International Nuclear Information System (INIS)
Mankiewicz, L.; Sawicki, M.
1989-01-01
Within a relativistically correct yet analytically solvable model of light-front quantum mechanics we construct the electromagnetic form factor of the two-body bound state and we study the validity of the static approximation to the full form factor. Upon comparison of full form factors calculated for different values of binding energy we observe an unexpected effect that for very strongly bound states further increase in binding leads to an increase in the size of the bound system. A similar effect is found for another quantum-mechanical model of relativistic dynamics
Relativistic bound-state problem of a one-dimensional system
International Nuclear Information System (INIS)
Sato, T.; Niwa, T.; Ohtsubo, H.; Tamura, K.
1991-01-01
A Poincare-covariant description of the two-body bound-state problem in one-dimensional space is studied by using the relativistic Schrodinger equation. We derive the many-body Hamiltonian, electromagnetic current and generators of the Poincare group in the framework of one-boson exchange. Our theory satisfies Poincare algebra within the one-boson-exchange approximation. We numerically study the relativistic effects on the bound-state wavefunction and the elastic electromagnetic form factor. The Lorentz boost of the bound-state wavefunction and the two-body exchange current are shown to play an important role in guaranteeing the Lorentz invariance of the form factor. (author)
Electromagnetic structure of a bound nucleon
International Nuclear Information System (INIS)
Nogami, Y.
1977-01-01
The effect of binding on the electromagnetic (e.m.) structure of a nucleon in a nucleus is examined by means of a model consisting of a single nucleon which is bound in a harmonic oscillator potential and also coupled to the pion field through the Chew-Low interaction. The 'two-pion contribution' to the e.m. structure is considered. This is the part which is probably most susceptible to the binding effect. By the binding effect it is meant the one which arises because the nucleon wave functions, in the intermediate state as well as in the initial and final states, are distorted by the potential in which the nucleon is bound. This may be compared to a similar correction to the impulse approximation for pion-nucleus scattering. Unlike the latter which is likely to be quite appreciable, the binding correction to the e.m. structure of the nucleon is found to be negligibly small. The so-called quenching effect due to the Pauli principle when there are other nucleons is also discussed [pt
Energy flow in a bound electromagnetic field: resolution of apparent paradoxes
International Nuclear Information System (INIS)
Kholmetskii, A L; Yarman, T
2008-01-01
In this paper, we present a resolution of apparent paradoxes formulated in (Kholmetskii A L 2006 Apparent paradoxes in classical electrodynamics: the energy-momentum conservation law for a bound electromagnetic field Eur. J. Phys. 27 825-38; Kholmetskii A L and Yarman T 2008 Apparent paradoxes in classical electrodynamics: a fluid medium in an electromagnetic field Eur. J. Phys. 29 1127) and dealing with the energy flux in a bound electromagnetic field
Do bound color octet states of liberated quarks exist
International Nuclear Information System (INIS)
Lipkin, H.J.
1979-01-01
In models where quarks are liberated and color can be excited, the three-quark color-octet state is shown to be unbound and unstable against breakup into free quarks and diquarks. The signature for color excitation in deep inelastic processes will not be a bound three-quark state which decays electromagnetically but a final state containing free quarks. (author)
Design of a bounded wave EMP (Electromagnetic Pulse) simulator
Sevat, P. A. A.
1989-06-01
Electromagnetic Pulse (EMP) simulators are used to simulate the EMP generated by a nuclear weapon and to harden equipment against the effects of EMP. At present, DREO has a 1 m EMP simulator for testing computer terminal size equipment. To develop the R and D capability for testing larger objects, such as a helicopter, a much bigger threat level facility is required. This report concerns the design of a bounded wave EMP simulator suitable for testing large size equipment. Different types of simulators are described and their pros and cons are discussed. A bounded wave parallel plate type simulator is chosen for it's efficiency and the least environmental impact. Detailed designs are given for 6 m and 10 m parallel plate type wire grid simulators. Electromagnetic fields inside and outside the simulators are computed. Preliminary specifications for a pulse generator required for the simulator are also given. Finally, the electromagnetic fields radiated from the simulator are computed and discussed.
Continuity equations for bound electromagnetic field and the electromagnetic energy-momentum tensor
International Nuclear Information System (INIS)
Kholmetskii, A L; Missevitch, O V; Yarman, T
2011-01-01
We analyze the application of the Poynting theorem to the bound (velocity-dependent) electromagnetic (EM) field and show that an often-used arbitrary elimination of the term of self-interaction in the product j·E (where j is the current density and E the electric field) represents, in general, an illegitimate operation, which leads to incorrect physical consequences. We propose correct ways of eliminating the terms of self-interaction from the Poynting theorem to transform it into the form that is convenient for problems with bound EM field, which yield the continuity equations for the proper EM energy density, the interaction part of EM energy density and the total EM energy density of bound fields, respectively. These equations indicate the incompleteness of the common EM energy-momentum tensor, and in our analysis, we find a missed term in its structure, which makes its trace non-vanished. Some implications of these results are discussed, in particular, in view of the notion of EM mass of charged particles.
Application of the N-quantum approximation method to bound state problems
International Nuclear Information System (INIS)
Raychaudhuri, A.
1977-01-01
The N-quantum approximation (NQA) method is examined in the light of its application to bound state problems. Bound state wave functions are obtained as expansion coefficients in a truncated Haag expansion. From the equations of motion for the Heisenberg field and the NQA expansion, an equation satisfied by the wave function is derived. Two different bound state systems are considered. In one case, the bound state problem of two identical scalars by scalar exchange is analyzed using the NQA. An integral equation satisfied by the wave function is derived. In the nonrelativistic limit, the equation is shown to reduce to the Schroedinger equation. The equation is solved numerically, and the results compared with those obtained for this system by other methods. The NQA method is also applied to the bound state of two spin 1/2 particles with electromagnetic interaction. The integral equation for the wave function is shown to agree with the corresponding Bethe Salpeter equation in the nonrelativistic limit. Using the Dirac (4 x 4) matrices the wave function is expanded in terms of structure functions and the equation for the wave function is reduced to two disjoint sets of coupled equation for the structure functions
Continuity equations for bound electromagnetic field and the electromagnetic energy-momentum tensor
Energy Technology Data Exchange (ETDEWEB)
Kholmetskii, A L [Department of Physics, Belarusian State University, 4 Nezavisimosti Avenue, 220030 Minsk (Belarus); Missevitch, O V [Institute for Nuclear Problems, Belarusian State University, 11 Bobruiskaya Street, 220030 Minsk (Belarus); Yarman, T, E-mail: khol123@yahoo.com [Department of Engineering, Okan University, Akfirat, Istanbul, Turkey and Savronik, Eskisehir (Turkey)
2011-05-01
We analyze the application of the Poynting theorem to the bound (velocity-dependent) electromagnetic (EM) field and show that an often-used arbitrary elimination of the term of self-interaction in the product j{center_dot}E (where j is the current density and E the electric field) represents, in general, an illegitimate operation, which leads to incorrect physical consequences. We propose correct ways of eliminating the terms of self-interaction from the Poynting theorem to transform it into the form that is convenient for problems with bound EM field, which yield the continuity equations for the proper EM energy density, the interaction part of EM energy density and the total EM energy density of bound fields, respectively. These equations indicate the incompleteness of the common EM energy-momentum tensor, and in our analysis, we find a missed term in its structure, which makes its trace non-vanished. Some implications of these results are discussed, in particular, in view of the notion of EM mass of charged particles.
International Nuclear Information System (INIS)
Inoue, J.; Ohtaka, K.
2004-01-01
We study virtual bound states in photonics, which are a vectorial extension of electron virtual bound states. The condition for these states is derived. It is found that the Mie resonant state which satisfies the condition that the size parameter is less than the angular momentum should be interpreted as a photon virtual bound state. In order to confirm the validity of the concept, we compare the photonic density of states, the width of which represents the lifetime of the photon virtual bound states, with numerical results
Parametric excitation electromagnetic radiation in a bounded non-equilibrium plasma
International Nuclear Information System (INIS)
Balakirev, V.A.; Tolstoluzhskij, A.P.
1981-01-01
An excitation mechanism of electromagnetic radiation in a bounded plasma-beam system which is based on the process of induced scattering of electron beam-strengthened high-frequency wave (HF) of a plasma waveguide with an ion-sound wave, is investigated. It is shown that the process under investigation is an effective mechanism of electromagnetic radiation production. Up to 73 % of the beam power is trabsformed to the electromagnetic radiation under the conditions considered. As the frequency of the irradiated wave is close to the plasma frequency it can vary within wide limits by the change in plasma density. It is noted that the necessary condition of electromagnetic radiation production in the mechanism under consideration has the form of inequality ωsub(l)-ωsub(s)/(ksub(l)-ksub(s)>c (ωsub(l) - frequency of HF wave, ωsub(s)- frequency of ion-sound wave) and is less rigid as compared with the synchronism conditions for three-wave resonant interaction of proper oscillations. Therefore, the considered induced scattering process is less sensitive to a possible inhomogeneity of plasma density [ru
Nonthreshold D-brane bound states and black holes with nonzero entropy
International Nuclear Information System (INIS)
Costa, M.S.; Cvetic, M.
1997-01-01
We start with Bogomol close-quote nyi-Prasad-Sommerfield- (BPS) saturated configurations of two (orthogonally) intersecting M-branes and use the electromagnetic duality or dimensional reduction along a boost, in order to obtain new p-brane bound states. In the first case the resulting configurations are interpreted as BPS-saturated nonthreshold bound states of intersecting p-branes, and in the second case as p-branes intersecting at angles and their duals. As a by-product we deduce the enhancement of supersymmetry as the angle approaches zero. We also comment on the D-brane theory describing these new bound states, and a connection between the angle and the world-volume gauge fields of the D-brane system. We use these configurations to find new embeddings of the four- and five-dimensional black holes with nonzero entropy, whose entropy now also depends on the angle and world-volume gauge fields. The corresponding D-brane configuration sheds light on the microscopic entropy of such black holes. copyright 1997 The American Physical Society
International Nuclear Information System (INIS)
Orzalesi, C.A.
1979-01-01
In relativistic quantum theory, bound states generate forces in the crossed channel; such forces can affect the binding and self-consistent solutions should be sought for the bound-state problem. The author investigates how self-consistency can be achieved by successive approximations, in a simple scalar model and with successive relativistic eikonal approximations (EAs). Within the generalized ladder approximation, some exact properties of the resulting ''first generation'' bound states are discussed. The binding energies in this approximation are rather small even for rather large values of the primary coupling constant. The coupling of the constituent particles to the first-generation reggeon is determined by a suitable EA and a new generalized ladder amplitude is constructed with rungs given either by the primary gluons or by the first-generation reggeons. The resulting new (second-generation) bound states are found in a reggeized EA. The size of the corrections to the binding energies due to the rebinding effects is surprisingly large. The procedure is then iterated, so as to find - again in an EA - the third-generation bound states. The procedure is found to be self-consistent already at this stage: the third-generation bound states coincide with those of second generation, and no further rebinding takes place in the higher iterations of the approximation method. Features - good and bad - of the model are discussed, as well as the possible relevance of rebinding mechanisms in hadron dynamics. (author)
Quantum mechanics of electromagnetically bounded spin-1/2 particles in expanding universes
International Nuclear Information System (INIS)
Audretsch, J.; Schaefer, G.
1978-01-01
In a preceding paper (Audretsch and Schaefer. Gen. Rel. Grav.; 9:243 (1977)) the central questions which justified the interest in an exact treatment of an electromagnetically bounded electron in expanding universes were outlined. Here the energy spectrum of the hydrogen atom in expanding Robertson-Walker universes is studied in detail using rigorous methods of functional analysis. Thereby, for closed universes (spherical case, epsilon = 1), the corresponding electromagnetic field needs special considerations. For the hyperbolic case (epsilon = -1) it is shown (a) that the Hamilton operator is uniquely self-adjoint, (b) that the continuous energy spectrum agrees with the one in 4-flat space-time and that the energy eigenvalues are bounded by +-msub(o), (c) that they approach Minkowski space spectrum for increasing curvature radius, and (d) that the hydrogen atom cannot be used as an atomic clock showing proper time. For the spherical case (epsilon 1) it is shown (a) that the Hamilton operator is uniquely self-adjoint and (b) that the energy spectrum is solely discrete. (author)
Schulz, Marc Daniel; Dusuel, Sébastien; Vidal, Julien
2016-11-01
We discuss the emergence of bound states in the low-energy spectrum of the string-net Hamiltonian in the presence of a string tension. In the ladder geometry, we show that a single bound state arises either for a finite tension or in the zero-tension limit depending on the theory considered. In the latter case, we perturbatively compute the binding energy as a function of the total quantum dimension. We also address this issue in the honeycomb lattice where the number of bound states in the topological phase depends on the total quantum dimension. Finally, the internal structure of these bound states is analyzed in the zero-tension limit.
Quasi-bound states in continuum
International Nuclear Information System (INIS)
Nakamura, Hiroaki; Hatano, Naomichi; Garmon, Sterling; Petrosky, Tomio
2007-08-01
We report the prediction of quasi-bound states (resonant states with very long lifetimes) that occur in the eigenvalue continuum of propagating states for a wide region of parameter space. These quasi-bound states are generated in a quantum wire with two channels and an adatom, when the energy bands of the two channels overlap. A would-be bound state that lays just below the upper energy band is slightly destabilized by the lower energy band and thereby becomes a resonant state with a very long lifetime (a second QBIC lays above the lower energy band). (author)
Fast Atom Ionization in Strong Electromagnetic Radiation
Apostol, M.
2018-05-01
The Goeppert-Mayer and Kramers-Henneberger transformations are examined for bound charges placed in electromagnetic radiation in the non-relativistic approximation. The consistent inclusion of the interaction with the radiation field provides the time evolution of the wavefunction with both structural interaction (which ensures the bound state) and electromagnetic interaction. It is shown that in a short time after switching on the high-intensity radiation the bound charges are set free. In these conditions, a statistical criterion is used to estimate the rate of atom ionization. The results correspond to a sudden application of the electromagnetic interaction, in contrast with the well-known ionization probability obtained by quasi-classical tunneling through classically unavailable non-stationary states, or other equivalent methods, where the interaction is introduced adiabatically. For low-intensity radiation the charges oscillate and emit higher-order harmonics, the charge configuration is re-arranged and the process is resumed. Tunneling ionization may appear in these circumstances. Extension of the approach to other applications involving radiation-induced charge emission from bound states is discussed, like ionization of molecules, atomic clusters or proton emission from atomic nuclei. Also, results for a static electric field are included.
Instanton bound states in ABJM theory
Energy Technology Data Exchange (ETDEWEB)
Hatsuda, Yasuyuki [DESY Hamburg (Germany). Theory Group; Tokyo Institute of Technology (Japan). Dept. of Physics; Moriyama, Sanefumi [Nagoya Univ. (Japan). Kobayashi Maskawa Inst. and Graduate School of Mathematics; Okuyama, Kazumi [Shinshu Univ., Matsumoto, Nagano (Japan). Dept. of Physics
2013-06-15
The partition function of the ABJM theory receives non-perturbative corrections due to instanton effects. We study these non-perturbative corrections, including bound states of worldsheet instantons and membrane instantons, in the Fermi-gas approach. We require that the total non-perturbative correction should be always finite for arbitrary Chern-Simons level. This finiteness is realized quite non-trivially because each bound state contribution naively diverges at some levels. The poles of each contribution should be canceled out in total. We use this pole cancellation mechanism to find unknown bound state corrections from known ones. We conjecture a general expression of the bound state contribution. Summing up all the bound state contributions, we find that the effect of bound states is simply incorporated into the worldsheet instanton correction by a redefinition of the chemical potential in the Fermi-gas system. Analytic expressions of the 3- and 4-membrane instanton corrections are also proposed.
Binding energies of two deltas bound states
International Nuclear Information System (INIS)
Sato, Hiroshi; Saito, Koichi.
1982-06-01
Bound states of the two-deltas system are investigated by employing the realistic one boson exchange potential. It is found that there exist many bound states in each isospin channel and also found that the tensor interaction plays important role in producing these bound states. Relationship between these bound states and dibaryon resonances is discussed. (J.P.N.)
Two-phonon bound states in imperfect crystals
International Nuclear Information System (INIS)
Behera, S.N.; Samsur, Sk.
1980-01-01
The question of the occurrence of two-phonon bound states in imperfect crystals is investigated. It is shown that the anharmonicity mediated two-phonon bound state which is present in perfect crystals gets modified due to the presence of impurities. Moreover, the possibility of the occurrence of a purely impurity mediated two-phonon bound state is demonstrated. The bound state frequencies are calculated using the simple Einstein oscillator model for the host phonons. The two-phonon density of states for the imperfect crystal thus obtained has peaks at the combination and difference frequencies of two host phonons besides the peaks at the bound state frequencies. For a perfect crystal the theory predicts a single peak at the two-phonon bound state frequency in conformity with experimental observations and other theoretical calculations. Experimental data on the two-phonon infrared absorption and Raman scattering from mixed crystals of Gasub(1-c)Alsub(c)P and Gesub(1-c)Sisub(c) are analysed to provide evidence in support of impurity-mediated two-phonon bound states. The relevance of the zero frequency (difference spectrum) peak to the central peak, observed in structural phase transitions, is conjectured. (author)
Chen, Jiangwei; Dai, Yuyao; Yan, Lin; Zhao, Huimin
2018-04-01
In this paper, we shall demonstrate theoretically that steady bound electromagnetic eigenstate can arise in an infinite homogeneous isotropic linear metamaterial with zero-real-part-of-impedance and nonzero-imaginary-part-of-wave-vector, which is partly attributed to that, here, nonzero-imaginary-part-of-wave-vector is not involved with energy losses or gain. Altering value of real-part-of-impedance of the metamaterial, the bound electromagnetic eigenstate may become to be a progressive wave. Our work may be useful to further understand energy conversion and conservation properties of electromagnetic wave in the dispersive and absorptive medium and provides a feasible route to stop, store and release electromagnetic wave (light) conveniently by using metamaterial with near-zero-real-part-of-impedance.
International Nuclear Information System (INIS)
Radozycki, T.
1990-01-01
The properties of the virtual cloud around the hydrogen atom in the ground state are studied with the use of quantum field theory methods. The relativistic expression for the electromagnetic energy density around the atom, with the electron spin taken into account, is obtained. The distribution of the angular momentum contained in the cloud and the self-interaction kernel for the electrons bound in atom are also investigated. (author)
International Nuclear Information System (INIS)
Zouzou, S.
1986-01-01
In the framework of simple non-relativistic potential models, we examine the system consisting of two quarks and two antiquarks with equal or unequal masses. We search for possible bound states below the threshold for the spontaneous dissociation into two mesons. We solve the four body problem by empirical or systematic variational methods and we include the virtual meson-meson components of the wave function. With standard two-body potentials, there is no proliferation of multiquarks. With unequal quark masses, we obtain however exotic (anti Qanti Qqq) bound states with a baryonic antidiquark-quark-quark structure very analogous to the heavy flavoured (Q'qq) baryons. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Arsenyev, S. A.; Koryagin, S. A., E-mail: koryagin@appl.sci-nnov.ru [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation)
2012-06-15
A classical analysis is presented of the electromagnetic radiation emitted by positive-energy electrons performing bound motion in the Coulomb field of a nucleus at rest in a strong uniform magnetic field. Bounded trajectories exist and span a wide range of velocity directions near the nucleus (compared to free trajectories with similar energies) when the electron Larmor radius is smaller than the distance at which the electron-nucleus Coulomb interaction energy is equal to the mechanical energy of an electron. The required conditions occur in magnetic white dwarf photospheres and have been achieved in experiments on production of antihydrogen. Under these conditions, the radiant power per unit volume emitted by positive-energy bound electrons is much higher than the analogous characteristic of bremsstrahlung (in particular, in thermal equilibrium) at frequencies that are below the electron cyclotron frequency but higher than the inverse transit time through the interaction region in a close collision in the absence of a magnetic field. The quantum energy discreteness of positive-energy bound states restricts the radiation from an ensemble of bound electrons (e.g., in thermal equilibrium) to nonoverlapping spectral lines, while continuum radiative transfer is dominated by linearly polarized bremsstrahlung.
Proximity effect tunneling into virtual bound state alloys
International Nuclear Information System (INIS)
Tang, I.M.; Roongkkeadsakoon, S.
1984-01-01
The effects of a narrow virtual bound state formed by transition metal impurities dissolved in the normal layer of a superconducting proximity effect sandwich are studied. Using standard renormalization techniques, we obtain the changes in the transition temperatures and the jumps in the specific heat at T/sub c/ as a function of the thickness of the normal layer, of the widths of the virtual bound states, and of the impurity concentrations. It is seen that narrow virtual bound states lead to decrease in the transition temperatures, while broad virtual bound states do not. It if further seen that the narrow virtual bound state causes the reduced specific heat jump at T/sub c/ to deviate from the BCS behavior expected of the pure sandwich
Unexpected strong attraction in the presence of continuum bound state
International Nuclear Information System (INIS)
Delfino, A.; Frederico, T.
1992-06-01
The result of few-particle ground-state calculation employing a two-particle non-local potential supporting a continuum bound state in addition to a negative-energy bound state has occasionally revealed unexpected large attraction in producing a very strongly bound ground state. In the presence of the continuum bound state the difference of phase shift between zero and infinite energies has an extra jump of φ as in the presence of an additional bound state. The wave function of the continuum bound state is identical with that of a strongly bound negative-energy state, which leads us to postulate a pseudo bound state in the two-particle system in order to explain the unexpected attraction. The role of the Pauli forbidden states is expected to be similar to these pseudo states. (author)
The bound state problem and quark confinement
International Nuclear Information System (INIS)
Chaichian, M.; Demichev, A.P.; Nelipa, N.F.
1980-01-01
A quantum field-theoretic model in which quark is confined is considered. System of equations for the Green functions of colour singlet and octet bound states is obtained. The method is based on the nonperturbative Schwinger-Dyson equations with the use of Slavnov-Taylor identities. It is shown that in the framework of the model if there exist singlet, then also exist octet bound states of the quark-antiquark system. Thus in general, confinement of free quarks does not mean absence of their coloured bound states. (author)
Entropic Lower Bound for Distinguishability of Quantum States
Directory of Open Access Journals (Sweden)
Seungho Yang
2015-01-01
Full Text Available For a system randomly prepared in a number of quantum states, we present a lower bound for the distinguishability of the quantum states, that is, the success probability of determining the states in the form of entropy. When the states are all pure, acquiring the entropic lower bound requires only the density operator and the number of the possible states. This entropic bound shows a relation between the von Neumann entropy and the distinguishability.
Relativistic bound state wave functions
International Nuclear Information System (INIS)
Micu, L.
2005-01-01
A particular method of writing the bound state wave functions in relativistic form is applied to the solutions of the Dirac equation with confining potentials in order to obtain a relativistic description of a quark antiquark bound system representing a given meson. Concerning the role of the effective constituent in the present approach we first observe that without this additional constituent we couldn't expand the bound state wave function in terms of products of free states. Indeed, we notice that if the wave function depends on the relative coordinates only, all the expansion coefficients would be infinite. Secondly we remark that the effective constituent enabled us to give a Lorentz covariant meaning to the potential energy of the bound system which is now seen as the 4th component of a 4-momentum. On the other side, by relating the effective constituent to the quantum fluctuations of the background field which generate the binding, we provided a justification for the existence of some spatial degrees of freedom accompanying the interaction potential. These ones, which are quite unusual in quantum mechanics, in our model are the natural consequence of the the independence of the quarks and can be seen as the effect of the imperfect cancellation of the vector momenta during the quantum fluctuations. Related with all these we remark that the adequate representation for the relativistic description of a bound system is the momentum representation, because of the transparent and easy way of writing the conservation laws and the transformation properties of the wave functions. The only condition to be fulfilled is to find a suitable way to take into account the potential energy of the bound system. A particular feature of the present approach is that the confining forces are due to a kind of glue where both quarks are embedded. This recalls other bound state models where the wave function is factorized in terms of constituent wave functions and the confinement is
A rigorous approach to relativistic corrections of bound state energies for spin-1/2 particles
International Nuclear Information System (INIS)
Gesztesy, F.; Thaller, B.; Grosse, H.
1983-01-01
Under fairly general conditions on the interactions we prove holomorphy of the Dirac resolvent around its nonrelativistic limit. As a consequences, perturbation theory in terms of resolvents (instead of Hamiltonians) yields holomorphy of Dirac eigenvalues and eigenfunctions with respect to c - 1 and a new method of calculating relativistic corrections to bound state energies. Due to a formulation in an abstract setting our method is applicable in many different concrete situation. In particular our approach covers the case of the relavistic hydrogen atom in external electromagnetic fields. (Author)
Dark-matter bound states from Feynman diagrams
Petraki, K.; Postma, M.; Wiechers, M.
2015-01-01
If dark matter couples directly to a light force mediator, then it may form bound states in the early universe and in the non-relativistic environment of haloes today. In this work, we establish a field-theoretic framework for the computation of bound-state formation cross-sections, de-excitation
Bound entangled states violate a nonsymmetric local uncertainty relation
International Nuclear Information System (INIS)
Hofmann, Holger F.
2003-01-01
As a consequence of having a positive partial transpose, bound entangled states lack many of the properties otherwise associated with entanglement. It is therefore interesting to identify properties that distinguish bound entangled states from separable states. In this paper, it is shown that some bound entangled states violate a nonsymmetric class of local uncertainty relations [H. F. Hofmann and S. Takeuchi, Phys. Rev. A 68, 032103 (2003)]. This result indicates that the asymmetry of nonclassical correlations may be a characteristic feature of bound entanglement
Two-nucleon bound states in quenched lattice QCD
International Nuclear Information System (INIS)
Yamazaki, T.; Kuramashi, Y.; Ukawa, A.
2011-01-01
We address the issue of bound state in the two-nucleon system in lattice QCD. Our study is made in the quenched approximation at the lattice spacing of a=0.128 fm with a heavy quark mass corresponding to m π =0.8 GeV. To distinguish a bound state from an attractive scattering state, we investigate the volume dependence of the energy difference between the ground state and the free two-nucleon state by changing the spatial extent of the lattice from 3.1 fm to 12.3 fm. A finite energy difference left in the infinite spatial volume limit leads us to the conclusion that the measured ground states for not only spin triplet but also singlet channels are bounded. Furthermore the existence of the bound state is confirmed by investigating the properties of the energy for the first excited state obtained by a 2x2 diagonalization method. The scattering lengths for both channels are evaluated by applying the finite volume formula derived by Luescher to the energy of the first excited states.
Charged boson bound states in the kerr-newman metric
International Nuclear Information System (INIS)
Li Yuanjie; Zhang Duanming
1986-01-01
Charged boson bound states in Kerr-Newman metric are discussed. It is found that massless boson cannot be attracted by Kerr-Newman black hole to form bound states. For the massive boson, the condition of the nonbound states when 0 2 - Q 2 and both the condition and wave functions of the bound states when a = √M 2 - Q 2 are obtained. The energy mode of the bound states is single, E = (m√M 2 - Q 2 + eQM)/(2M 2 - Q 2 ). When Q = 0 or e = 0, the conclusion is in agreement with that of Zhang Shiwei and Su Rukeng
Strength distributions of electromagnetic transitions in light nuclei
International Nuclear Information System (INIS)
Kostin, V.Ya.; Koval', A.A.; Kopanets, E.G.; Tsytko, S.P.
1980-01-01
Distributions of probabilities of electromagnetic transitions from resonance levels of light nuclei with masses A=Z-40 for eight types of transition (epsilon1, epsilon2, M1, M8, isoscalar and isovector) are obtained. Recommended upper limits (RUL) of transition probabilities are determined for each type of transitions. A comparison with analogous characteristics for transitions between bound states is carried out. It has been causes found that RUL for resonance states substantially differ from RUL for transitions between bound states. Possible causes of such difference are discussed
Cosmological implications of Dark Matter bound states
Energy Technology Data Exchange (ETDEWEB)
Mitridate, Andrea [Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126, Pisa (Italy); Redi, Michele; Smirnov, Juri [INFN, Sezione di Firenze, and Dipartimento di Fisica e Astronomia, Università di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Strumia, Alessandro, E-mail: andrea.mitridate@gmail.com, E-mail: michele.redi@fi.infn.it, E-mail: juri.smirnov@mpi-hd.mpg.de, E-mail: alessandro.strumia@cern.ch [Dipartimento di Fisica dell' Università di Pisa and INFN, Pisa (Italy)
2017-05-01
We present generic formulæ for computing how Sommerfeld corrections together with bound-state formation affects the thermal abundance of Dark Matter with non-abelian gauge interactions. We consider DM as a fermion 3plet (wino) or 5plet under SU(2) {sub L} . In the latter case bound states raise to 11.5 TeV the DM mass required to reproduce the cosmological DM abundance and give indirect detection signals such as (for this mass) a dominant γ-line around 70 GeV. Furthermore, we consider DM co-annihilating with a colored particle, such as a squark or a gluino, finding that bound state effects are especially relevant in the latter case.
Microscopic observation of magnon bound states and their dynamics.
Fukuhara, Takeshi; Schauß, Peter; Endres, Manuel; Hild, Sebastian; Cheneau, Marc; Bloch, Immanuel; Gross, Christian
2013-10-03
The existence of bound states of elementary spin waves (magnons) in one-dimensional quantum magnets was predicted almost 80 years ago. Identifying signatures of magnon bound states has so far remained the subject of intense theoretical research, and their detection has proved challenging for experiments. Ultracold atoms offer an ideal setting in which to find such bound states by tracking the spin dynamics with single-spin and single-site resolution following a local excitation. Here we use in situ correlation measurements to observe two-magnon bound states directly in a one-dimensional Heisenberg spin chain comprising ultracold bosonic atoms in an optical lattice. We observe the quantum dynamics of free and bound magnon states through time-resolved measurements of two spin impurities. The increased effective mass of the compound magnon state results in slower spin dynamics as compared to single-magnon excitations. We also determine the decay time of bound magnons, which is probably limited by scattering on thermal fluctuations in the system. Our results provide a new way of studying fundamental properties of quantum magnets and, more generally, properties of interacting impurities in quantum many-body systems.
Yukawa Bound States and Their LHC Phenomenology
Directory of Open Access Journals (Sweden)
Enkhbat Tsedenbaljir
2013-01-01
Full Text Available We present the current status on the possible bound states of extra generation quarks. These include phenomenology and search strategy at the LHC. If chiral fourth-generation quarks do exist their strong Yukawa couplings, implied by current experimental lower bound on their masses, may lead to formation of bound states. Due to nearly degenerate 4G masses suggested by Precision Electroweak Test one can employ “heavy isospin” symmetry to classify possible spectrum. Among these states, the color-octet isosinglet vector ω 8 is the easiest to be produced at the LHC. The discovery potential and corresponding decay channels are covered in this paper. With possible light Higgs at ~125 GeV two-Higgs doublet version is briefly discussed.
Bound state and localization of excitation in many-body open systems
Cui, H. T.; Shen, H. Z.; Hou, S. C.; Yi, X. X.
2018-04-01
We study the exact bound state and time evolution for single excitations in one-dimensional X X Z spin chains within a non-Markovian reservoir. For the bound state, a common feature is the localization of single excitations, which means the spontaneous emission of excitations into the reservoir is prohibited. Exceptionally, the pseudo-bound state can be found, for which the single excitation has a finite probability of emission into the reservoir. In addition, a critical energy scale for bound states is also identified, below which only one bound state exists, and it is also the pseudo-bound state. The effect of quasirandom disorder in the spin chain is also discussed; such disorder induces the single excitation to locate at some spin sites. Furthermore, to display the effect of bound state and disorder on the preservation of quantum information, the time evolution of single excitations in spin chains is studied exactly. An interesting observation is that the excitation can stay at its initial location with high probability only when the bound state and disorder coexist. In contrast, when either one of them is absent, the information of the initial state can be erased completely or becomes mixed. This finding shows that the combination of bound state and disorder can provide an ideal mechanism for quantum memory.
Scattering theory methods for bound state problems
International Nuclear Information System (INIS)
Raphael, R.B.; Tobocman, W.
1978-01-01
For the analysis of the properties of a bound state system one may use in place of the Schroedinger equation the Lippmann-Schwinger (LS) equation for the wave function or the LS equation for the reactance operator. Use of the LS equation for the reactance operator constrains the solution to have correct asymptotic behaviour, so this approach would appear to be desirable when the bound state wave function is to be used to calculate particle transfer form factors. The Schroedinger equation based N-level analysis of the s-wave bound states of a square well is compared to the ones based on the LS equation. It is found that the LS equation methods work better than the Schroedinger equation method. The method that uses the LS equation for the wave function gives the best results for the wave functions while the method that uses the LS equation for the reactance operator gives the best results for the binding energies. The accuracy of the reactance operator based method is remarkably insensitive to changes in the oscillator constant used for the harmonic oscillator function basis set. It is also remarkably insensitive to the number of nodes in the bound state wave function. (Auth.)
Bound States in the Mirror TBA
Arutyunov, G.E.; Frolov, S.; van Tongeren, S.J.
2012-01-01
The spectrum of the light-cone AdS_5 \\times S^5 superstring contains states composed of particles with complex momenta including in particular those which turn into bound states in the decompactification limit. We propose the mirror TBA description for these states. We focus on a three-particle
Relativistic shifts of bound negative-muon precession frequencies
International Nuclear Information System (INIS)
Brewer, J.H.; Froese, A. M.; Fryer, B.A.; Ghandi, K.
2005-01-01
High-field negative-muon spin precession experiments have been performed using a backward-muon beam with substantial transverse spin polarization, facilitating high-precision measurements of the magnetogyric ratio of negative muons bound to nuclei in the ground states of muonic atoms. These results may provide a testing ground for quantum electrodynamics in very strong electromagnetic fields
A note on BPS vortex bound states
Directory of Open Access Journals (Sweden)
A. Alonso-Izquierdo
2016-02-01
Full Text Available In this note we investigate bound states, where scalar and vector bosons are trapped by BPS vortices in the Abelian Higgs model with a critical ratio of the couplings. A class of internal modes of fluctuation around cylindrically symmetric BPS vortices is characterized mathematically, analyzing the spectrum of the second-order fluctuation operator when the Higgs and vector boson masses are equal. A few of these bound states with low values of quantized magnetic flux are described fully, and their main properties are discussed.
A note on BPS vortex bound states
Energy Technology Data Exchange (ETDEWEB)
Alonso-Izquierdo, A., E-mail: alonsoiz@usal.es [Departamento de Matematica Aplicada, Universidad de Salamanca (Spain); Garcia Fuertes, W., E-mail: wifredo@uniovi.es [Departamento de Fisica, Universidad de Oviedo (Spain); Mateos Guilarte, J., E-mail: guilarte@usal.es [Departamento de Fisica Fundamental, Universidad de Salamanca (Spain)
2016-02-10
In this note we investigate bound states, where scalar and vector bosons are trapped by BPS vortices in the Abelian Higgs model with a critical ratio of the couplings. A class of internal modes of fluctuation around cylindrically symmetric BPS vortices is characterized mathematically, analyzing the spectrum of the second-order fluctuation operator when the Higgs and vector boson masses are equal. A few of these bound states with low values of quantized magnetic flux are described fully, and their main properties are discussed.
Volume dependence of N-body bound states
König, Sebastian; Lee, Dean
2018-04-01
We derive the finite-volume correction to the binding energy of an N-particle quantum bound state in a cubic periodic volume. Our results are applicable to bound states with arbitrary composition and total angular momentum, and in any number of spatial dimensions. The only assumptions are that the interactions have finite range. The finite-volume correction is a sum of contributions from all possible breakup channels. In the case where the separation is into two bound clusters, our result gives the leading volume dependence up to exponentially small corrections. If the separation is into three or more clusters, there is a power-law factor that is beyond the scope of this work, however our result again determines the leading exponential dependence. We also present two independent methods that use finite-volume data to determine asymptotic normalization coefficients. The coefficients are useful to determine low-energy capture reactions into weakly bound states relevant for nuclear astrophysics. Using the techniques introduced here, one can even extract the infinite-volume energy limit using data from a single-volume calculation. The derived relations are tested using several exactly solvable systems and numerical examples. We anticipate immediate applications to lattice calculations of hadronic, nuclear, and cold atomic systems.
International Nuclear Information System (INIS)
Yu, Yafei; Zhan, Mingsheng; Feng, Jian
2003-01-01
We compare remote quantum information concentration by a Greenberger-Horne-Zeilinger (GHZ) state with an unlockable bound entangled state. We find that in view of communication security the bound entangled state works better than the GHZ state
Ionization in a quantized electromagnetic field
International Nuclear Information System (INIS)
Gonoskov, I. A.; Vugalter, G. A.; Mironov, V. A.
2007-01-01
An analytical expression for a matrix element of the transition from a bound state of an electron in an atom to continuum states is obtained by solving the problem of interaction of the electron with a quantized electromagnetic field. This expression is used to derive formulas for the photoelectron spectrum and the rate of ionization of the simplest model atomic system upon absorption of an arbitrary number of photons. The expressions derived are analyzed and compared with the corresponding relationships obtained via other approaches. It is demonstrated that there are differences as compared to the case of the classical field. In particular, the photoelectron spectrum exhibits dips due to the destructive interference of the transition amplitudes in the quantized electromagnetic field
Effect of Bound Entanglement on the Convertibility of Pure States
International Nuclear Information System (INIS)
Ishizaka, Satoshi
2004-01-01
I show that bound entanglement strongly influences the quantum entanglement processing of pure states: If N distant parties share appropriate bound entangled states with positive partial transpose, all N-partite pure entangled states become inter-convertible by stochastic local operations and classical communication (SLOCC) at the single copy level. This implies that the Schmidt rank of a bipartite pure entangled state can be increased, and that two incomparable tripartite entanglement of the GHZ and W type can be inter-converted by the assistance of bound entanglement. Further, I propose the simplest experimental scheme for the demonstration of the corresponding bound-entanglement-assisted SLOCC. This scheme does not need quantum gates and is feasible for the current experimental technology of linear optics
Bound states in weakly disordered spin ladders
Energy Technology Data Exchange (ETDEWEB)
Arlego, M. [Departamento de Fisica, Universidad Nacional de La Plata, CC 67 (1900) La Plata (Argentina)]. E-mail: arlego@venus.fisica.unlp.edu.ar; Brenig, W. [Institut fuer Theoretische Physik, Technische Universitaet Braunschweig (Germany); Cabra, D.C. [Laboratoire de Physique Theorique, Universite Louis Pasteur Strasbourg (France); Heidrich-Meisner, F. [Institut fuer Theoretische Physik, Technische Universitaet Braunschweig (Germany); Honecker, A. [Institut fuer Theoretische Physik, Technische Universitaet Braunschweig (Germany); Rossini, G. [Departamento de Fisica, Universidad Nacional de La Plata, CC 67 (1900) La Plata (Argentina)
2005-04-30
We study the appearance of bound states in the spin gap of spin-12 ladders induced by weak bond disorder. Starting from the strong-coupling limit, i.e., the limit of weakly coupled dimers, we perform a projection on the single-triplet subspace and derive the position of bound states for the single impurity problem of one modified coupling as well as for small impurity clusters. The case of a finite concentration of impurities is treated with the coherent-potential approximation (CPA) in the strong-coupling limit and compared with numerical results. Further, we analyze the details in the structure of the density of states and relate their origin to the influence of impurity clusters.
Toward a minimum branching fraction for dark matter annihilation into electromagnetic final states
International Nuclear Information System (INIS)
Dent, James B.; Scherrer, Robert J.; Weiler, Thomas J.
2008-01-01
Observational limits on the high-energy neutrino background have been used to place general constraints on dark matter that annihilates only into standard model particles. Dark matter particles that annihilate into neutrinos will also inevitably branch into electromagnetic final states through higher-order tree and loop diagrams that give rise to charged leptons, and these charged particles can transfer their energy into photons via synchrotron radiation or inverse Compton scattering. In the context of effective field theory, we calculate the loop-induced branching ratio to charged leptons and show that it is generally quite large, typically > or approx. 1%, when the scale of the dark matter mass exceeds the electroweak scale, M W . For a branching fraction >or approx. 3%, the synchrotron radiation bounds on dark matter annihilation are currently stronger than the corresponding neutrino bounds in the interesting mass range from 100 GeV to 1 TeV. For dark matter masses below M W , our work provides a plausible framework for the construction of a model for 'neutrinos-only' dark matter annihilations.
Coupled elasto-electromagnetic waves in bounded piezoelectric structures
Energy Technology Data Exchange (ETDEWEB)
Darinskii, A N [Institute of Crystallography RAS, Leninskiy pr. 59, Moscow, 119333 (Russian Federation); Clezio, E Le [Universite Francois Rabelais de Tours, ENI Val de Loire, LUSSI, FRE CNRS 2448, rue de la Chocolaterie, BP3410, 41034 Blois (France); Feuillard, G [Universite Francois Rabelais de Tours, ENI Val de Loire, LUSSI, FRE CNRS 2448, rue de la Chocolaterie, BP3410, 41034 Blois (France)
2007-12-15
The work studies theoretically the effect of electromagnetic wave generation on the acoustic wave reflection/transmission in anisotropic materials possessing piezoelectric properties. We are concerned with quasi-normal incidence at angles {theta}{sub i} {>=} v{sub a}/v{sub el} {approx} 10{sup -3} to 10{sup -5}, where v{sub a} and v{sub el} are the typical velocities of the acoustic and electromagnetic waves. It is shown that electromagnetic and acoustic waves are able to interact strongly despite a huge difference in velocities so that the wave behavior of time-dependent electric fields can drastically change the coefficients of mode conversion. In particular, examples exist of the situations where the acoustic wave must be totally reflected but quasi-electrostatic calculations predict almost total transmission.
