 1/3 . We also compare the results for two different solvents with each other, and with earlier Θ solvent results