International Nuclear Information System (INIS)
Yu, Terri M.; Brown, Kenneth R.; Chuang, Isaac L.
2005-01-01
The role of mixed-state entanglement in liquid-state nuclear magnetic resonance (NMR) quantum computation is not yet well understood. In particular, despite the success of quantum-information processing with NMR, recent work has shown that quantum states used in most of those experiments were not entangled. This is because these states, derived by unitary transforms from the thermal equilibrium state, were too close to the maximally mixed state. We are thus motivated to determine whether a given NMR state is entanglable - that is, does there exist a unitary transform that entangles the state? The boundary between entanglable and nonentanglable thermal states is a function of the spin system size N and its temperature T. We provide bounds on the location of this boundary using analytical and numerical methods; our tightest bound scales as N∼T, giving a lower bound requiring at least N∼22 000 proton spins to realize an entanglable thermal state at typical laboratory NMR magnetic fields. These bounds are tighter than known bounds on the entanglability of effective pure states
Color-suppression of non-planar diagrams in bosonic bound states
Alvarenga Nogueira, J. H.; Ji, Chueng-Ryong; Ydrefors, E.; Frederico, T.
2018-02-01
We study the suppression of non-planar diagrams in a scalar QCD model of a meson system in 3 + 1 space-time dimensions due to the inclusion of the color degrees of freedom. As a prototype of the color-singlet meson, we consider a flavor-nonsinglet system consisting of a scalar-quark and a scalar-antiquark with equal masses exchanging a scalar-gluon of a different mass, which is investigated within the framework of the homogeneous Bethe-Salpeter equation. The equation is solved by using the Nakanishi representation for the manifestly covariant bound-state amplitude and its light-front projection. The resulting non-singular integral equation is solved numerically. The damping of the impact of the cross-ladder kernel on the binding energies are studied in detail. The color-suppression of the cross-ladder effects on the light-front wave function and the elastic electromagnetic form factor are also discussed. As our results show, the suppression appears significantly large for Nc = 3, which supports the use of rainbow-ladder truncations in practical non-perturbative calculations within QCD.
Maximum and minimum entropy states yielding local continuity bounds
Hanson, Eric P.; Datta, Nilanjana
2018-04-01
Given an arbitrary quantum state (σ), we obtain an explicit construction of a state ρɛ * ( σ ) [respectively, ρ * , ɛ ( σ ) ] which has the maximum (respectively, minimum) entropy among all states which lie in a specified neighborhood (ɛ-ball) of σ. Computing the entropy of these states leads to a local strengthening of the continuity bound of the von Neumann entropy, i.e., the Audenaert-Fannes inequality. Our bound is local in the sense that it depends on the spectrum of σ. The states ρɛ * ( σ ) and ρ * , ɛ (σ) depend only on the geometry of the ɛ-ball and are in fact optimizers for a larger class of entropies. These include the Rényi entropy and the minimum- and maximum-entropies, providing explicit formulas for certain smoothed quantities. This allows us to obtain local continuity bounds for these quantities as well. In obtaining this bound, we first derive a more general result which may be of independent interest, namely, a necessary and sufficient condition under which a state maximizes a concave and Gâteaux-differentiable function in an ɛ-ball around a given state σ. Examples of such a function include the von Neumann entropy and the conditional entropy of bipartite states. Our proofs employ tools from the theory of convex optimization under non-differentiable constraints, in particular Fermat's rule, and majorization theory.
Bound states of 'dressed' particles
International Nuclear Information System (INIS)
Shirokov, M.I.
1994-01-01
A new approach to the problem of bound states in relativistic quantum field theories is suggested. It uses the creation - destruction operators of 'dresses' particles which have been granted by Faddeev's (1963) 'dressing' formalism. Peculiarities of the proposed approach as compared to the known ones are discussed. 8 refs. (author)
Majorana bound states in a disordered quantum dot chain
International Nuclear Information System (INIS)
Zhang, P; Nori, Franco
2016-01-01
We study Majorana bound states in a disordered chain of semiconductor quantum dots proximity-coupled to an s -wave superconductor. By calculating its topological quantum number, based on the scattering-matrix method and a tight-binding model, we can identify the topological property of such an inhomogeneous one-dimensional system. We study the robustness of Majorana bound states against disorder in both the spin-independent terms (including the chemical potential and the regular spin-conserving hopping) and the spin-dependent term, i.e., the spin-flip hopping due to the Rashba spin–orbit coupling. We find that the Majorana bound states are not completely immune to the spin-independent disorder, especially when the latter is strong. Meanwhile, the Majorana bound states are relatively robust against spin-dependent disorder, as long as the spin-flip hopping is of uniform sign (i.e., the varying spin-flip hopping term does not change its sign along the chain). Nevertheless, when the disorder induces sign-flip in spin-flip hopping, the topological-nontopological phase transition takes place in the low-chemical-potential region. (paper)
Exchange interaction in scattering on the bound state
International Nuclear Information System (INIS)
Arkhipov, A.A.; Savrin, V.I.
1975-01-01
In the framework of the one-time formulation of three-body problem in quantum field theory, the problem of scattering on the bound state is considered for the case when one of the incident particles is identical to one of the particles of the target. It is shown that due to the identical nature of these particles the exchange interaction takes place which can be connected with the mechanism of scattering on the bound state with the rearrangement
Electromagnetic interactions in relativistic systems of many bodies
International Nuclear Information System (INIS)
Cook, A.H.
1987-09-01
In a previous report (Cook, 1986, 1987) on a formulation of a quasi-relativistic quantum mechanical equation of motion for many particles, little was said of the electromagnetic interactions that keep a set of particles in a bound state. That omission is to some extent repaired in this report. (author). 3 refs
Kinetic theory of electromagnetic plane wave obliquely incident on bounded plasma slab
International Nuclear Information System (INIS)
Angus, J. R.; Krasheninnikov, S. I.; Smolyakov, A. I.
2010-01-01
The effects of electromagnetic plane waves obliquely incident on a warm bounded plasma slab of finite length L are studied by solving the coupled Vlasov-Maxwell set of equations. It is shown that the solution can be greatly simplified in the limit where thermal effects are most important by expanding in small parameters and introducing self-similar variables. These solutions reveal that the coupling of thermal effects with the angle of incidence is negligible in the region of bounce resonance and anomalous skin effect. In the region of the anomalous skin effect, the heating is shown to scale linearly with the anomalous skin depth δ a when δ a a >>L, the heating is shown to decay with 1/δ a 3 . The transmission is found to be exponentially larger than that predicted from a local theory in the appropriate region of the anomalous skin effect.
Effects of QCD bound states on dark matter relic abundance
Energy Technology Data Exchange (ETDEWEB)
Liew, Seng Pei [Department of Physics, The University of Tokyo,Bunkyo-ku, Tokyo 113-0033 (Japan); Luo, Feng [Kavli IPMU (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan)
2017-02-17
We study scenarios where there exists an exotic massive particle charged under QCD in the early Universe. We calculate the formation and dissociation rates of bound states formed by pairs of these particles, and apply the results in dark matter (DM) coannihilation scenarios, including also the Sommerfeld effect. We find that on top of the Sommerfeld enhancement, bound-state effects can further significantly increase the largest possible DM masses which can give the observed DM relic abundance, by ∼30–100% with respect to values obtained by considering the Sommerfeld effect only, for the color triplet or octet exotic particles we consider. In particular, it indicates that the Bino DM mass in the right-handed stop-Bino coannihilation scenario in the Minimal Supersymmetric extension of the Standard Model (MSSM) can reach ∼2.5 TeV, even though the potential between the stop and antistop prior to forming a bound state is repulsive. We also apply the bound-state effects in the calculations of relic abundance of long-lived or metastable massive colored particles, and discuss the implications on the BBN constraints and the abundance of a super-weakly interacting DM. The corrections for the bound-state effect when the exotic massive colored particles also carry electric charges, and the collider bounds are also discussed.
Bound states in curved quantum waveguides
International Nuclear Information System (INIS)
Exner, P.; Seba, P.
1987-01-01
We study free quantum particle living on a curved planar strip Ω of a fixed width d with Dirichlet boundary conditions. It can serve as a model for electrons in thin films on a cylindrical-type substrate, or in a curved quantum wire. Assuming that the boundary of Ω is infinitely smooth and its curvature decays fast enough at infinity, we prove that a bound state with energy below the first transversal mode exists for all sufficiently small d. A lower bound on the critical width is obtained using the Birman-Schwinger technique. (orig.)
Relativistic bound state approach to fundamental forces including gravitation
Directory of Open Access Journals (Sweden)
Morsch H.P.
2012-06-01
Full Text Available To describe the structure of particle bound states of nature, a relativistic bound state formalism is presented, which requires a Lagrangian including scalar coupling of two boson fields. The underlying mechanisms are quite complex and require an interplay of overlapping boson fields and fermion-antifermion production. This gives rise to two potentials, a boson-exchange potential and one identified with the long sought confinement potential in hadrons. With minimal requirements, two elementary massless fermions (quantons - with and without charge - and one gauge boson, hadrons and leptons but also atoms and gravitational systems are described by bound states with electric and magnetic coupling between the charges and spins of quantons. No need is found for colour, Higgs-coupling and supersymmetry.
Majorana bound states in a coupled quantum-dot hybrid-nanowire system
DEFF Research Database (Denmark)
Deng, M. T.; Vaitiekenas, S.; Hansen, E. B.
2016-01-01
Hybrid nanowires combining semiconductor and superconductor materials appear well suited for the creation, detection, and control of Majorana bound states (MBSs). We demonstrate the emergence of MBSs from coalescing Andreev bound states (ABSs) in a hybrid InAs nanowire with epitaxial Al, using...... with the end-dot bound state, which is in agreement with a numerical model. The ABS/MBS spectra provide parameters that are useful for understanding topological superconductivity in this system....
International Nuclear Information System (INIS)
Ritchie, Burke
2006-01-01
The Hamiltonian for Dirac's second-order equation depends nonlinearly on the potential V and the energy E. For this reason the magnetic contribution to the Hamiltonian for s-waves, which has a short range, is attractive for a repulsive Coulomb potential (V>0) and repulsive for an attractive Coulomb potential (V 2 . Usually solutions are found in the regime E=mc 2 +ε , where except for high Z, ε 2 . Here it is shown that for V>0 the attractive magnetic term and the linear repulsive term combine to support a bound state near E=0.5mc 2 corresponding to a binding energy E b =-ε =0.5mc 2
Roy, Chiranjeeb
In this thesis we study the role of nonradiative degrees of freedom on quantum optical properties of mesoscopic quantum dots placed in the structured electromagnetic reservoir of a photonic crystal. We derive a quantum theory of the role of acoustic and optical phonons in modifying the optical absorption lineshape, polarization dynamics, and population dynamics of a two-level atom (quantum dot) in the "colored" electromagnetic vacuum of a photonic band gap (PBG) material. This is based on a microscopic Hamiltonian describing both radiative and vibrational processes quantum mechanically. Phonon sidebands in an ordinary electromagnetic reservoir are recaptured in a simple model of optical phonons using a mean-field factorization of the atomic and lattice displacement operators. Our formalism is then used to treat the non-Markovian dynamics of the same system within the structured electromagnetic density of states of a photonic crystal. We elucidate the extent to which phonon-assisted decay limits the lifetime of a single photon-atom bound state and derive the modified spontaneous emission dynamics due to coupling to various phonon baths. We demonstrate that coherent interaction with undamped phonons can lead to enhanced lifetime of a photon-atom bound state in a PBG by (i) dephasing and reducing the transition electric dipole moment of the atom and (ii) reducing the quantum mechanical overlap of the state vectors of the excited and ground state (polaronic shift). This results in reduction of the steady-state atomic polarization but an increase in the fractionalized upper state population in the photon-atom bound state. We demonstrate, on the other hand, that the lifetime of the photon-atom bound state in a PBG is limited by the lifetime of phonons due to lattice anharmonicities (break-up of phonons into lower energy phonons) and purely nonradiative decay. We demonstrate how these additional damping effects limit the extent of the polaronic (Franck-Condon) shift of
Quasi-bound states, resonance tunnelling, and tunnelling times ...
Indian Academy of Sciences (India)
analysis of bound states below the threshold energy E = 0 and continuum above the threshold .... p are time reversal states of each other. Similarly, the ... are occurring at above-barrier energies and we do not treat them as QB states. They can ...
Rizov, V A; Todorov, I T
1975-01-01
A recently proposed local quasipotential equation is reviewed and applied to the electromagnetic interaction of a spin-0 and a spin-/sup 1///sub 2/ particle. The Dirac particle is treated in a covariant two- component formalism in the neighbourhood of the mass shell. The fine structure of the bound state energy levels and the main part of the Lamb shift (of order alpha /sup 5/In(1/ alpha ) are evaluated with full account of relativistic recoil effects (without using any inverse mass expansion). Possible relevance of the techniques developed in this paper to fine structure calculations for meso-atomic systems is pointed out. (14 refs).
Relativistic bound states: a mass formula for vector mesons
International Nuclear Information System (INIS)
Richard, J.L.; Sorba, P.
1975-07-01
In the framework of a relativistic description of two particles bound states, a mass formula for vector mesons considered as quark-antiquark systems bound by harmonic oscillator like forces is proposed. Results in good agreement with experimental values are obtained [fr
Two-vibron bound states in the β–Fermi–Pasta–Ulam model
International Nuclear Information System (INIS)
Hu Xinguang; Tang Yi
2008-01-01
This paper studies the two-vibron bound states in the β–Fermi–Pasta–Ulam model by means of the number conserving approximation combined with the number state method. The results indicate that on-site, adjacent-site and mixed two-vibron bound states may exist in the model. Specially, wave number has a significant effect on such bound states, which may be considered as the quantum effects of the localized states in quantum systems. (condensed matter: structure, thermal and mechanical properties)
Bound states embedded into continuous spectrum as 'gathered' (compactified) scattering waves
International Nuclear Information System (INIS)
Zakhar'ev, B.N.; Chabanov, V.M.
1995-01-01
It is shown that states of continuous spectrum (the half-line case) can be considered as bound states normalized by unity but distributed on the infinite interval with vanishing density. Then the algorithms of shifting the range of primary localization of a chosen bound state in potential well of finite width appear to be applicable to scattering functions. The potential perturbations of the same type (but now on half-axis) concentrate the scattering wave in near vicinity of the origin, which leads to creation of bound state embedded into continuous spectrum. (author). 8 refs., 7 figs
Spectrum of gluino bound states
International Nuclear Information System (INIS)
Chanowitz, M.; Sharpe, S.; California Univ., Berkeley
1983-01-01
Using the bag model to first order in αsub(s) we find that if light gluinos exist they will appear as constituents of electrically charged bound states which are stable against strong interaction decay. We review the present experimental constraints and conclude that light, long-lived charged hadrons containing gluinos might exist with lifetimes between 2x10 - 8 and 10 - 14 s. (orig.)
Usefulness of bound-state approximations in reaction theory
International Nuclear Information System (INIS)
Adhikari, S.K.
1981-01-01
A bound-state approximation when applied to certain operators, such as the many-body resolvent operator for a two-body fragmentation channel, in many-body scattering equations, reduces such equations to equivalent two-body scattering equations which are supposed to provide a good description of the underlying physical process. In this paper we test several variants of bound-state approximations in the soluble three-boson Amado model and find that such approximations lead to weak and unacceptable kernels for the equivalent two-body scattering equations and hence to a poor description of the underlying many-body process
Improved Rosen's conditions on bound states of Schroedinger operators
International Nuclear Information System (INIS)
Exner, P.
1984-01-01
We derive a necessary condition on a Schroedinger operator H=-Δ+V on Lsup(2)(Rsup(d)), d>=3 to have a bound state below a given energy epsilon, and a lower bound to the ground-state energy of H. These conditions are expressed in terms of the potential V alone, and generalize the recent results of Rosen to the dimensions d>3 and to the potentials that are not necessarily rapidly decreasing. Some examples are given
Systematic assignment of Feshbach resonances via an asymptotic bound state model
Goosen, M.; Kokkelmans, SJ.J.M.F.
2008-01-01
We present an Asymptotic Bound state Model (ABM), which is useful to predict Feshbach resonances. The model utilizes asymptotic properties of the interaction potentials to represent coupled molecular wavefunctions. The bound states of this system give rise to Feshbach resonances, localized at the
Fano effect and Andreev bound states in T-shape double quantum dots
International Nuclear Information System (INIS)
Calle, A.M.; Pacheco, M.; Orellana, P.A.
2013-01-01
In this Letter, we investigate the transport through a T-shaped double quantum dot coupled to two normal metal leads left and right and a superconducting lead. Analytical expressions of Andreev transmission and local density of states of the system at zero temperature have been obtained. We study the role of the superconducting lead in the quantum interferometric features of the double quantum dot. We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. Our results show that as a consequence of quantum interference and proximity effect, the transmission from normal to normal lead exhibits Fano resonances due to Andreev bound states. We find that this interference effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. - Highlights: • Transport properties of a double quantum dot coupled in T-shape configuration to conducting and superconducting leads are studied. • We report Fano antiresonances in the normal transmission due to the Andreev reflections in the superconducting lead. • We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. • Fano effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. • Andreev bound states survives even for strong dot-superconductor coupling
Connection between bound-states of bosons moving in one dimension
International Nuclear Information System (INIS)
Coutinho, F.A.B.
1982-06-01
It is shown that when a system of two identical bosons moving in one dimension have a bound state of energy ν sub(o), then the N body system will also have a bound state at a specific energy given by equation W(N+1) = 2N/1-N ]W(N)] - N+1/1-N ]W(N-1)]. (Author) [pt
International Nuclear Information System (INIS)
Jackson, J.D.
1994-01-01
The Born-Oppenheimer approximation is used as an exploratory tool to study bound states, quasibound states, and scattering resonances in muon (μ)--hydrogen (x)--hydrogen (y) molecular ions. Our purpose is to comment on the existence and nature of the narrow states reported in three-body calculations, for L=0 and 1, at approximately 55 eV above threshold and the family of states in the same partial waves reported about 1.9 keV above threshold. We first discuss the motivation for study of excited states beyond the well-known and well-studied bound states. Then we reproduce the energies and other properties of these well-known states to show that, despite the relatively large muon mass, the Born-Oppenheimer approximation gives a good, semiquantitative description containing all the essential physics. Born-Oppenheimer calculations of the s- and p-wave scattering of d-(dμ), d-(tμ), and t-(tμ) are compared with the accurate three-body results, again with general success. The places of disagreement are understood in terms of the differences in location of slightly bound (or unbound) states in the Born-Oppenheimer approximation compared to the accurate three-body calculations
Quarks as quasiparticles of bound states
International Nuclear Information System (INIS)
Tyapkin, A.A.
1977-01-01
Interpretation of quarks as strongly bound subsystems of the baryon structure, being in various states with integer the quantum numbers Q and B, is considered. Three original quark states, distinguished by Q, B, and J, are unambiguously determined from the condition that the quarks have the corresponding fractional quantum numbers while the integer quantum numbers for the whole system are known. With this in view the new quantum number ''colour'' is interpreted as a quantity, specifying the appearance of the subsystems in various eigen-states. Basing on the generalized Sakata model, the self-consistency of change of the colour states in the three-quark system is explained
Shooting quasiparticles from Andreev bound states in a superconducting constriction
Energy Technology Data Exchange (ETDEWEB)
Riwar, R.-P.; Houzet, M.; Meyer, J. S. [University of Grenoble Alpes, INAC-SPSMS (France); Nazarov, Y. V., E-mail: Y.V.Nazarov@tudelft.nl [Delft University of Technology, Kavli Institute of NanoScience (Netherlands)
2014-12-15
A few-channel superconducting constriction provides a set of discrete Andreev bound states that may be populated with quasiparticles. Motivated by recent experimental research, we study the processes in an a.c. driven constriction whereby a quasiparticle is promoted to the delocalized states outside the superconducting gap and flies away. We distinguish two processes of this kind. In the process of ionization, a quasiparticle present in the Andreev bound state is transferred to the delocalized states leaving the constriction. The refill process involves two quasiparticles: one flies away while another one appears in the Andreev bound state. We notice an interesting asymmetry of these processes. The electron-like quasiparticles are predominantly emitted to one side of the constriction while the hole-like ones are emitted to the other side. This produces a charge imbalance of accumulated quasiparticles, that is opposite on opposite sides of the junction. The imbalance may be detected with a tunnel contact to a normal metal lead.
Atom collisions in a strong electromagnetic field
International Nuclear Information System (INIS)
Smirnov, V.S.; Chaplik, A.V.
1976-01-01
It is shown that the long-range part of interatomic interaction is considerably altered in a strong electromagnetic field. Instead of the van der Waals law the potential asymptote can best be described by a dipole-dipole R -3 law. Impact broadening and the line shift in a strong nonresonant field are calculated. The possibility of bound states of two atoms being formed in a strong light field is discussed
Electromagnetic decay of two-phonon states
International Nuclear Information System (INIS)
Catara, F.; Chomaz, Ph.; Van Giai, N.; Paris-11 Univ., 91 - Orsay
1991-01-01
The electromagnetic decay of two-phonon states corresponding to the multi-excitation of giant resonances is studied. The calculations are performed within a boson expansion approach and the elementary modes are constructed in random phase approximation (RPA). The rates for direct transition of two-phonon states to the ground state turn out to be not negligibly smaller than those from the (single) giant resonances. The former transitions are accompanied by a γ-ray whose energy is equal to the sum of the two phonon energies. Thus the detection of such high energy γ-rays could provide a signature of the excitation of two-phonon states. (author) 9 refs., 3 tabs
Universal extra dimensions and Kaluza-Klein bound states
International Nuclear Information System (INIS)
Carone, Christopher D.; Conroy, Justin M.; Sher, Marc; Turan, Ismail
2004-01-01
We study the bound states of the Kaluza-Klein (KK) excitations of quarks in certain models of universal extra dimensions. Such bound states may be detected at future lepton colliders in the cross section for the pair production of KK quarks near threshold. For typical values of model parameters, we find that 'KK quarkonia' have widths in the 10-100 MeV range, and production cross sections of the order of a few picobarns for the lightest resonances. Two body decays of the constituent KK quarks lead to distinctive experimental signatures. We point out that such KK resonances may be discovered before any of the higher KK modes
Threshold energy dependence as a function of potential strength and the nonexistence of bound states
International Nuclear Information System (INIS)
Aronson, I.; Kleinman, C.J.; Spruch, L.
1975-01-01
The difficulty in attempting to prove that a given set of particles cannot form a bound state is the absence of a margin of error; the possibility of a bound state of arbitrarily small binding energy must be ruled out. At the sacrifice of rigor, one can hope to bypass the difficulty by studying the ground-state energy E(lambda) associated with H(lambda) identical with H/sub true/ + lambda/sub ν/, where H/sub true/ is the true Hamiltonian, ν is an artificial attractive potential, and lambda greater than 0. E(lambda) can be estimated via a Rayleigh-Ritz calculation. If H/sub true/ falls just short of being able to support a bound state, H(lambda) for lambda ''not too small'' will support a bound state of some significant binding. A margin of error is thereby created; the inability to find a bound state for lambda ''not too small'' suggests not only that H(lambda) can support at best a weakly bound state but that H/sub true/ cannot support a bound state at all. To give the argument real substance, one studies E(lambda) in the neighborhood of lambda = lambda 0 , the (unknown) smallest value for lambda for which H(lambda) can support a bound state. A comparison of E(lambda) determined numerically with the form of E(lambda) obtained with the use of a crude bound-state wave function in the Feynman theorem gives a rough self-consistency check. One thereby obtains a believable lower bound on the energy of a possible bound state of H/sub true/ or a believable argument that no such bound state exists. The method is applied to the triplet state of H -
Surface-bound states in nanodiamonds
Han, Peng; Antonov, Denis; Wrachtrup, Jörg; Bester, Gabriel
2017-05-01
We show via ab initio calculations and an electrostatic model that the notoriously low, but positive, electron affinity of bulk diamond becomes negative for hydrogen passivated nanodiamonds and argue that this peculiar situation (type-II offset with a vacuum level at nearly midgap) and the three further conditions: (i) a surface dipole with positive charge on the outside layer, (ii) a spherical symmetry, and (iii) a dielectric mismatch at the surface, results in the emergence of a peculiar type of surface state localized just outside the nanodiamond. These states are referred to as "surface-bound states" and have consequently a strong environmental sensitivity. These type of states should exist in any nanostructure with negative electron affinity. We further quantify the band offsets of different type of nanostructures as well as the exciton binding energy and contrast the results with results for "conventional" silicon quantum dots.
Crossover from bound to free states in plasmas
International Nuclear Information System (INIS)
Lankin, Alexander V; Norman, Genri E
2009-01-01
A self-consistent joint description of free and weakly bound electron states in strongly coupled plasmas is presented. The existence of two problems is emphasized. The first one is a well-known restriction of the number of atomic excited states. Another one is a description of the smooth crossover from bound pair electron-ion excited states to collective excitations of free electrons. The fluctuation approach is developed to study the spectrum domain intermediate between low-lying excited atoms and free electron continuous energy levels. The molecular dynamics method is applied to study the plasma model since the method is able to distinguish all kinds of fluctuations. The electron-ion interaction is described by the temperature-independent cut-off Coulomb potential. The diagnostics of pair electron-ion fluctuations is developed. The concept of pair fluctuations elucidates the smooth vanishing of atomic states near the ionization limit. The approach suggested removes the artificial break of the electron state density at the ionization limit: atomic state density divergent at the negative energy side and free electron state density starting from zero density at the positive energy side
First observation of bound-state β-decay
International Nuclear Information System (INIS)
Jung, M.; Bosch, F.; Beckert, K.; Eickhoff, H.; Folger, H.; Franzke, B.; Kienle, P.; Klepper, O.; Koenig, W.; Kozhuharov, C.; Mann, R.; Moshammer, R.; Nolden, F.; Schaaf, U.; Soff, G.; Spaedtke, P.; Steck, M.; Stoehlker, T.; Suemmerer, K.
1992-06-01
Bound-state Β - decay was observed for the first time by storing bare 66 163 Dy 66+ ions in a heavy-ion storage ring. From the number of 67 163 Ho 66+ daughter ions, measured as a function of the storage time, a half-life of 47 4 +5 - d was derived. By comparing this result with reported half-lives for electron capture (EC) from the M 1 and M 2 shells of neutral 67 163 Ho, bounds for both the Q EC value of neutral 67 163 Ho and for the electron neutrino mass were set. (orig.)
Bound-state quark and gluon contributions to structure functions in QCD
International Nuclear Information System (INIS)
Brodsky, S.J.
1991-01-01
One can distinguish two types of contributions to the quark and gluon structure functions of hadrons in quantum chromodynamics: 'intrinsic' contributions, which are due to the direct scattering on the bound-state constituents, and 'extrinsic' contributions, which are derived from particles created in the collision. In this talk, I discuss several aspects of deep inealstic structure functions in which the bound-state structure of the proton plays a crucial role: (1) the properties of the intrinsic gluon distribution associated with the proton bound-state wavefunction; (2) the separation of the quark structure function of the proton into intrinsic 'bound-valence' and extrinsic 'non-valence' components which takes into account the Pauli principle; (3) the properties and identification of intrinsic heavy quark structure functions; and (4) a theory of shadowing and anti-shadowing of nuclear structure functions, directly related to quark-nucleon interactions and the gluon saturation phenomenon. (orig.)
Bound-state quark and gluon contributions to structure functions in QCD
International Nuclear Information System (INIS)
Brodsky, S.J.
1990-08-01
One can distinguish two types of contributions to the quark and gluon structure functions of hadrons in quantum chromodynamics: ''intrinsic'' contributions, which are due to the direct scattering on the bound-state constituents, and ''extrinsic'' contributions, which are derived from particles created in the collision. In this talk, I discussed several aspects of deep inelastic structure functions in which the bound-state structure of the proton plays a crucial role: the properties of the intrinsic gluon distribution associated with the proton bound-state wavefunction; the separation of the quark structure function of the proton onto intrinsic ''bound-valence'' and extrinsic ''non-valence'' components which takes into account the Pauli principle; the properties and identification of intrinsic heavy quark structure functions; and a theory of shadowing and anti-shadowing of nuclear structure functions, directly related to quark-nucleon interactions and the gluon saturation phenomenon. 49 refs., 5 figs
Tunable hybridization of Majorana bound states at the quantum spin Hall edge
Keidel, Felix; Burset, Pablo; Trauzettel, Björn
2018-02-01
Confinement at the helical edge of a topological insulator is possible in the presence of proximity-induced magnetic (F) or superconducting (S) order. The interplay of both phenomena leads to the formation of localized Majorana bound states (MBS) or likewise (under certain resonance conditions) the formation of ordinary Andreev bound states (ABS). We investigate the properties of bound states in junctions composed of alternating regions of F or S barriers. Interestingly, the direction of magnetization in F regions and the relative superconducting phase between S regions can be exploited to hybridize MBS or ABS at will. We show that the local properties of MBS translate into a particular nonlocal superconducting pairing amplitude. Remarkably, the symmetry of the pairing amplitude contains information about the nature of the bound state that it stems from. Hence this symmetry can in principle be used to distinguish MBS from ABS, owing to the strong connection between local density of states and nonlocal pairing in our setup.
Bound states in quantum field theory and coherent states: A fresh look
International Nuclear Information System (INIS)
Misra, S.P.
1986-09-01
We consider here bound state equations in quantum field theory where the state explicitly includes radiation quanta as constituents with the number of such quanta not fixed. The fully interacting system is dealt with through equal time commutators/anticommutators of field operators. The multiparticle channel for the radiation field is approximated through coherent state representations. (author)
Accidental bound states in the continuum in an open Sinai billiard
Energy Technology Data Exchange (ETDEWEB)
Pilipchuk, A.S. [Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk (Russian Federation); Siberian Federal University, 660080 Krasnoyarsk (Russian Federation); Sadreev, A.F., E-mail: almas@tnp.krasn.ru [Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk (Russian Federation)
2017-02-19
The fundamental mechanism of the bound states in the continuum is the full destructive interference of two resonances when two eigenlevels of the closed system are crossing. There is, however, a wide class of quantum chaotic systems which display only avoided crossings of eigenlevels. As an example of such a system we consider the Sinai billiard coupled with two semi-infinite waveguides. We show that notwithstanding the absence of degeneracy bound states in the continuum occur due to accidental decoupling of the eigenstates of the billiard from the waveguides. - Highlights: • Bound states in the continuum in open chaotic billiards occur to accidental vanishing of coupling of eigenstate of billiard with waveguides.
Electromagnetic local density of states in graphene-covered porous silicon carbide
Energy Technology Data Exchange (ETDEWEB)
Zhou, Ting [Department of Physics, Nanchang University, Nanchang 330031 (China); Wang, Tong-Biao, E-mail: tbwang@ncu.edu.cn [Department of Physics, Nanchang University, Nanchang 330031 (China); Liao, Qing-Hua; Liu, Jiang-Tao; Yu, Tian-Bao [Department of Physics, Nanchang University, Nanchang 330031 (China); Liu, Nian-Hua [Institute for Advanced Study, Nanchang University, Nanchang 330031 (China)
2017-06-21
Surface phonon polariton supported by silicon carbide (SiC) can be strongly coupled with graphene plasmon in the graphene-covered SiC bulk. The spectrum of the electromagnetic local density of states exhibits two peaks whose positions can be tuned by the chemical potential of graphene. In this work, we study the electromagnetic local density of states in the proximity of a graphene-covered SiC with periodic hole arrays. The well-known peak from the coupling of surface polariton supported by SiC and graphene plasmon splits into two. With increased volume ratio of holes, one of the split peak shifts towards high frequencies, whereas the other moves towards low frequencies. The dependence of split-peak positions on the chemical potential and permittivity of filling materials in the holes are also investigated. This study offers another method of modulating the electromagnetic local density of states. - Highlights: • The electromagnetic local density of states in the proximity of graphene-covered anisotropic SiC is firstly studied. • The peak from resonance of surface phonon polaritons in the EM-LDOS spectrum can be split into two. • The split peaks can be tuned by chemical potential, filling factor, and filling materials. • Our results provide a new method to modulate the EM-LDOS.
Andreev bound states. Some quasiclassical reflections
International Nuclear Information System (INIS)
Lin, Y.; Leggett, A. J.
2014-01-01
We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it
Andreev bound states. Some quasiclassical reflections
Energy Technology Data Exchange (ETDEWEB)
Lin, Y., E-mail: yiriolin@illinois.edu; Leggett, A. J. [University of Illinois at Urhana-Champaign, Dept. of Physics (United States)
2014-12-15
We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it.
Three-nucleon forces and the trinucleon bound states
International Nuclear Information System (INIS)
Friar, J.L.; Frois, B.
1986-04-01
A summary of the bound-state working group session of the ''International Symposium on the Three-Body Force in the Three-Nucleon System'' is presented. The experimental evidence for three-nucleon forces has centered on two ground state properties: the tritium binding energy and the trinucleon form factors. Both are discussed
Detecting Stealth Dark Matter Directly through Electromagnetic Polarizability.
Appelquist, T; Berkowitz, E; Brower, R C; Buchoff, M I; Fleming, G T; Jin, X-Y; Kiskis, J; Kribs, G D; Neil, E T; Osborn, J C; Rebbi, C; Rinaldi, E; Schaich, D; Schroeder, C; Syritsyn, S; Vranas, P; Weinberg, E; Witzel, O
2015-10-23
We calculate the spin-independent scattering cross section for direct detection that results from the electromagnetic polarizability of a composite scalar "stealth baryon" dark matter candidate, arising from a dark SU(4) confining gauge theory-"stealth dark matter." In the nonrelativistic limit, electromagnetic polarizability proceeds through a dimension-7 interaction leading to a very small scattering cross section for dark matter with weak-scale masses. This represents a lower bound on the scattering cross section for composite dark matter theories with electromagnetically charged constituents. We carry out lattice calculations of the polarizability for the lightest "baryon" states in SU(3) and SU(4) gauge theories using the background field method on quenched configurations. We find the polarizabilities of SU(3) and SU(4) to be comparable (within about 50%) normalized to the stealth baryon mass, which is suggestive for extensions to larger SU(N) groups. The resulting scattering cross sections with a xenon target are shown to be potentially detectable in the dark matter mass range of about 200-700 GeV, where the lower bound is from the existing LUX constraint while the upper bound is the coherent neutrino background. Significant uncertainties in the cross section remain due to the more complicated interaction of the polarizablity operator with nuclear structure; however, the steep dependence on the dark matter mass, 1/m(B)(6), suggests the observable dark matter mass range is not appreciably modified. We briefly highlight collider searches for the mesons in the theory as well as the indirect astrophysical effects that may also provide excellent probes of stealth dark matter.
Probing Andreev bound states in one-atom superconducting contacts
Energy Technology Data Exchange (ETDEWEB)
Pothier, Hugues; Janvier, Camille; Tosi, Leandro; Girit, Caglar; Goffman, Marcelo; Esteve, Daniel; Urbina, Cristian [Quantronics Group, SPEC, CEA-Saclay (France)
2015-07-01
Superconductors are characterized by a dissipationless current. Since the work of Josephson 50 years ago, it is known that a supercurrent can even flow through tunnel junctions between superconductors. This Josephson effect also occurs through any type of ''weak links'' between superconductors: non-superconducting materials, constrictions,.. A unified understanding of the Josephson effect has emerged from a mesoscopic description of weak links. It relies on the existence of doublets of localized states that have energies below the superconducting gap: the Andreev bound states. I will present experiments performed on the simplest conductor possible, a single-atom contact between superconductors, that illustrate these concepts. The most recent work demonstrates time-domain manipulation of quantum superpositions of Andreev bound states.
Classical electromagnetic radiation of the Dirac electron
Lanyi, G.
1973-01-01
A wave-function-dependent four-vector potential is added to the Dirac equation in order to achieve conservation of energy and momentum for a Dirac electron and its emitted electromagnetic field. The resultant equation contains solutions which describe transitions between different energy states of the electron. As a consequence it is possible to follow the space-time evolution of such a process. This evolution is shown in the case of the spontaneous emission of an electromagnetic field by an electron bound in a hydrogen-like atom. The intensity of the radiation and the spectral distribution are calculated for transitions between two eigenstates. The theory gives a self-consistent deterministic description of some simple radiation processes without using quantum electrodynamics or the correspondence principle.
Bound-state formation for thermal relic dark matter and unitarity
International Nuclear Information System (INIS)
Harling, Benedict von; Petraki, Kalliopi
2014-01-01
We show that the relic abundance of thermal dark matter annihilating via a long-range interaction, is significantly affected by the formation and decay of dark matter bound states in the early universe, if the dark matter mass is above a few TeV . We determine the coupling required to obtain the observed dark matter density, taking into account both the direct 2-to-2 annihilations and the formation of bound states, and provide an analytical fit. We argue that the unitarity limit on the inelastic cross-section is realized only if dark matter annihilates via a long-range interaction, and we determine the upper bound on the mass of thermal-relic dark matter to be about 197 (139) TeV for (non)-self-conjugate dark matter
Amplification of non-Markovian decay due to bound state absorption into continuum
International Nuclear Information System (INIS)
Garmon, S.; Simine, L.; Segal, D.; Petrosky, T.
2013-01-01
It is known that quantum systems yield non-exponential (power law) decay on long time scales, associated with continuum threshold effects contributing to the survival probability for a prepared initial state. For an open quantum system consisting of a discrete state coupled to continuum, we study the case in which a discrete bound state of the full Hamiltonian approaches the energy continuum as the system parameters are varied. We find in this case that at least two regions exist yielding qualitatively different power law decay behaviors; we term these the long time 'near zone' and long time 'far zone'. In the near zone the survival probability falls off according to a t -1 power law, and in the far zone i t falls off as t -3 . We show that the timescale T Q separating these two regions is inversely related to the gap between the discrete bound state energy and the continuum threshold. In the case that the bound state is absorbed into the continuum and vanishes, then the time scale T Q diverges and the survival probability follows the t -1 power law even on asymptotic scales. Conversely, one could study the case of an anti-bound state approaching the threshold before being ejected from the continuum to form a bound state. Again the t -1 power law dominates precisely at the point of ejection. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Deeply bound pionic states and modifications of hadrons
International Nuclear Information System (INIS)
Hirenzaki, S.
2000-01-01
We have studied the structure and formation of mesic atoms and mesic nuclei theoretically. The latest results on the deeply bound pionic atoms, the kaonic atoms and the sigma states are reported. (author)
Experimental and theoretical study of bound and quasibound states of Ce{sup -}
Energy Technology Data Exchange (ETDEWEB)
Walter, C. W.; Gibson, N. D.; Li, Y.-G.; Matyas, D. J.; Alton, R. M.; Lou, S. E.; Field, R. L. III; Hanstorp, D.; Pan, Lin; Beck, Donald R. [Department of Physics and Astronomy, Denison University, Granville, Ohio 43023 (United States); Department of Physics, University of Gothenburg, SE-412 96 Gothenburg (Sweden); Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States)
2011-09-15
The negative ion of cerium is investigated experimentally with tunable infrared laser photodetachment spectroscopy and theoretically with relativistic configuration interaction in the continuum formalism. The relative cross section for neutral atom production is measured with a crossed ion-beam-laser-beam apparatus over the photon energy range of 0.54-0.75 eV. A rich resonance spectrum is revealed near the threshold with, at least, 12 peaks observed due to transitions from bound states of Ce{sup -} to either bound or quasibound excited states of the negative ion. Theoretical calculations of the photodetachment cross sections enable identification of the transitions responsible for the measured peaks. Two of the peaks are due to electric dipole-allowed bound-bound transitions in Ce{sup -}, making cerium only the second atomic negative ion that has been demonstrated to support multiple bound states of opposite parity. In addition, combining the experimental data with the theoretical analysis determines the electron affinity of cerium to be 0.628(10) eV and the fine structure splitting of the ground state of Ce{sup -} ({sup 4} H{sub 7/2}-{sup 4} H{sub 9/2}) to be 0.097 75(4) eV.
Resolving the Spatial Structures of Bound Hole States in Black Phosphorus.
Qiu, Zhizhan; Fang, Hanyan; Carvalho, Alexandra; Rodin, A S; Liu, Yanpeng; Tan, Sherman J R; Telychko, Mykola; Lv, Pin; Su, Jie; Wang, Yewu; Castro Neto, A H; Lu, Jiong
2017-11-08
Understanding the local electronic properties of individual defects and dopants in black phosphorus (BP) is of great importance for both fundamental research and technological applications. Here, we employ low-temperature scanning tunnelling microscope (LT-STM) to probe the local electronic structures of single acceptors in BP. We demonstrate that the charge state of individual acceptors can be reversibly switched by controlling the tip-induced band bending. In addition, acceptor-related resonance features in the tunnelling spectra can be attributed to the formation of Rydberg-like bound hole states. The spatial mapping of the quantum bound states shows two distinct shapes evolving from an extended ellipse shape for the 1s ground state to a dumbbell shape for the 2p x excited state. The wave functions of bound hole states can be well-described using the hydrogen-like model with anisotropic effective mass, corroborated by our theoretical calculations. Our findings not only provide new insight into the many-body interactions around single dopants in this anisotropic two-dimensional material but also pave the way to the design of novel quantum devices.
Quantum mechanics of electromagnetically bounded spin-1/2 particles in an expanding universe
International Nuclear Information System (INIS)
Audretsch, J.; Schaefer, G.
1978-01-01
The quantum mechanically described electron in an external electromagnetic field, both embedded in an expanding universe with shear, is discussed. This is important for the fundamental question as to whether a quantum mechanically treated atomic clock in curved space-time (based on a hydrogen atom) shows proper or gravitational time. Contradictory results reported by other authors seem to imply that quantum mechanics cannot be reconciled with curved space-time. It is shown that this is not the case for expanding Robertson-Walker universes. A Hilbert space formulation of the problem with special regard to the Hamiltonian is given. The respective influence of the cosmic expansion and the intrinsic and extrinsic curvatures of the cosmic hypersurfaces on bound quantum mechanical systems is treated in general. For the special case of an expanding 3-flat (epsilon= 0) Robertson-Walker universe it is shown that the energy levels of a hydrogen atom agree completely with the one in 4-flat space-time, so that in this case the hydrogen atom can be taken as atomic clock showing proper time. (author)
Possible Existence of (cc¯)–Nucleus Bound States
International Nuclear Information System (INIS)
Yokota, Akira; Oka, Makoto; Hiyama, Emiko
2014-01-01
Charmonium (cc¯) bound states in few-nucleon systems, 2 H, 4 He and 8 Be, are studied via Gaussian Expansion Method (GEM). We adopt a Gaussian potential as an effective (cc¯)–nucleon (N) interaction. The relation between two-body (cc¯)–N scattering length a cc¯−N and the binding energies B of (cc¯)–nucleus bound states are given. Recent lattice QCD data of a cc¯−N corresponds to B≃0.5 MeV for (cc¯)− 4 He and 2 MeV for (cc¯)− 8 Be in our results. (author)
Heavy-to-light form factors for non-relativistic bound states
International Nuclear Information System (INIS)
Bell, G.; Feldmann, Th.
2007-01-01
We investigate transition form factors between non-relativistic QCD bound states at large recoil energy. Assuming the decaying quark to be much heavier than its decay product, the relativistic dynamics can be treated according to the factorization formula for heavy-to-light form factors obtained from the heavy-quark expansion in QCD. The non-relativistic expansion determines the bound-state wave functions to be Coulomb-like. As a consequence, one can explicitly calculate the so-called 'soft-overlap' contribution to the transition form factor
Closed form bound-state perturbation theory
Directory of Open Access Journals (Sweden)
Ollie J. Rose
1980-01-01
Full Text Available The perturbed Schrödinger eigenvalue problem for bound states is cast into integral form using Green's Functions. A systematic algorithm is developed and applied to the resulting equation giving rise to approximate solutions expressed as functions of the given perturbation parameter. As a by-product, convergence radii for the traditional Rayleigh-Schrödinger and Brillouin-Wigner perturbation theories emerge in a natural way.
Tunneling spectroscopy of quasiparticle bound states in a spinful Josephson junction.
Chang, W; Manucharyan, V E; Jespersen, T S; Nygård, J; Marcus, C M
2013-05-24
The spectrum of a segment of InAs nanowire, confined between two superconducting leads, was measured as function of gate voltage and superconducting phase difference using a third normal-metal tunnel probe. Subgap resonances for odd electron occupancy-interpreted as bound states involving a confined electron and a quasiparticle from the superconducting leads, reminiscent of Yu-Shiba-Rusinov states-evolve into Kondo-related resonances at higher magnetic fields. An additional zero-bias peak of unknown origin is observed to coexist with the quasiparticle bound states.
Steady Particle States of Revised Electromagnetics
Directory of Open Access Journals (Sweden)
Lehnert B.
2006-07-01
Full Text Available A revised Lorentz invariant electromagnetic theory leading beyond Maxwell's equations, and to a form of extended quantum electrodynamics, has been elaborated on the basis of a nonzero electric charge density and a nonzero electric field divergence in the vacuum state. Among the applications of this theory, there are steady electromagnetic states having no counterpart in conventional theory and resulting in models of electrically charged and neutral leptons, such as the electron and the neutrino. The analysis of the electron model debouches into a point-charge-like geometry with a very small characteristic radius but having finite self-energy. This provides an alternative to the conventional renormalization procedure. In contrast to conventional theory, an integrated radial force balance can further be established in which the electron is prevented from "exploding" under the action of its net self-charge. Through a combination of variational analysis and an investigation of the radial force balance, a value of the electronic charge has been deduced which deviates by only one percent from that obtained in experiments. This deviation requires further investigation. A model of the neutrino finally reproduces some of the basic features, such as a small but nonzero rest mass, an angular momentum but no magnetic moment, and long mean free paths in solid matter.
On bound states of photons in noncommutative U(1) gauge theory
International Nuclear Information System (INIS)
Fatollahi, A.H.; Jafari, A.
2006-01-01
We consider the possibility that photons of noncommutative U(1) gauge theory can make bound states. Using the potential model, developed based on the constituent gluon picture of QCD glue-balls, arguments are presented in favor of the existence of these bound states. The basic ingredient of the potential model is that the self-interacting massless gauge particles may get mass by the inclusion of non-perturbative effects. (orig.)
Electromagnetic production of very light gluinos
Energy Technology Data Exchange (ETDEWEB)
Carlson, C.E.; Sher, M. [College of William and Mary, Williamsburg, VA (United States); Weinstein, L. [Old Dominion Univ., Norfolk, VA (United States)
1994-04-01
Current experiments allow the possibility of gluino masses below about 600 MeV if the lifetime of the gluino is longer than 100 picoseconds. If the mass and lifetime are in this window, then electromagnetic production of pairs of gluino-gluon bound states can provide a means to observe them. The cross section is large enough that the window can be fully explored, up to lifetimes exceeding a microsecond, at high luminosity electron accelerators. A discussion of signatures and a table of event rates for various possibilities at CEBAF is given.
Electromagnetic production of very light gluinos
International Nuclear Information System (INIS)
Carlson, C.E.; Sher, M.; Weinstein, L.
1994-01-01
Current experiments allow the possibility of gluino masses below about 600 MeV if the lifetime of the gluino is longer than 100 picoseconds. If the mass and lifetime are in this window, then electromagnetic production of pairs of gluino-gluon bound states can provide a means to observe them. The cross section is large enough that the window can be fully explored, up to lifetimes exceeding a microsecond, at high luminosity electron accelerators. A discussion of signatures and a table of event rates for various possibilities at CEBAF is given
Bound states in the two-dimension massive quantum electrodynamics (Qed2)
International Nuclear Information System (INIS)
Alves, V.S.; Gomes, M.
1994-01-01
This work studies the fermion-antifermion bound states in the (1+1)D two-dimension massive quantum electrodynamic in the 1/N expansion. The scattering matrices in the non-relativistic approximation have been calculated through TQC, and compared with the cross section in the Born approximation, and therefore the potential responsible by the interactions in the scattering processes have been obtained. Using Schroedinger equation, the existence of possible bound states have been investigated
Electromagnetic fields in an expanding universe
International Nuclear Information System (INIS)
Hogan, P.A.; Ellis, G.F.R.
1989-01-01
The asymptotic form of the electromagnetic field due to a bounded distribution of charge current in an open, expanding Friedmann--Lemaitre--Robertson--Walker universe is studied. The technique used is to first describe a mechanism for passing from a solution of Maxwell's vacuum field equations on Minkowskian space-time to a solution of Maxwell's field equations in a region free of charge current on the cosmological background. This is tested on the field of an accelerating point charge and then applied to the rigorous treatment of the asymptotic electromagnetic field of a bounded charge-current distribution in Minkowskian space-time given by Goldberg and Kerr [J. Math. Phys. 5, 172 (1964)]. A ''peeling expansion'' of the electromagnetic field in the expanding universe is obtained in inverse powers of a parameter that is proportional to the area distance along the generators of future null cones with vertices on the world line of a fundamental observer. The algebraic character of the two leading coefficients in the expansion is the same as that of the two leading coefficients in the Goldberg--Kerr expansion in Minkowskian space-time. In addition, bounds can be calculated, at any instant in the history of a fundamental observer, on all the coefficients in the peeling expansion, as a consequence of the evaluation of such bounds by Goldberg and Kerr in the case treated by them
Energy Technology Data Exchange (ETDEWEB)
Eminov, P.A., E-mail: peminov@mail.ru [Moscow State University of Instrument Engineering and Computer Sciences, 20 Stromynka Street, Moscow 2107996 (Russian Federation); National Research University Higher School of Economics, 3/12 Bolshoy Trekhsvyatskiy pereulok, Moscow 109028 (Russian Federation)
2013-10-01
Ionization processes for a two dimensional quantum dot subjected to combined electrostatic and alternating electric fields of the same direction are studied using quantum mechanical methods. We derive analytical equations for the ionization probability in dependence on characteristic parameters of the system for both extreme cases of a constant electric field and of a linearly polarized electromagnetic wave. The ionization probabilities for a superposition of dc and low frequency ac electric fields of the same direction are calculated. The impulse distribution of ionization probability for a system bound by short range forces is found for a superposition of constant and alternating fields. The total probability for this process per unit of time is derived within exponential accuracy. For the first time the influence of alternating electric field on electron tunneling probability induced by an electrostatic field is studied taking into account the pre-exponential term.
Hyperon polarizabilities in the bound-state soliton model
International Nuclear Information System (INIS)
Gobbi, C.; Scoccola, N.N.
1996-01-01
A detailed calculation of electric and magnetic static polarizabilities of octet hyperons is presented in the framework of the bound-state soliton model. Both seagull and dispersive contributions are considered, and the results are compared with different model predictions. (orig.)
K-nuclear bound states in a dynamical model
Czech Academy of Sciences Publication Activity Database
Mareš, Jiří; Friedman, E.; Gal, A.
2006-01-01
Roč. 770, 1/2 (2006), s. 84-105 ISSN 0375-9474 Institutional research plan: CEZ:AV0Z10480505 Keywords : kaonic atoms * K-nuclear bound states * K-nucleus interaction Subject RIV: BE - Theoretical Physics Impact factor: 2.155, year: 2006
Models for light QCD bound states
International Nuclear Information System (INIS)
LaCourse, D.P.
1992-01-01
After a brief overview of Regge, tower, and heavy-quark experimental data, this thesis examines two massless wave equations relevant to quark bound states. We establish general conditions on the Lorentz scalar and Lorentz vector potentials which yield arbitrary leading Regge trajectories for the case of circular classical motion. A semi-classical approximation which includes radial motion reproduces remarkably well the exact solutions. Conditions for tower structure are examined, and found to be incompatible with conditions which give a Nambu stringlike Regge slope. The author then proposes a generalization of the usual potential model of quark bound states in which the confining flux tube is a dynamical object carrying both angular momentum and energy. The Q bar Q-string system with spinless quarks is quantized using an implicit operator technique and the resulting relativistic wave equation is solved. For heavy quarks the usual Schroedinger valence-quark model is recovered. The Regge slope with light quarks agree with the classical rotating-string result and is significantly larger and the effects of short-range forces are also considered. A relativistic generalization of the quantized flux tube model predicts the glueball ground state mass to be √3/α' ≅ 1.9 GeV where α' is the normal Regge slope. The groundstate as well as excited levels like considerably above the expectations of previous models and also above various proposed experimental candidates. The glueball Regge slope is only about three-eighths that for valence quark hadrons. A semi-classical calculation of the Regge slope is in good agreement with a numerically exact value
International Nuclear Information System (INIS)
Fortescue, Ben; Lo, H.-K.
2005-01-01
We derive lower limits on the inefficiency and classical communication costs of dilution between two-term bipartite pure states that are partially entangled. We first calculate explicit relations between the allowable error and classical communication costs of entanglement dilution using a previously described protocol, then consider a two-stage dilution from singlets with this protocol followed by some unknown protocol for conversion between partially entangled states. Applying overall lower bounds on classical communication and inefficiency to this two-stage protocol, we derive bounds for the unknown protocol. In addition we derive analogous (but looser) bounds for general pure states
Bound states and scattering in four-body systems
International Nuclear Information System (INIS)
Narodetsky, I.M.
1979-01-01
It is the purpose of this review to provide the clear and elementary introduction in the integral equation method and to demonstrate explicitely its usefulness for the physical applications. The existing results concerning the application of the integral equation technique for the four-nucleon bound states and scattering are reviewed.The treatment is based on the quasiparticle approach that permits the simple interpretation of the equations in terms of quasiparticle scattering. The mathematical basis for the quasiparticle approach is the Hilbert-Schmidt theorem of the Fredholm integral equation theory. This paper contains the detailed discussion of the Hilbert-Schmidt expansion as applied to the 2-particle amplitudes and to the 3 + 1 and 2 + 2 amplitudes which are the kernels of the four-body equations. The review contains essentially the discussion of the four-body quasiparticle equations and results obtained for bound states and scattering
Fano-type coupling of a bound paramagnetic state with 2D continuum
International Nuclear Information System (INIS)
Rozhansky, I. V.; Averkiev, N. S.; Lähderanta, E.
2013-01-01
We analyze an effect of a bound impurity state located at a tunnel distance from a quantum well (QW). The study is focused on the resonance case when the bound state energy lies within the continuum of the QW states. Using the developed theory we calculate spin polarization of 2D holes induced by paramagnetic (Mn) delta-layer in the vicinity of the QW and indirect exchange interaction between two impurities located at a tunnel distance from electron gas
Steady Particle States of Revised Electromagnetics
Directory of Open Access Journals (Sweden)
Lehnert B.
2006-07-01
Full Text Available A revised Lorentz invariant electromagnetic theory leading beyond Maxwell’s equations, and to a form of extended quantum electrodynamics, has been elaborated on the basis of a nonzero electric charge density and a nonzero electric field divergence in the vacuum state. Among the applications of this theory, there are steady electromagnetic states having no counterpart in conventional theory and resulting in models of electrically charged and neutral leptons, such as the electron and the neutrino. The analysis of the electron model debouches into a point-charge-like geometry with a very small characteristic radius but having finite self-energy. This provides an alternative to the conventional renormalization procedure. In contrast to conventional theory, an integrated radial force balance can further be established in which the electron is prevented from “exploding” under the action of its net self-charge. Through a combination of variational analysis and an investigation of the radial force balance, a value of the electronic charge has been deduced which deviates by only one percent from that obtained in experiments. This deviation requires further investigation. A model of the neutrino finally reproduces some of the basic features, such as a small but nonzero rest mass, an angular momentum but no magnetic moment, and long mean free paths in solid matter.
Generation of bound states of pulses in a SESAM mode-locked Cr:ZnSe laser
Bu, Xiangbao; Shi, Yuhang; Xu, Jia; Li, Huijuan; Wang, Pu
2018-06-01
We report on the generation of bound states of pulses in a SESAM mode-locked Cr:ZnSe laser around 2415 nm. A thulium-doped double-clad fiber laser at 1908 nm was used as the pump source. Bound states with various pulse separations at different dispersion regimes were obtained. Especially, in the anomalous dispersion regime, vibrating bound state of solitons exhibiting an evolving phase was obtained.
Dipole-bound states as doorways in (dissociative) electron attachment
International Nuclear Information System (INIS)
Sommerfeld, Thomas
2005-01-01
This communication starts with a comparison of dissociative recombination and dissociative attachment placing emphasis on the role of resonances as reactive intermediates. The main focus is then the mechanism of electron attachment to polar molecules at very low energies (100 meV). The scheme considered consists of two steps: First, an electron is captured in a diffuse dipole-bound state depositing its energy in the vibrational degrees of freedom, in other words, a vibrational Feshbach resonance is formed. Then, owing to the coupling with a valence state, the electron is transferred into a compact valence orbital, and depending on the electron affinities of the valence state and possible dissociation products, as well as on the details of the intramolecular redistribution of vibrational energy, long-lived anions can be generated or dissociation reactions can be initiated. The key property in this context is the electronic coupling strength between the diffuse dipole-bound and the compact valence states. We describe how the coupling strength can be extracted from ab initio data, and present results for Nitromethane, Uracil and Cyanoacetylene
Signatures of Majorana bound states in one-dimensional topological superconductors
International Nuclear Information System (INIS)
Pientka, Falko
2014-01-01
Topological states of matter have fascinated condensed matter physicists for the past three decades. Famous examples include the integer and fractional quantum Hall states exhibiting a spectacular conductance quantization as well as topological insulators in two and three dimensions featuring gapless Dirac fermions at the boundary. Very recently, novel topological phases in superconductors have been subject of intense experimental and theoretical investigation. One-dimensional topological superconductors are particularly intriguing as they host exotic Majorana end states. These are zero-energy bound states with nonabelian exchange statistics potentially useful for topologically protected quantum computing. Recent theoretical and experimental advances have put the realization of Majorana states within reach of current measurement techniques. In this thesis we investigate signatures of Majorana bound states in realistic experiments aiming to improve the theoretical understanding of ongoing experimental efforts and to design novel measurement schemes, which exhibit convincing signatures of Majoranas. In particular we account for nonideal experimental conditions which can lead to qualitatively new features. Possible signatures of Majoranas can be accessed in the Josephson current through a weak link between two topological superconductors although the signatures in the dc Josephson effect are typically obscured by inevitable quasiparticle relaxation in the superconductor. Here we propose a measurement scheme in mesoscopic superconducting rings, where Majorana signatures persist even for infinitely fast relaxation. In a separate project we outline an alternative to the standard Josephson experiment in topological superconductors based on quantum wires. We delineate how Majoranas can be detected, when the Josephson current is induced by noncollinear magnetic fields applied to the two banks of the junction instead of a superconducting phase difference. Another important
Some simple conditions of bound states of Schroedinger operators in dimension d >= 3
International Nuclear Information System (INIS)
Exner, P.
1984-01-01
A necessary condition for existence of bound states below a given energy of a Schroedinger operator H=-Δ+V on L 2 (Rsup(d)), d>=3, together with a lower bound to the ground-state energy of H are derived using the Sobolev inequalities. It generalizes some recent results to the dimensions d>3 and to the potentials that are not necessarily rapidly decreasing. Comparison to other known necessary conditions is given. The examples of the d-dimensional hydrogen-like atom and the d-dimensional harmonic oscillator are discussed. In both of them the bound to the ground-state energy becomes remarkably tight for large values of d
On resonances and bound states of Smilansky Hamiltonian
Czech Academy of Sciences Publication Activity Database
Exner, Pavel; Lotoreichik, Vladimir; Tater, Miloš
2016-01-01
Roč. 7, č. 5 (2016), s. 789-802 ISSN 2220-8054 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : Smilansky Hamiltonian * resonances * resonance free region * weak coupling asymptotics * Riemann surface * bound states Subject RIV: BE - Theoretical Physics
Accurate calculations of bound rovibrational states for argon trimer
Energy Technology Data Exchange (ETDEWEB)
Brandon, Drew; Poirier, Bill [Department of Chemistry and Biochemistry, and Department of Physics, Texas Tech University, Box 41061, Lubbock, Texas 79409-1061 (United States)
2014-07-21
This work presents a comprehensive quantum dynamics calculation of the bound rovibrational eigenstates of argon trimer (Ar{sub 3}), using the ScalIT suite of parallel codes. The Ar{sub 3} rovibrational energy levels are computed to a very high level of accuracy (10{sup −3} cm{sup −1} or better), and up to the highest rotational and vibrational excitations for which bound states exist. For many of these rovibrational states, wavefunctions are also computed. Rare gas clusters such as Ar{sub 3} are interesting because the interatomic interactions manifest through long-range van der Waals forces, rather than through covalent chemical bonding. As a consequence, they exhibit strong Coriolis coupling between the rotational and vibrational degrees of freedom, as well as highly delocalized states, all of which renders accurate quantum dynamical calculation difficult. Moreover, with its (comparatively) deep potential well and heavy masses, Ar{sub 3} is an especially challenging rare gas trimer case. There are a great many rovibrational eigenstates to compute, and a very high density of states. Consequently, very few previous rovibrational state calculations for Ar{sub 3} may be found in the current literature—and only for the lowest-lying rotational excitations.
Bound states in strongly correlated magnetic and electronic systems
International Nuclear Information System (INIS)
Trebst, S.
2002-02-01
A novel strong coupling expansion method to calculate two-particle spectra of quantum lattice models is developed. The technique can be used to study bosonic and fermionic models and in principle it can be applied to systems in any dimension. A number of strongly correlated magnetic and electronic systems are examined including the two-leg spin-half Heisenberg ladder, the dimerized Heisenberg chain with a frustrating next-nearest neighbor interaction, coupled Heisenberg ladders, and the one-dimensional Kondo lattice model. In the various models distinct bound states are found below the two-particle continuum. Quantitative calculations of the dispersion, coherence length and binding energy of these bound states are used to describe spectroscopic experiments on (Ca,La) 14 Cu 24 O 41 and NaV 2 O 5 . (orig.)
Asymptotical behaviour of pion electromagnetic form factor in QCD
International Nuclear Information System (INIS)
Efremov, A.V.; Radyushkin, A.V.
1978-01-01
In the framework of the renormalizable quantum field theory a new approach is developed to the investigation of asymptotical behaviour of two-particle bound state electromagnetic form factor. It is shown that the behaviour of the pion EM form factor in quantum chromodynamics at sufficiently large momentum transfers is controlled by the short-distance dynamics only. The formula is obtained which expresses the asymptotical behaviour of the pion form factor in terms of the fundamental constants of the theory
Reduced conservatism in stability robustness bounds by state transformation
Yedavalli, R. K.; Liang, Z.
1986-01-01
This note addresses the issue of 'conservatism' in the time domain stability robustness bounds obtained by the Liapunov approach. A state transformation is employed to improve the upper bounds on the linear time-varying perturbation of an asymptotically stable linear time-invariant system for robust stability. This improvement is due to the variance of the conservatism of the Liapunov approach with respect to the basis of the vector space in which the Liapunov function is constructed. Improved bounds are obtained, using a transformation, on elemental and vector norms of perturbations (i.e., structured perturbations) as well as on a matrix norm of perturbations (i.e., unstructured perturbations). For the case of a diagonal transformation, an algorithm is proposed to find the 'optimal' transformation. Several examples are presented to illustrate the proposed analysis.
Delta and Omega electromagnetic form factors in a Dyson-Schwinger/Bethe-Salpeter approach
Energy Technology Data Exchange (ETDEWEB)
Diana Nicmorus, Gernot Eichmann, Reinhard Alkofer
2010-12-01
We investigate the electromagnetic form factors of the Delta and the Omega baryons within the Poincare-covariant framework of Dyson-Schwinger and Bethe-Salpeter equations. The three-quark core contributions of the form factors are evaluated by employing a quark-diquark approximation. We use a consistent setup for the quark-gluon dressing, the quark-quark bound-state kernel and the quark-photon interaction. Our predictions for the multipole form factors are compatible with available experimental data and quark-model estimates. The current-quark mass evolution of the static electromagnetic properties agrees with results provided by lattice calculations.
New approximation to the bound states of Schroedinger operators with coulomb interaction
International Nuclear Information System (INIS)
Nunez, M.A.; Izquierdo B., G.
1994-01-01
In this work, the authors present a mathematical formulation of the physical fact that the bound states of a quantum system confined into a box Ω (with impenetrable walls) are similar to those of the unconfined system, if the box Ω is sufficiently large, and it is shown how the bound states of atomic and molecular Hamiltonians can be approximated by those of the system confined for a box Ω large enough (Dirichlet eigenproblem in Ω). Thus, a method for computing bound states is obtained which has the advantage of reducing the problem to the case of compact operators. This implies that a broad class of numerical and analytic techniques used for solving the Dirichlet problem, may be applied in full strength to obtain accurate computations of energy levels, wave functions, and other physical properties of interest
Stieltjes electrostatic model interpretation for bound state problems
Indian Academy of Sciences (India)
In this paper, it is shown that Stieltjes electrostatic model and quantum Hamilton Jacobi formalism are analogous to each other. This analogy allows the bound state problem to mimic as unit moving imaginary charges i ℏ , which are placed in between the two fixed imaginary charges arising due to the classical turning ...
Emergent low-energy bound states in the two-orbital Hubbard model
Núñez-Fernández, Y.; Kotliar, G.; Hallberg, K.
2018-03-01
A repulsive Coulomb interaction between electrons in different orbitals in correlated materials can give rise to bound quasiparticle states. We study the nonhybridized two-orbital Hubbard model with intra- (inter)orbital interaction U (U12) and different bandwidths using an improved dynamical mean-field theory numerical technique which leads to reliable spectra on the real energy axis directly at zero temperature. We find that a finite density of states at the Fermi energy in one band is correlated with the emergence of well-defined quasiparticle states at excited energies Δ =U -U12 in the other band. These excitations are interband holon-doublon bound states. At the symmetric point U =U12 , the quasiparticle peaks are located at the Fermi energy, leading to a simultaneous and continuous Mott transition settling a long-standing controversy.
Covalently bound molecular states in beryllium and carbon isotopes
International Nuclear Information System (INIS)
Wolfram von, Oertzen; Hans-Gerhard, Bohlen; Wolfram von, Oertzen
2003-01-01
Nuclear clustering in N=Z nuclei has been studied since many decades. States close to the decay thresholds, as described by the Ikeda diagram, are of particular interest. Recent studies in loosely bound systems, as observed with neutron-rich nuclei has revived the interest in cluster structures in nuclei, with additional valence neutrons, which give rise to pronounced covalent molecular structures. The Beryllium isotopes represent the first example of such unique states in nuclear physics with extreme deformations. In the deformed shell model these are referred to as super- and hyper-deformation. These states can be described explicitly by molecular concepts, with neutrons in covalent binding orbits. Examples of recent experiments performed at the HMI-Berlin demonstrating the molecular structure of the rotational bands in Beryllium isotopes are presented. Further work on chain states (nuclear polymers) in the carbon isotopes is in progress, these are the first examples of deformed structures in nuclei with an axis ratio of 3:1. A threshold diagram with clusters bound via neutrons in covalent molecular configurations can be established, which can serve as a guideline for future work. (authors)
Σ hypernuclear bound state observed in stopped K- reaction on 4He
International Nuclear Information System (INIS)
Hayano, R.S.; Ishikawa, T.; Iwasaki, M.; Outa, H.; Takada, E.; Tamura, H.; Sakaguchi, A.; Aoki, M.; Yamazaki, T.
1988-12-01
Results are presented of inclusive measurements of π ± momentum spectra from K - absorption at rest in liquid helium. We found a peak in the π - spectrum. The (K - , π + ) spectrum does not exhibit a clear peak in the Σ - bound region. Comparison of these two spectra suggests that the peak in the π - spectrum is due to the formation of the S = 0, I = 1/2 ground state of Σ-nucleus bound state. (J.P.N.)
Parity lifetime of bound states in a proximitized semiconductor nanowire
DEFF Research Database (Denmark)
Higginbotham, Andrew Patrick; Albrecht, Sven Marian; Kirsanskas, Gediminas
2015-01-01
Quasiparticle excitations can compromise the performance of superconducting devices, causing high frequency dissipation, decoherence in Josephson qubits, and braiding errors in proposed Majorana-based topological quantum computers. Quasiparticle dynamics have been studied in detail in metallic...... superconductor layer, yielding an isolated, proximitized nanowire segment. We identify Andreev-like bound states in the semiconductor via bias spectroscopy, determine the characteristic temperatures and magnetic fields for quasiparticle excitations, and extract a parity lifetime (poisoning time) of the bound...
The hyperbolic step potential: Anti-bound states, SUSY partners and Wigner time delays
Energy Technology Data Exchange (ETDEWEB)
Gadella, M. [Departamento de Física Teórica, Atómica y Óptica and IMUVA, Universidad de Valladolid, E-47011 Valladolid (Spain); Kuru, Ş. [Department of Physics, Faculty of Science, Ankara University, 06100 Ankara (Turkey); Negro, J., E-mail: jnegro@fta.uva.es [Departamento de Física Teórica, Atómica y Óptica and IMUVA, Universidad de Valladolid, E-47011 Valladolid (Spain)
2017-04-15
We study the scattering produced by a one dimensional hyperbolic step potential, which is exactly solvable and shows an unusual interest because of its asymmetric character. The analytic continuation of the scattering matrix in the momentum representation has a branch cut and an infinite number of simple poles on the negative imaginary axis which are related with the so called anti-bound states. This model does not show resonances. Using the wave functions of the anti-bound states, we obtain supersymmetric (SUSY) partners which are the series of Rosen–Morse II potentials. We have computed the Wigner reflection and transmission time delays for the hyperbolic step and such SUSY partners. Our results show that the more bound states a partner Hamiltonian has the smaller is the time delay. We also have evaluated time delays for the hyperbolic step potential in the classical case and have obtained striking similitudes with the quantum case. - Highlights: • The scattering matrix of hyperbolic step potential is studied. • The scattering matrix has a branch cut and an infinite number of poles. • The poles are associated to anti-bound states. • Susy partners using antibound states are computed. • Wigner time delays for the hyperbolic step and partner potentials are compared.
New approach to calculate bound state eigenvalues
International Nuclear Information System (INIS)
Gerck, E.; Gallas, J.A.C.
1983-01-01
A method of solving the radial Schrodinger equation for bound states is discussed. The method is based on a new piecewise representation of the second derivative operator on a set of functions that obey the boundary conditions. This representation is trivially diagonalised and leads to closed form expressions of the type E sub(n)=E(ab+b+c/n+...) for the eigenvalues. Examples are given for the power-law and logarithmic potentials. (Author) [pt
Pair condensation and bound states in fermionic systems
International Nuclear Information System (INIS)
Sedrakian, Armen; Clark, John W.
2006-01-01
We study the finite temperature-density phase diagram of an attractive fermionic system that supports two-body (dimer) and three-body (trimer) bound states in free space. Using interactions characteristic for nuclear systems, we obtain the critical temperature T c2 for the superfluid phase transition and the limiting temperature T c3 for the extinction of trimers. The phase diagram features a Cooper-pair condensate in the high-density, low-temperature domain which, with decreasing density, crosses over to a Bose condensate of strongly bound dimers. The high-temperature, low-density domain is populated by trimers whose binding energy decreases toward the density-temperature domain occupied by the superfluid and vanishes at a critical temperature T c3 >T c2
Coherent states of an electron in a quantized electromagnetic wave
International Nuclear Information System (INIS)
Bagrov, V.G.; Bukhbinder, I.L.; Gitman, D.M.; Lavrov, P.M.
1977-01-01
Coherent states for interacting electrons and photons in a plane elecmagnetic wave are found. Trajectories of the electron and the characteristics of the electromagnetic field are investigated. Limiting transition to the given external field is studied
Rate Reduction for State-labelled Markov Chains with Upper Time-bounded CSL Requirements
Directory of Open Access Journals (Sweden)
Bharath Siva Kumar Tati
2016-07-01
Full Text Available This paper presents algorithms for identifying and reducing a dedicated set of controllable transition rates of a state-labelled continuous-time Markov chain model. The purpose of the reduction is to make states to satisfy a given requirement, specified as a CSL upper time-bounded Until formula. We distinguish two different cases, depending on the type of probability bound. A natural partitioning of the state space allows us to develop possible solutions, leading to simple algorithms for both cases.
A study of the bound states for square potential wells with position-dependent mass
International Nuclear Information System (INIS)
Ganguly, A.; Kuru, S.; Negro, J.; Nieto, L.M.
2006-01-01
A potential well with position-dependent mass is studied for bound states. Applying appropriate matching conditions, a transcendental equation is derived for the energy eigenvalues. Numerical results are presented graphically and the variation of the energy of the bound states are calculated as a function of the well-width and mass
Magnetic moment of a two-particle bound state in quantum electrodynamics
International Nuclear Information System (INIS)
Martynenko, A.P.; Faustov, R.N.
2002-01-01
A quasipotential method for calculating relativistic and radiative corrections to the magnetic moment of a two-particle bound state is formulated for particles of arbitrary spin. It is shown that the expression for the g factors of bound particles involve O(α 2 ) terms depending on the particle spin. Numerical values are obtained for the g factors of the electron in the hydrogen atom and in deuterium
Bounds on the entanglement entropy of droplet states in the XXZ spin chain
Beaud, V.; Warzel, S.
2018-01-01
We consider a class of one-dimensional quantum spin systems on the finite lattice Λ ⊂Z , related to the XXZ spin chain in its Ising phase. It includes in particular the so-called droplet Hamiltonian. The entanglement entropy of energetically low-lying states over a bipartition Λ = B ∪ Bc is investigated and proven to satisfy a logarithmic bound in terms of min{n, |B|, |Bc|}, where n denotes the maximal number of down spins in the considered state. Upon addition of any (positive) random potential, the bound becomes uniformly constant on average, thereby establishing an area law. The proof is based on spectral methods: a deterministic bound on the local (many-body integrated) density of states is derived from an energetically motivated Combes-Thomas estimate.
Aspects of Majorana Bound States in One-Dimensional Systems with and without Time-Reversal Symmetry
DEFF Research Database (Denmark)
Wölms, Konrad Udo Hannes
In recent years there has been a lot of interest in topological phases of matter. Unlike conventional phases of matter, topological phases are not distinguished by symmetries, but by so-called topological invariants which have more subtle physical implications. It comes therefore as no surprise...... phase the edge excitations are called Majorana bound states and they are interesting in themselves. There has been a lot of eort in detecting Majorana bound states in the lab. One reason is that these excitations provide evidence that a system is indeed in a topological phase. It is therefore required...... to have unambiguous experimental evidence for the presence Majorana bound states, which in turn requires a good theoretical understanding of the physics associated with Majorana bound states. In particular for the most common experimental methods that are used to study them, the signature of Majorana...
International Nuclear Information System (INIS)
Oset, E.; Cabrera, D.; Li, Q.B.; Magas, V.K.; Vicente Vacas, M.J.
2005-01-01
We study the binding energy and the width of the Θ + in nuclei, associated to the KN and KπN components. The first one leads to negligible contributions while the second one leads to a sizeable attraction, enough to bind the Θ + in nuclei. Pauli blocking and binding effects on the KN decay reduce considerably the Θ + decay width in nuclei and medium effects associated to the KπN component also lead to a very small width, as a consequence of which one finds separation between the bound levels considerably larger than the width of the states
Relativistic treatment of fermion-antifermion bound states
International Nuclear Information System (INIS)
Lucha, W.; Rupprecht, H.; Schoeberl, F.F.
1990-01-01
We discuss the relativistic treatment of fermion-antifermion bound states by an effective-Hamiltonian method which imitates their description in terms of nonrelativistic potential models: the effective interaction potential, to be used in a Schroedinger equation which incorporates relativistic kinematics, is derived from the underlying quantum field theory. This approach is equivalent to the instantaneous approximation to the Bethe-Salpeter equation called Salpeter equation but comes closer to physical intuition than the latter one. (Author) 14 refs
Bound states and scattering coefficients of the -aδ(x)+bδ'(x) potential
International Nuclear Information System (INIS)
Gadella, M.; Negro, J.; Nieto, L.M.
2009-01-01
We show that a one-dimensional Schroedinger equation in which the potential is a delta well plus a δ ' interaction at the same point has a bound state, and we obtain the energy of this bound state in terms of the parameters. In addition, the expression of the reflection and transmission coefficients is also fully determined
Parra-Rivas, Pedro; Gomila, Damia; Colet, Pere; Gelens, Lendert
2017-07-01
Bound states, also called soliton molecules, can form as a result of the interaction between individual solitons. This interaction is mediated through the tails of each soliton that overlap with one another. When such soliton tails have spatial oscillations, locking or pinning between two solitons can occur at fixed distances related with the wavelength of these oscillations, thus forming a bound state. In this work, we study the formation and stability of various types of bound states in the Lugiato-Lefever equation by computing their interaction potential and by analyzing the properties of the oscillatory tails. Moreover, we study the effect of higher order dispersion and noise in the pump intensity on the dynamics of bound states. In doing so, we reveal that perturbations to the Lugiato-Lefever equation that maintain reversibility, such as fourth order dispersion, lead to bound states that tend to separate from one another in time when noise is added. This separation force is determined by the shape of the envelope of the interaction potential, as well as an additional Brownian ratchet effect. In systems with broken reversibility, such as third order dispersion, this ratchet effect continues to push solitons within a bound state apart. However, the force generated by the envelope of the potential is now such that it pushes the solitons towards each other, leading to a null net drift of the solitons. Contribution to the Topical Issue "Theory and Applications of the Lugiato-Lefever Equation", edited by Yanne K. Chembo, Damia Gomila, Mustapha Tlidi, Curtis R. Menyuk.
Static and dynamic properties of QCD bound states
International Nuclear Information System (INIS)
Kubrak, Stanislav
2015-01-01
The QCD phenomenology can be faced with the framework of the coupled quark DSE, meson BSE and baryon Faddeev equation, providing non-perturbative, continuum and Poincare invariant scientific approach. The research performed throughout this thesis is twofold. From one perspective we focus on the investigation of mass spectra for mesons with total spin quantum number J=3 and arising Regge-trajectory for natural parity states J PC =1 -- ,2 ++ ,3 -- within rainbow-ladder single gluon exchange model. The other findings are concerning the impact of the pion cloud effect on J>2 meson states, baryon masses, namely on Nucleon and Delta three-body bound states and meson dynamical properties like the pion form factor.
Li, Song-Song
2018-01-01
We put forward a scheme on how to generate entangled state of Bose-Einstein condensate (BEC) using electromagnetically induced transparency (EIT). It is shown that we can rapidly generate the entangled state in the dynamical process and the entangled state maintained a long time interval. It is also shown that the better entangled state can be generated by decreasing coupling strengths of two classical laser fields, increasing two-photon detuning and total number of atoms.
Gate-tunable Andreev bound states in InSb nanowire Josephson junction
Energy Technology Data Exchange (ETDEWEB)
Kang, Ning; Li, Sen; Fan, Dingxun; Xu, Hongqi [Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871 (China); Caroff, Philippe [Division of Solid State Physics, Lund University, P. O. Box 118, S-221 00 Lund (Sweden)
2016-07-01
Hybrid InSb nanowire-superconductor devices are promising candidates for investigating Majorana modes in solid-state devices and future technologies of topological quantum manipulation. Here, we report low-temperature transport measurements on an individual InSb nanowire quantum dot coupled to superconducting contacts that exhibit an interplay between the Kondo effects and superconductivity. We observed two types of subgap resonance states within the superconducting gap, which can be attributed to gate-tunable Andreev bound states in Coulomb valleys with different Kondo temperatures. The presence of the gate-tunable 0 and pi junction allow us to investigate the fundamental 0- pi transition. Detailed magnetic field and temperature evolution of level spectroscopy demonstrate different behavior of two types of the Andreev bound states. Our results exhibit that the InSb nanowires can provide a promising platform for exploring phase coherence transport and the effect of spin-orbit coupling in semiconductor nanowire-superconductor hybrid device.
Coexistence of a bound state and scattering at the same energy value: a quantum paradox
International Nuclear Information System (INIS)
Chabanov, V.M.; Zakhar'ev, B.N.
1998-01-01
The example of a multi-channel system which possesses both bound (not quasi-bound !) and scattering states at the same energy value E is demonstrated. A special interaction has ability to confine waves near the origin and simultaneously admit scattering (even with transparency) at the fixed spectral point. These interaction matrices and wave functions can be continued to the whole axis. As another multi-channel peculiarity having no one-channel analogues was found a class of absolutely transparent interaction matrices without bound states
A narrow quasi-bound state of the DNN system
International Nuclear Information System (INIS)
Doté, A.; Bayar, M.; Xiao, C.W.; Hyodo, T.; Oka, M.; Oset, E.
2013-01-01
We have investigated a charmed system of DNN (composed of two nucleons and a D meson) by a complementary study with a variational calculation and a Faddeev calculation with fixed-center approximation (Faddeev-FCA). In the present study, we employ a DN potential based on a vector–meson exchange picture in which a resonant Λ c (2595) is dynamically generated as a DN quasi-bound state, similarly to the Λ(1405) as a K ¯ N one in the strange sector. As a result of the study of variational calculation with an effective DN potential and three kinds of NN potentials, the DNN(J π =0 − ,I=1/2) is found to be a narrow quasi-bound state below Λ c (2595)N threshold: total binding energy ∼225 MeV and mesonic decay width ∼25 MeV. On the other hand, the J π =1 − state is considered to be a scattering state of Λ c (2595) and a nucleon. These results are essentially supported by the Faddeev-FCA calculation. By the analysis of the variational wave function, we have found a unique structure in the DNN(J π =0 − ,I=1/2) such that the D meson stays around the center of the total system due to the heaviness of the D meson
A search for bound states of the /eta/-meson in light nuclei
International Nuclear Information System (INIS)
Pile, P.H.
1988-01-01
This paper describes an experiment designed to search for a new form of nuclear matter--a bound /eta/-nucleus system. The (π + ,p) reaction was used to study the possible formation of an /eta/-mesic nucleus. No narrow /eta/-nuclear bound states were observed using 7 Li, 12 C, 16 O and 27 Al targets. 7 refs., 4 figs., 1 tab
Energy Technology Data Exchange (ETDEWEB)
Higashi, Yoichi, E-mail: higashiyoichi@ms.osakafu-u.ac.jp [Department of Mathematical Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai 599-8531 (Japan); Nagai, Yuki [CCSE, Japan Atomic Energy Agency, 178-4-4, Wakashiba, Kashiwa, Chiba 277-0871 (Japan); Yoshida, Tomohiro [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Kato, Masaru [Department of Mathematical Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai 599-8531 (Japan); Yanase, Youichi [Department of Physics, Niigata University, Niigata 950-2181 (Japan)
2015-11-15
Highlights: • We focus on the pair-density wave state in bilayer Rashba superconductors. • The zero energy Bogoliubov wave functions are localized at the edge and vortex core. • We investigate the excitation spectra of edge and vortex bound states. - Abstract: We study the excitation spectra and the wave functions of quasiparticle bound states at a vortex and an edge in bilayer Rashba superconductors under a magnetic field. In particular, we focus on the quasiparticle states at the zero energy in the pair-density wave state in a topologically non-trivial phase. We numerically demonstrate that the quasiparticle wave functions with zero energy are localized at both the edge and the vortex core if the magnetic field exceeds the critical value.
International Nuclear Information System (INIS)
Fuchs, J; Duffy, G J; Rowlands, W J; Lezama, A; Hannaford, P; Akulshin, A M
2007-01-01
We present an experimental study of sub-natural width resonances in fluorescence from a collimated beam of 6 Li atoms excited on the D 1 and D 2 lines by a bichromatic laser field. We show that in addition to ground-state Zeeman coherence, coherent population oscillations between ground and excited states contribute to the sub-natural resonances. High-contrast resonances of electromagnetically induced transparency and electromagnetically induced absorption due to both effects, i.e., ground-state Zeeman coherence and coherent population oscillations, are observed
Bound and resonant states in Coulomb-like potentials
International Nuclear Information System (INIS)
Papp, Z.
1985-12-01
The potential separable expansion method was generalized for calculating bound and resonant states in Coulomb-like potentials. The complete set of Coulomb-Sturmian functions was taken as the basis to expand the short-range potential. On this basis the matrix elements of the Coulomb-Green functions were given in closed form as functions of the (complex) energy. The feasibility of the method is demonstrated by a numerical example. (author)
Boson bound states in the β-Fermi–Pasta–Ulam model
Indian Academy of Sciences (India)
The bound states of four bosons in the quantum -Fermi–Pasta–Ulam model are investigated and some interesting results are presented using the number conserving approximation combined ... Proceedings of the International Workshop/Conference on Computational Condensed Matter Physics and Materials Science
An upper bound for the proton temperature anisotrophy
International Nuclear Information System (INIS)
Gary, S.P.
1994-01-01
This tutorial describes recent research concerning the upper bound on the hot proton temperature anisotropy imposed by wave-particle scattering due to enhanced fluctuations from the electromagnetic proton cyclotron anisotropy instability. This upper bound, which has been observed in both the magnetosheath and the outer magnetosphere, represents a limited closure relation for the equations of anisotropic magnetohydrodynamics. Such a closure relation has the potential to improve the predictive capability of large-scale anisotropic models of the magnetosphere
Fermionic bound states in distinct kinklike backgrounds
Energy Technology Data Exchange (ETDEWEB)
Bazeia, D. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil); Mohammadi, A. [Universidade Federal de Campina Grande, Departamento de Fisica, Caixa Postal 10071, Campina Grande, Paraiba (Brazil)
2017-04-15
This work deals with fermions in the background of distinct localized structures in the two-dimensional spacetime. Although the structures have a similar topological character, which is responsible for the appearance of fractionally charged excitations, we want to investigate how the geometric deformations that appear in the localized structures contribute to the change in the physical properties of the fermionic bound states. We investigate the two-kink and compact kinklike backgrounds, and we consider two distinct boson-fermion interactions, one motivated by supersymmetry and the other described by the standard Yukawa coupling. (orig.)
Absorption enhancement in type-II coupled quantum rings due to existence of quasi-bound states
Hsieh, Chi-Ti; Lin, Shih-Yen; Chang, Shu-Wei
2018-02-01
The absorption of type-II nanostructures is often weaker than type-I counterpart due to spatially separated electrons and holes. We model the bound-to-continuum absorption of type-II quantum rings (QRs) using a multiband source-radiation approach using the retarded Green function in the cylindrical coordinate system. The selection rules due to the circular symmetry for allowed transitions of absorption are utilized. The bound-tocontinuum absorptions of type-II GaSb coupled and uncoupled QRs embedded in GaAs matrix are compared here. The GaSb QRs act as energy barriers for electrons but potential wells for holes. For the coupled QR structure, the region sandwiched between two QRs forms a potential reservoir of quasi-bound electrons. Electrons in these states, though look like bound ones, would ultimately tunnel out of the reservoir through barriers. Multiband perfectly-matched layers are introduced to model the tunneling of quasi-bound states into open space. Resonance peaks are observed on the absorption spectra of type-II coupled QRs due to the formation of quasi-bound states in conduction bands, but no resonance exist in the uncoupled QR. The tunneling time of these metastable states can be extracted from the resonance and is in the order of ten femtoseconds. Absorption of coupled QRs is significantly enhanced as compared to that of uncoupled ones in certain spectral windows of interest. These features may improve the performance of photon detectors and photovoltaic devices based on type-II semiconductor nanostructures.
Symanzik approach in modeling of bound states of Dirac particle in singular background
Directory of Open Access Journals (Sweden)
Pismak Yu. M.
2017-01-01
Full Text Available In the model of interaction of spinor field with homogeneous isotropic material plane constructed in framework of Symanzik approach, the bound states are studied. For localized near plane Dirac particle the expression for current, charge and density are presented. For bound state with massless dispersion law the current, charge and density are calculated for simplified model with 2 parameter exactly.The model can find application to a wide class of phenomena arising by the interaction of fields of quantum electrodynamics with two-dimensional materials.
Does the Higgs mechanism favour electron-electron bound states in Maxwell-Chern-Simons QED3?
International Nuclear Information System (INIS)
Belich, Humberto; Helayeel-Neto, Jose Abdalla; Ferreira Junior, Manoel Messias
2000-01-01
Full text follows: We show that low-energy electron-electron bound states appear in the Maxwell-Chern-Simons (MCS) planar QED. In spite of the repulsive interaction mediated by the MCS gauge field, a net attractive interaction stems due to the Higgs mechanism through an Yukawa-type interaction. The spontaneous breaking of a local U(1)-symmetry is realized by a γ 6 -type potential. We conclude, by using the Schroedinger equation associated to the net attractive scattering potential, that electron-electron bound states arise in the model. Therefore, the Higgs mechanism overcomes the difficulties found out by Girotti et al. (Phys. Rev. Lett. 69 (1992) 2623) in searching for bound states in the MCS planar QED. (author)
Lower bounds for ballistic current and noise in non-equilibrium quantum steady states
Directory of Open Access Journals (Sweden)
Benjamin Doyon
2015-03-01
Full Text Available Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality.
Ultraheavy Yukawa-bound states of fourth-generation at Large ...
Indian Academy of Sciences (India)
2012-10-05
Oct 5, 2012 ... Abstract. A study of bound states of the fourth-generation quarks in the range of 500–700 GeV is presented, where the binding energies are expected to be mainly of Yukawa origin, with QCD subdominant. Near degeneracy of their masses exhibits a new 'isospin'. The production of a colour- octet, isosinglet ...
Spectroscopy of strontium Rydberg states using electromagnetically induced transparency
International Nuclear Information System (INIS)
Mauger, S; Millen, J; Jones, M P A
2007-01-01
We report on the all-optical detection of Rydberg states in an effusive atomic beam of strontium atoms using electromagnetically induced transparency (EIT). Using narrow-linewidth CW lasers we obtain an EIT linewidth of 5 MHz. To illustrate the high spectroscopic resolution offered by this method, we have measured isotope shifts of the 5s18d 1 D 2 and 5s19s 1 S 0 Rydberg states. This technique could be applied to high-resolution, non-destructive measurements of ultra-cold Rydberg gases and plasmas. (fast track communication)
Bound-state β decay of a neutron in a strong magnetic field
International Nuclear Information System (INIS)
Kouzakov, Konstantin A.; Studenikin, Alexander I.
2005-01-01
The β decay of a neutron into a bound (pe - ) state and an antineutrino in the presence of a strong uniform magnetic field (B > or approx. 10 13 G) is considered. The β decay process is treated within the framework of the standard model of weak interactions. A Bethe-Salpeter formalism is employed for description of the bound (pe - ) system in a strong magnetic field. For the field strengths 10 13 18 G the estimate for the ratio of the bound-state decay rate w b and the usual (continuum-state) decay rate w c is derived. It is found that in such strong magnetic fields w b /w c ∼0.1-0.4. This is in contrast to the field-free case, where w b /w c ≅4.2x10 -6 [J. N. Bahcall, Phys. Rev. 124, 495 (1961); L. L. Nemenov, Sov. J. Nucl. Phys. 15, 582 (1972); X. Song, J. Phys. G: Nucl. Phys. 13, 1023 (1987)]. The dependence of the ratio w b /w c on the magnetic field strength B exhibits a logarithmiclike behavior. The obtained results can be important for applications in astrophysics and cosmology
Localized bound states of fermions interacting via massive vector bosons
International Nuclear Information System (INIS)
Ionescu, D.C.; Reinhardt, J.; Mueller, B.; Greiner, W.; Soff, G.
1988-11-01
A model for composite consisting of fermions with internal degrees of freedom interacting via intermediate vector bosons (IVB) is constructed. We find highly localized, low-mass bound states in the Hartree-Fock approximation. We investigate the dependence of these states as function of the coupling constant and vector boson mass. In the limit of infinite vector boson mass the interaction is described by Fermi-type contact forces. (orig.)
Boson bound states in the β-Fermi–Pasta–Ulam model
Indian Academy of Sciences (India)
5. — journal of. November 2013 physics pp. 839–848. Boson bound states in the ... of Basic Sciences, The First Aeronautical Institute of the Air Force, Xinyang 464000, ..... [4] N Boechler, G Theocharis, S Job, P G Kevrekidis, M A Porter and C ...
Topologically protected bound states in one-dimensional Floquet acoustic waveguide systems
Peng, Yu-Gui; Geng, Zhi-Guo; Zhu, Xue-Feng
2018-03-01
Topological manipulation of sound has recently been a hot spot in acoustics due to the fascinating property of defect immune transport. To the best of our knowledge, the studies on one-dimensional (1D) topological acoustic systems hitherto mainly focus on the case of the Su-Schrieffer-Heeger model. Here, we show that topologically protected bound states may also exist in 1D periodically modulated acoustic waveguide systems, viz., 1D Floquet topological insulators. The results show that tuning the coupling strength in a waveguide lattice could trigger topological phase transition, which gives rise to topologically protected interface states as we put together two waveguide lattices featured with different topological phases or winding numbers. However, for the combined lattice, input at the waveguides other than the interfacial ones will excite bulk states. We have further verified the robustness of interface bound states against the variation of coupling strengths between the two distinct waveguide lattices. This work extends the scope of topological acoustics and may promote potential applications for acoustic devices with topological functionalities.
Ab initio investigation on the valence and dipole-bound states of CNa - and SiNa -
Kalcher, Josef; Sax, Alexander F.
2000-08-01
CNa - and SiNa - have been studied by the CAS-ACPF method. The 3Σ- ground states have binding energies of 5420 and 7517 cm -1, respectively. The 5Σ- excited states are 494 and 1551 cm -1 above the respective ground states. The 1Δ , 3Π , and 1Π valence-excited states for SiNa - should be at least metastable. CNa - and SiNa - possess dipole-bound 5Σ- and 3Σ- states. Binding energies of these states in CNa - are 217 and 236 cm -1, respectively. SiNa - has two stable 5Σ- dipole-bound states, whose binding energies are 246 and 118 cm -1, respectively.
Scattering integral equations and four nucleon problem. Four nucleon bound states and scattering
International Nuclear Information System (INIS)
Narodetskij, I.M.
1981-01-01
Existing results from the application of integral equation technique four-nucleon bound states and scattering are reviewed. The purpose of this review is to provide a clear and elementary introduction in the integral equation method and to demonstrate its usefulness in physical applications. Developments in the actual numerical solutions of Faddeev-Yakubovsky type equations are such that a detailed comparison can be made with experiment. Bound state calculations indicate that a nonrelativistic description with pairwise nuclear forces does not suffice and additional degrees of freedom are noted [ru
In-gap bound states induced by interstitial Fe impurities in iron-based superconductors
Energy Technology Data Exchange (ETDEWEB)
Zhang, Degang, E-mail: degangzhang@yahoo.com
2015-12-15
Highlights: • We provide an explanation for the interesting STM observation of the robust zero energy bound state on the interstitial Fe impurities in iron-based superconductors. - Abstract: Based on a two-orbit four-band tight binding model, we investigate the low-lying electronic states around the interstitial excess Fe ions in the iron-based superconductors by using T-matrix approach. It is shown that the local density of states at the interstitial Fe impurity (IFI) possesses a strong resonance inside the gap, which seems to be insensitive to the doping and the pairing symmetry in the Fe–Fe plane, while a single or two resonances appear at the nearest neighboring (NN) Fe sites. The location and height of the resonance peaks only depend on the hopping t and the pairing parameter Δ{sub I} between the IFI and the NN Fe sites. These in-gap resonances are originated in the Andreev’s bound states due to the quasiparticle tunneling through the IFI, leading to the change of the magnitude of the superconducting order parameter. When both t and Δ{sub I} are small, this robust zero-energy bound state near the IFI is consistent with recent scanning tunneling microscopy observations.
Long, Junling; Ku, H. S.; Wu, Xian; Gu, Xiu; Lake, Russell E.; Bal, Mustafa; Liu, Yu-xi; Pappas, David P.
2018-02-01
Quantum networks will enable extraordinary capabilities for communicating and processing quantum information. These networks require a reliable means of storage, retrieval, and manipulation of quantum states at the network nodes. A node receives one or more coherent inputs and sends a conditional output to the next cascaded node in the network through a quantum channel. Here, we demonstrate this basic functionality by using the quantum interference mechanism of electromagnetically induced transparency in a transmon qubit coupled to a superconducting resonator. First, we apply a microwave bias, i.e., drive, to the qubit-cavity system to prepare a Λ -type three-level system of polariton states. Second, we input two interchangeable microwave signals, i.e., a probe tone and a control tone, and observe that transmission of the probe tone is conditional upon the presence of the control tone that switches the state of the device with up to 99.73% transmission extinction. Importantly, our electromagnetically induced transparency scheme uses all dipole allowed transitions. We infer high dark state preparation fidelities of >99.39 % and negative group velocities of up to -0.52 ±0.09 km /s based on our data.
International Nuclear Information System (INIS)
Dodonov, V V
2012-01-01
Exact and approximate formulas for the upper bound of the relative energy difference of two Gaussian states with a fixed fidelity between them are derived. The reciprocal formulas for the upper bound of the fidelity for the fixed value of the relative energy difference are also obtained. The bounds appear higher for pure states than for mixed ones, and their maximal values correspond to squeezed vacuum states. In particular, to guarantee the relative energy difference less than 10%, for quite arbitrary Gaussian states, the fidelity between them must exceed the level 0.998866. (fast track communication)
Inelastic processes in interaction of an atom with ultrashort pulse of an electromagnetic field
International Nuclear Information System (INIS)
Matveev, V.I.; Gusarevich, E.S.; Pashev, I.N.
2005-01-01
Electron transitions occurring when a heavy relativistic atom interacts with a spatially inhomogeneous ultrashort electromagnetic pulse are considered. Transition probabilities are expressed in terms of the known inelastic atomic form factors. By way of example, the inelastic processes accompanying the interaction of ultrashort pulses with hydrogen-like atoms are considered. The probabilities of ionization and production of a bound-free electron-positron pair on a bare nucleus, which are accompanied by the formation of a hydrogen-like atom in the final state and a positron in the continuum, are calculated. The developed technique makes it possible to take into exact account magnetic interaction besides spatial inhomogeneity of an ultrashort electromagnetic pulse [ru
Rapisarda, P.; Trentelman, H.L.; Minh, H.B.
We illustrate an algorithm that starting from the image representation of a strictly bounded-real system computes a minimal balanced state variable, from which a minimal balanced state realization is readily obtained. The algorithm stems from an iterative procedure to compute a storage function,
R-matrix calculations for few-quark bound states
International Nuclear Information System (INIS)
Shalchi, M.A.; Hadizadeh, M.R.
2016-01-01
The R-matrix method is implemented to study the heavy charm and bottom diquark, triquark, tetraquark, and pentaquarks in configuration space, as the bound states of quark-antiquark, diquark-quark, diquark-antidiquark, and diquark-antitriquark systems, respectively. The mass spectrum and the size of these systems are calculated for different partial wave channels. The calculated masses are compared with recent theoretical results obtained by other methods in momentum and configuration spaces and also by available experimental data. (orig.)
Robustness of Majorana bound states in the short-junction limit
Sticlet, D.C.; Nijholt, B.; Akhmerov, A.R.
2017-01-01
We study the effects of strong coupling between a superconductor and a semiconductor nanowire on the creation of the Majorana bound states, when the quasiparticle dwell time in the normal part of the nanowire is much shorter than the inverse superconducting gap. This "short-junction" limit is
Manipulation of Squeezed Two-Phonon Bound States using Femtosecond Laser Pulses
Directory of Open Access Journals (Sweden)
Nakamura Kazutaka G.
2013-03-01
Full Text Available Two-phonon bound states have been excited exclusively in ZnTe(110 via impulsive stimulated second-order Raman scattering, essentially being squeezed states due to phase coherent excitation of two identical components anticorrelated in the wave vector. By using coherent control technique with a pair of femtosecond laser pulses, the manipulation of squeezed states has been demonstrated in which both the amplitude and lifetime of coherent oscillations of squeezed states are modulated, indicating the feasibility to control the quantum noise and the quantum nature of phonon squeezed states, respectively.
International Nuclear Information System (INIS)
Toki, Hiroshi; Yamazaki, Toshimitsu
1989-01-01
The standard method of pionic atom formation does not produce deeply bound pionic atoms. A study is made on the properties of deeply bound pionic atom states by using the standard pion-nucleus optical potential. Another study is made to estimate the cross sections of the formation of ls pionic atom states by various methods. The pion-nucleus optical potential is determined by weakly bound pionic atom states and pion nucleus scattering. Although this potential may not be valid for deeply bound pionic atoms, it should provide some hint on binding energies and level widths of deeply bound states. The width of the ls state comes out to be 0.3 MeV and is well separated from the rest. The charge dependence of the ls state is investigated. The binding energies and the widths increase linearly with Z azbove a Z of 30. The report then discusses various methods to populate deeply bound pionic atoms. In particular, 'pion exchange' reactions are proposed. (n, pπ) reaction is discussed first. The cross section is calculated by assuming the in- and out-going nucleons on-shell and the produced pion in (n1) pionic atom states. Then, (n, dπ - ) cross sections are estimated. (p, 2 Heπ - ) reaction would have cross sections similar to the cross section of (n, dπ - ) reaction. In conclusion, it seems best to do (n, p) experiment on heavy nuclei for deeply bound pionic atom. (Nogami, K.)
The electromagnetic bio-field: clinical experiments and interferences.
Burnei, G; Hodorogea, D; Georgescu, I; Gavriliu, Ş; Drăghici, I; Dan, D; Vlad, C; Drăghici, L
2012-06-12
One of the most important factors is the technical and scientifically rapid development that is continually modifying the world we live in and polluting it with electromagnetic radiations. A functional and structural influence of magnetic and electromagnetic field on living organisms is presented in the literature by many performed experiments. The notion of bio-field represents the electromagnetic field generated by the bio-structures, not only in their normal physiological activities but also in their pathological states. There is a tight interdependency between the bio-field and the bio-structure, which respects the primary notion of an electromagnetic field given by the Maxwell-Faraday laws, in which, the electromagnetic phenomena are simplified to the field variations. These variations can be expressed in a coherent differential equation system that bounds the field vectors to different space points at different time moments. The living organisms cannot contain electrostatic and magneto-static fields due to the intense activity of the bio-structures. The biochemical reactions that have high rhythms and speeds always impose the electrodynamics character of the biologic field that also corresponds to the stability of the protein molecule that can be explained only through a dynamic way. The existent energy is not considered an exciting agent, and it does not lead to any effects. The parameters of these elementary bio-fields cannot yet be fully known due to technical reasons. The biological structures are very complex ones and undergo continuous dynamical activity. That is why the calculus model should be related to the constant dynamics, nowadays being very difficult to express.
Nonlinear spectroscopy of the bound exciton states in CdSe single crystals
International Nuclear Information System (INIS)
Lisitsa, M.P.; Onishchenko, N.A.; Stolyarenko, A.V.; Ananchenko, V.V.; Polishchuk, S.V.
1989-01-01
The study is devoted to the pulsed laser radiation effect on the time-resolved variations of free and bound exciton bands region at the helium temperature. A gradual disappearance of the bound I 2 exciton state is observed with increase of the excitation intensity I in CdSe transmission spectra. This phenomenon is explained by the fact that despite of the shorter life of I 2 excitons as compared to the free ones, the concentration of the centres on which they localize is rather low (≤10 16 cm -3 ) while the evolution of the light-generated electron-hole pairs is such as the most probable recombination through the bound excitons. The transmission spectrum kinetics is studied. The intensity limitation of the laser pulse transmitted through the crystal in the region of the exciton ground state region is shown to be related with two-photon absorption (TPA) in which the exciton state is an intermediate level. The calculation results are in good agreement with the experiment. The estimations show the giant TPA coefficient of ∼10 3 cm/MW. The evolution of photoexcited nonequilibrium electron-hole pairs is studied. The possibility of using CdSe single crystals as spectrum-selective limiters of the laser pulses is shown. (author)
Bag-model analyses of proton-antiproton scattering and atomic bound states
International Nuclear Information System (INIS)
Alberg, M.A.; Freedman, R.A.; Henley, E.M.; Hwang, W.P.; Seckel, D.; Wilets, L.
1983-01-01
We study proton-antiproton (pp-bar ) scattering using the static real potential of Bryan and Phillips outside a cutoff radius rsub0 and two different shapes for the imaginary potential inside a radius R*. These forms, motivated by bag models, are a one-gluon-annihilation potential and a simple geometric-overlap form. In both cases there are three adjustable parameters: the effective bag radius R*, the effective strong coupling constant αsubssup*, and rsub0. There is also a choice for the form of the real potential inside the cutoff radius rsub0. Analysis of the pp-bar scattering data in the laboratory-momentum region 0.4--0.7 GeV/c yields an effective nucleon bag radius R* in the range 0.6--1.1 fm, with the best fit obtained for R* = 0.86 fm. Arguments are presented that the deduced value of R* is likely to be an upper bound on the isolated nucleon bag radius. The present results are consistent with the range of bag radii in current bag models. We have also used the resultant optical potential to calculate the shifts and widths of the sup3Ssub1 and sup1Ssub0 atomic bound states of the pp-bar system. For both states we find upward (repulsive) shifts and widths of about 1 keV. We find no evidence for narrow, strongly bound pp-bar states in our potential model
Lower bounds for the ground states of He-isoelectronic series
International Nuclear Information System (INIS)
Fraga, Serafin
1981-01-01
A formulation, based on the concept of null local kinetic energy regions, has been developed for the determination of lower bounds for the ground state of a two-electron atom. Numerical results, obtained from Hartree-Fock functions, are presented for the elements He through Kr of the two-electron series
Interaction of D0-brane bound states and Ramond-Ramond photons
International Nuclear Information System (INIS)
Fatollahi, Amir H.
2002-01-01
We consider the problem of the interaction between a D0-brane bound state and one-form Ramond-Ramond (RR) photons using the world-line theory. Based on the fact that in the world-line theory the RR gauge fields depend on the matrix coordinates of D0-branes, the gauge fields also appear as matrices in the formulation. At the classical level, we derive the Lorentz-like equations of motion for D0-branes, and it is observed that the center of mass is colorless with respect to the SU(N) sector of the background. Using the path integral method, the perturbation theory for the interaction between the bound state and the RR background is developed. Qualitative considerations show that the possibility of the existence of a map between the world-line theory and the non-Abelian gauge theory is very considerable
What can Andreev bound states tell us about superconductors?
Millo, Oded; Koren, Gad
2018-08-06
Zero-energy Andreev bound states, which manifest themselves in the tunnelling spectra as zero-bias conductance peaks (ZBCPs), are abundant at interfaces between superconductors and other materials and on the nodal surface of high-temperature superconductors. In this review, we focus on the information such excitations can provide on the properties of superconductor systems. First, a general introduction to the physics of Andreev bound states in superconductor/normal metal interfaces is given with a particular emphasis on why they appear at zero energy in d -wave superconductors. Then, specific spectroscopic tunnelling studies of thin films, bilayers and junctions are described, focusing on the corresponding ZBCP features. Scanning tunnelling spectroscopy (STS) studies show that the ZBCPs on the c -axis YBa 2 Cu 3 O 7- δ (YBCO) films are correlated with the surface morphology and appear only in proximity to (110) facets. STS on c -axis La 1.88 Sr 0.12 CuO 4 (LSCO) films exhibiting the 1/8 anomaly shows spatially modulated peaks near zero bias associated with the anti-phase ordering of the d -wave order parameter predicted at this doping level. ZBCPs were also found in micrometre-size edge junctions of YBCO/SrRuO 3 /YBCO, where SrRuO 3 is ferromagnetic. Here, the results are consistent with a crossed Andreev reflection effect (CARE) at the narrow domain walls of the SrRuO 3 ZBCPs measured in STS studies of manganite/cuprate bilayers could not be attributed to CARE because the manganite's domain wall is much larger than the coherence length in YBCO, and instead are attributed to proximity-induced triplet-pairing superconductivity with non-conventional symmetry. And finally, ZBCPs found in junctions of non-intentionally doped topological insulator films of Bi 2 Se 3 and the s -wave superconductor NbN are attributed to proximity-induced p x + ip y triplet order parameter in the topological material.This article is part of the theme issue 'Andreev bound states'.
Relativistic description of quark-antiquark bound states. Spin-independent treatment
International Nuclear Information System (INIS)
Gara, A.; Durand, B.; Durand, L.; Nickisch, L.J.
1989-01-01
We present the results of a detailed study of light- and heavy-quark--antiquark bound states in the context of the reduced Bethe-Salpeter equation with static vector and scalar interactions. In the present paper, we consider the spin-averaged spectra. Spin effects are considered in a separate paper. We find that this approach, although apparently successful for the heavy-quark b bar b and c bar c states, fails for the s bar s, l bar l, and light-heavy states. The reasons for the failure are intrinsic to the method, as we discuss. Difficulties are already evident for the c bar c states
Quantum Bocce: Magnon–magnon collisions between propagating and bound states in 1D spin chains
International Nuclear Information System (INIS)
Longo, Paolo; Greentree, Andrew D.; Busch, Kurt; Cole, Jared H.
2013-01-01
The dynamics of two magnons in a Heisenberg spin chain under the influence of a non-uniform magnetic field is investigated by means of a numerical wave-function-based approach using a Holstein–Primakoff transformation. The magnetic field is localized in space such that it supports exactly one single-particle bound state. We study the interaction of this bound mode with an incoming spin wave and the interplay between transmittance, energy and momentum matching. We find analytic criteria for maximizing the interconversion between propagating single-magnon modes and true propagating two-magnon states. The manipulation of bound and propagating magnons is an essential step towards quantum magnonics.
Bound-state perturbation theory and annihilation effects in positronium
International Nuclear Information System (INIS)
Abbasabadi, A.; Repko, W.W.
1987-01-01
Working in Coulomb gauge and using the lowest-order equation proposed by Barbieri and Remiddi it is calculated, in the one-loop order of perturbation theory, the decay rate and the energy shift of the ground states of parapositronium and orthopositronium, respectively. Our result for the decay rate agrees with that of Harris and Brown. For contribution of one-photon-annihilation channel to the energy shift, it is confirmed the result of Karplus and Klein. These results are derived completely within the bound-state formalism and avoid the necessity of performing on-mass-shell wave function and vertex renormalization subtractions
The electromagnetic multipole moments of the charged open-flavor {Z}_{\\bar{c}q} states
Azizi, K.; Özdem, U.
2018-05-01
The electromagnetic multipole moments of the open-flavor {Z}\\bar{cq} states are investigated by assuming a diquark–antidiquark picture for their internal structure and quantum numbers {J}{PC}={1}+- for their spin-parity. In particular, their magnetic and quadrupole moments are extracted in the framework of light-cone QCD sum rule by the help of the photon distribution amplitudes. The electromagnetic multipole moments of the open-flavor {Z}\\bar{cq} states are important dynamical observables, which encode valuable information on their underlying structure. The results obtained for the magnetic moments of different structures are considerably large and can be measured in future experiments. We obtain very small values for the quadrupole moments of {Z}\\bar{cq} states indicating a nonspherical charge distribution.
Another comment on 'relativistic description of quark-antiquark bound states'
International Nuclear Information System (INIS)
Lucha, W.; Rupprecht, H.; Schoeberl, F.F.
1991-04-01
We point out some ambiguities in the treatment of fermion-antifermion bound states by solving the reduced Salpeter equation in coordinate space. Our observations allow to cast some doubt on the validity of the conclusion of Gara et al. that moving from a nonrelativistic to a relativistic description makes things worse. (authors)
Entanglement negativity bounds for fermionic Gaussian states
Eisert, Jens; Eisler, Viktor; Zimborás, Zoltán
2018-04-01
The entanglement negativity is a versatile measure of entanglement that has numerous applications in quantum information and in condensed matter theory. It can not only efficiently be computed in the Hilbert space dimension, but for noninteracting bosonic systems, one can compute the negativity efficiently in the number of modes. However, such an efficient computation does not carry over to the fermionic realm, the ultimate reason for this being that the partial transpose of a fermionic Gaussian state is no longer Gaussian. To provide a remedy for this state of affairs, in this work, we introduce efficiently computable and rigorous upper and lower bounds to the negativity, making use of techniques of semidefinite programming, building upon the Lagrangian formulation of fermionic linear optics, and exploiting suitable products of Gaussian operators. We discuss examples in quantum many-body theory and hint at applications in the study of topological properties at finite temperature.
A nonlinear programming approach to lower bounds for the ground-state energy of helium
International Nuclear Information System (INIS)
Porras, I.; Feldmann, D.M.; King, F.W.
1999-01-01
Lower-bound estimates for the ground-state energy of the helium atom are determined using nonlinear programming techniques. Optimized lower bounds are determined for single-particle, radially correlated, and general correlated wave functions. The local nature of the method employed makes it a very severe test of the accuracy of the wave function
International Nuclear Information System (INIS)
Lee, Hwasung; Lee, Y J
2007-01-01
We derive analytic expressions of the recursive solutions to Schroedinger's equation by means of a cutoff-potential technique for one-dimensional piecewise-constant potentials. These solutions provide a method for accurately determining the transmission probabilities as well as the wavefunction in both classically accessible regions and inaccessible regions for any barrier potentials. It is also shown that the energy eigenvalues and the wavefunctions of bound states can be obtained for potential-well structures by exploiting this method. Calculational results of illustrative examples are shown in order to verify this method for treating barrier and potential-well problems
Bound states and Cooper pairs of molecules in 2D optical lattices bilayer
Energy Technology Data Exchange (ETDEWEB)
Camacho-Guardian, A.; Dominguez-Castro, G.A.; Paredes, R. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico (Mexico)
2016-08-15
We investigate the formation of Cooper pairs, bound dimers and the dimer-dimer elastic scattering of ultracold dipolar Fermi molecules confined in a 2D optical lattice bilayer configuration. While the energy and their associated bound states are determined in a variational way, the correlated two-molecule pair is addressed as in the original Cooper formulation. We demonstrate that the 2D lattice confinement favors the formation of zero center mass momentum bound states. Regarding the Cooper pairs binding energy, this depends on the molecule populations in each layer. Maximum binding energies occur for non-zero (zero) pair momentum when the Fermi system is polarized (unpolarized). We find an analytic expression for the dimer-dimer effective interaction in the deep BEC regime. The present analysis represents a route for addressing the BCS-BEC crossover in dipolar Fermi gases confined in 2D optical lattices within the current experimental panorama. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Bound states in the (2+1)D scalar electrodynamics with Chern-Simons term
International Nuclear Information System (INIS)
Gomes, M.O.C.; Malacarne, L.C.
1994-01-01
This work studies the existence of bound states for the 3-dimensions scalar electrodynamics, with the Chern-Simons. Quantum field theory is used for calculation of the M fi scattering matrices, in the non-relativistic approximation. The field propagators responsible for the interaction in the scattering processes have been calculated, and scattering matrices have been constructed. After obtaining the scattering matrix, the cross section in the quantum field theory has been compared with the quantum mechanic cross section in the Born approximation, allowing to obtain the form of the potential responsible for the interactions in the scattering processes. The possibility of bound states are analyzed by using the Schroedinger equation
Morse potential, symmetric Morse potential and bracketed bound-state energies
Czech Academy of Sciences Publication Activity Database
Znojil, Miloslav
2016-01-01
Roč. 31, č. 14 (2016), s. 1650088 ISSN 0217-7323 R&D Projects: GA ČR GA16-22945S Institutional support: RVO:61389005 Keywords : quantum bound states * special functions * Morse potential * symmetrized Morse potential * upper and lower energy estimates * computer-assisted symbolic manipulations Subject RIV: BE - Theoretical Physics Impact factor: 1.165, year: 2016
Final state interactions in electron induced trinucleon breakup reactions
International Nuclear Information System (INIS)
Meijgaard, E. van.
1989-01-01
This thesis presents an exact analysis of the electromagnetic breakup process of a trinucleon system. The one-photon exchange mechanism is reviewed. The relevant components of the nuclear current are discussed and the off-shell one-body current matrix elements are derived to accommodate the evaluation of the trinucleon nuclear structure functions. The Faddeev equations are introduced. To facilitate the numerical evaluations the unitary pole expansion (UPE) is employed to describe a local S-wave spin-dependent interaction in a series of separable potential terms. The UPE convergence properties for the trinucleon bound state as well as for the N-N and N-d scattering observables are investigated. In view of the electromagnetic two-body and three-body breakup analysis the half off-shell wave functions for 3N→Nd and 3N→3N scattering are calculated. The nuclear structure functions of the electromagnetic two-body breakup structure functions of the electromagnetic two-body breakup processes are derived and exactly calculated. Results are presented and discussed for several kinetamic configurations. The nuclear response functions of the trinucleon breakup processes are calculated for a momentum transfer Q = 400 MeV/c. The results are compared with recent experimental data for the longitudinal and transverse response of both trinucleon systems. The three-body contributions to the response functions result from an essentially fourfold numerical integration of the invariant electromagnetic three-body breakup amplitude. A detailed derivation of this amplitude is presented and the treatment of the subsequent integration is discussed. An extension is formulated to include D-state components in the trinucleon bound state as well as in the disconnected final state components for the two-body breakup process. One kinematic situation is studied with the D-state extension. For the three-body breakup processes only the PWIA response is determined with the D-state component in the
Meson bound states and inclusive hardon scattering in quantum chromodynamics
International Nuclear Information System (INIS)
Beavis, D.R.
1980-01-01
In the first part we study the charmonium and UPSILON systems with a simple Coulomb plus linear potential. The parameters of the potential are determined by the charmonium states other than 1 S 0 states. We successfully predict that the states X(2830) and x(3450) are not the 1 S 0 partners of J/psi and psi'. The same effective potential also gives a good description of the UPSILON system. The Lorentz nature of the confinement potential is determined to be an equal mixture of vector and scalar. In the second part we extend a method for obtaining bound states and wavefunctions for relativistic confined systems. The important aspect of this treatment is the input of the asymptotic expansion of the two-point functions. We test the bound state approximation for a system defined by an equivalent potential V(r) = lambda 2 tanh 2 (g 2 r/lambda). Excellent results are obtained, even though a threshold is present. Finally, in the third section, we analyze the 100 GeV/c π - p→π 0 X data of Barnes et al. for moderate t, 1.5 less than or equal to -t less than or equal to 4.0 (GeV/c) 2 with the constituent scattering models. We obtain very good agreement in normalization and the x and t behavior of dsigma/dtdx using the FF1 model. The analysis of π - p→etaX gives additional support to this interpretation. The predictions of perturbative QCD and FF1 for π - p→π 0 X are given
QCD bound states at finite temperature and baryon number
International Nuclear Information System (INIS)
Kalinovsky, Yu.L.; Muenchow, L.
1991-04-01
Quark-antiquark bound states are described within the Bethe-Salpeter equation for a class of quark models with instantaneous 4-quark interaction at finite temperature. Thereby decompositions of the Bethe-Salpeter vertex and wave functions according to their Lorentz structures and the particles content are used. As an application of general scheme, we determine the mass spectrum of low-lying mesons for a special Nambu-Jona-Lasinio model inspired by QCD for hadrons. (orig.)
High precision hyperfine measurements in Bismuth challenge bound-state strong-field QED.
Ullmann, Johannes; Andelkovic, Zoran; Brandau, Carsten; Dax, Andreas; Geithner, Wolfgang; Geppert, Christopher; Gorges, Christian; Hammen, Michael; Hannen, Volker; Kaufmann, Simon; König, Kristian; Litvinov, Yuri A; Lochmann, Matthias; Maaß, Bernhard; Meisner, Johann; Murböck, Tobias; Sánchez, Rodolfo; Schmidt, Matthias; Schmidt, Stefan; Steck, Markus; Stöhlker, Thomas; Thompson, Richard C; Trageser, Christian; Vollbrecht, Jonas; Weinheimer, Christian; Nörtershäuser, Wilfried
2017-05-16
Electrons bound in highly charged heavy ions such as hydrogen-like bismuth 209 Bi 82+ experience electromagnetic fields that are a million times stronger than in light atoms. Measuring the wavelength of light emitted and absorbed by these ions is therefore a sensitive testing ground for quantum electrodynamical (QED) effects and especially the electron-nucleus interaction under such extreme conditions. However, insufficient knowledge of the nuclear structure has prevented a rigorous test of strong-field QED. Here we present a measurement of the so-called specific difference between the hyperfine splittings in hydrogen-like and lithium-like bismuth 209 Bi 82+,80+ with a precision that is improved by more than an order of magnitude. Even though this quantity is believed to be largely insensitive to nuclear structure and therefore the most decisive test of QED in the strong magnetic field regime, we find a 7-σ discrepancy compared with the theoretical prediction.
Covariant equations for the three-body bound state
International Nuclear Information System (INIS)
Stadler, A.; Gross, F.; Frank, M.
1997-01-01
The covariant spectator (or Gross) equations for the bound state of three identical spin 1/2 particles, in which two of the three interacting particles are always on shell, are developed and reduced to a form suitable for numerical solution. The equations are first written in operator form and compared to the Bethe-Salpeter equation, then expanded into plane wave momentum states, and finally expanded into partial waves using the three-body helicity formalism first introduced by Wick. In order to solve the equations, the two-body scattering amplitudes must be boosted from the overall three-body rest frame to their individual two-body rest frames, and all effects which arise from these boosts, including Wigner rotations and p-spin decomposition of the shell-particle, are treated exactly. In their final form, the equations reduce to a coupled set of Faddeev-like double integral equations with additional channels arising from the negative p-spin states of the off-shell particle
Hunt for the 11P1 bound state of charmonium
International Nuclear Information System (INIS)
Porter, F.C.
1982-02-01
Using the Crystal Ball detector at SPEAR, we have looked for evidence of the isospin-violating decay psi' → π 01 P 1 , where 1 P 1 is the predicted spin-singlet p-wave bound state of charmonium. For a 1 P 1 state at the predicted mass (approx. 3520 MeV), we obtain the 95% confidence level limits: BR(psi' → π 01 P 1 ) 01 P 1 )BR( 1 P 1 → γn/sub c/ < 0.14%. These limits are compared with simple theoretical predictions
Deeply quasi-bound state in single- and double-K nuclear clusters
Energy Technology Data Exchange (ETDEWEB)
Marri, S.; Kalantari, S.Z. [Isfahan University of Technology, Department of Physics, Isfahan (Iran, Islamic Republic of); Esmaili, J. [Shahrekord University, Department of Physics, Faculty of Basic Sciences, Shahrekord (Iran, Islamic Republic of)
2016-12-15
New calculations of the quasi-bound state positions in K{sup -}K{sup -}pp kaonic nuclear cluster are performed using non-relativistic four-body Faddeev-type equations in AGS form. The corresponding separable approximation for the integral kernels in the three- and four-body kaonic clusters is obtained by using the Hilbert-Schmidt expansion procedure. Different phenomenological models of anti KN-πΣ potentials with one- and two-pole structure of Λ(1405) resonance and separable potential models for anti K- anti K and nucleon-nucleon interactions, are used. The dependence of the resulting four-body binding energy on models of anti KN-πΣ interaction is investigated. We obtained the binding energy of the K{sup -}K{sup -}pp quasi-bound state ∝ 80-94 MeV with the phenomenological anti KN potentials. The width is about ∝ 5-8 MeV for the two-pole models of the interaction, while the one-pole potentials give ∝ 24-31 MeV width. (orig.)
Relativistic actions for bound-states and applications in the meson spectroscopy
International Nuclear Information System (INIS)
Silva Carvalho, Hendly da.
1991-08-01
We study relativistic equations for bound states of two-body systems using Dirac's constraint formalism and supersymmetry. The two-body system can be of spinless particles, one of them spinning and the other one spinless, or both of them spinning. The interaction is described by scalar, timelike four-vector and spacelike four-vector potentials under Lorentz transformations. As an application we use the relativistic wave equation for two scalar particles and calculate the mass spectra of the mesons treating them as spinless quark-antiquark bound states. The interaction potential in this case is a convenient adaptation of the potential employed in non-relativistic calculations. Finally, we compare our results with more recent experimental data and with theoretical results obtained with the same potential used by us but with a non-relativistic wave equation. We also compare our results with results obtained with the relativistic wave equation but with a different interaction potential. (author). 38 refs, 9 figs, 8 tabs
Electromagnetic properties of low-spin states in 102,104Pd
International Nuclear Information System (INIS)
Luontama, M.; Julin, R.; Kantele, J.; Passoja, A.; Trzaska, W.; Baecklin, A.; Jonsson, N.G.; Westerberg, L.
1985-12-01
Electromagnetic transitions from low-lying 0 + , 2 + , 4 + and 3 - states in 102 , 104 Pd have been studied with (p,2n) and (p,p) reactions and with Coulomb excitation. The E2 transition probabilities from the 0 3 + state in 102 Pd (13 W.u.) and from the 0 2 + state in 104 Pd (14 W.u.) are somewhat low for two-phonon states. Generally, the E2 transition rates are reasonably well reproduced by the IBA-2 and by the boson-expansion description. The intruding 0 2 + state (tsub(1/2) = 14.3 ns) in 102 Pd is connected to the 2 2 + and 2 3 + states via strong E2 transitions: B(E2;0 2 + →2 2 + )=96+-40 W.u.; B(E2;2 3 + →0 2 + )=17+-8 W.u
International Nuclear Information System (INIS)
Blokhintsev, L. D.; Savin, D. A.
2016-01-01
An exactly solvable potential model is used to study the possibility of deducing information about the features of bound states for the system under consideration (binding energies and asymptotic normalization coefficients) on the basis of data on continuum states. The present analysis is based on an analytic approximation and on the subsequent continuation of a partial-wave scattering function from the region of positive energies to the region of negative energies. Cases where the system has one or two bound states are studied. The α+d and α+"1"2C systems are taken as physical examples. In the case of one bound state, the scattering function is a smooth function of energy, and the procedure of its analytic continuation for different polynomial approximations leads to close results, which are nearly coincident with exact values. In the case of two bound states, the scattering function has two poles—one in the region of positive energies and the other in the region of negative energies between the energies corresponding to the two bound states in question. Padéapproximants are used to reproduce these poles. The inclusion of these poles proves to be necessary for correctly describing the properties of the bound states.
The search for deeply bound kaonic states with FOPI
International Nuclear Information System (INIS)
Schmid, P.; Buehler, P.; Cargnelli, M.; Marton, J.; Widmann, E.; Zmeskal, J.
2006-01-01
Full text: New formation mechanisms for the creation of dense, exotic nuclear systems involving strangeness were recently proposed by Y. Akaishi and T. Yamazaki. Their calculations show that a K - might form deeply bound states in light nuclei - so called kaonic clusters - with central densities of several times the normal nuclear density. In the presentation a short overview of these exotic nuclear systems will be given and a new experiment with FOPI at GSI will be discussed. The aim of this experiment was to search for the simplest cluster - a ppK - state. This state is produced at GSI in the following high energy reaction: p + ''d'' → ppK - + K + + n'' with incident energies of 3.5 GeV. The experimental set-up will be presented in detail. (author)
Hadamard States for the Klein-Gordon Equation on Lorentzian Manifolds of Bounded Geometry
Gérard, Christian; Oulghazi, Omar; Wrochna, Michał
2017-06-01
We consider the Klein-Gordon equation on a class of Lorentzian manifolds with Cauchy surface of bounded geometry, which is shown to include examples such as exterior Kerr, Kerr-de Sitter spacetime and the maximal globally hyperbolic extension of the Kerr outer region. In this setup, we give an approximate diagonalization and a microlocal decomposition of the Cauchy evolution using a time-dependent version of the pseudodifferential calculus on Riemannian manifolds of bounded geometry. We apply this result to construct all pure regular Hadamard states (and associated Feynman inverses), where regular refers to the state's two-point function having Cauchy data given by pseudodifferential operators. This allows us to conclude that there is a one-parameter family of elliptic pseudodifferential operators that encodes both the choice of (pure, regular) Hadamard state and the underlying spacetime metric.
Harz, Julia; Petraki, Kalliopi
2018-01-01
We compute the cross-sections for the radiative capture of non-relativistic particles into bound states, in unbroken perturbative non-Abelian theories. We find that the formation of bound states via emission of a gauge boson can be significant for a variety of dark matter models that feature non-Abelian long-range interactions, including multi-TeV scale WIMPs and dark matter co-annihilating with coloured partners. Our results disagree with previous computations, on the relative sign of the Ab...
Diabetes Among United States-Bound Adult Refugees, 2009-2014.
Benoit, Stephen R; Gregg, Edward W; Zhou, Weigong; Painter, John A
2016-12-01
We reported diabetes prevalence among all US-bound adult refugees and assessed factors associated with disease. We analyzed overseas medical evaluations of US-bound refugees from 2009 through 2014 by using CDC's Electronic Disease Notification System. We identified refugees with diabetes by searching for diabetes-related keywords and medications in examination forms with text-parsing techniques. Age-adjusted prevalence rates were reported and factors associated with diabetes were assessed by using logistic regression. Of 248,850 refugees aged ≥18 years examined over 5 years, 5767 (2.3 %) had diabetes. Iraqis had the highest crude (5.1 %) and age-adjusted (8.9 %) prevalence of disease. Higher age group and body mass index were associated with diabetes in all regions. Diabetes prevalence varied by refugee nationality. Although the absolute rates were lower than rates in the United States, the prevalence is still concerning given the younger age of the population and their need for health services upon resettlement.
The light bound states of N=1 supersymmetric SU(3) Yang-Mills theory on the lattice
Ali, Sajid; Bergner, Georg; Gerber, Henning; Giudice, Pietro; Montvay, Istvan; Münster, Gernot; Piemonte, Stefano; Scior, Philipp
2018-03-01
In this article we summarise our results from numerical simulations of N=1 supersymmetric Yang-Mills theory with gauge group SU(3). We use the formulation of Curci and Veneziano with clover-improved Wilson fermions. The masses of various bound states have been obtained at different values of the gluino mass and gauge coupling. Extrapolations to the limit of vanishing gluino mass indicate that the bound states form mass-degenerate supermultiplets.
Light-Front Hamiltonian Approach to the Bound-State Problem in Quantum Electrodynamics
Jones, Billy D.
1997-10-01
Why is the study of the Lamb shift in hydrogen, which at the level of detail found in this paper was largely completed by Bethe in 1947, of any real interest today? While completing such a calculation using new techniques may be very interesting for formal and academic reasons, our primary motivation is to lay groundwork for precision bound-state calculations in QCD. The Lamb shift provides an excellent pedagogical tool for illustrating light-front Hamiltonian techniques, which are not widely known; but more importantly it presents three of the central dynamical and computational problems that we must face to make these techniques useful for solving QCD: How does a constituent picture emerge in a gauge field theory? How do bound-state energy scales emerge non-perturbatively? How does rotational symmetry emerge in a non-perturbative light-front calculation?
Large N Chern-Simons with massive fundamental fermions — A model with no bound states
International Nuclear Information System (INIS)
Frishman, Yitzhak; Sonnenschein, Jacob
2014-01-01
In a previous paper http://dx.doi.org/10.1007/JHEP12(2013)091, we analyzed the theory of massive fermions in the fundamental representation coupled to a U(N) Chern-Simons gauge theory in three dimensions at level K. It was done in the large N, large K limits where λ=(N/K) was kept fixed. Among other results, we showed there that there are no high mass “quark anti-quark" bound states. Here we show that there are no bound states at all.
Hyperquarks and bosonic preon bound states
International Nuclear Information System (INIS)
Schmid, Michael L.; Buchmann, Alfons J.
2009-01-01
In a model in which leptons, quarks, and the recently introduced hyperquarks are built up from two fundamental spin-(1/2) preons, the standard model weak gauge bosons emerge as preon bound states. In addition, the model predicts a host of new composite gauge bosons, in particular, those responsible for hyperquark and proton decay. Their presence entails a left-right symmetric extension of the standard model weak interactions and a scheme for a partial and grand unification of nongravitational interactions based on, respectively, the effective gauge groups SU(6) P and SU(9) G . This leads to a prediction of the Weinberg angle at low energies in good agreement with experiment. Furthermore, using evolution equations for the effective coupling strengths, we calculate the partial and grand unification scales, the hyperquark mass scale, as well as the mass and decay rate of the lightest hyperhadron.
NLIE of Dirichlet sine-Gordon model for boundary bound states
International Nuclear Information System (INIS)
Ahn, Changrim; Bajnok, Zoltan; Palla, Laszlo; Ravanini, Francesco
2008-01-01
We investigate boundary bound states of sine-Gordon model on the finite-size strip with Dirichlet boundary conditions. For the purpose we derive the nonlinear integral equation (NLIE) for the boundary excited states from the Bethe ansatz equation of the inhomogeneous XXZ spin 1/2 chain with boundary imaginary roots discovered by Saleur and Skorik. Taking a large volume (IR) limit we calculate boundary energies, boundary reflection factors and boundary Luescher corrections and compare with the excited boundary states of the Dirichlet sine-Gordon model first considered by Dorey and Mattsson. We also consider the short distance limit and relate the IR scattering data with that of the UV conformal field theory
Universal bounds on current fluctuations.
Pietzonka, Patrick; Barato, Andre C; Seifert, Udo
2016-05-01
For current fluctuations in nonequilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. This bound allows for the prediction of the asymptotic growth of the generating function. Even though our results are restricted to networks with a finite number of states, we show that the parabolic bound is also valid for three paradigmatic examples of driven diffusive systems for which the generating function can be calculated using the additivity principle. Our bounds provide a general class of constraints for nonequilibrium systems.
Bound states in continuum: Quantum dots in a quantum well
Energy Technology Data Exchange (ETDEWEB)
Prodanović, Nikola, E-mail: elnpr@leeds.ac.uk [Institute of Microwaves and Photonics, School of Electronic and Electrical Engineering, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Milanović, Vitomir [School of Electrical Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, 11000 Belgrade (Serbia); Ikonić, Zoran; Indjin, Dragan; Harrison, Paul [Institute of Microwaves and Photonics, School of Electronic and Electrical Engineering, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom)
2013-11-01
We report on the existence of a bound state in the continuum (BIC) of quantum rods (QR). QRs are novel elongated InGaAs quantum dot nanostructures embedded in the shallower InGaAs quantum well. BIC appears as an excited confined dot state and energetically above the bottom of a well subband continuum. We prove that high height-to-diameter QR aspect ratio and the presence of a quantum well are indispensable conditions for accommodating the BIC. QRs are unique semiconductor nanostructures, exhibiting this mathematical curiosity predicted 83 years ago by Wigner and von Neumann.
Complex bounds and microstructural recovery from measurements of sea ice permittivity
International Nuclear Information System (INIS)
Gully, A.; Backstrom, L.G.E.; Eicken, H.; Golden, K.M.
2007-01-01
Sea ice is a porous composite of pure ice with brine, air, and salt inclusions. The polar sea ice packs play a key role in the earth's ocean-climate system, and they host robust algal and bacterial communities that support the Arctic and Antarctic ecosystems. Monitoring the sea ice packs on global or regional scales is an increasingly important problem, typically involving the interaction of an electromagnetic wave with sea ice. In the quasistatic regime where the wavelength is much longer than the composite microstructural scale, the electromagnetic behavior is characterized by the effective complex permittivity tensor ε*. In assessing the impact of climate change on the polar sea ice covers, current satellites and algorithms can predict ice extent, but the thickness distribution remains an elusive, yet most important feature. In recent years, electromagnetic induction devices using low frequency waves have been deployed on ships, helicopters and planes to obtain thickness data. Here we compare two sets of theoretical bounds to extensive outdoor tank and in situ field data on ε* at 50MHz taken in the Arctic and Antarctic. The sea ice is assumed to be a two phase composite of ice and brine with known constituent permittivities. The first set of bounds assumes only knowledge of the brine volume fraction or porosity, and the second set further assumes statistical isotropy of the microstructure. We obtain excellent agreement between theory and experiment, and are able to observe the apparent violation of the isotropic bounds as the vertically oriented microstructure becomes increasingly connected for higher porosities. Moreover, these bounds are inverted to obtain estimates of the porosity from the measurements of ε*. We find that the temporal variations of the reconstructed porosity, which is directly related to temperature, closely follow the actual behavior
Inelastic Processes in the Interaction of an Atom with an Ultrashort Electromagnetic Pulse
International Nuclear Information System (INIS)
Matveev, V.I.; Gusarevich, E.S.; Pashev, I.N.
2005-01-01
Electron transitions occurring during the interaction of a heavy relativistic atom with a spatially inhomogeneous ultrashort electromagnetic pulse are considered by solving the Dirac equation. The corresponding transition probabilities are expressed in terms of known inelastic atomic form factors, which are widely used in the theory of relativistic collisions between charged particles and atoms. By way of example, the inelastic processes accompanying the interaction of ultrashort pulses with hydrogen-like atoms are considered. The probabilities of ionization and production of a bound-free electron-positron pair on a bare nucleus, which are accompanied by the formation of a hydrogen-like atom in the final state and a positron in the continuum, are calculated. The developed technique makes it possible to take into account exactly not only the spatial inhomogeneity of an ultrashort electromagnetic pulse, but also the magnetic interaction
On the bound states of Schrodinger operators with -interactions on conical surfaces
Czech Academy of Sciences Publication Activity Database
Lotoreichik, Vladimir; Ourmieres-Bonafos, T.
2016-01-01
Roč. 41, č. 6 (2016), s. 999-1028 ISSN 0360-5302 Institutional support: RVO:61389005 Keywords : conical and hyperconical surfaces * delta-interaction * existence of bound states * Schrodinger operator * spectral asymptotics Subject RIV: BE - Theoretical Physics Impact factor: 1.608, year: 2016
Fermionic bound states in Minkowski space. Light-cone singularities and structure
Energy Technology Data Exchange (ETDEWEB)
Paula, Wayne de; Frederico, Tobias; Pimentel, Rafael [Instituto Tecnologico de Aeronautica, DCTA, Dept. de Fisica, Sao Jose dos Campos, Sao Paulo (Brazil); Salme, Giovanni [Istituto Nazionale di Fisica Nucleare, Rome (Italy); Viviani, Michele [Istituto Nazionale di Fisica Nucleare, Pisa (Italy)
2017-11-15
The Bethe-Salpeter equation for two-body bound system with spin 1/2 constituent is addressed directly in the Minkowski space. In order to accomplish this aim we use the Nakanishi integral representation of the Bethe-Salpeter amplitude and exploit the formal tool represented by the exact projection onto the null-plane. This formal step allows one (i) to deal with end-point singularities one meets and (ii) to find stable results, up to strongly relativistic regimes, which settle in strongly bound systems. We apply this technique to obtain the numerical dependence of the binding energies upon the coupling constants and the light-front amplitudes for a fermion-fermion 0{sup +} state with interaction kernels, in ladder approximation, corresponding to scalar-, pseudoscalar- and vector-boson exchanges, respectively. After completing the numerical survey of the previous cases, we extend our approach to a quark-antiquark system in 0{sup -} state, taking both constituent-fermion and exchanged-boson masses, from lattice calculations. Interestingly, the calculated light-front amplitudes for such a mock pion show peculiar signatures of the spin degrees of freedom. (orig.)
Chen, Jiao-Kai
2018-04-01
We present one reduction of the Bethe-Salpeter equation for the bound states composed of two off-mass-shell constituents. Both the relativistic effects and the virtuality effects can be considered in the obtained spinless virtuality distribution equation. The eigenvalues of the spinless virtuality distribution equation are perturbatively calculated and the bound states e+e-, μ+μ-, τ+τ-, μ+e-, and τ+e- are discussed.
Role of dressed-state interference in electromagnetically induced transparency
International Nuclear Information System (INIS)
Khan, Sumanta; Bharti, Vineet; Natarajan, Vasant
2016-01-01
Highlights: • Role of dressed-state interference is investigated on lambda, ladder and vee type EIT systems. • The effect of interference decreases with increasing Rabi frequency of the control laser. • Dressed-state interference plays an important role in lambda system and a negligible role in ladder and vee systems. - Abstract: Electromagnetically induced transparency (EIT) in three-level systems uses a strong control laser on one transition to modify the absorption of a weak probe laser on a second transition. The control laser creates dressed states whose decay pathways show interference. We study the role of dressed-state interference in causing EIT in the three types of three-level systems—lambda (Λ), ladder (Ξ), and vee (V). In order to get realistic values for the linewidths of the energy levels involved, we consider appropriate hyperfine levels of "8"7Rb. For such realistic systems, we find that dressed-state interference causes probe absorption—given by the imaginary part of the susceptibility—to go to zero in a Λ system, but plays a negligible role in Ξ and V systems.
Role of dressed-state interference in electromagnetically induced transparency
Energy Technology Data Exchange (ETDEWEB)
Khan, Sumanta; Bharti, Vineet; Natarajan, Vasant
2016-12-16
Highlights: • Role of dressed-state interference is investigated on lambda, ladder and vee type EIT systems. • The effect of interference decreases with increasing Rabi frequency of the control laser. • Dressed-state interference plays an important role in lambda system and a negligible role in ladder and vee systems. - Abstract: Electromagnetically induced transparency (EIT) in three-level systems uses a strong control laser on one transition to modify the absorption of a weak probe laser on a second transition. The control laser creates dressed states whose decay pathways show interference. We study the role of dressed-state interference in causing EIT in the three types of three-level systems—lambda (Λ), ladder (Ξ), and vee (V). In order to get realistic values for the linewidths of the energy levels involved, we consider appropriate hyperfine levels of {sup 87}Rb. For such realistic systems, we find that dressed-state interference causes probe absorption—given by the imaginary part of the susceptibility—to go to zero in a Λ system, but plays a negligible role in Ξ and V systems.
Monopole-fermion and dyon-fermion bound states. Pt. 5
International Nuclear Information System (INIS)
Osland, P.; Harvard Univ., Cambridge, MA; Schultz, C.L.; Wu, T.T.
1985-02-01
We present explicit, approximate, remarkably precise results for the Kazama-Yang hamiltonian, which describes a Dirac monopole interacting with a spin-1/2 fermion that has an extra magnetic moment. The results are valid for bound states of angular momentum j >= Zvertical strokeegvertical stroke+1/2, where the radial wave functions are determined by four coupled differential equations. These equations have been solved analytically for M - E << M, which is a limit of considerable practical interest. Binding energies and wave functions are given. (orig.)
Bound states for non-symmetric evolution Schroedinger potentials
Energy Technology Data Exchange (ETDEWEB)
Corona, Gulmaro Corona [Area de Analisis Matematico y sus Aplicaciones, Universidad Autonoma Metropolitana-Azcapotalco, Atzcapotzalco, DF (Mexico)). E-mail: ccg@correo.azc.uam.mx
2001-09-14
We consider the spectral problem associated with the evolution Schroedinger equation, (D{sup 2}+ k{sup 2}){phi}=u{phi}, where u is a matrix-square-valued function, with entries in the Schwartz class defined on the real line. The solution {phi}, called the wavefunction, consists of a function of one real variable, matrix-square-valued with entries in the Schwartz class. This problem has been dealt for symmetric potentials u. We found for the present case that the bound states are localized similarly to the scalar and symmetric cases, but by the zeroes of an analytic matrix-valued function. If we add an extra condition to the potential u, we can determine these states by an analytic scalar function. We do this by generalizing the scalar and symmetric cases but without using the fact that the Wronskian of a pair of wavefunction is constant. (author)
Electromagnetic form factors of composite systems
International Nuclear Information System (INIS)
Nowak, E.J.
1978-01-01
Electromagnetic form factors are examined for a spin-zero, two-body composite system with emphasis on the case of small momentum transfer and/or deep (relativistic) binding. Perturbation theory calculations are first performed using spin-zero and then spin-one-half constituents. A dispersion representation of the bound-state vertex function is conjectured first for scalar and then for fermion constituents. Then a relativistic effective range approximation (RERA) is developed for each case and applied to the calculation of the electromagnetic form factor. The approach is applied to the study of the charge radii of the K 0 and K + mesons. The K/sub l3/ form factor is calculated in the fermion constituent RERA model, and restrictions are imposed on the model parameters from available experimental data. With these restrictions the limits 0.24fm less than or equal to √[abs. value ( 2 >/sub K 0 /)] less than or equal to = 0.36fm and 0.66fm less than or equal to = √( 2 >/sub K + /) less than or equal to 0.79fm are obtained for the kaon charge radii, and -.22 less than or equal to xi less than or equal to -.13 is found for the ratio of the neutral to charged kaon charge radius squared
Applications of the infinite momentum method to quantum electrodynamics and bound state problem
International Nuclear Information System (INIS)
Brodsky, S.J.
1973-01-01
It is shown that the infinite momentum method is a valid and useful calculational alternative to standard perturbation theory methods. The most exciting future applications may be in bound state problems in quantum electrodynamics
International Nuclear Information System (INIS)
O’Carroll, Michael
2012-01-01
We consider the interaction of particles in weakly correlated lattice quantum field theories. In the imaginary time functional integral formulation of these theories there is a relative coordinate lattice Schroedinger operator H which approximately describes the interaction of these particles. Scalar and vector spin, QCD and Gross-Neveu models are included in these theories. In the weakly correlated regime H=H o +W where H o =−γΔ l , 0 l is the d-dimensional lattice Laplacian: γ=β, the inverse temperature for spin systems and γ=κ 3 where κ is the hopping parameter for QCD. W is a self-adjoint potential operator which may have non-local contributions but obeys the bound ‖W(x, y)‖⩽cexp ( −a(‖x‖+‖y‖)), a large: exp−a=β/β o (1/2) (κ/κ o ) for spin (QCD) models. H o , W, and H act in l 2 (Z d ), d⩾ 1. The spectrum of H below zero is known to be discrete and we obtain bounds on the number of states below zero. This number depends on the short range properties of W, i.e., the long range tail does not increase the number of states.
Measuring the electromagnetic chirality of 2D arrays under normal illumination.
Garcia-Santiago, X; Burger, S; Rockstuhl, C; Fernandez-Corbaton, I
2017-10-15
We present an electromagnetic chirality measure for 2D arrays of subwavelength periodicities under normal illumination. The calculation of the measure uses only the complex reflection and transmission coefficients from the array. The measure allows the ordering of arrays according to their electromagnetic chirality, which further allows a quantitative comparison of different design strategies. The measure is upper bounded, and the extreme properties of objects with high values of electromagnetic chirality make them useful in both near- and far-field applications. We analyze the consequences that different possible symmetries of the array have on its electromagnetic chirality. We use the measure to study four different arrays. The results indicate the suitability of helices for building arrays of high electromagnetic chirality, and the low effectiveness of a substrate for breaking the transverse mirror symmetry.
Radiative bound-state-formation cross-sections for dark matter interacting via a Yukawa potential
Energy Technology Data Exchange (ETDEWEB)
Petraki, Kalliopi [LPTHE, CNRS, UMR 7589,4 Place Jussieu, F-75252, Paris (France); Nikhef,Science Park 105, 1098 XG Amsterdam (Netherlands); Postma, Marieke; Vries, Jordy de [Nikhef,Science Park 105, 1098 XG Amsterdam (Netherlands)
2017-04-13
We calculate the cross-sections for the radiative formation of bound states by dark matter whose interactions are described in the non-relativistic regime by a Yukawa potential. These cross-sections are important for cosmological and phenomenological studies of dark matter with long-range interactions, residing in a hidden sector, as well as for TeV-scale WIMP dark matter. We provide the leading-order contributions to the cross-sections for the dominant capture processes occurring via emission of a vector or a scalar boson. We offer a detailed inspection of their features, including their velocity dependence within and outside the Coulomb regime, and their resonance structure. For pairs of annihilating particles, we compare bound-state formation with annihilation.
Influence of low-energy scattering on loosely bound states
International Nuclear Information System (INIS)
Sparenberg, Jean-Marc; Capel, Pierre; Baye, Daniel
2010-01-01
Compact algebraic equations are derived that connect the binding energy and the asymptotic normalization constant (ANC) of a subthreshold bound state with the effective-range expansion of the corresponding partial wave. These relations are established for positively charged and neutral particles, using the analytic continuation of the scattering (S) matrix in the complex wave-number plane. Their accuracy is checked on simple local potential models for the 16 O+n, 16 O+p, and 12 C+α nuclear systems, with exotic nuclei and nuclear astrophysics applications in mind.
Electron-electron bound states in parity-preserving QED3
International Nuclear Information System (INIS)
Belich, H.; Helayel-Neto, J.A.; Centro Brasileiro de Pesquisas Fisicas; Cima, O.M. del; Ferreira Junior, M.M.; Maranhao Univ., Sao Luis, MA
2002-04-01
By considering the Higgs mechanism in the framework of a parity-preserving Planar Quantum Electrodynamics, one shows that an attractive electron-electron interaction may dominate. The e - e - interaction potential emerges as the non-relativistic limit of the Moeller scattering amplitude and it results attractive with a suitable choice of parameters. Numerically values of the e - e - binding energy are obtained by solving the two-dimensional Schroedinger equation. The existence of bound states is a strong indicative that this model may be adopted to address the pairing mechanism of high-T c superconductivity. (author)
Electromagnetic compatibility of nuclear power plants
International Nuclear Information System (INIS)
Cabayan, H.S.
1983-01-01
Lately, there has been a mounting concern about the electromagnetic compatibility of nuclear-power-plant systems mainly because of the effects due to the nuclear electromagnetic pulse, and also because of the introduction of more-sophisticated and, therefore, more-susceptible solid-state devices into the plants. Questions have been raised about the adequacy of solid-state-device protection against plant electromagnetic-interference sources and transients due to the nuclear electromagnetic pulse. In this paper, the author briefly reviews the environment, and the coupling, susceptibility, and vulnerability assessment issues of commercial nuclear power plants
Bound state solution of the Grassmannian nonlinear sigma model with fermions
International Nuclear Information System (INIS)
Abdalla, E.; Lima-Santos, A.
1987-11-01
We construct the s matrix for bound state (gauge-invariant) scattering for nonlinear sigma models defined on the manifold SU(N)/S(U(p)x (lower casex)U(n-p)) with fermions. It is not possible to compute gauge non-singlet matrix elements. In the present language they are not submitted to sufficiently many constraints derived from higher conservation laws. (author) [pt
Energy Technology Data Exchange (ETDEWEB)
Datta, Nilanjana, E-mail: n.datta@statslab.cam.ac.uk [Statistical Laboratory, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Hsieh, Min-Hsiu, E-mail: Min-Hsiu.Hsieh@uts.edu.au [Centre for Quantum Computation and Intelligent Systems, Faculty of Engineering and Information Technology, University of Technology Sydney, NSW 2007 (Australia); Oppenheim, Jonathan, E-mail: j.oppenheim@ucl.ac.uk [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Department of Computer Science and Centre for Quantum Technologies, National University of Singapore, Singapore 119615 (Singapore)
2016-05-15
State redistribution is the protocol in which given an arbitrary tripartite quantum state, with two of the subsystems initially being with Alice and one being with Bob, the goal is for Alice to send one of her subsystems to Bob, possibly with the help of prior shared entanglement. We derive an upper bound on the second order asymptotic expansion for the quantum communication cost of achieving state redistribution with a given finite accuracy. In proving our result, we also obtain an upper bound on the quantum communication cost of this protocol in the one-shot setting, by using the protocol of coherent state merging as a primitive.
International Nuclear Information System (INIS)
Colavita, E.; Hacyan, S.
2014-01-01
We analyze the solutions of the Klein–Gordon and Dirac equations describing a charged particle in an electromagnetic plane wave combined with a magnetic field parallel to the direction of propagation of the wave. It is shown that the Klein–Gordon equation admits coherent states as solutions, while the corresponding solutions of the Dirac equation are superpositions of coherent and displaced-number states. Particular attention is paid to the resonant case in which the motion of the particle is unbounded. -- Highlights: •We study a relativistic electron in a particular electromagnetic field configuration. •New exact solutions of the Klein–Gordon and Dirac equations are obtained. •Coherent and displaced number states can describe a relativistic particle
Ionization and bound-state relativistic quantum dynamics in laser-driven multiply charged ions
International Nuclear Information System (INIS)
Hetzheim, Henrik
2009-01-01
The interaction of ultra-strong laser fields with multiply charged hydrogen-like ions can be distinguished in an ionization and a bound dynamics regime. Both are investigated by means of numerically solving the Dirac equation in two dimensions and by a classical relativistic Monte-Carlo simulation. For a better understanding of highly nonlinear physical processes the development of a well characterized ultra-intense relativistic laser field strength has been driven forward, capable of studying e.g. the magnetic field effects of the laser resulting in an additional electron motion in the laser propagation direction. A novel method to sensitively measure these ultra-strong laser intensities is developed and employed from the optical via the UV towards the XUV frequency regime. In the bound dynamics field, the determination of multiphoton transition matrixelements has been investigated between different bound states via Rabi oscillations. (orig.)
Ionization and bound-state relativistic quantum dynamics in laser-driven multiply charged ions
Energy Technology Data Exchange (ETDEWEB)
Hetzheim, Henrik
2009-01-14
The interaction of ultra-strong laser fields with multiply charged hydrogen-like ions can be distinguished in an ionization and a bound dynamics regime. Both are investigated by means of numerically solving the Dirac equation in two dimensions and by a classical relativistic Monte-Carlo simulation. For a better understanding of highly nonlinear physical processes the development of a well characterized ultra-intense relativistic laser field strength has been driven forward, capable of studying e.g. the magnetic field effects of the laser resulting in an additional electron motion in the laser propagation direction. A novel method to sensitively measure these ultra-strong laser intensities is developed and employed from the optical via the UV towards the XUV frequency regime. In the bound dynamics field, the determination of multiphoton transition matrixelements has been investigated between different bound states via Rabi oscillations. (orig.)
Bounded energy states in homogeneous turbulent shear flow: An alternative view
Bernard, Peter S.; Speziale, Charles G.
1990-01-01
The equilibrium structure of homogeneous turbulent shear flow is investigated from a theoretical standpoint. Existing turbulence models, in apparent agreement with physical and numerical experiments, predict an unbounded exponential time growth of the turbulent kinetic energy and dissipation rate; only the anisotropy tensor and turbulent time scale reach a structural equilibrium. It is shown that if vortex stretching is accounted for in the dissipation rate transport equation, then there can exist equilibrium solutions, with bounded energy states, where the turbulence production is balanced by its dissipation. Illustrative calculations are present for a k-epsilon model modified to account for vortex stretching. The calculations indicate an initial exponential time growth of the turbulent kinetic energy and dissipation rate for elapsed times that are as large as those considered in any of the previously conducted physical or numerical experiments on homogeneous shear flow. However, vortex stretching eventually takes over and forces a production-equals-dissipation equilibrium with bounded energy states. The validity of this result is further supported by an independent theoretical argument. It is concluded that the generally accepted structural equilibrium for homogeneous shear flow with unbounded component energies is in need of re-examination.
Electromagnetic spatial coherence wavelets
International Nuclear Information System (INIS)
Castaneda, R.; Garcia-Sucerquia, J.
2005-10-01
The recently introduced concept of spatial coherence wavelets is generalized for describing the propagation of electromagnetic fields in the free space. For this aim, the spatial coherence wavelet tensor is introduced as an elementary amount, in terms of which the formerly known quantities for this domain can be expressed. It allows analyzing the relationship between the spatial coherence properties and the polarization state of the electromagnetic wave. This approach is completely consistent with the recently introduced unified theory of coherence and polarization for random electromagnetic beams, but it provides a further insight about the causal relationship between the polarization states at different planes along the propagation path. (author)
A lower bound on the relative error of mixed-state cloning and related operations
International Nuclear Information System (INIS)
Rastegin, A E
2003-01-01
We extend the concept of the relative error to mixed-state cloning and related physical operations, in which the ancilla contains some information a priori about the input state. The lower bound on the relative error is obtained. It is shown that this result provides further support for a stronger no-cloning theorem
Quartified leptonic color, bound states, and future electron–positron collider
Directory of Open Access Journals (Sweden)
Corey Kownacki
2017-06-01
Full Text Available The [SU(3]4 quartification model of Babu, Ma, and Willenbrock (BMW, proposed in 2003, predicts a confining leptonic color SU(2 gauge symmetry, which becomes strong at the keV scale. It also predicts the existence of three families of half-charged leptons (hemions below the TeV scale. These hemions are confined to form bound states which are not so easy to discover at the Large Hadron Collider (LHC. However, just as J/ψ and ϒ appeared as sharp resonances in e−e+ colliders of the 20th century, the corresponding ‘hemionium’ states are expected at a future e−e+ collider of the 21st century.
Proof of the insecurity of quantum secret sharing based on the Smolin bound entangled states
International Nuclear Information System (INIS)
Ya-Fei, Yu; Zhi-Ming, Zhang
2009-01-01
This paper reconsiders carefully the possibility of using the Smolin bound entangled states as the carrier for sharing quantum secret. It finds that the process of quantum secret sharing based on Smolin states has insecurity though the Smolin state was reported to violate maximally the two-setting Bell-inequality. The general proof is given. (general)
Contribution of Bound States to the Harmonic Generation in Hydrogen at Moderate Laser Intensities
National Research Council Canada - National Science Library
Davis, Jack
2002-01-01
.... The disappearance of bound parabolic states with large electric dipole moments in moderately strong fields leads to the simplification of the expression for the total time-dependent dipole moment of the atom...
Huang, Dao-Ling; Zhu, Guo-Zhu; Wang, Lai-Sheng
2016-06-01
Deprotonated thymine can exist in two different forms, depending on which of its two N sites is deprotonated: N1[T-H]^- or N3[T-H]^-. Here we report a photodetachment study of the N1[T-H]^- isomer cooled in a cryogenic ion trap and the observation of an excited dipole-bound state. Eighteen vibrational levels of the dipole-bound state are observed, and its vibrational ground state is found to be 238 ± 5 wn below the detachment threshold of N1[T-H]^-. The electron affinity of the deprotonated thymine radical (N1[T-H]^.) is measured accruately to be 26 322 ± 5 wn (3.2635 ± 0.0006 eV). By tuning the detachment laser to the sixteen vibrational levels of the dipole-bound state that are above the detachment threshold, highly non-Franck-Condon resonant-enhanced photoelectron spectra are obtained due to state- and mode-selective vibrational autodetachment. Much richer vibrational information is obtained for the deprotonated thymine radical from the photodetachment and resonant-enhanced photoelectron spectroscopy. Eleven fundamental vibrational frequencies in the low-frequency regime are obtained for the N1[T-H]^. radical, including the two lowest-frequency internal rotational modes of the methyl group at 70 ± 8 wn and 92 ± 5 wn. D. L. Huang, H. T. Liu, C. G. Ning, G. Z. Zhu and L. S. Wang, Chem. Sci., 6, 3129-3138 (2015)
Energy Technology Data Exchange (ETDEWEB)
Hod, Shahar [The Ruppin Academic Center, Emeq Hefer (Israel); The Hadassah Academic College, Jerusalem (Israel)
2017-05-15
The quasi-bound states of charged massive scalar fields in the near-extremal charged Reissner-Nordstroem black-hole spacetime are studied analytically. These discrete resonant modes of the composed black-hole-field system are characterized by the physically motivated boundary condition of ingoing waves at the black-hole horizon and exponentially decaying (bounded) radial eigenfunctions at spatial infinity. Solving the Klein-Gordon wave equation for the linearized scalar fields in the black-hole spacetime, we derive a remarkably compact analytical formula for the complex frequency spectrum which characterizes the quasi-bound state resonances of the composed Reissner-Nordstroem-black-hole-charged-massive-scalar-field system. (orig.)
Bound states of quarks calculated with stochastic integration of the Bethe-Salpeter equation
International Nuclear Information System (INIS)
Salomon, M.
1992-07-01
We have computed the masses, wave functions and sea quark content of mesons in their ground state by integrating the Bethe-Salpeter equation with a stochastic algorithm. This method allows the inclusion of a large set of diagrams. Inspection of the kernel of the equation shows that q-q-bar pairs with similar constituent masses in a singlet spin state exhibit a high bound state which is not present in other pairs. The pion, kaon and eta belongs to this category. 19 refs., 2 figs., 2 tabs
The Fermionic Signature Operator and Hadamard States in the Presence of a Plane Electromagnetic Wave
Finster, Felix; Reintjes, Moritz
2017-05-01
We give a non-perturbative construction of a distinguished state for the quantized Dirac field in Minkowski space in the presence of a time-dependent external field of the form of a plane electromagnetic wave. By explicit computation of the fermionic signature operator, it is shown that the Dirac operator has the strong mass oscillation property. We prove that the resulting fermionic projector state is a Hadamard state.
Ionization from short-range potential under action of electromagnetic field of complex configuration
Rodionov, V N; Kravtsova, G A
2002-01-01
The transcendental equation for the complex energy is obtained on the basis of the exactly solvable 3D model of the short-acting potential and the Green time function in the intensive electromagnetic field, constituting the combination of the constant magnetic field and the circular-polarization wave field. The electron quasistationary states parameters in the delta-potential with an account of the action of the intensive external field of complex configuration are calculated. The problem on the possibility of stabilizing the bound states decay of the spinor and scalar particles through the intensive magnetic field is clarified. It is established that the obtained results regime the reexamination of the accepted notion on the stabilizing role of the strong magnetic field by the atoms ionization
Gravitationally self-bound quantum states in unstable potentials
Jääskeläinen, Markku
2018-04-01
Quantum mechanics at present cannot be unified with the theory of gravity at the deepest level, and to guide research towards the solution of this fundamental problem, we need to look for ways to observe or refute predictions originating from attempts to combine quantum theory with gravity. The influence of the gravitational field created by the material density given by the wave function itself gives rise to nontrivial phenomena. In this study I consider the wave function for the center-of-mass coordinate of a spherical mass distribution under the influence of the self-interaction of Newtonian gravity. I solve numerically for the ground state in the presence of an unstable potential and find that the energy of the free-space bound state can be lowered despite the nontrapping character of the potential. The center-of-mass ground state becomes increasingly localized for the used unstable potentials, although only in a limited parameter regime. The feebleness of the energy shift makes the observation of these effects demanding and requires further developments in the cooling of material particles. In addition, the influence of gravitational perturbations that are present in typical laboratory settings necessitates the use of extremely quiet and controlled environments such as those provided by recently proposed space-borne experiments.
International Nuclear Information System (INIS)
Wells, J.C.; Oberacker, V.E.; Umar, A.S.
1993-01-01
The prospect of new colliding-beam accelerators capable of producing collisions of highly stripped high-Z ions, at fixed-target energies per nucleon up to 20 TeV or more, has motivated much interest in lepton-pair production from the QED vacuum. The time-dependent and essentially classical electromagnetic fields involved in such collisions contain larger Fourier components which give rise to sizable lepton-pair production in addition to many other exotic particles. The process of electron-positron production with electron capture is a principal beam-loss mechanism for highly charged ions in a storage ring. In this process, the electron is created in a bound state of one of the participant heavy ions (most likely the 1s state), thus changing the ion's charge state and causing it to be deflected out of the beam. There is a long and sometimes controversial history concerning the use of perturbative methods in studying electromagnetic lepton-pair production; however, reliable perturbative calculations have been used as input into design models for the Relativistic Heavy-Ion Collider (RHIC). Applying perturbation theory to these processes at high energies and small impact parameters results in probabilities which violate unitarity, and cross sections which violate the Froissart bound. This evidence, along with the initial nonperturbative studies, suggests that higher-order QED effects will be important for extreme relativistic collisions. Clearly, large nonperturbative effects in electron-pair production with capture would have important implications for RHIC. In this paper, the authors briefly discuss recent progress in nonperturbative studies of the capture problem. In Section 2, they state the Dirac equation for a lepton in the time-dependent external field of a heavy ion which must be solved to compute lepton-capture probabilities. Section 4 surveys results from recent applications of coupled-channel and lattice techniques to the lepton-capture problem
Bound states and molecular structure of systems with hyperons
International Nuclear Information System (INIS)
Akaishi, Y.
1992-01-01
Microscopic calculations are done for Σ-hypernuclear few-body systems by a method named ATMS. Among two- to five-body systems, only the Σ 4 He(0 + ) and Σ 4 H(0 + ) hypernuclei are expected to be bound: The binding energy and the width of the former are calculated to be 3.7 ∼ 4.6 MeV and 4.5 ∼ 7.9 MeV, respectively. The observation of Σ 4 He at KEK is in good agreement with the above prediction. The nucleus-Σ potential has a strong Lane term and a repulsive bump at short distance. The Lane term makes the system bound and the bump suppresses the ΣN → ΛN conversion. X-ray measurement of level shifts in the 4 He-Σ - , 3 He-Σ - and 3 H-Σ - atoms can provide another information on the Lane term. In 208 Pb, there may exist a peculiar state, Coulomb-assisted (atomnucleus) hybrid state, where Σ - is trapped in the surface region by the strong interaction with the aid of the inner centrifugal repulsion and the outer Coulomb attraction. An analysis is given for new data of Ξ -.12 C atomic or nuclear systems from the emulsion-counter experiment at KEK. The double-Λ hypernucleus formation rate is calculated for a stopped Ξ - on 4 He. A high branching ratio of 37% is obtained for the ΛΛ 4 H formation from a Ξ -.4 He atom. The detection of about 2.3 MeV neutron is proposed to search for lightest double-Λ hypernucleus ΛΛ 4 H. (author)
High-Precision Measurements of the Bound Electron’s Magnetic Moment
Directory of Open Access Journals (Sweden)
Sven Sturm
2017-01-01
Full Text Available Highly charged ions represent environments that allow to study precisely one or more bound electrons subjected to unsurpassed electromagnetic fields. Under such conditions, the magnetic moment (g-factor of a bound electron changes significantly, to a large extent due to contributions from quantum electrodynamics. We present three Penning-trap experiments, which allow to measure magnetic moments with ppb precision and better, serving as stringent tests of corresponding calculations, and also yielding access to fundamental quantities like the fine structure constant α and the atomic mass of the electron. Additionally, the bound electrons can be used as sensitive probes for properties of the ionic nuclei. We summarize the measurements performed so far, discuss their significance, and give a detailed account of the experimental setups, procedures and the foreseen measurements.
The ordering of low-lyiing bound states of three identical particles
International Nuclear Information System (INIS)
Richard, J.M.; Taxil, P.
1990-01-01
New results are presented on the ordering of bound states of three identical particles, a problem inspired by baryon spectroscopy. We first study the case of a perturbed harmonic oscillator and relate the splitting pattern to the level spacings in the two-body problem. We also obtain much more general results, valid for almost any symmetric potential, not necessarily pairwise. The proof is given in the framework of the hyperspherical formalism. (orig.)
Bound states on the lattice with partially twisted boundary conditions
International Nuclear Information System (INIS)
Agadjanov, D.; Guo, F.-K.; Ríos, G.; Rusetsky, A.
2015-01-01
We propose a method to study the nature of exotic hadrons by determining the wave function renormalization constant Z from lattice simulations. It is shown that, instead of studying the volume-dependence of the spectrum, one may investigate the dependence of the spectrum on the twisting angle, imposing twisted boundary conditions on the fermion fields on the lattice. In certain cases, e.g., the case of the DK bound state which is addressed in detail, it is demonstrated that the partial twisting is equivalent to the full twisting up to exponentially small corrections.
Spectroscopy of the hghest Rb2 bound states with 10 kHz precision
Verhaar, B.J.; Kokkelmans, S.J.J.M.F.; van Kempen, E.G.M.; Freeland, R.S.; Wynar, R.; Comparat, D.; Ryu, C.; Heinzen, D.J.
2001-01-01
We have measured the binding energy of four of the highest bound vibrational levels of the ground electronic states of the ^87Rb2 molecule with a precision better than 10 kHz. The measurements were carried out using stimulated Raman photoassociation in an ^87Rb Bose-Einstein condensate. We have
Energy Technology Data Exchange (ETDEWEB)
Fox, Zachary [School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Neuert, Gregor [Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 (United States); Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232 (United States); Department of Biomedical Engineering, Vanderbilt University School of Engineering, Nashville, Tennessee 37232 (United States); Munsky, Brian [School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)
2016-08-21
Emerging techniques now allow for precise quantification of distributions of biological molecules in single cells. These rapidly advancing experimental methods have created a need for more rigorous and efficient modeling tools. Here, we derive new bounds on the likelihood that observations of single-cell, single-molecule responses come from a discrete stochastic model, posed in the form of the chemical master equation. These strict upper and lower bounds are based on a finite state projection approach, and they converge monotonically to the exact likelihood value. These bounds allow one to discriminate rigorously between models and with a minimum level of computational effort. In practice, these bounds can be incorporated into stochastic model identification and parameter inference routines, which improve the accuracy and efficiency of endeavors to analyze and predict single-cell behavior. We demonstrate the applicability of our approach using simulated data for three example models as well as for experimental measurements of a time-varying stochastic transcriptional response in yeast.
Kholmetskii, Alexander; Missevitch, Oleg; Yarman, Tolga
2016-02-01
We address to the Poynting theorem for the bound (velocity-dependent) electromagnetic field, and demonstrate that the standard expressions for the electromagnetic energy flux and related field momentum, in general, come into the contradiction with the relativistic transformation of four-vector of total energy-momentum. We show that this inconsistency stems from the incorrect application of Poynting theorem to a system of discrete point-like charges, when the terms of self-interaction in the product {\\varvec{j}} \\cdot {\\varvec{E}} (where the current density {\\varvec{j}} and bound electric field {\\varvec{E}} are generated by the same source charge) are exogenously omitted. Implementing a transformation of the Poynting theorem to the form, where the terms of self-interaction are eliminated via Maxwell equations and vector calculus in a mathematically rigorous way (Kholmetskii et al., Phys Scr 83:055406, 2011), we obtained a novel expression for field momentum, which is fully compatible with the Lorentz transformation for total energy-momentum. The results obtained are discussed along with the novel expression for the electromagnetic energy-momentum tensor.
Interband type-II miniband-to-bound state diode lasers for the midinfrared
International Nuclear Information System (INIS)
Mermelstein, C.; Schmitz, J.; Kiefer, R.; Walther, M.; Wagner, J.
2004-01-01
A design for midinfrared diode lasers based on interband type-II miniband-to-bound state transitions is proposed and has been demonstrated experimentally. Type-II miniband-to-bound state laser structures emitting at 3.25 μm with active regions consisting of 5 and 10 W periods were grown by solid-source molecular-beam epitaxy and processed into ridge waveguide lasers. Substrate-side down mounted devices with a 10 period active region and uncoated facets could be operated in continuous-wave (cw) mode up to 185 K and as high as 260 K in pulsed mode. A high characteristic temperature of 100 K has been achieved for heat-sink temperatures below 140 K, decreasing to 33 K for the 140 to 185 K interval. At 110 K, a 5 period laser structure exhibited a threshold current density of 177 A/cm 2 and a slope efficiency of 61 mW/A. Single-ended output powers of 144 mW in cw mode and exceeding 330 mW in pulsed operation were obtained for a substrate-side down mounted 5 period diode laser with high-reflection/antireflection coated mirror facets, operated at 110 K
International Nuclear Information System (INIS)
Jones, N J A; Minns, R S; Patel, R; Fielding, H H
2008-01-01
The Stark spectra of Rydberg states of NO below the υ + = 0 ionization limit, with principal quantum numbers n = 25-30, have been investigated in the presence of dc electric fields in the range 0-150 V cm -1 . The Stark states were accessed by two-colour, double-resonance excitation via the υ' = 0, N' = 0 rovibrational state of the A 2 Σ + state. The N( 2 D) atoms produced by predissociation were measured by (2 + 1) resonance-enhanced multiphoton ionization, and compared with pulsed-field ionization spectra of the bound Rydberg state population (Patel et al 2007 J. Phys. B: At. Mol. Opt. Phys. 40 1369)
Energy Technology Data Exchange (ETDEWEB)
Schneider, E.; Kern, R.; Theiner, W.A. [Fraunhofer Inst. fuer Zerstoerungsfreie Pruefverfahren, IZFP, Saarbruecken (Germany)
1999-08-01
The electromagnetic and ultrasonic techniques are comparably recent NDT methods for determination of stress states of components. They are simple in application, but require pre-measurement preparation: Electromagnetic techniques need calibration, and quantitative stress analysis by ultrasonic techniques needs reference values, i.e. verified materials-specific quantities to be obtained with representative specimens. Electromagnetic and ultrasonic techniques have been developed for specific tests at defined components, and the corresponding instruments and sensors have been used in practice for several years now. The paper summarizes fundamental aspects and explains the state of the art by means of several examples. (orig./CB) [Deutsch] Elektromagnetische und Ultraschallverfahren sind vergleichsweise neue zerstoerungsfreie Verfahren zur Bestimmung von Eigenspannungen in Bauteilen. Ihre Anwendung ist einfach, setzt aber Vorarbeiten voraus: Elektromagnetische Verfahren muessen kalibriert und zur quantitativen Spannungsanalyse mittels Ultraschallverfahren muessen materialspezifische Kenngroessen an repraesentativen Materialproben ermittelt werden. Elektromagnetische und Ultraschallverfahren sind fuer konkrete Anwendungen an Bauteilen entwickelt, angepasste Geraete und Sensoren seit Jahren in der Nutzung. Der Beitrag fasst die Grundlagen zusammen und stellt den Stand der Technik anhand ausgewaehlter Anwendungen dar. (orig.)
Variational lower bound on the scattering length
International Nuclear Information System (INIS)
Rosenberg, L.; Spruch, L.
1975-01-01
The scattering length A characterizes the zero-energy scattering of one system by another. It was shown some time ago that a variational upper bound on A could be obtained using methods, of the Rayleigh-Ritz type, which are commonly employed to obtain upper bounds on energy eigenvalues. Here we formulate a method for obtaining a variational lower bound on A. Once again the essential idea is to express the scattering length as a variational estimate plus an error term and then to reduce the problem of bounding the error term to one involving bounds on energy eigenvalues. In particular, the variational lower bound on A is rigorously established provided a certin modified Hamiltonian can be shown to have no discrete states lying below the level of the continuum threshold. It is unfortunately true that necessary conditions for the existence of bound states are not available for multiparticle systems in general. However, in the case of positron-atom scattering the adiabatic approximation can be introduced as an (essentially) solvable comparison problem to rigorously establish the nonexistence of bound states of the modified Hamiltonian. It has recently been shown how the validity of the variational upper bound on A can be maintained when the target ground-state wave function is imprecisely known. Similar methods can be used to maintain the variational lower bound on A. Since the bound is variational, the error in the calculated scattering length will be of second order in the error in the wave function. The use of the adiabatic approximation in the present context places no limitation in principle on the accuracy achievable
DEFF Research Database (Denmark)
Damgård, Ivan Bjerre; Faust, Sebastian; Mukherjee, Pratyay
2013-01-01
Related key attacks (RKAs) are powerful cryptanalytic attacks where an adversary can change the secret key and observe the effect of such changes at the output. The state of the art in RKA security protects against an a-priori unbounded number of certain algebraic induced key relations, e.......g., affine functions or polynomials of bounded degree. In this work, we show that it is possible to go beyond the algebraic barrier and achieve security against arbitrary key relations, by restricting the number of tampering queries the adversary is allowed to ask for. The latter restriction is necessary......-protocols (including the Okamoto scheme, for instance) are secure even if the adversary can arbitrarily tamper with the prover’s state a bounded number of times and obtain some bounded amount of leakage. Interestingly, for the Okamoto scheme we can allow also independent tampering with the public parameters. We show...
Integral methods in low-frequency electromagnetics
Solin, Pavel; Karban, Pavel; Ulrych, Bohus
2009-01-01
A modern presentation of integral methods in low-frequency electromagnetics This book provides state-of-the-art knowledge on integral methods in low-frequency electromagnetics. Blending theory with numerous examples, it introduces key aspects of the integral methods used in engineering as a powerful alternative to PDE-based models. Readers will get complete coverage of: The electromagnetic field and its basic characteristics An overview of solution methods Solutions of electromagnetic fields by integral expressions Integral and integrodifferential methods
New rational extensions of solvable potentials with finite bound state spectrum
International Nuclear Information System (INIS)
Grandati, Yves
2012-01-01
Using the disconjugacy properties of the Schrödinger equation, we develop a new type of generalized SUSY QM partnership which allows generating new solvable rational extensions for translationally shape invariant potentials having a finite bound state spectrum. For this we prolong the dispersion relation relating the energy to the quantum number out of the physical domain until a disconjugacy sector. By Darboux–Bäcklund Transformations built on these prolonged states we obtain new regular isospectral extensions of the initial potential. We give the spectra of these extensions in terms of new orthogonal polynomials and study their shape invariance properties. -- Highlights: ► New solvable quantum potentials. ► SUSY quantum partnership generalized to excited states. ► Based on disconjugacy theorems and asymptotic behaviour. ► Exact spectrum in terms of new orthogonal polynomials. ► Enlarged shape invariance property.
Impurity bound states in mesoscopic topological superconducting loops
Jin, Yan-Yan; Zha, Guo-Qiao; Zhou, Shi-Ping
2018-06-01
We study numerically the effect induced by magnetic impurities in topological s-wave superconducting loops with spin-orbit interaction based on spin-generalized Bogoliubov-de Gennes equations. In the case of a single magnetic impurity, it is found that the midgap bound states can cross the Fermi level at an appropriate impurity strength and the circulating spin current jumps at the crossing point. The evolution of the zero-energy mode can be effectively tuned by the located site of a single magnetic impurity. For the effect of many magnetic impurities, two independent midway or edge impurities cannot lead to the overlap of zero modes. The multiple zero-energy modes can be effectively realized by embedding a single Josephson junction with impurity scattering into the system, and the spin current displays oscillatory feature with increasing the layer thickness.
A search for deeply-bound kaonic nuclear states at J-PARC
Directory of Open Access Journals (Sweden)
Sakaguchi A.
2010-04-01
Full Text Available The J-PARC E15 experiment will be performed to search for the simplest kaonic nuclear bound state, K− pp, by the in-ﬂight 3He(K−,n reaction. The exclusive measurement can be performed by a simultaneous measurement of the missing mass using the primary neutron and the invariant mass via the expected decay, K− pp → Λp → pπ− p. In this report, an overview of the experiment and the preparation status are presented.
Turbulence anisotropy and coherent structures in electromagnetically generated vortex patterns
International Nuclear Information System (INIS)
Kenjereš, S
2011-01-01
Numerical investigations addressing influence of the localised electromagnetic forcing on turbulent thermal convection of a weakly electrically conductive fluid in a wall-bounded rectangular enclosure are performed over a wide range of working parameters (10 4 ≤Ra≤5×10 5 , Pr = 7). An asymmetrical electromagnetic forcing (EMF) is applied originating from combined effects of the imposed magnetic fields (originating from an array of 5×7 permanent magnets with |b 0 | max = 1 T each, located beneath the lower thermally active wall) and electric fields (originating from two electrodes supplied with dc current of different intensities, 0≤I≤10 A). Subgrid turbulent stress is modelled by electromagnetically extended Smagorinsky model and subgrid turbulent heat flux is represented by a simple gradient diffusion hypothesis. Simulations revealed two interesting findings: the electromagnetic forcing generated significant overall heat transfer increase (more than 500% for lower values of Ra) compared to its neutral case, and, the turbulence anisotropy was reduced in the central part of the enclosure.
Lower Bounds on the Capacity of the Relay Channel with States at the Source
Directory of Open Access Journals (Sweden)
Abdellatif Zaidi
2009-01-01
Full Text Available We consider a state-dependent three-terminal full-duplex relay channel with the channel states noncausally available at only the source, that is, neither at the relay nor at the destination. This model has application to cooperation over certain wireless channels with asymmetric cognition capabilities and cognitive interference relay channels. We establish lower bounds on the channel capacity for both discrete memoryless (DM and Gaussian cases. For the DM case, the coding scheme for the lower bound uses techniques of rate-splitting at the source, decode-and-forward (DF relaying, and a Gel'fand-Pinsker-like binning scheme. In this coding scheme, the relay decodes only partially the information sent by the source. Due to the rate-splitting, this lower bound is better than the one obtained by assuming that the relay decodes all the information from the source, that is, full-DF. For the Gaussian case, we consider channel models in which each of the relay node and the destination node experiences on its link an additive Gaussian outside interference. We first focus on the case in which the links to the relay and to the destination are corrupted by the same interference; and then we focus on the case of independent interferences. We also discuss a model with correlated interferences. For each of the first two models, we establish a lower bound on the channel capacity. The coding schemes for the lower bounds use techniques of dirty paper coding or carbon copying onto dirty paper, interference reduction at the source and decode-and-forward relaying. The results reveal that, by opposition to carbon copying onto dirty paper and its root Costa's initial dirty paper coding (DPC, it may be beneficial in our setup that the informed source uses a part of its power to partially cancel the effect of the interference so that the uninformed relay benefits from this cancellation, and so the source benefits in turn.
Electron-electron bound states in parity-preserving QED{sub 3}
Energy Technology Data Exchange (ETDEWEB)
Belich, H.; Helayel-Neto, J.A. [Universidade Catolica do Petropolis, RJ (Brazil). Grupo de Fisica Teorica]|[Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Teoria de Campos e Particulas; Cima, O.M. del [Universidade Catolica do Petropolis, RJ (Brazil). Grupo de Fisica Teorica; Ferreira Junior, M.M. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Teoria de Campos e Particulas]|[Maranhao Univ., Sao Luis, MA (Brazil). Dept. de Fisica
2002-04-01
By considering the Higgs mechanism in the framework of a parity-preserving Planar Quantum Electrodynamics, one shows that an attractive electron-electron interaction may dominate. The e{sup -}e{sup -} interaction potential emerges as the non-relativistic limit of the Moeller scattering amplitude and it results attractive with a suitable choice of parameters. Numerically values of the e{sup -}e{sup -} binding energy are obtained by solving the two-dimensional Schroedinger equation. The existence of bound states is a strong indicative that this model may be adopted to address the pairing mechanism of high-T{sub c} superconductivity. (author)
Nonlinear surface electromagnetic phenomena
Ponath, H-E
1991-01-01
In recent years the physics of electromagnetic surface phenomena has developed rapidly, evolving into technologies for communications and industry, such as fiber and integrated optics. The variety of phenomena based on electromagnetism at surfaces is rich and this book was written with the aim of summarizing the available knowledge in selected areas of the field. The book contains reviews written by solid state and optical physicists on the nonlinear interaction of electromagnetic waves at and with surfaces and films. Both the physical phenomena and some potential applications are
International Nuclear Information System (INIS)
Logrado, P.G.; Vianna, J.D.M.
Upper and lower bounds for the energy eigenvalues is Schoenberg's perturbation-theory ground state are studied. After a review of the characteristic features of the partitioning techniques the perturbative expansion proposed by Schoenberg is generated from an exact operator equation. The upper and lower bounds for the ground state eigenvalue are derived by using reaction and wave operators concepts, the bracketing function and operator inequalities. (Author) [pt
Observations of bound and unbound states of Ce−
International Nuclear Information System (INIS)
Walter, C W; Li, Y-G; Matyas, D J; Alton, R M; Lou, S E; III, R L Field; Gibson, N D; Hanstorp, D
2012-01-01
The negative ion of cerium has been investigated with tunable infrared laser photodetachment spectroscopy over selected photon energy ranges between 0.56 − 0.70 eV. The spectrum reveals several sharp peaks due to negative ion resonances and possible bound-bound transitions in Ce − . The newly observed transitions, together with our previous measurements, provide insight into the rich near-threshold spectrum of this lanthanide negative ion.
Influence of gravitation on the propagation of electromagnetic radiation
Mashhoon, B.
1975-01-01
The existence of a general helicity-rotation coupling is demonstrated for electromagnetic waves propagating in the field of a slowly rotating body and in the Goedel universe. This coupling leads to differential focusing of circularly polarized radiation by a gravitational field which is detectable for a rapidly rotating collapsed body. The electromagnetic perturbations and their frequency spectrum are given for the Goedel universe. The spectrum of frequencies is bounded from below by the characteristic rotation frequency of the Goedel universe. If the universe were rotating, the differential focusing effect would be extremely small due to the present upper limit on the anisotropy of the microwave background radiation.
Three-photon laser spectroscopy of even-parity bound states of samarium atom
International Nuclear Information System (INIS)
Gomonaj, O.Yi.; Kudelich, O.Yi.
2002-01-01
The energy spectrum of highly-excited even-parity bound states of a Sm atom, lying in the energy range 34421.1 - 36031.8 cm -1 , is investigated using three-photon resonance-ionization spectroscopy. The energies and total momenta of 48 levels are determined. Eight new levels not observed before are discovered. Thirteen intense two-photon transitions, which can be used in the schemes of Sm atom effective photoionization, are observed
The electromagnetic dark sector
International Nuclear Information System (INIS)
Jimenez, Jose Beltran; Maroto, Antonio L.
2010-01-01
We consider electromagnetic field quantization in an expanding universe. We find that the covariant (Gupta-Bleuler) method exhibits certain difficulties when trying to impose the quantum Lorenz condition on cosmological scales. We thus explore the possibility of consistently quantizing without imposing such a condition. In this case there are three physical states, which are the two transverse polarizations of the massless photon and a new massless scalar mode coming from the temporal and longitudinal components of the electromagnetic field. An explicit example in de Sitter space-time shows that it is still possible to eliminate the negative norm state and to ensure the positivity of the energy in this theory. The new state is decoupled from the conserved electromagnetic currents, but is non-conformally coupled to gravity and therefore can be excited from vacuum fluctuations by the expanding background. The cosmological evolution ensures that the new state modifies Maxwell's equations in a totally negligible way on sub-Hubble scales. However, on cosmological scales it can give rise to a non-negligible energy density which could explain in a natural way the present phase of accelerated expansion of the universe.
Nucleon Viewed as a Borromean Bound-State
Segovia, Jorge; Mezrag, Cédric; Chang, Lei; Roberts, Craig D.
2018-05-01
We explain how the emergent phenomenon of dynamical chiral symmetry breaking ensures that Poincaré covariant analyses of the three valence-quark scattering problem in continuum quantum field theory yield a picture of the nucleon as a Borromean bound-state, in which binding arises primarily through the sum of two separate contributions. One involves aspects of the non-Abelian character of Quantum Chromodynamics that are expressed in the strong running coupling and generate tight, dynamical color-antitriplet quark-quark correlations in the scalar-isoscalar and pseudovector-isotriplet channels. This attraction is magnified by quark exchange associated with diquark breakup and reformation, which is required in order to ensure that each valence-quark participates in all diquark correlations to the complete extent allowed by its quantum numbers. Combining these effects, we arrive at a properly antisymmetrised Faddeev wave function for the nucleon and calculate, e.g. the flavor-separated versions of the Dirac and Pauli form factors and the proton's leading-twist parton distribution amplitude. We conclude that available data and planned experiments are capable of validating the proposed picture.
Semi-inclusive B->K(K*)X decays with initial bound state effects
International Nuclear Information System (INIS)
He, Xiao-Gang; Jin, Changhao; Ma, J. P.
2001-01-01
The effects of the initial b quark bound state for the semi-inclusive decays B->K(K * )X are studied using light cone expansion and heavy quark effective theory methods. We find that the initial bound state effects on the branching ratios and CP asymmetries are small. In the light cone expansion approach, the CP-averaged branching ratios are increased by about 2% with respect to the free b-quark decay. For {bar B} 0 ->K - (K *- )X, the CP-averaged branching ratios are sensitive to the phase γ and the CP asymmetry can be as large as 7% (14%), whereas for B - ->{bar K} 0 ({bar K} *0 )X the CP-averaged branching ratios are not sensitive to γ and the CP asymmetries are small ( -4 [(0.25 - 2.0)x10 -4 ] for {bar B} 0 ->K - (K *- )X and (0.77 - 0.84)x10 -4 [(0.67 - 0.74)x10 -4 ] for B - ->{bar K} 0 ({bar K} *0 )X, depending on the value of the CP violating phase γ. In the heavy quark effective theory approach, we find that the branching ratios are decreased by about 10% and the CP asymmetries are not affected. These predictions can be tested in the near future
Bound entanglement and local realism
International Nuclear Information System (INIS)
Kaszlikowski, Dagomir; Zukowski, Marek; Gnacinski, Piotr
2002-01-01
We show using a numerical approach, which gives necessary and sufficient conditions for the existence of local realism, that the bound entangled state presented in Bennett et al. [Phys. Rev. Lett. 82, 5385 (1999)] admits a local and realistic description. We also find the lowest possible amount of some appropriate entangled state that must be ad-mixed to the bound entangled state so that the resulting density operator has no local and realistic description and as such can be useful in quantum communication and quantum computation
International Nuclear Information System (INIS)
Soldatov, A.; Seke, J.; Adam, G.; Polak, M.
2008-01-01
Full text: A closed analytic form for relativistic transition matrix elements between bound-bound, bound-unbound and unbound-unbound relativistic eigenstates of hydrogenic atoms by using the plane-wave expansion for the electromagnetic-field vector potential was derived in a form convenient for large-scale numerical calculations in QED. By applying the obtained formulae, these transition matrix elements can be evaluated analytically and numerically. These exact matrix elements, which to our knowledge have not been calculated as yet, are of great importance in the analysis of various atom-field interaction processes where retardation effects cannot be ignored. The ultimate goal of the ongoing research is to develop a general universal calculation technique for Seke's approximation and renormalization method in QED, for which the usage of the plane vector expansion for the vector potential is a preferable choice. However, our primary interest lies in the Lamb-shift calculation. Our nearest objective is to carry out the plain-style relativistic calculations of the Lamb shift of the energy levels of hydrogen-like atoms and ions from first principles in the second and higher perturbative orders, using the corresponding convenient as well as novel expressions for the magnitude in question as they stand, i.e. without any additional approximations. Due to that there is no way to achieve all the above-declared goals without recourse to large-scale laborious and time-consuming high-precision numerical calculations, having the transition matrix elements of all possible types in an analytic, convenient for their efficient numerical evaluation form, would be highly advantageous and even unavoidable, especially for calculations of various QED effects in higher perturbative orders be it, equally, in traditional or novel approach. (author)
Bound states of water in gelatin discriminated by near-infrared spectroscopy
Otsuka, Yukiko; Shirakashi, Ryo; Hirakawa, Kazuhiko
2017-11-01
By near-infrared spectroscopy, we classified water molecules in hydrated gelatin membranes in a drying process. Absorbance spectra in the frequency range of 4500-5500 cm-1 were resolved into three peaks, S0, S1, and S2, that correspond to water molecules with different hydrogen bond states. From the areas of the absorbance peaks as a function of the water content of gelatin, together with the information on the freezing properties of water measured by differential scanning calorimetry, we found that, when the water content is less than 20%, free water disappears and only weakly and strongly bound waters remain. We also found that the weakly bound water consists of S0, S1, and S2 water molecules with a simple composition of \\text{S}0:\\text{S}1:\\text{S}2 ≈ 1:2:0. Using this information, most of the freezable water was determined to be free water. Our classification provides a simple method of estimating the retention and freezing properties of processed foods or drugs by infrared spectroscopy.
Nuclear research with electromagnetic probe. Progress report
International Nuclear Information System (INIS)
1990-01-01
The electromagnetic probe is used to address some of the forefront questions in nuclear physics. Two questions are of special interest in this project, one is related to the electromagnetic properties of the nucleon in the nuclear medium, the other concerns the transition between nucleons-mesons and quarks-gluons degrees of freedom when describing nuclei at medium energies. The electromagnetic properties of free protons have been extensively studied and are used as basic input to describe any of the electric or magnetic properties of nuclei. However, inclusive and semi-exclusive experiments measurements in the quasielastic and the deep inelastic region seem to indicate that the properties of bound nucleons are modified significantly in the nuclear medium. It is therefore of first importance to understand how the free properties of nucleons are modified in order to have a realistic description of nuclei. It was suggested, for example, that nucleons are swollen in nuclei. The physical consequences of such an idea are of great impact on the description of nuclei
Large impedances and Majorana bound states in superconducting circuits
International Nuclear Information System (INIS)
Ulrich, Jascha
2017-01-01
Superconducting circuits offer the opportunity to study quantum mechanics on mesoscopic scales unimpeded by dissipation. This fact and the nonlinearity of the Josephson inductance make it possible to use superconducting circuits as artificial atoms whose long-lived states can be selectively addressed and studied. A pronounced nonlinearity of the energy spectrum, however, requires quantum fluctuations of the flux across the Josephson junction which are large on the scale of the superconducting flux quantum Φ Q =h/2e. This implies charge fluctuations below the single Cooper-pair limit via flux-charge duality. The localization of charge leads to a strong susceptibility to interactions with charges in the environment which has motivated the search for schemes to decouple charges from their environment. This thesis is concerned with theoretical challenges arising from two complementary approaches to this problem: the realization of large impedances and the fractionalization of electrons by means of Majorana bound states. In recent years, the decoupling of charges from the environment through reactive large impedances, so-called ''superinductances'' L, has attracted much interest. These inductances feature small parasitic capacitance C such that the characteristic impedance √(L/C) is much larger than the superconducting resistance quantum R Q =h/4e 2 . Superinductances have various applications ranging from qubit designs such as the 0-π qubit or the fluxonium to impedance matching, Bloch oscillations and the stabilization of phase slips in superconducting nanowires. Although there exists a well-established formalism for the quantization of superconducting circuits in terms of node fluxes, this formalism is ill-suited for the description of fast flux transport with localized charges in large-impedance environments. In particular, the nonlinear capacitive behavior of phase slip junctions cannot be modeled in a straightforward way using node fluxes
Bounding approaches to system identification
Norton, John; Piet-Lahanier, Hélène; Walter, Éric
1996-01-01
In response to the growing interest in bounding error approaches, the editors of this volume offer the first collection of papers to describe advances in techniques and applications of bounding of the parameters, or state variables, of uncertain dynamical systems. Contributors explore the application of the bounding approach as an alternative to the probabilistic analysis of such systems, relating its importance to robust control-system design.
Orthogonality-condition model for bound states with a separable expansion of the potential
International Nuclear Information System (INIS)
Pal, K.F.
1984-01-01
A very efficient solution of the equation of Saito's orthogonality-condition model (OCM) is reported for bound states by means of a separable expansion of the potential (PSE method). Some simplifications of the published formulae of the PSE method is derived, which facilitate its application to the OCM and may be useful in solving the Schroedinger equation as well. (author)
Quantum localization and bound-state formation in Bose-Einstein condensates
International Nuclear Information System (INIS)
Franzosi, Roberto; Giampaolo, Salvatore M.; Illuminati, Fabrizio
2010-01-01
We discuss the possibility of exponential quantum localization in systems of ultracold bosonic atoms with repulsive interactions in open optical lattices without disorder. We show that exponential localization occurs in the maximally excited state of the lowest energy band. We establish the conditions under which the presence of the upper energy bands can be neglected, determine the successive stages and the quantum phase boundaries at which localization occurs, and discuss schemes to detect it experimentally by visibility measurements. The discussed mechanism is a particular type of quantum localization that is intuitively understood in terms of the interplay between nonlinearity and a bounded energy spectrum.
Measuring and slowing decoherence in Electromagnetically induced transparency medium
International Nuclear Information System (INIS)
Shuker, M.; Firstenberg, O.; Sagi, Y.; Ben-Kish, A.; Fisher, A.; Ron, A.; Davidson, N.
2005-01-01
Full Text:Electromagnetically induced transparency is a unique light-matter interaction that exhibits extremely narrow-band spectroscopic features along with low absorption. Recent interest in this phenomenon is driven by its possible applications in quantum information (slow light, storage of light), atomic clocks and precise magnetometers. The Electromagnetically induced transparency phenomenon takes place when an atomic ensemble is driven to a coherent superposition of its ground state sub-levels by two phase-coherent radiation fields. A key parameter of the Electromagnetically induced transparency medium, that limits its applicability, is the coherence lifetime of this superposition (decoherence rate). We have developed a simple technique to measure decay rates within the ground state of an atomic ensemble, and specifically the decoherence rate of the Electromagnetically induced transparency coherent superposition. Detailed measurements were performed in a Rubidium vapor cell at 60 - 80 with 30 Torr of Neon buffer gas. We have found that the Electromagnetically induced transparency decoherence is dominated by spin-exchange collisions between Rubidium atoms. We discuss the sensitivity of various quantum states of the atomic ensemble to spin exchange decoherence, and find a set of quantum states that minimize this effect. Finally, we demonstrate a unique quantum state which is both insensitive to spin exchange decoherence and constitutes an Electromagnetically induced transparency state of the medium
DEFF Research Database (Denmark)
Naqvi, Mohsin M; Heiðarsson, Pétur Orri; Otazo, Mariela R
2015-01-01
, at least transiently, at resting Ca(2+) conditions. Here, we used optical tweezers to study the folding behavior of individual NCS-1 molecules in the presence of Mg(2+) and in the absence of divalent ions. Under tension, the Mg(2+)-bound state of NCS-1 unfolds and refolds in a three-state process...... in a variety of cellular processes in which it has been linked to a number of disorders such as schizophrenia and autism. Despite extensive studies on the Ca(2+)-activated state of NCS proteins, little is known about the conformational dynamics of the Mg(2+)-bound and apo states, both of which are populated...... by populating one intermediate state consisting of a folded C-domain and an unfolded N-domain. The interconversion at equilibrium between the different molecular states populated by NCS-1 was monitored in real time through constant-force measurements and the energy landscapes underlying the observed transitions...
Simple functional-differential equations for the bound-state wave-function components
International Nuclear Information System (INIS)
Kamuntavicius, G.P.
1986-01-01
The author presents a new method of a direct derivation of differential equations for the wave-function components of identical-particles systems. The method generates in a simple manner all the possible variants of these equations. In some cases they are the differential equations of Faddeev or Yakubovskii. It is shown that the case of the bound states allows to formulate very simple equations for the components which are equivalent to the Schroedinger equation for the complete wave function. The components with a minimal antisymmetry are defined and the corresponding equations are derived. (Auth.)
Measurement of the electromagnetic lifetimes of the first four excited states of /sup 192/Pt
Energy Technology Data Exchange (ETDEWEB)
Butt, D K; Raoof, M A; Raoof, S A [Birkbeck Coll., London (UK)
1976-11-01
Measurements of the electromagnetic lifetimes of the first four excited states of /sup 192/Pt have been made by the self-comparison method using electron-electron coincidences. The partial lifetimes of the gamma transitions involved have been interpreted in terms of the pairing-plus-quadrupole model of Kumar and Baranger.
Meson-meson bound state in a 2+1 lattice QCD model with two flavors and strong coupling
International Nuclear Information System (INIS)
Faria da Veiga, Paulo A.; O'Carroll, Michael; Neto, Antonio Francisco
2005-01-01
We consider the existence of bound states of two mesons in an imaginary-time formulation of lattice QCD. We analyze an SU(3) theory with two flavors in 2+1 dimensions and two-dimensional spin matrices. For a small hopping parameter and a sufficiently large glueball mass, as a preliminary, we show the existence of isoscalar and isovector mesonlike particles that have isolated dispersion curves (upper gap up to near the two-particle threshold ∼-4lnκ). The corresponding meson masses are equal up to and including O(κ 3 ) and are asymptotically of order -2lnκ-κ 2 . Considering the zero total isospin sector, we show that there is a meson-meson bound state solution to the Bethe-Salpeter equation in a ladder approximation, below the two-meson threshold, and with binding energy of order bκ 2 ≅0.02359κ 2 . In the context of the strong coupling expansion in κ, we show that there are two sources of meson-meson attraction. One comes from a quark-antiquark exchange. This is not a meson exchange, as the spin indices are not those of the meson particle, and we refer to this as a quasimeson exchange. The other arises from gauge field correlations of four overlapping bonds, two positively oriented and two of opposite orientation. Although the exchange part gives rise to a space range-one attractive potential, the main mechanism for the formation of the bound state comes from the gauge contribution. In our lattice Bethe-Salpeter equation approach, this mechanism is manifested by an attractive distance-zero energy-dependent potential. We recall that no bound state appeared in the one-flavor case, where the repulsive effect of Pauli exclusion is stronger
Possibility of a 4He2 bound state, effective range theory, and very low energy He--He scattering
International Nuclear Information System (INIS)
Uang, Y.; Stwalley, W.C.
1982-01-01
The best available intermolecular potential for helium by Aziz, Nain, Carley, Taylor, and McConville is shown here for the first time to have a 4 He 2 bound state. Two numerical analyses, namely, eigenvalue solution and effective range theory, are used to support this conclusion. Unlike usual chemically bound species, the binding energy of this very weakly bound level is found to be only 8.3 x 10 -4 K, which is four orders of magnitude smaller than the potential well depth epsilon = 10.8 K. The scattering length for He+He collisions, determined from effective range theory, is used to calculate the elastic cross section in the very low energy limit. The results (1.878 x 10 5 A 2 for 4 He+ 4 He and 6.035 x 10 2 A for 3 He+ 3 He) are consistent with measurements at the lowest velocities yet attained. In terms of the estimated uncertainties of the parameters of the potential of Aziz and co-workers, it is shown that it is very likely that a bound state of the 4 He 2 molecule does in fact exist
Gauge-invariant, nonperturbative approach to the infrared-finite bound-state problem in QCD
International Nuclear Information System (INIS)
Gogokhia, V.Sh.
1989-09-01
Gauge invariant, nonperturbative approach to the bound state problem within the infrared finite Bethe-Salpeter equation is presented. Condition of cancellation of the nonperturbative infrared divergences is derived. Solutions for the quark propagator and corresponding quark gluon vertex function are written down which can be directly applied to the Bethe-Salpeter equation, in particular to the 'generalized ladder' approximation of this equation. (author) 18 refs.; 3 figs
Variational energy for Θ+ - 2H bound state
International Nuclear Information System (INIS)
Shoeb, Mohammad; Naz, Tabassum; Siddiqah, Mariyah
2015-01-01
Pentaquark is considered to be a exotic particle with valency structure of four quarks and antiquark. Diakonov et. al. have made a prediction for the existence of strangeness S= +1 and isospin zero pentaquark Θ + (uudds¯) of mass 1.54 GeV with a narrow width and j p = 1/2 + which is a member of an antidecuplet. Small width is assumed to be a consequence of even parity. We may point out that many experimental searches for the existence of Θ + that have been made in the past have remained inconclusive. Miller has proposed a schematic model where coherent interaction of us¯ and ds¯ pairs leads to very large attractive residual interaction which in turn produces a strongly attractive Θ-nucleon spin-independent local potential, sufficient to produce a bound state of Θ-nuclear matter that is stable against strong decay. In the model under discussion the Θ has been regarded as a collective vibration of nucleon
Full-potential multiple scattering theory with space-filling cells for bound and continuum states.
Hatada, Keisuke; Hayakawa, Kuniko; Benfatto, Maurizio; Natoli, Calogero R
2010-05-12
We present a rigorous derivation of a real-space full-potential multiple scattering theory (FP-MST) that is free from the drawbacks that up to now have impaired its development (in particular the need to expand cell shape functions in spherical harmonics and rectangular matrices), valid both for continuum and bound states, under conditions for space partitioning that are not excessively restrictive and easily implemented. In this connection we give a new scheme to generate local basis functions for the truncated potential cells that is simple, fast, efficient, valid for any shape of the cell and reduces to the minimum the number of spherical harmonics in the expansion of the scattering wavefunction. The method also avoids the need for saturating 'internal sums' due to the re-expansion of the spherical Hankel functions around another point in space (usually another cell center). Thus this approach provides a straightforward extension of MST in the muffin-tin (MT) approximation, with only one truncation parameter given by the classical relation l(max) = kR(b), where k is the electron wavevector (either in the excited or ground state of the system under consideration) and R(b) is the radius of the bounding sphere of the scattering cell. Moreover, the scattering path operator of the theory can be found in terms of an absolutely convergent procedure in the l(max) --> ∞ limit. Consequently, this feature provides a firm ground for the use of FP-MST as a viable method for electronic structure calculations and makes possible the computation of x-ray spectroscopies, notably photo-electron diffraction, absorption and anomalous scattering among others, with the ease and versatility of the corresponding MT theory. Some numerical applications of the theory are presented, both for continuum and bound states.
On the spontaneous emission of electromagnetic radiation in the CSL model
International Nuclear Information System (INIS)
Donadi, Sandro; Deckert, Dirk-André; Bassi, Angelo
2014-01-01
Spontaneous photon emission in the Continuous Spontaneous Localization (CSL) model is studied one more time. In the CSL model each particle interacts with a noise field that induces the collapse of its wave function. As a consequence of this interaction, when the particle is electrically charged, it radiates. As discussed in Adler (2013) the formula for the emission rate, to first perturbative order, contains two terms: one is proportional to the Fourier component of the noise field at the same frequency as that of the emitted photon and one is proportional to the zero Fourier component of the noise field. As discussed in previous works, this second term seems unphysical. In Adler (2013) it was shown that the unphysical term disappears when the noise is confined to a bounded region and the final particle’s state is a wave packet. Here we investigate the origin of this unphysical term and why it vanishes according to the previous prescription. We will see that perturbation theory is formally not valid in the large time limit since the effect of the noise accumulates continuously in time. Therefore either one performs an exact calculation (or at least in some way includes higher order terms) as we do here, or one finds a way to make a perturbative calculation meaningful, e.g., by confining the system as in Adler (2013). -- Highlights: •We compute the electromagnetic radiation emission in collapse models. •Under only the dipole approximation, the equations of motion are solved exactly. •The electromagnetic interaction must be treated exactly. •In order to obtain the correct emission rate the particle must be bounded
International Nuclear Information System (INIS)
Stadler, A.; Gibson, B.F.
1994-01-01
Motivated by the Σ-hypernuclear states reported in (K - ,π ± ) experiments, we have explored the possibility that there exists a particle-stable Σ - nn bound state. For the Juelich A hyperon-nucleon, realistic-force model, our calculations yield little reason to expect a positive-parity bound state or resonance in either the J=1/2 or the J=3/2 channels
Multiple-Pulse Operation and Bound States of Solitons in Passive Mode-Locked Fiber Lasers
Directory of Open Access Journals (Sweden)
A. Komarov
2012-01-01
Full Text Available We present results of our research on a multiple-pulse operation of passive mode-locked fiber lasers. The research has been performed on basis of numerical simulation. Multihysteresis dependence of both an intracavity energy and peak intensities of intracavity ultrashort pulses on pump power is found. It is shown that the change of a number of ultrashort pulses in a laser cavity can be realized by hard as well as soft regimes of an excitation and an annihilation of new solitons. Bound steady states of interacting solitons are studied for various mechanisms of nonlinear losses shaping ultrashort pulses. Possibility of coding of information on basis of soliton trains with various bonds between neighboring pulses is discussed. The role of dispersive wave emitted by solitons because of lumped intracavity elements in a formation of powerful soliton wings is analyzed. It is found that such powerful wings result in large bounding energies of interacting solitons in steady states. Various problems of a soliton interaction in passive mode-locked fiber lasers are discussed.
International Nuclear Information System (INIS)
Levin, F.S.; Krueger, H.
1977-01-01
We propose in this article that the non-Hermitian equations typical of some many-body scattering theories be used to help solve many-body bound-state problems. The basic idea is to exploit the channel nature of many-body bound states that must exist because bound states are obvious negative-energy extensions of scattering states. Since atomic, molecular, and nuclear systems all display multichannel effects for E > 0, at least through Pauli-principle effects if not through mass-transfer reactions, this use of positive-energy methods for solving bound-state problems could have wide applicability. The development used here is based on the channel-component-state method of the channel-coupling-array theory, recently described in detail for the E > 0 case, and various aspects of the formalism are discussed. Detailed calculations using simple approximations are discussed for H 2 + , one of the simplest systems displaying channel structure. Comparison with the exact, Born-Oppenheimer results of Wind show that the non-Hermitian-equation, channel-component values of the equilibrium separation and total binding energy are accurate to within 2%, while the dissociation energy is accurate to 10%. The resulting wave function is identical to that arising from the simplest MO calculation, for which these numbers are less accurate than the preceding by at least a factor of 3. We also show that identical particle symmetry for the H 2 + case reduces the pair of coupled (two-channel) equations to a single equation with an exchange term. Similar reductions will occur for larger numbers of identical particles, thus suggesting application of the formalism to atomic structure problems. A detailed analysis of the present numerical results, their general implications, and possible applications is also given
Search for quasi bound η mesons
International Nuclear Information System (INIS)
Machner, H
2015-01-01
The search for a quasi bound η meson in atomic nuclei is reviewed. This tentative state is studied theoretically as well as experimentally. The theory starts from elastic η nucleon scattering which is derived from production data within some models. From this interaction the η nucleus interaction is derived. Model calculations predict binding energies and widths of the quasi bound state. Another method is to derive the η nucleus interaction from excitation functions of η production experiments. The s wave interaction is extracted from such data via final state interaction (FSI) theorem. We give the derivation of s wave amplitudes in partial wave expansion and in helicity amplitudes and their relation to observables. Different experiments extracting the FSI are discussed as are production experiments. So far only three experiments give evidence for the existence of the quasi bound state: a pion double charge exchange experiment, an effective mass measurement, and a transfer reaction at recoil free kinematics with observation of the decay of the state. (topical review)
Electromagnetic wave analogue of electronic diode
Shadrivov, Ilya V.; Powell, David A.; Kivshar, Yuri S.; Fedotov, Vassili A.; Zheludev, Nikolay I.
2010-01-01
An electronic diode is a nonlinear semiconductor circuit component that allows conduction of electrical current in one direction only. A component with similar functionality for electromagnetic waves, an electromagnetic isolator, is based on the Faraday effect of the polarization state rotation and is also a key component of optical and microwave systems. Here we demonstrate a chiral electromagnetic diode, which is a direct analogue of an electronic diode: its functionality is underpinned by ...
Two-dimensional electron states bound to an off-plane donor in a magnetic field
International Nuclear Information System (INIS)
Bruno-Alfonso, A; Candido, L; Hai, G-Q
2010-01-01
The states of an electron confined in a two-dimensional (2D) plane and bound to an off-plane donor impurity center, in the presence of a magnetic field, are investigated. The energy levels of the ground state and the first three excited states are calculated variationally. The binding energy and the mean orbital radius of these states are obtained as a function of the donor center position and the magnetic field strength. The limiting cases are discussed for an in-plane donor impurity (i.e. a 2D hydrogen atom) as well as for the donor center far away from the 2D plane in strong magnetic fields, which corresponds to a 2D harmonic oscillator.
Bound states of the Dirac equation with some physical potentials by the Nikiforov-Uvarov method
Energy Technology Data Exchange (ETDEWEB)
Setare, Mohammad R; Haidari, S [Department of Physics, University of Kurdistan, Pasdaran Avenue, Sanandaj (Iran, Islamic Republic of)], E-mail: rezakord@ipm.ir, E-mail: heidary.somayeh@gmail.com
2010-01-15
Exact analytical solutions for the s-wave Dirac equation with the reflectionless-type, Rosen-Morse and Manning-Rosen potentials are obtained, under the condition of spin symmetry. We obtained bound state energy eigenvalues and corresponding spinor wave function in the framework of the Nikiforov-Uvarov (NU) method.
International Nuclear Information System (INIS)
Shen Yong; Yang Jian; Guo Hong
2009-01-01
Security of a continuous-variable quantum key distribution protocol based on noisy coherent states and channel is analysed. Assuming that the noise of coherent states is induced by Fred, a neutral party relative to others, we prove that the prepare-and-measurement scheme (P and M) and entanglement-based scheme (E-B) are equivalent. Then, we show that this protocol is secure against Gaussian collective attacks even if the channel is lossy and noisy, and, further, a lower bound to the secure key rate is derived.
Energy Technology Data Exchange (ETDEWEB)
Shen Yong; Yang Jian; Guo Hong, E-mail: hongguo@pku.edu.c [CREAM Group, State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) and Institute of Quantum Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China)
2009-12-14
Security of a continuous-variable quantum key distribution protocol based on noisy coherent states and channel is analysed. Assuming that the noise of coherent states is induced by Fred, a neutral party relative to others, we prove that the prepare-and-measurement scheme (P and M) and entanglement-based scheme (E-B) are equivalent. Then, we show that this protocol is secure against Gaussian collective attacks even if the channel is lossy and noisy, and, further, a lower bound to the secure key rate is derived.
Meson-nucleus potentials and the search for meson-nucleus bound states
Metag, V.; Nanova, M.; Paryev, E. Ya.
2017-11-01
Recent experiments studying the meson-nucleus interaction to extract meson-nucleus potentials are reviewed. The real part of the potentials quantifies whether the interaction is attractive or repulsive while the imaginary part describes the meson absorption in nuclei. The review is focused on mesons which are sufficiently long-lived to potentially form meson-nucleus quasi-bound states. The presentation is confined to meson production off nuclei in photon-, pion-, proton-, and light-ion induced reactions and heavy-ion collisions at energies near the production threshold. Tools to extract the potential parameters are presented. In most cases, the real part of the potential is determined by comparing measured meson momentum distributions or excitation functions with collision model or transport model calculations. The imaginary part is extracted from transparency ratio measurements. Results on K+ ,K0 ,K- , η ,η‧ , ω, and ϕ mesons are presented and compared with theoretical predictions. The interaction of K+ and K0 mesons with nuclei is found to be weakly repulsive, while the K- , η ,η‧ , ω and ϕ meson-nucleus potentials are attractive, however, with widely different strengths. Because of meson absorption in the nuclear medium the imaginary parts of the meson-nucleus potentials are all negative, again with a large spread. An outlook on planned experiments in the charm sector is given. In view of the determined potential parameters, the criteria and chances for experimentally observing meson-nucleus quasi-bound states are discussed. The most promising candidates appear to be the η and η‧ mesons.
The number of bound states for a discrete Schroedinger operator on ZN, N≥1, lattices
International Nuclear Information System (INIS)
Karachalios, N I
2008-01-01
We consider the discrete Schroedinger operator -Δ d +U in Z N , N≥1 in the case of a potential with negative part in an appropriate l σ -space (decays with an appropriate rate). We present a discrete analog of the method of Li and Yau (1983 Commun. Math. Phys. 88 309-18), proving an explicit upper estimate on the number of bound states N d (0)={j:μ j ≤0}, which is independent of the dimension of the lattice. This is a major difference with the continuous counterpart estimate, which is not valid when N = 1, 2. As a consequence, a dimension-independent smallness criterion for the existence of bound states is derived in contrast to the continuous case as well as to the discrete case of vanishing potential. A short comment is made on possible applications of the results to the study of the dynamics of some particular spatially discrete nonlinear systems
International Nuclear Information System (INIS)
Araujo Junior, C.F. de; Adhikari, S.K.; Tomio, L.
1993-10-01
Complex Kohn variational principle is applied to the numerical solution of the fully off-shell Lippmann-Schwinger equation for nucleon-nucleon scattering for various partial waves including the coupled 3 S 1 - 3 D 1 channel. Analytic expressions are obtained for all the integrals in the method for a suitable choice of expansion functions. Calculations with the partial waves 1 S 0 , 1 P 1 , 1 D 2 , and 3 S 1 - 3 D 1 of the Reid soft core potential show that the method converges faster than other solution schemes not only for the phase shift but also for the off-shell t matrix elements. It is also shown that its is trivial to modify this variational principle in order to make it suitable for bound-stage calculations. The bound-state approach is illustrated for the 3 S 1 - 3 D 1 channel of the Reid soft-core potential for calculating the deuteron binding, wave function and the D state asymptotic parameters. (author)
Probing the Dark Sector with Dark Matter Bound States.
An, Haipeng; Echenard, Bertrand; Pospelov, Maxim; Zhang, Yue
2016-04-15
A model of the dark sector where O(few GeV) mass dark matter particles χ couple to a lighter dark force mediator V, m_{V}≪m_{χ}, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic halos. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of χ, such as 0^{-+} and 1^{--} states, η_{D} and ϒ_{D}, is an important search channel. We show that e^{+}e^{-}→η_{D}+V or ϒ_{D}+γ production at B factories for α_{D}>0.1 is sufficiently strong to result in multiple pairs of charged leptons and pions via η_{D}→2V→2(l^{+}l^{-}) and ϒ_{D}→3V→3(l^{+}l^{-}) (l=e,μ,π). The absence of such final states in the existing searches performed at BABAR and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, e^{+}e^{-}→χχ[over ¯]+nV, resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter.
Computation of Quantum Bound States on a Singly Punctured Two-Torus
International Nuclear Information System (INIS)
Kar-Tim Chan; Zainuddin Hishamuddin; Molladavoudi Saeid
2013-01-01
We study a quantum mechanical system on a singly punctured two-torus with bound states described by the Maass waveforms which are eigenfunctions of the hyperbolic Laplace—Beltrami operator. Since the discrete eigenvalues of the Maass cusp form are not known analytically, they are solved numerically using an adapted algorithm of Hejhal and Then to compute Maass cusp forms on the punctured two-torus. We report on the computational results of the lower lying eigenvalues for the punctured two-torus and find that they are doubly-degenerate. We also visualize the eigenstates of selected eigenvalues using GridMathematica
Andreev bound states probed in three-terminal quantum dots
Gramich, J.; Baumgartner, A.; Schönenberger, C.
2017-11-01
Andreev bound states (ABSs) are well-defined many-body quantum states that emerge from the hybridization of individual quantum dot (QD) states with a superconductor and exhibit very rich and fundamental phenomena. We demonstrate several electron transport phenomena mediated by ABSs that form on three-terminal carbon nanotube (CNT) QDs, with one superconducting (S) contact in the center and two adjacent normal-metal (N) contacts. Three-terminal spectroscopy allows us to identify the coupling to the N contacts as the origin of the Andreev resonance (AR) linewidths and to determine the critical coupling strengths to S, for which a ground state (or quantum phase) transition in such S-QD systems can occur. In addition, we ascribe replicas of the lowest-energy ABS resonance to transitions between the ABS and odd-parity excited QD states, a process we call excited state ABS resonances. In the conductance between the two N contacts we find a characteristic pattern of positive and negative differential subgap conductance, which we explain by considering two nonlocal processes, the creation of Cooper pairs in S by electrons from both N terminals, and a transport mechanism we call resonant ABS tunneling, possible only in multiterminal QD devices. In the latter process, electrons are transferred via the ABS without effectively creating Cooper pairs in S. The three-terminal geometry also allows spectroscopy experiments with different boundary conditions, for example by leaving S floating. Surprisingly, we find that, depending on the boundary conditions and the device parameters, the experiments either show single-particle Coulomb blockade resonances, ABS characteristics, or both in the same measurements, seemingly contradicting the notion of ABSs replacing the single-particle states as eigenstates of the QD. We qualitatively explain these results as originating from the finite time scale required for the coherent oscillations between the superposition states after a single
Backbone resonance assignments for G protein α(i3) subunit in the GDP-bound state.
Mase, Yoko; Yokogawa, Mariko; Osawa, Masanori; Shimada, Ichio
2014-10-01
Guanine-nucleotide binding proteins (G proteins) serve as molecular switches in signaling pathways, by coupling the activation of G protein-coupled receptors (GPCRs) at the cell surface to intracellular responses. In the resting state, G protein forms a heterotrimer, consisting of the G protein α subunit with GDP (Gα·GDP) and the G protein βγ subunit (Gβγ). Ligand binding to GPCRs promotes the GDP-GTP exchange on Gα, leading to the dissociation of the GTP-bound form of Gα (Gα·GTP) and Gβγ. Then, Gα·GTP and Gβγ bind to their downstream effector enzymes or ion channels and regulate their activities, leading to a variety of cellular responses. Finally, Gα hydrolyzes the bound GTP to GDP and returns to the resting state by re-associating with Gβγ. The G proteins are classified with four major families based on the amino acid sequences of Gα: i/o, s, q/11, and 12/13. Here, we established the backbone resonance assignments of human Gαi3, a member of the i/o family with a molecular weight of 41 K, in complex with GDP. The chemical shifts were compared with those of Gα(i3) in complex with a GTP-analogue, GTPγS, which we recently reported, indicating that the residues with significant chemical shift differences are mostly consistent with the regions with the structural differences between the GDP- and GTPγS-bound states, as indicated in the crystal structures. The assignments of Gα(i3)·GDP would be useful for the analyses of the dynamics of Gα(i3) and its interactions with various target molecules.
International Nuclear Information System (INIS)
Tyson, Jon
2009-01-01
Matrix monotonicity is used to obtain upper bounds on minimum-error distinguishability of arbitrary ensembles of mixed quantum states. This generalizes one direction of a two-sided bound recently obtained by the author [J. Tyson, J. Math. Phys. 50, 032106 (2009)]. It is shown that the previously obtained special case has unique properties.
Bounding species distribution models
Directory of Open Access Journals (Sweden)
Thomas J. STOHLGREN, Catherine S. JARNEVICH, Wayne E. ESAIAS,Jeffrey T. MORISETTE
2011-10-01
Full Text Available Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for “clamping” model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART and maximum entropy (Maxent models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5: 642–647, 2011].
Bounding Species Distribution Models
Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.
2011-01-01
Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].
Topologically protected states in one-dimensional systems
Fefferman, C L; Weinstein, M I
2017-01-01
The authors study a class of periodic Schrödinger operators, which in distinguished cases can be proved to have linear band-crossings or "Dirac points". They then show that the introduction of an "edge", via adiabatic modulation of these periodic potentials by a domain wall, results in the bifurcation of spatially localized "edge states". These bound states are associated with the topologically protected zero-energy mode of an asymptotic one-dimensional Dirac operator. The authors' model captures many aspects of the phenomenon of topologically protected edge states for two-dimensional bulk structures such as the honeycomb structure of graphene. The states the authors construct can be realized as highly robust TM-electromagnetic modes for a class of photonic waveguides with a phase-defect.
Mutual friction in superfluid 3He: Effects of bound states in the vortex core
International Nuclear Information System (INIS)
Kopnin, N.B.; Salomaa, M.M.
1991-01-01
The motion of singular quantized vortex lines in superfluid 3 He is considered for the A and B phases. Mutual friction is calculated within a microscopic quantum-mechanical Green's-function formalism, valid for dynamical processes. This enables us to include all the different physical phenomena in a unified approach. We consider axisymmetric vortices for temperatures considerably lower than T c . In this regime, the main contribution to the force exerted on a moving vortex originates from the localized Fermi excitations occupying quantized energy eigenstates in the vortex core. These 3 He quasiparticle states are similar to the quantized motion of charge in a magnetic field; thus vortex motion in 3 He resembles the Hall phenomenon in metals. The outcome is that the viscous drag cannot simply be expressed through the cross sections for 3 He quasiparticles scattering off the vortex, but is rather due to the mutual interactions between the localized quasiparticles and the normal excitations. Our calculations conform with the experimental values for the mutual-friction parameters. We also discuss vortex oscillations, and predict that strong dissipation should be observed at a resonant frequency of about 10 kHz, owing to transitions between the bound-state energy levels. This effect could be used for detecting and measuring the quantization of the bound-state spectrum for superfluid 3 He in the vortex-core matter
Two-magnon bound state causes ultrafast thermally induced magnetisation switching
Barker, J.; Atxitia, U.; Ostler, T. A.; Hovorka, O.; Chubykalo-Fesenko, O.; Chantrell, R. W.
2013-01-01
There has been much interest recently in the discovery of thermally induced magnetisation switching using femtosecond laser excitation, where a ferrimagnetic system can be switched deterministically without an applied magnetic field. Experimental results suggest that the reversal occurs due to intrinsic material properties, but so far the microscopic mechanism responsible for reversal has not been identified. Using computational and analytic methods we show that the switching is caused by the excitation of two-magnon bound states, the properties of which are dependent on material factors. This discovery allows us to accurately predict the onset of switching and the identification of this mechanism will allow new classes of materials to be identified or designed for memory devices in the THz regime. PMID:24253110
Detection of a π-μ coulomb bound states
International Nuclear Information System (INIS)
Coombes, R.; Flexer, R.; Hall, A.
1977-01-01
The detection of hydrogen-like atoms is reported consisting of a negative (or positive) pion and a positive (or negative) muon in a coulomb bound state. These π-μ atoms are formed when the PI and μ from the decay have sufficiently small relative momentum to bind. Only the evidence related to the detection of these atoms is discussed. The Ksub(L)sup(0) particles which give rise to ''atomic beam'' are produced by 30 GeV proton beam striking a 10 cm beryllium target. From analysis of data 33 events are chosen. For each of these events the parameter α = Psub(π)-Psub(μ)/Psub(π)+Psub(μ) is plotted, where PPI is the pion momentum, and Pμ is the muon momentum. A study of this parameter through an examination of e + e - pairs indicates that the acceptance of apparatus is flat within 30%. The data shows a clear peak at the predicted point containing a total of 21 events with an estimated background of 3 events. The width of the peak is consistent with that expected from measurement errors
Unified description of bound, resonant and scattering states
International Nuclear Information System (INIS)
Konya, B.; Levai, G.; Papp, Z.
2000-01-01
Recently we have introduced a general method for calculating the discrete Hilbert-space basis representation of the Green's operators of those Hamiltonians which have infinite symmetric tridiagonal matrix forms. The elements of this matrix are used in the calculation of the Green's matrix in terms of a three-term recurrence relation and continued fractions. We specified our general approach to the case of the Coulomb problem and the Coulomb-Sturmian basis associated with it. As a further step, we can combine this new way of calculating the Coulomb-Green's matrix with a technique of solving integral equations in discrete Hilbert-space-basis representations. This provides us with a quantum mechanical approximation method which is rather general in the sense that it is equally applicable to solving bound-, resonant- and scattering-state problems with practically any potential of physical relevance. The method is especially suited to problems where Coulomb-like asymptotics have to be treated, but the formalism also contains the case of the free Green's operator as a special case. (author)
International Nuclear Information System (INIS)
Rudin, S.I.
1984-01-01
The three-body bound states of particles moving on a lattice and interacting with two-body point-like potentials are studied in two dimensions (2D) and three dimensions (3D) for spin 1/2 fermions and spin O bosons (with application to magnons). When a three boson bound state forms in 3D, it does so discontinuously implying a finite size of approximately two lattice constants. This phenomenon does not occur in 2D. For three fermions, interactions are effectively absent in the state S = 3/2. In the state S = 1/2, when there is an interaction, the three particles complex is unstable against breakup into a bound pair S = 0 and a free third particle. A finite density of states for 2D lattice makes this result relevant for BCS theory of superconductivity in 3D in confirming the choice of singlet pair (Cooper pair) as the fundamental entity. Results for bosons allows estimation of the limits of validity of spin wave theory as applied to the anisotropic Heisenberg ferromagnet in 3D with J/sub z/ > J/sub x/ = J/sub y/
Bounded energy states in homogeneous turbulent shear flow - An alternative view
Bernard, P. S.; Speziale, C. G.
1992-01-01
The equilibrium structure of homogeneous turbulent shear flow is investigated from a theoretical standpoint. Existing turbulence models, in apparent agreement with physical and numerical experiments, predict an unbounded exponential time growth of the turbulent kinetic energy and dissipation rate; only the anisotropy tensor and turbulent time scale reach a structural equilibrium. It is shown that if a residual vortex stretching term is maintained in the dissipation rate transport equation, then there can exist equilibrium solutions, with bounded energy states, where the turbulence production is balanced by its dissipation. Illustrative calculations are presented for a k-epsilon model modified to account for net vortex stretching.
Electromagnetic Characterization Of Metallic Sensory Alloy
Wincheski, Russell A.; Simpson, John; Wallace, Terryl A.; Newman, John A.; Leser, Paul; Lahue, Rob
2012-01-01
Ferromagnetic shape-memory alloy (FSMA) particles undergo changes in both electromagnetic properties and crystallographic structure when strained. When embedded in a structural material, these attributes can provide sensory output of the strain state of the structure. In this work, a detailed characterization of the electromagnetic properties of a FSMA under development for sensory applications is performed. In addition, a new eddy current probe is used to interrogate the electromagnetic properties of individual FSMA particles embedded in the sensory alloy during controlled fatigue tests on the multifunctional material.
The covariant-evolution-operator method in bound-state QED
International Nuclear Information System (INIS)
Lindgren, Ingvar; Salomonson, Sten; Aasen, Bjoern
2004-01-01
The methods of quantum-electrodynamical (QED) calculations on bound atomic systems are reviewed with emphasis on the newly developed covariant-evolution-operator method. The aim is to compare that method with other available methods and also to point out possibilities to combine that with standard many-body perturbation theory (MBPT) in order to perform accurate numerical QED calculations, including quasi-degeneracy, also for light elements, where the electron correlation is relatively strong. As a background, the time-independent many-body perturbation theory (MBPT) is briefly reviewed, particularly the method with extended model space. Time-dependent perturbation theory is discussed in some detail, introducing the time-evolution operator and the Gell-Mann-Low relation, generalized to an arbitrary model space. Three methods of treating the bound-state QED problem are discussed. The standard S-matrix formulation, which is restricted to a degenerate model space, is discussed only briefly. Two methods applicable also to the quasi-degenerate problem are treated in more detail, the two-times Green's-function and the covariant-evolution-operator techniques. The treatment is concentrated on the latter technique, which has been developed more recently and which has not been discussed in more detail before. A comparison of the two-times Green's-function and the covariant-evolution-operator techniques, which have great similarities, is performed. In the appendix a simple procedure is derived for expressing the evolution-operator diagrams of arbitrary order. The possibilities of merging QED in the covariant evolution-operator formulation with MBPT in a systematic way is indicated. With such a technique it might be feasible to perform accurate QED calculations also on light elements, which is presently not possible with the techniques available
Electromagnetic force support for thermonuclear device
International Nuclear Information System (INIS)
Sugimoto, Makoto; Yoshida, Kiyoshi; Tachikawa, Nobuo; Omori, Junji.
1992-01-01
The device of the present invention certainly supports electromagnetic force exerted on toroidal magnetic field coils. That is, a pair of support members are disposed being abutted against each other between toroidal magnetic field coils disposed radially in the torus direction of a vacuum vessel. Both of the support members are connected under an insulative state by way of an insulative structural portion having an insulation key. In addition, each of the support members and each of the toroidal magnetic field coils are connected by electromagnetic force support portions having a metal taper key and a metal spacer and supporting the electromagnetic force. With such a constitution, the electromagnetic force exerted on the toroidal magnetic field coils is supported by the electromagnetic force support portion having the metal taper key and the metal spacer. As a result, stable electromagnetic force support can be attained. Further, since the insulative structural portion has the insulation key, it can be assembled easily. (I.S.)
Bounded Rationality and Budgeting
Ibrahim, Mukdad
2016-01-01
This article discusses the theory of bounded rationality which had been introduced by Herbert Simon in the 1950s. Simon introduced the notion of bounded rationality stating that while decision-makers strive for rationality, they are limited by the effect of the environment, their information process capacity and by the constraints on their information storage and retrieval capabilities. Moreover, this article tries to specifically blend this notion into budgeting, using the foundations of inc...
A bridge between hyperspherical and integro-differential approaches to the many-body bound states
International Nuclear Information System (INIS)
Fabre de la Ripelle, M.
1986-01-01
The solution of the Schroedinger equation can be obtained from the one of a system of coupled differential equations generated from the potential harmonic expansion of the bound-state wave function of a system of identical particles governed by two-body central interactions. It is shown that the system of coupled equations can be transformed into an equivalent integro-differential equation. For three bosons in S states this equation is identical to the Faddeev equation as written by Noyes. The integro-differential equations describing the triton for non-central realistic N-N forces are explicitly given. (Auth.)
Antennas and Electromagnetics Instrumentation for Research and Education
2016-06-01
Antennas and Electromagnetics Instrumentation for Research and Education The objective of this proposal is to enhance the instrumentation of FIU’s... ElectroMagnetics Lab (EMLab) directed by Dr. Georgakopoulos and create a state-of-the art lab that will support the following: (a) Dr. Georgakopoulos...funded research on reconfigurable antennas and wireless power transfer, (b) other research on advanced electromagnetic technologies that support
Supersymmetric relations among electromagnetic dipole operators
International Nuclear Information System (INIS)
Graesser, Michael; Thomas, Scott
2002-01-01
Supersymmetric contributions to all leptonic electromagnetic dipole operators have essentially identical diagrammatic structure. With approximate slepton universality this allows the muon anomalous magnetic moment to be related to the electron electric dipole moment in terms of supersymmetric phases, and to radiative flavor changing lepton decays in terms of small violations of slepton universality. If the current discrepancy between the measured and standard model values of the muon anomalous magnetic moment is due to supersymmetry, the current bound on the electron electric dipole moment then implies that the phase of the electric dipole operator is less than 2x10 -3 . Likewise the current bound on μ→eγ decay implies that the fractional selectron-smuon mixing in the left-left mass squared matrix, δm μ-tildee-tilde) 2 /m l-tilde) 2 , is less than 10 -4 . These relations and constraints are fairly insensitive to details of the superpartner spectrum for moderate to large tan β
International Nuclear Information System (INIS)
Aleksandrov, L.; Drenska, M.; Karadzhov, D.
1986-01-01
A generalization of the core spline method is given in the case of solution of the general bound state problem for a system of M linear differential equations with coefficients depending on the spectral parameter. The recursion scheme for construction of basic splines is described. The wave functions are expressed as linear combinations of basic splines, which are approximate partial solutions of the system. The spectral parameter (the eigenvalue) is determined from the condition for existence of a nontrivial solution of a (MxM) linear algebraic system at the last collocation point. The nontrivial solutions of this system determine (M - 1) coefficients of the linear spans, expressing the wave functions. The last unknown coefficient is determined from a boundary (or normalization) condition for the system. The computational aspects of the method are discussed, in particular, its concrete algorithmic realization used in the RODSOL program. The numerical solution of the Dirac system for the bound states of a hydrogen atom is given is an example
Generalized Hofmann quantum process fidelity bounds for quantum filters
Sedlák, Michal; Fiurášek, Jaromír
2016-04-01
We propose and investigate bounds on the quantum process fidelity of quantum filters, i.e., probabilistic quantum operations represented by a single Kraus operator K . These bounds generalize the Hofmann bounds on the quantum process fidelity of unitary operations [H. F. Hofmann, Phys. Rev. Lett. 94, 160504 (2005), 10.1103/PhysRevLett.94.160504] and are based on probing the quantum filter with pure states forming two mutually unbiased bases. Determination of these bounds therefore requires far fewer measurements than full quantum process tomography. We find that it is particularly suitable to construct one of the probe bases from the right eigenstates of K , because in this case the bounds are tight in the sense that if the actual filter coincides with the ideal one, then both the lower and the upper bounds are equal to 1. We theoretically investigate the application of these bounds to a two-qubit optical quantum filter formed by the interference of two photons on a partially polarizing beam splitter. For an experimentally convenient choice of factorized input states and measurements we study the tightness of the bounds. We show that more stringent bounds can be obtained by more sophisticated processing of the data using convex optimization and we compare our methods for different choices of the input probe states.
Upper bounds on the entropy of radiation systems
Institute of Scientific and Technical Information of China (English)
汪定雄
1997-01-01
The upper bounds on the entropy of a radiation system confined to a spherical box are calculated in six cases by using the equation of state of radiation in flat spacetime and the equation of state of radiation near black-hole horizon,which was derived by Li and Liu (hereafter the Li-Liu equation).It turns out that the Li-Liu equation does have unique advantage in dealing with the entropy bound of critical self-gravitating radiation systems,while the usual equation of state will result in entropy divergence.In the case of non-self-gravitating radiation systems and non-critical self-gravitating radiation systems,there is no difference in the entropy bounds derived by these two equations of state.
Dissecting zero modes and bound states on BPS vortices in Ginzburg-Landau superconductors
Energy Technology Data Exchange (ETDEWEB)
Izquierdo, A. Alonso [Departamento de Matematica Aplicada, Universidad de Salamanca,Facultad de Ciencias Agrarias y Ambientales,Av. Filiberto Villalobos 119, E-37008 Salamanca (Spain); Fuertes, W. Garcia [Departamento de Fisica, Universidad de Oviedo, Facultad de Ciencias,Calle Calvo Sotelo s/n, E-33007 Oviedo (Spain); Guilarte, J. Mateos [Departamento de Fisica Fundamental, Universidad de Salamanca, Facultad de Ciencias,Plaza de la Merced, E-37008 Salamanca (Spain)
2016-05-12
In this paper the zero modes of fluctuation of cylindrically symmetric self-dual vortices are analyzed and described in full detail. These BPS topological defects arise at the critical point between Type II and Type I superconductors, or, equivalently, when the masses of the Higgs particle and the vector boson in the Abelian Higgs model are equal. In addition, novel bound states of Higss and vector bosons trapped by the self-dual vortices at their core are found and investigated.
Analysis of bound-state spectra near the threshold of neutral particle interaction potentials
International Nuclear Information System (INIS)
Ou Fang; Cao Zhuangqi; Chen Jianping; Xu Junjie
2006-01-01
It is understood that conventional semiclassical approximations deteriorate towards threshold in a typical neutral particle interaction potential which is important for the study of ultra-cold atoms and molecules. In this Letter we give an example of the Lennard-Jones potential with tuning of the strength parameter on the basis of the analytical transfer matrix (ATM) method. Highly accurate quantum mechanical results, such as number of the bound states, energy level density and the eigenvalues with extremely low energies have been derived
Numerical solution of the Schrodinger equation for stationary bound states using nodel theorem
International Nuclear Information System (INIS)
Chen Zhijiang; Kong Fanmei; Din Yibin
1987-01-01
An iterative procedure for getting the numerical solution of Schrodinger equation on stationary bound states is introduced. The theoretical foundtion, the practical steps and the method are presented. An example is added at the end. Comparing with other methods, the present one requires less storage, less running time but posesses higher accuracy. It can be run on the personal computer or microcomputer with 256 K memory and 16 bit word length such as IBM/PC, MC68000/83/20, PDP11/23 etc
International Nuclear Information System (INIS)
Batiz, Zoltan; Gross, Franz
2000-01-01
The momentum conservation sum rule for deep inelastic scattering (DIS) from composite particles is investigated using the general theory of relativity. For two (1+1)-dimensional examples, it is shown that covariant theories automatically satisy the DIS momentum conservation sum rule provided the bound state is covariantly normalized. Therefore, in these cases the two DIS sum rules for baryon conservation and momentum conservation are equivalent. (c) 2000 The American Physical Society
National Research Council Canada - National Science Library
Foster, Jr., John S; Gjelde, Earl; Graham, William R; Hermann, Robert J; Kluepfel, Henry M; Lawson, Richard L; Soper, Gordon K; Wood, Lowell L; Woodard, Joan B
2008-01-01
...) attack on our critical national infrastructures. An earlier report, Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP), Volume 1: Executive Report (2004...
Czech Academy of Sciences Publication Activity Database
Pavelková, Lenka
2011-01-01
Roč. 47, č. 3 (2011), s. 370-384 ISSN 0023-5954 R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : non-linear state space model * bounded uncertainty * missing measurements * state filtering * vehicle position estimation Subject RIV: BC - Control Systems Theory Impact factor: 0.454, year: 2011 http://library.utia.cas.cz/separaty/2011/AS/pavelkova-0360239.pdf
Ultra-Wideband, Short Pulse Electromagnetics 9
Rachidi, Farhad; Kaelin, Armin; Sabath, Frank; UWB SP 9
2010-01-01
Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-wideband Short-Pulse Electromagnetics 9 presents selected papers of deep technical content and high scientific quality from the UWB-SP9 Conference, which was held from July 21-25, 2008, in Lausanne, Switzerland. The wide-ranging coverage includes contributions on electromagnetic theory, time-domain computational techniques, modeling, antennas, pulsed-power, UWB interactions, radar systems, UWB communications, and broadband systems and components. This book serves as a state-of-the-art r...
Energy Technology Data Exchange (ETDEWEB)
Miserev, D. S., E-mail: d.miserev@student.unsw.edu.au, E-mail: erazorheader@gmail.com [University of New South Wales, School of Physics (Australia)
2016-06-15
The problem of localized states in 1D systems with a relativistic spectrum, namely, graphene stripes and carbon nanotubes, is studied analytically. The bound state as a superposition of two chiral states is completely described by their relative phase, which is the foundation of the variable phase method (VPM) developed herein. Based on our VPM, we formulate and prove the relativistic Levinson theorem. The problem of bound states can be reduced to the analysis of closed trajectories of some vector field. Remarkably, the Levinson theorem appears as the Poincaré index theorem for these closed trajectories. The VPM equation is also reduced to the nonrelativistic and semiclassical limits. The limit of a small momentum p{sub y} of transverse quantization is applicable to an arbitrary integrable potential. In this case, a single confined mode is predicted.
Electromagnetic analysis of groundwater on the Arizona-Utah border
Vander Vis, T.; Porter, R. C.; Macy, J. P.
2016-12-01
Understanding subsurface structure and groundwater flow is an essential part of managing groundwater resources, especially in southwestern United States where supply is limited and demand is increasing. This study describes the preliminary results of a transient electromagnetic survey conducted on the Arizona-Utah border to better understand the groundwater system which supplies water to many wells and springs in the region. Electromagnetic surveys are ideal for groundwater investigations because they can locate and characterize areas of high conductivity, which often are indicative of groundwater. The study area is on the southwestern margin of the Colorado Plateau and consists of uplifted, flat-lying sedimentary units. Regionally, groundwater is located within the Navajo Sandstone and underlying Kayenta Formation as an unconfined aquifer that extends from Pipe Springs National Monument north to the East Fork of the Virgin River. This area is characterized by step-like structural blocks that accommodate small amounts of extension and are bounded by long north-south-trending normal faults. The Sevier Fault runs through the sedimentary units near the study area and has been shown to influence groundwater movement by offsetting permeable units west of the fault adjacent to impermeable units east of the fault. Electromagnetic measurements were recorded with a Zonge GDP-32 receiver at 30 receiver locations at 16 and 32 Hz with a 100mx100m transmitter loop. These data were used to create a subsurface conductivity model. Water levels from local wells and local geologic data were utilized to relate the geophysical data to the groundwater system. Preliminary results define the depth to water table and the location of the groundwater divide between the groundwater that flows north towards the springs that feed the East Fork of the Virgin River and the groundwater that flows south towards Pipe Springs National Monument.
Bound-state wave functions at rest in describing deep inelastic scattering
International Nuclear Information System (INIS)
Khvedelidze, A.M.; Kvinikhidze, A.N.
1991-01-01
The deep inelastic process of the lepton-hadron scattering is studied in the bound-state rest frame. A new version of expanding structure functions in interaction constant powers is proposed, each term in it having spectral properties. This expansion makes it possible to consider contributions of composites in the final state to the cross section. It is shown that, as compared with the system P z →∞, the impulse approximation is insufficient for describing correctly the elastic limit in the composite particle rest frame. The leading asymptotics of structure functions as χ Bj →1 can be obtained by taking into account the interaction of contituents in the final state. It is shown that in contrast to the 'light-cone' formalism the ratio F 2 en (χ)/F 2 ep (χ) as χ Bj →1 depends on the explicit form of the spatial part of the nucleon wave function and, in particular, assuming the relativistic character of internal motion, it may be lower than the well-known prediction (i.e. 3/7). This is due to the correct consideration of spin degrees of freedom of the wave function of the nucleon at rest. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Luque, A., E-mail: a.luque@upm.es [Instituto de Energía Solar, Universidad Politécnica de Madrid (Spain); Mellor, A.; Tobías, I.; Antolín, E.; Linares, P.G.; Ramiro, I.; Martí, A. [Instituto de Energía Solar, Universidad Politécnica de Madrid (Spain)
2013-03-15
The effective mass Schrödinger equation of a QD of parallelepipedic shape with a square potential well is solved by diagonalizing the exact Hamiltonian matrix developed in a basis of separation-of-variables wavefunctions. The expected below bandgap bound states are found not to differ very much from the former approximate calculations. In addition, the presence of bound states within the conduction band is confirmed. Furthermore, filamentary states bounded in two dimensions and extended in one dimension and layered states with only one dimension bounded, all within the conduction band—which are similar to those originated in quantum wires and quantum wells—coexist with the ordinary continuum spectrum of plane waves. All these subtleties are absent in spherically shaped quantum dots, often used for modeling.
Highly excited bound-state resonances of short-range inverse power-law potentials
Energy Technology Data Exchange (ETDEWEB)
Hod, Shahar [The Ruppin Academic Center, Emeq Hefer (Israel); The Hadassah Academic College, Jerusalem (Israel)
2017-11-15
We study analytically the radial Schroedinger equation with long-range attractive potentials whose asymptotic behaviors are dominated by inverse power-law tails of the form V(r) = -β{sub n}r{sup -n} with n > 2. In particular, assuming that the effective radial potential is characterized by a short-range infinitely repulsive core of radius R, we derive a compact analytical formula for the threshold energy E{sub l}{sup max} = E{sub l}{sup max}(n, β{sub n}, R), which characterizes the most weakly bound-state resonance (the most excited energy level) of the quantum system. (orig.)
Low-frequency electromagnetic radiation field interaction with cerebral nervous MT
International Nuclear Information System (INIS)
Gao Feng; Zhou Yi; Xiao Detao; Zhang Dengyu
2009-01-01
We investigate the interaction characteristics and mechanism of electromagnetic radiation field and cerebral nervous system. When the electromagnetic radiation is non-ionization low-frequency electromagnetic field, the two-state physical system in the cytoskeletal microtubule (MT) can be quantized. The state of information bits in cerebral neurons system is described by density matrix, and the system dynamics equation is established and solved. It indicates that when the brain is exposed to non-ionization low-frequency electromagnetic field, the density matrix non-opposite angle element of cerebral nervous qubit will never be zero, its quantum coherence characteristic can keep well, and the brain function will also be not damaged. (authors)
QCD constraints for the electromagnetic form factor of the pion
International Nuclear Information System (INIS)
Machet, B.
1980-07-01
Using the modulus representation, we derive constraints for the behaviour of the electromagnetic form factor of the pion in the time like region [1 GeV 2 , + infinity[, from information given by perturbative QCD in the space like region [-μ 2 , - infinity[. A phenomenological μ dependent upper bound for the exponent of the first non leading logarithmic correction is deduced. Restrictions and problems of the method are discussed
Electromagnetic properties of nuclei at high spins
International Nuclear Information System (INIS)
Leander, G.A.
1986-01-01
A photon emitted by an excited state is likely to carry away, at most, 1 or 2 h-bar of angular momentum. Therefore, a profusion of photons is needed to deexcite the rapidly rotating states of nuclei formed by heavy-ion reactions. The study of electromagnetic properties has become the primary source of information on nuclear structure at high spins and, also, at the warm temperatures present in the initial stage of the electromagnetic cascade process. The purpose of this paper is a review of the E1, M1, and E2 properties of such highly excited states. 42 refs., 5 figs
Souto, R Seoane; Martín-Rodero, A; Yeyati, A Levy
2016-12-23
We analyze the quantum quench dynamics in the formation of a phase-biased superconducting nanojunction. We find that in the absence of an external relaxation mechanism and for very general conditions the system gets trapped in a metastable state, corresponding to a nonequilibrium population of the Andreev bound states. The use of the time-dependent full counting statistics analysis allows us to extract information on the asymptotic population of even and odd many-body states, demonstrating that a universal behavior, dependent only on the Andreev state energy, is reached in the quantum point contact limit. These results shed light on recent experimental observations on quasiparticle trapping in superconducting atomic contacts.
Electromagnetic shower detector-calorimeters
International Nuclear Information System (INIS)
Appel, J.A.
1975-01-01
A brief review of the state-of-the-art of electromagnetic calorimeters is presented. The choice of detector based on the experimental requirements in cost, spatial resolution, energy resolution, and hadron rejection is discussed
Directory of Open Access Journals (Sweden)
J. Adam
2016-01-01
Full Text Available We present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possible Λn‾ bound state. The search is performed with the ALICE detector in central (0–10% Pb–Pb collisions at sNN=2.76 TeV, by invariant mass analysis in the decay modes Λn‾→d‾π+ and H-dibaryon →Λpπ−. No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound states, like the deuteron and the hypertriton.
Bound states of Dirac fermions in monolayer gapped graphene in the presence of local perturbations
International Nuclear Information System (INIS)
Yarmohammadi, Mohsen; Zareyan, Malek
2016-01-01
In graphene, conductance electrons behave as massless relativistic particles and obey an analogue of the Dirac equation in two dimensions with a chiral nature. For this reason, the bounding of electrons in graphene in the form of geometries of quantum dots is impossible. In gapless graphene, due to its unique electronic band structure, there is a minimal conductivity at Dirac points, that is, in the limit of zero doping. This creates a problem for using such a highly motivated new material in electronic devices. One of the ways to overcome this problem is the creation of a band gap in the graphene band structure, which is made by inversion symmetry breaking (symmetry of sublattices). We investigate the confined states of the massless Dirac fermions in an impured graphene by the short-range perturbations for “local chemical potential” and “local gap”. The calculated energy spectrum exhibits quite different features with and without the perturbations. A characteristic equation for bound states (BSs) has been obtained. It is surprisingly found that the relation between the radial functions of sublattices wave functions, i.e., , , and , , can be established by SO (2) group. (paper)
Bound state properties of ABC-stacked trilayer graphene quantum dots
Xiong, Haonan; Jiang, Wentao; Song, Yipu; Duan, Luming
2017-06-01
The few-layer graphene quantum dot provides a promising platform for quantum computing with both spin and valley degrees of freedom. Gate-defined quantum dots in particular can avoid noise from edge disorders. In connection with the recent experimental efforts (Song et al 2016 Nano Lett. 16 6245), we investigate the bound state properties of trilayer graphene (TLG) quantum dots (QDs) through numerical simulations. We show that the valley degeneracy can be lifted by breaking the time reversal symmetry through the application of a perpendicular magnetic field. The spectrum under such a potential exhibits a transition from one group of Landau levels to another group, which can be understood analytically through perturbation theory. Our results provide insight into the transport property of TLG QDs, with possible applications to study of spin qubits and valleytronics in TLG QDs.
International Nuclear Information System (INIS)
Kuang Leman; Zhou Lan
2003-01-01
In this paper, we present a method to generate continuous-variable-type entangled states between photons and atoms in atomic Bose-Einstein condensate (BEC). The proposed method involves an atomic BEC with three internal states, a weak quantized probe laser, and a strong classical coupling laser, which form a three-level Λ-shaped BEC system. We consider a situation where the BEC is in electromagnetically induced transparency with the coupling laser being much stronger than the probe laser. In this case, the upper and intermediate levels are unpopulated, so that their adiabatic elimination enables an effective two-mode model involving only the atomic field at the lowest internal level and the quantized probe laser field. Atom-photon quantum entanglement is created through laser-atom and interatomic interactions, and two-photon detuning. We show how to generate atom-photon entangled coherent states and entangled states between photon (atom) coherent states and atom-(photon-) macroscopic quantum superposition (MQS) states, and between photon-MQS and atom-MQS states
International Nuclear Information System (INIS)
Kuang, L.-M.; Chen Zengbing; Pan Jianwei
2007-01-01
We propose a method to generate entangled coherent states between two spatially separated atomic Bose-Einstein condensates (BECs) via the technique of electromagnetically induced transparency (EIT). Two strong coupling laser beams and two entangled probe laser beams are used to cause two distant BECs to be in EIT states and to generate an atom-photon entangled state between probe lasers and distant BECs. The two BECs are initially in unentangled product coherent states while the probe lasers are initially in an entangled state. Entangled states of two distant BECs can be created through the performance of projective measurements upon the two outgoing probe lasers under certain conditions. Concretely, we propose two protocols to show how to generate entangled coherent states of the two distant BECs. One is a single-photon scheme in which an entangled single-photon state is used as the quantum channel to generate entangled distant BECs. The other is a multiphoton scheme where an entangled coherent state of the probe lasers is used as the quantum channel. Additionally, we also obtain some atom-photon entangled states of particular interest such as entangled states between a pair of optical Bell states (or quasi-Bell-states) and a pair of atomic entangled coherent states (or quasi-Bell-states)
Circumvention of Parker's bound on galactic magnetic monopoles
International Nuclear Information System (INIS)
Dicus, D.A.; Teplitz, V.L.; Maryland Univ., College Park
1983-01-01
There is a possibility that a magnetic monopole has been observed. The monopole density implied by the observation appears to violate bounds on the density of such particles derived from the total mass density of the Universe and from the existence of galactic magnetic fields. It is shown that the observation is not inconsistent with these bounds if the monopoles and antimonopoles are bound into positronium like states with principal quantum n high enough so that the Earth's magnetic field will break them apart, but small enough so that the weaker galactic magnetic field will not. A range of values for n are determined and show that lifetimes for such bound states are longer than the current age of the Universe. (author)
Modelling, simulation and visualisation for electromagnetic non-destructive testing
International Nuclear Information System (INIS)
Ilham Mukriz Zainal Abidin; Abdul Razak Hamzah
2010-01-01
This paper reviews the state-of-the art and the recent development of modelling, simulation and visualization for eddy current Non-Destructive Testing (NDT) technique. Simulation and visualization has aid in the design and development of electromagnetic sensors and imaging techniques and systems for Electromagnetic Non-Destructive Testing (ENDT); feature extraction and inverse problems for Quantitative Non-Destructive Testing (QNDT). After reviewing the state-of-the art of electromagnetic modelling and simulation, case studies of Research and Development in eddy current NDT technique via magnetic field mapping and thermography for eddy current distribution are discussed. (author)
Prediction of new tightly bound-states of H2+(d2+) and ''cold fusion''-experiments
International Nuclear Information System (INIS)
Barut, A.O.
1989-06-01
It is suggested that in the ''cold-fusion'' experiments of Fleischmann and Pons new tightly-bound molecular states of D 2 + are formed with binding energies predicted to be of the order of 50 keV accounting for the heat released without appreciable fusion. Other tests of the suggested mechanism are proposed and the derivation of the new energy levels is given. (author). 3 refs
Bound states for square well potentials extending to infinity in D ≥ 2
International Nuclear Information System (INIS)
Rupertsberger, H.
1992-01-01
It is well known that quantum mechanics allows the penetration into classically forbidden regions (tunneling). Less well known seems to be the fact that in some sense the converse is true also. Potentials with classically allowed regions where a particle can move freely to infinity can nevertheless lead to bound states in quantum mechanics due to the stringent requirements of the boundary conditions, thus forbidding an escape to infinity. This effect is demonstrated by using an obvious generalization of the well known one-dimensional (D = 1) square well potential to arbitray space dimensions. (author)
Ultra-Wideband Electromagnetic Pulse Propagation through Causal Media
2016-03-04
AFRL-AFOSR-VA-TR-2016-0112 Ultra-Wideband Electromagnetic Pulse Propagation through Causal Media Natalie Cartwright RESEARCH FOUNDATION OF STATE... Electromagnetic Pulse Propagation through Causal Media 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-13-1-0013 5c. PROGRAM ELEMENT NUMBER 61102F 6...SUPPLEMENTARY NOTES 14. ABSTRACT When an electromagnetic pulse travels through a dispersive material each frequency of the transmitted pulse changes in both
Few-Body Techniques Using Coordinate Space for Bound and Continuum States
Garrido, E.
2018-05-01
These notes are a short summary of a set of lectures given within the frame of the "Critical Stability of Quantum Few-Body Systems" International School held in the Max Planck Institute for the Physics of Complex Systems (Dresden). The main goal of the lectures has been to provide the basic ingredients for the description of few-body systems in coordinate space. The hyperspherical harmonic and the adiabatic expansion methods are introduced in detail, and subsequently used to describe bound and continuum states. The expressions for the cross sections and reaction rates for three-body processes are derived. The case of resonant scattering and the complex scaling method as a tool to obtain the resonance energy and width is also introduced.
Relativistic description of quark-antiquark bound states. II. Spin-dependent treatment
International Nuclear Information System (INIS)
Gara, A.; Durand, B.; Durand, L.
1990-01-01
We present the results of a study of light- and heavy-quark--antiquark bound states in the context of the reduced Bethe-Salpeter equation, including the full spin dependence. We obtain good fits to the observed spin splittings in the b bar b and c bar c systems using a short-distance single-gluon-exchange interaction, and a long-distance scalar confining interaction. However, we cannot obtain satisfactory fits to the centers of gravity of the b bar b and c bar c spin multiplets at the same time, and the splittings calculated for q bar Q mesons containing the lighter quarks are very poor. The difficulty appears to be intrinsic to the reduced Salpeter equation for reasons which we discuss
Acoustic and electromagnetic emission as a tool for crack localization
International Nuclear Information System (INIS)
Sedlak, P; Sikula, J; Lokajicek, T; Mori, Y
2008-01-01
The creation of cracks is accompanied by electric charge redistribution due to loosened chemical bounds. Electric charge on a crack wall creates dipole moments. Vibrations of crack walls produce time-dependent dipole moments and, consequently, electric and magnetic fields are generated. An electric signal is induced on metal electrodes. Simultaneously with the electromagnetic emission (EME) signal, an acoustic emission (AE) signal is generated, but due to the different velocities of propagation of both waves, the detection of the AE signal is delayed. This time delay presents the time of the wave propagation from the individual acoustic emission sensor to the crack. The defect can be located by means of these time intervals. This paper describes the localization using acoustic and electromagnetic emission signals for the two-dimensional case
Directory of Open Access Journals (Sweden)
Irwin Yousept
2010-07-01
Full Text Available An optimal control problem arising in the context of 3D electromagnetic induction heating is investigated. The state equation is given by a quasilinear stationary heat equation coupled with a semilinear time harmonic eddy current equation. The temperature-dependent electrical conductivity and the presence of pointwise inequality state-constraints represent the main challenge of the paper. In the first part of the paper, the existence and regularity of the state are addressed. The second part of the paper deals with the analysis of the corresponding linearized equation. Some suffcient conditions are presented which guarantee thesolvability of the linearized system. The final part of the paper is concerned with the optimal control. The aim of the optimization is to find the optimal voltage such that a desired temperature can be achieved optimally. The corresponding first-order necessary optimality condition is presented.
Huber, Felix; Eltschka, Christopher; Siewert, Jens; Gühne, Otfried
2018-04-01
A pure multipartite quantum state is called absolutely maximally entangled (AME), if all reductions obtained by tracing out at least half of its parties are maximally mixed. Maximal entanglement is then present across every bipartition. The existence of such states is in many cases unclear. With the help of the weight enumerator machinery known from quantum error correction and the shadow inequalities, we obtain new bounds on the existence of AME states in dimensions larger than two. To complete the treatment on the weight enumerator machinery, the quantum MacWilliams identity is derived in the Bloch representation. Finally, we consider AME states whose subsystems have different local dimensions, and present an example for a 2×3×3×3 system that shows maximal entanglement across every bipartition.
Andreev reflection properties in a parallel mesoscopic circuit with Majorana bound states
Energy Technology Data Exchange (ETDEWEB)
Mu, Jin-Tao; Han, Yu [Physics Department, Liaoning University, Shenyang 110036 (China); Gong, Wei-Jiang, E-mail: gwj@mail.neu.edu.cn [College of Sciences, Northeastern University, Shenyang 110819 (China)
2017-03-15
We investigate the Andreev reflection in a parallel mesoscopic circuit with Majorana bound states (MBSs). It is found that in such a structure, the Andreev current can be manipulated in a highly efficient way, by the adjustment of bias voltage, dot levels, inter-MBS coupling, and the applied magnetic flux. Besides, the dot-MBS coupling manner is an important factor to modulate the Andreev current, because it influences the period of the conductance oscillation. By discussing the underlying quantum interference mechanism, the Andreev-reflection property is explained in detail. We believe that all the results can assist to understand the nontrivial role of the MBSs in driving the Andreev reflection.
Neutron scattering from elemental indium, the optical model, and the bound-state potential
Energy Technology Data Exchange (ETDEWEB)
Chiba, S. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)); Guenther, P.T.; Lawson, R.D.; Smith, A.B. (Argonne National Lab., IL (USA))
1990-06-01
Neutron differential elastic-scattering cross sections of elemental indium are measured from 4.5 to 10 MeV at incident-energy intervals of {approx}500 keV. Seventy or more differential values are obtained at each incident energy, distributed between {approx}18{degree} and 160{degree}. These experimental results are combined with lower-energy values previously obtained at this laboratory, and with 11 and 14 MeV results in the literature, to form a comprehensive elastic-scattering database extending from {approx}1.5 to 14 MeV. These data are interpreted in terms of a conventional spherical optical model. The resulting potential is extrapolated to the bound-state regime. It is shown that in the middle of the 50--82 neutron shell, the potential derived from the scattering results adequately describes the binding energies of article states, but does not do well for hole states. The latter shortcoming is attributed to the holes states having occupational probabilities sufficiently different from unity, so that the exclusion principle become a factor, and to the rearrangement of the neutron core. 68 refs.
Neutron scattering from elemental indium, the optical model, and the bound-state potential
International Nuclear Information System (INIS)
Chiba, S.; Guenther, P.T.; Lawson, R.D.; Smith, A.B.
1990-01-01
Neutron differential elastic-scattering cross sections of elemental indium are measured from 4.5 to 10 MeV at incident-energy intervals of ∼500 keV. Seventy or more differential values are obtained at each incident energy, distributed between ∼18 degree and 160 degree. These experimental results are combined with lower-energy values previously obtained at this laboratory, and with 11 and 14 MeV results in the literature, to form a comprehensive elastic-scattering database extending from ∼1.5 to 14 MeV. These data are interpreted in terms of a conventional spherical optical model. The resulting potential is extrapolated to the bound-state regime. It is shown that in the middle of the 50--82 neutron shell, the potential derived from the scattering results adequately describes the binding energies of article states, but does not do well for hole states. The latter shortcoming is attributed to the holes states having occupational probabilities sufficiently different from unity, so that the exclusion principle become a factor, and to the rearrangement of the neutron core. 68 refs
Electron-electron bound states in Maxwell-Chern-Simons-Proca QED3
International Nuclear Information System (INIS)
Belich, H.; Helayel-Neto, J.A.; Ferreira, M.M. Jr.; Maranhao Univ., Sao Luis, MA
2002-10-01
We start from a parity-breaking MCS QED 3 model with spontaneous breaking of the gauge symmetry as a framework for evaluation of the electron-electron interaction potential and for attainment of numerical values for the e - e - - bound state. Three expressions V eff↓↓ , V eff↓↑ , V eff↓↓ ) are obtained according to the polarization state of the scattered electrons. In an energy scale compatible with condensed matter electronic excitations, these potentials become degenerated. The resulting potential is implemented in the Schroedinger equation and the variational method is applied to carry out the electronic binding energy. The resulting binding energies in the scale of 10-100 meV and a correlation length in the scale of 10 - 30 Angstrom are possible indications that the MCS-QED 3 model adopted may be suitable to address an eventual case of e - e - pairing in the presence of parity-symmetry breakdown. The data analyzed here suggest an energy scale of 10-100 meV to fix the breaking of the U(1)-symmetry. (author)
International Nuclear Information System (INIS)
Boyer, T.H.
1975-01-01
The theory of classical electrodynamics with classical electromagnetic zero-point radiation is outlined here under the title random electrodynamics. The work represents a reanalysis of the bounds of validity of classical electron theory which should sharpen the understanding of the connections and distinctions between classical and quantum theories. The new theory of random electrodynamics is a classical electron theory involving Newton's equations for particle motion due to the Lorentz force, and Maxwell's equations for the electromagnetic fields with point particles as sources. However, the theory departs from the classical electron theory of Lorentz in that it adopts a new boundary condition on Maxwell's equations. It is assumed that the homogeneous boundary condition involves random classical electromagnetic radiation with a Lorentz-invariant spectrum, classical electromagnetic zero-point radiation. The implications of random electrodynamics for atomic structure, atomic spectra, and particle-interference effects are discussed on an order-of-magnitude or heuristic level. Some detailed mathematical connections and some merely heuristic connections are noted between random electrodynamics and quantum theory. (U.S.)
Lower bound on inconclusive probability of unambiguous discrimination
International Nuclear Information System (INIS)
Feng Yuan; Zhang Shengyu; Duan Runyao; Ying Mingsheng
2002-01-01
We derive a lower bound on the inconclusive probability of unambiguous discrimination among n linearly independent quantum states by using the constraint of no signaling. It improves the bound presented in the paper of Zhang, Feng, Sun, and Ying [Phys. Rev. A 64, 062103 (2001)], and when the optimal discrimination can be reached, these two bounds coincide with each other. An alternative method of constructing an appropriate measurement to prove the lower bound is also presented
Majorana bound state of a Bogoliubov-de Gennes-Dirac Hamiltonian in arbitrary dimensions
Energy Technology Data Exchange (ETDEWEB)
Imura, Ken-Ichiro, E-mail: imura@hiroshima-u.ac.jp [Department of Quantum Matter, AdSM, Hiroshima University, 739-8530 (Japan); Fukui, Takahiro; Fujiwara, Takanori [Department of Physics, Ibaraki University, Mito 310-8512 (Japan)
2012-01-11
We study a Majorana zero-energy state bound to a hedgehog-like point defect in a topological superconductor described by a Bogoliubov-de Gennes (BdG)-Dirac type effective Hamiltonian. We first give an explicit wave function of a Majorana state by solving the BdG equation directly, from which an analytical index can be obtained. Next, by calculating the corresponding topological index, we show a precise equivalence between both indices to confirm the index theorem. Finally, we apply this observation to reexamine the role of another topological invariant, i.e., the Chern number associated with the Berry curvature proposed in the study of protected zero modes along the lines of topological classification of insulators and superconductors. We show that the Chern number is equivalent to the topological index, implying that it indeed reflects the number of zero-energy states. Our theoretical model belongs to the BDI class from the viewpoint of symmetry, whereas the spatial dimension d of the system is left arbitrary throughout the paper.
Pentaquark as a NK* bound state with TJP=0(3/2)-
International Nuclear Information System (INIS)
Takeuchi, Sachiko; Shimizu, Kiyotaka
2005-01-01
We have investigated negative-parity uudds pentaquarks by employing a quark model with the meson exchange and the effective gluon exchange as qq and qq interactions. The system of five quarks is dynamically solved; the qq and qq correlations are taken into account in the wave function. The masses of the pentaquarks are found to be reasonably low. It is found that the lowest-mass state is TJ P =0(1/2) - and the next lowest one is 0(3/2) - . The former is reported to have a large width. We argue that the observed narrow peak corresponds to the latter state. It is still necessary to introduce an extra attraction to reduce the mass further by 140-280 MeV to reproduce the observed Θ + mass. Since their level splitting is less than 80 MeV, the lower level will not become a bound state below the NK threshold even after such an attraction is introduced. It is also found that the relative distance of two quarks with the attractive interaction is found to be by about 1.2-1.3 times closer than that of the repulsive one. The two-body correlation seems important in the pentaquark systems
In-Medium K^+ Electromagnetic Form Factor with a Symmetric Vertex in a Light Front Approach
Yabusaki, George H. S.; de Melo, J. P. B. C.; de Paula, Wayne; Tsushima, K.; Frederico, T.
2018-05-01
Using the light-front K^ +-Meson wave function based on a Bethe-Salpeter amplitude model for the Quark-Antiquark bound state, we study the Electromagnetic Form Factor (EMFF) of the K^ +-Meson in nuclear medium within the framework of light-front field theory. The K^ +-Meson model we adopt is well constrained by previous and recent studies to explain its properties in vacuum. The in-medium K^ +-Meson EMFF is evaluated for the plus-component of the electromagnetic current, J^+, in the Breit frame. In order to consistently incorporate the constituent up and antistrange Quarks of the K^ +-Meson immersed in symmetric nuclear matter, we use the Quark-Meson coupling model, which has been widely applied to various hadronic and nuclear phenomena in a nuclear medium with success. We predict the in-medium modification of the K^ +-Meson EMFF in symmetric nuclear matter. It is found that, after a fine tuning of the regulator mass, i.e. m_R = 0.600 GeV, the model is suitable to fit the available experimental data in vacuum within the theoretical uncertainties, and based on this we predict the in-medium modification of the K^ +-Meson EMFF.
International Nuclear Information System (INIS)
Faria da Veiga, Paulo A.; O'Carroll, Michael
2006-01-01
We determine baryon-baryon bound states in (3+1)-dimensional SU(3) lattice QCD with two flavors, 4x4 spin matrices, and in an imaginary time formulation. For small hopping parameter κ>0 and large glueball mass (strong coupling), we show the existence of three-quark isospin 1/2 particles (proton and neutron) and isospin 3/2 baryons (delta particles), with asymptotic masses -3lnκ and isolated dispersion curves. Baryon-baryon bound states of isospin zero are found with binding energy of order κ 2 , using a ladder approximation to a lattice Bethe-Salpeter equation. The dominant baryon-baryon interaction is an energy-independent spatial range-one attractive potential with an O(κ 2 ) strength. There is also attraction arising from gauge field correlations associated with six overlapping bonds, but it is counterbalanced by Pauli repulsion to give a vanishing zero-range potential. The overall range-one potential results from a quark, antiquark exchange with no meson exchange interpretation; the repulsive or attractive nature of the interaction depends on the isospin and spin of the two-baryon state
Recent advances in bound state quantum electrodynamics
International Nuclear Information System (INIS)
Brodsky, S.J.; Lepage, G.P.
1977-06-01
Recent developments are reviewed in four areas of computational quantum electrodynamics: a new relativistic two-body formalism equal in rigor to the Bethe-Salpeter formalism but with strong calculational advantages is discussed; recent work on the computation of the decay rate of bound systems (positronium in particular) is presented; limits on possible composite structure of leptons are discussed; a new multidimensional integration program ('VEGAS') suitable for higher order calculations is presented
Czech Academy of Sciences Publication Activity Database
Znojil, Miloslav
2017-01-01
Roč. 96, č. 1 (2017), č. článku 012127. ISSN 2469-9926 R&D Projects: GA ČR GA16-22945S Institutional support: RVO:61389005 Keywords : non-Hermitian * PT symmetric * bound states Subject RIV: BE - Theoretical Physics OBOR OECD: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) Impact factor: 2.925, year: 2016
Electromagnetic topology: Characterization of internal electromagnetic coupling
Parmantier, J. P.; Aparicio, J. P.; Faure, F.
1991-01-01
The main principles are presented of a method dealing with the resolution of electromagnetic internal problems: Electromagnetic Topology. A very interesting way is to generalize the multiconductor transmission line network theory to the basic equation of the Electromagnetic Topology: the BLT equation. This generalization is illustrated by the treatment of an aperture as a four port junction. Analytical and experimental derivations of the scattering parameters are presented. These concepts are used to study the electromagnetic coupling in a scale model of an aircraft, and can be seen as a convenient means to test internal electromagnetic interference.
Possible circumvention of Parker's bound on galactic magnetic monopoles
International Nuclear Information System (INIS)
Dicus, D.A.; Teplitz, V.L.
1983-04-01
There is a possibility that a magnetic monople has observed. The monopole density implied by the observation appears to violate bounds on the density of such particles derived from the total mass density of the universe and from the existence of galactic magnetic fields. We show that the observation is not inconsistent with these bounds if the monopoles and antimonopoles are bound into positronium - like states with principal quantum n high enough so that the earth's magnetic field will break them apart, but small enough so that the weaker galactic mangetic field will not. We determine a range of values for n and show that lifetimes for such bound states are longer than the current age of the universe
International Nuclear Information System (INIS)
Kim, Se Yun
2009-01-01
This book deals with engineering electromagnetics. It contains seven chapters, which treats understanding of engineering electromagnetics such as magnet and electron spin, current and a magnetic field and an electromagnetic wave, Essential tool for engineering electromagnetics on rector and scalar, rectangular coordinate system and curl vector, electrostatic field with coulomb rule and method of electric images, Biot-Savart law, Ampere law and magnetic force, Maxwell equation and an electromagnetic wave and reflection and penetration of electromagnetic plane wave.
International Nuclear Information System (INIS)
Li Rui; Zhang Jiaxing; Hou Shimin; Qian Zekan; Shen Ziyong; Zhao Xingyu; Xue Zengquan
2007-01-01
We discuss two problems in the conventional approach for studying charge transport in molecular electronic devices that is based on the non-equilibrium Green's function formalism and density functional theory, i.e., the bound states and the numerical integration of the non-equilibrium density matrix. A scheme of filling the bound states in the bias window and a method of patching the non-equilibrium integration are proposed, both of which are referred to as the non-equilibrium correction. The discussion is illustrated by means of calculations on a model system consisting of a 4,4 bipyridine molecule connected to two semi-infinite gold monatomic chains
Reaching the Quantum Cramér-Rao Bound for Transmission Measurements
Woodworth, Timothy; Chan, Kam Wai Clifford; Marino, Alberto
2017-04-01
The quantum Cramér-Rao bound (QCRB) is commonly used to quantify the lower bound for the uncertainty in the estimation of a given parameter. Here, we calculate the QCRB for transmission measurements of an optical system probed by a beam of light. Estimating the transmission of an optical element is important as it is required for the calibration of optimal states for interferometers, characterization of high efficiency photodetectors, or as part of other measurements, such as those in plasmonic sensors or in ellipsometry. We use a beam splitter model for the losses introduced by the optical system to calculate the QCRB for different input states. We compare the bound for a coherent state, a two-mode squeezed-state (TMSS), a single-mode squeezed-state (SMSS), and a Fock state and show that it is possible to obtain an ultimate lower bound, regardless of the state used to probe the system. We prove that the Fock state gives the lowest possible uncertainty in estimating the transmission for any state and demonstrate that the TMSS and SMSS approach this ultimate bound for large levels of squeezing. Finally, we show that a simple measurement strategy for the TMSS, namely an intensity difference measurement, is able to saturate the QCRB. Work supported by the W.M. Keck Foundation.
Capacity Bounds for Parallel Optical Wireless Channels
Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim
2016-01-01
A system consisting of parallel optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. Under perfect channel-state information at the transmitter (CSIT), the bounds have to be optimized with respect to the power allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the KKT conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose low-complexity power allocation algorithms which are nearly optimal. The optimized capacity lower bound nearly coincides with the capacity at high SNR. Without CSIT, our capacity bounds lead to upper and lower bounds on the outage probability. The outage probability bounds meet at high SNR. The system with average and peak intensity constraints is also discussed.
Trif, Mircea; Dmytruk, Olesia; Bouchiat, Hélène; Aguado, Ramón; Simon, Pascal
2018-02-01
We theoretically study a Josephson junction based on a semiconducting nanowire subject to a time-dependent flux bias. We establish a general density-matrix approach for the dynamical response of the Majorana junction and calculate the resulting flux-dependent susceptibility using both microscopic and effective low-energy descriptions for the nanowire. We find that the diagonal component of the susceptibility, associated with the dynamics of the Majorana state populations, dominates over the standard Kubo contribution for a wide range of experimentally relevant parameters. The diagonal term, explored, in this Rapid Communication, in the context of Majorana physics, allows probing accurately the presence of Majorana bound states in the junction.
International Nuclear Information System (INIS)
Sturm, Sven
2012-01-01
This thesis describes the ultra-precise determination of the g-factor of the electron bound to hydrogenlike 28 Si 13+ . The experiment is based on the simultaneous determination of the cyclotron- and Larmor frequency of a single ion, which is stored in a triple Penning-trap setup. The continuous Stern-Gerlach effect is used to couple the spin of the bound electron to the motional frequencies of the ion via a magnetic bottle, which allows the non-destructive determination of the spin state. To this end, a highly sensitive, cryogenic detection system was developed, which allowed the direct, non-destructive detection of the eigenfrequencies with the required precision. The development of a novel, phase sensitive detection technique finally allowed the determination of the g-factor with a relative accuracy of 4 . 10 -11 , which was previously inconceivable. The comparison of the hereby determined value with the value predicted by quantumelectrodynamics (QED) allows the verification of the validity of this fundamental theory under the extreme conditions of the strong binding potential of a highly charged ion. The exact agreement of theory and experiment is an impressive demonstration of the exactness of QED. The experimental possibilities created in this work will allow in the near future not only further tests of theory, but also the determination of the mass of the electron with a precision that exceeds the current literature value by more than an order of magnitude.
Electromagnetic pulse (EMP) survey of the Idaho State Emergency Operating Center, Boise, Idaho
Energy Technology Data Exchange (ETDEWEB)
Crutcher, R.I.; Buchanan, M.E.; Jones, R.W.
1992-02-01
The purpose of this report is to develop an engineering design package to protect the Federal Emergency Management Agency (FEMA) National Radio System (FNARS) facilities from the effects of high- altitude electromagnetic pulses (HEMPs). This report was developed specifically for the Idaho State Emergency Operating Center (EOC) in Boise, Idaho. It is highly probable that there will be a heavy dependence upon high-frequency (hf) radio communications for long- haul communications following a nuclear attack on the continental United States, should one occur. To maintain the viability of the FEMA hf radio network during such a situation, steps must be taken to protect the FNARS facilities against the effects of HEMP that are likely to be created in a nuclear confrontation. The solution must than be to reduce HEMP-induced stresses on the system by means of tailored retrofit hardening measures using commercial protection devices when available. It is the intent of this report to define the particular hardening measures that will minimize the susceptibility of system components to HEMP effects. To the extent economically viable, protective actions have been recommended for implementation, along with necessary changes or additions, during the period of the FNARS upgrade program. This report addresses electromagnetic pulse (EMP) effects only and disregards any condition in which radiation effects may be a factor. It has been established that, except for the source region of a surface burst, EMP effects of high-altitude bursts are more severe than comparable detonations in either air or surface regions. Any system hardened to withstand the more extreme EMP environment will survive the less severe EMP conditions. The threatening environment will therefore be limited to HEMP situations.
Calculations of antiproton nucleus quasi-bound states using the Paris (N)over-barN potential
Czech Academy of Sciences Publication Activity Database
Hrtánková, Jaroslava; Mareš, Jiří
2018-01-01
Roč. 969, č. 1 (2018), s. 45-59 ISSN 0375-9474 R&D Projects: GA ČR(CZ) GA15-04301S Institutional support: RVO:61389005 Keywords : antiproton-nucleus interaction * Paris (N)over-barN potential * antiproton-nuclear bound states Subject RIV: BE - Theoretical Physics OBOR OECD: Atomic, molecular and chemical physics ( physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) Impact factor: 1.916, year: 2016
Transition from thermal to turbulent equilibrium with a resulting electromagnetic spectrum
Energy Technology Data Exchange (ETDEWEB)
Ziebell, L. F., E-mail: luiz.ziebell@ufrgs.br [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States); School of Space Research, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of); Gaelzer, R. [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); Instituto de Física e Matemática, UFPel, Pelotas, RS (Brazil); Pavan, J. [Instituto de Física e Matemática, UFPel, Pelotas, RS (Brazil)
2014-01-15
A recent paper [Ziebell et al., Phys. Plasmas 21, 010701 (2014)] discusses a new type of radiation emission process for plasmas in a state of quasi-equilibrium between the particles and enhanced Langmuir turbulence. Such a system may be an example of the so-called “turbulent quasi-equilibrium.” In the present paper, it is shown on the basis of electromagnetic weak turbulence theory that an initial thermal equilibrium state (i.e., only electrostatic fluctuations and Maxwellian particle distributions) transitions toward the turbulent quasi-equilibrium state with enhanced electromagnetic radiation spectrum, thus demonstrating that the turbulent quasi-equilibrium discussed in the above paper correctly describes the weakly turbulent plasma dynamically interacting with electromagnetic fluctuations, while maintaining a dynamical steady-state in the average sense.
Elastic metamaterials for tuning circular polarization of electromagnetic waves.
Zárate, Yair; Babaee, Sahab; Kang, Sung H; Neshev, Dragomir N; Shadrivov, Ilya V; Bertoldi, Katia; Powell, David A
2016-06-20
Electromagnetic resonators are integrated with advanced elastic material to develop a new type of tunable metamaterial. An electromagnetic-elastic metamaterial able to switch on and off its electromagnetic chiral response is experimentally demonstrated. Such tunability is attained by harnessing the unique buckling properties of auxetic elastic materials (buckliballs) with embedded electromagnetic resonators. In these structures, simple uniaxial compression results in a complex but controlled pattern of deformation, resulting in a shift of its electromagnetic resonance, and in the structure transforming to a chiral state. The concept can be extended to the tuning of three-dimensional materials constructed from the meta-molecules, since all the components twist and deform into the same chiral configuration when compressed.
Lévy noise improves the electrical activity in a neuron under electromagnetic radiation.
Wu, Juan; Xu, Yong; Ma, Jun
2017-01-01
As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected.
Lévy noise improves the electrical activity in a neuron under electromagnetic radiation.
Directory of Open Access Journals (Sweden)
Juan Wu
Full Text Available As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected.
Upper bounds on entangling rates of bipartite Hamiltonians
International Nuclear Information System (INIS)
Bravyi, Sergey
2007-01-01
We discuss upper bounds on the rate at which unitary evolution governed by a nonlocal Hamiltonian can generate entanglement in a bipartite system. Given a bipartite Hamiltonian H coupling two finite dimensional particles A and B, the entangling rate is shown to be upper bounded by c log(d) parallel H parallel, where d is the smallest dimension of the interacting particles parallel H parallel is the operator norm of H, and c is a constant close to 1. Under certain restrictions on the initial state we prove an analogous upper bound for the ancilla-assisted entangling rate with a constant c that does not depend upon dimensions of local ancillas. The restriction is that the initial state has at most two distinct Schmidt coefficients (each coefficient may have arbitrarily large multiplicity). Our proof is based on analysis of a mixing rate - a functional measuring how fast entropy can be produced if one mixes a time-independent state with a state evolving unitarily
Vinas, Adolfo F.; Moya, Pablo S.; Navarro, Roberto; Araneda, Jamie A.
2014-01-01
Two fundamental challenging problems of laboratory and astrophysical plasmas are the understanding of the relaxation of a collisionless plasmas with nearly isotropic velocity distribution functions and the resultant state of nearly equipartition energy density with electromagnetic plasma turbulence. Here, we present the results of a study which shows the role that higher-order-modes play in limiting the electromagnetic whistler-like fluctuations in a thermal and non-thermal plasma. Our main results show that for a thermal plasma the magnetic fluctuations are confined by regions that are bounded by the least-damped higher order modes. We further show that the zone where the whistler-cyclotron normal modes merges the electromagnetic fluctuations shifts to longer wavelengths as the beta(sub e) increases. This merging zone has been interpreted as the beginning of the region where the whistler-cyclotron waves losses their identity and become heavily damped while merging with the fluctuations. Our results further indicate that in the case of nonthermal plasmas, the higher-order modes do not confine the fluctuations due to the effective higher-temperature effects and the excess of suprathermal plasma particles. The analysis presented here considers the second-order theory of fluctuations and the dispersion relation of weakly transverse fluctuations, with wave vectors parallel to the uniform background magnetic field, in a finite temperature isotropic bi-Maxwellian and Tsallis-kappa-like magnetized electron-proton plasma. Our results indicate that the spontaneously emitted electromagnetic fluctuations are in fact enhanced over these quasi modes suggesting that such modes play an important role in the emission and absorption of electromagnetic fluctuations in thermal or quasi-thermal plasmas.
Far-Field Superresolution of Thermal Electromagnetic Sources at the Quantum Limit.
Nair, Ranjith; Tsang, Mankei
2016-11-04
We obtain the ultimate quantum limit for estimating the transverse separation of two thermal point sources using a given imaging system with limited spatial bandwidth. We show via the quantum Cramér-Rao bound that, contrary to the Rayleigh limit in conventional direct imaging, quantum mechanics does not mandate any loss of precision in estimating even deep sub-Rayleigh separations. We propose two coherent measurement techniques, easily implementable using current linear-optics technology, that approach the quantum limit over an arbitrarily large range of separations. Our bound is valid for arbitrary source strengths, all regions of the electromagnetic spectrum, and for any imaging system with an inversion-symmetric point-spread function. The measurement schemes can be applied to microscopy, optical sensing, and astrometry at all wavelengths.
International Nuclear Information System (INIS)
Ikhdair, S.M.; Hamzavi, M.; Rajabi, A.A.
2013-01-01
Approximate bound-state solutions of the Dirac equation with q-deformed Woods–Saxon (WS) plus a new generalized ring-shaped (RS) potential are obtained for any arbitrary l-state. The energy eigenvalue equation and corresponding two-component wave functions are calculated by solving the radial and angular wave equations within a shortcut of the Nikiforov–Uvarov (NU) method. The solutions of the radial and polar angular parts of the wave function are expressed in terms of the Jacobi polynomials. A new approximation being expressed in terms of the potential parameters is carried out to deal with the strong singular centrifugal potential term l(l+1)r -2 . Under some limitations, we can obtain solution for the RS Hulthen potential and the standard usual spherical WS potential (q = 1). (author)
A cluster expansion for bound three-alpha particles as a three-body problem
International Nuclear Information System (INIS)
Osman, A.
1981-08-01
A three-body model is proposed to study the nuclear bound states. The nucleus is described as a bound state of three clusters. A cluster expansion is introduced for the three cluster bound state problem. The present integral equations are treated by simple approximate solutions, which lead to effective potentials by using the present cluster expansion. The 12 C nucleus is described as a three-alpha particle bound state. The binding energy of 12 C is calculated numerically using the present cluster expansion as bound three-alpha clusters. The present three-body cluster expansion calculations are very near to the exact three-body calculations using separable potentials. The present theoretical calculations are in good agreement with the experimental measurements. (author)
Integral equation methods for electromagnetics
Volakis, John
2012-01-01
This text/reference is a detailed look at the development and use of integral equation methods for electromagnetic analysis, specifically for antennas and radar scattering. Developers and practitioners will appreciate the broad-based approach to understanding and utilizing integral equation methods and the unique coverage of historical developments that led to the current state-of-the-art. In contrast to existing books, Integral Equation Methods for Electromagnetics lays the groundwork in the initial chapters so students and basic users can solve simple problems and work their way up to the mo
Comments upon a bound state model for a two body system
International Nuclear Information System (INIS)
Micu, L.
2005-01-01
We show that in classical mechanics, classical and relativistic quantum mechanics it is possible to replace the equation of the relative motion for a two-body bound system at rest by individual dynamical equations with correlated solutions. We compare the representations of a bound system in terms of the relative and individual coordinates and mention some of the observable differences. (author)
Gauge theory of weak, electromagnetic and dual electromagnetic interactions
International Nuclear Information System (INIS)
Soln, J.
1980-01-01
An SU 2 x U 1 algebra, in addition to the ordinary electric charge, also establishes the existence of the dual electric charge. This is taken as an indication of the existence of dual electromagnetic interactions in nature. Here, the unification of weak, electromagnetic and dual electromagnetic interactions is performed. The Yang-Mills-type group which contains the electromagnetic, dual electromagnetic and weak currents is SUsub(L,2) x U 1 x U' 1 . The masses of vector mesons are generated through the Higgs-Kibble mechanism. A simple consistency requirement suggests that dual electromagnetism and ordinary electromagnetism have the same strengths, leading the theory to a rather good agreement with experiments. (author)
Nucleon electromagnetic form factors using lattice simulations at the physical point
International Nuclear Information System (INIS)
Alexandrou, C.; Cyprus Univ., Nicosia; Constantinou, M.; Hadjiyiannakou, K.; Kallidonis, C.; Koutsou, G.; Jansen, K.; Vaquero Aviles-Casco, A.
2017-01-01
We present results for the nucleon electromagnetic form factors using an ensemble of maximally twisted mass clover-improved fermions with pion mass of about 130 MeV. We use multiple sink-source separations and three analysis methods to probe ground-state dominance. We evaluate both the connected and disconnected contributions to the nucleon matrix elements. We find that the disconnected quark loop contributions to the isoscalar matrix elements are small giving an upper bound of up to 2% of the connected and smaller than its statistical error. We present results for the isovector and isoscalar electric and magnetic Sachs form factors and the corresponding proton and neutron form factors. By fitting the momentum dependence of the form factors to a dipole form or to the z-expansion we extract the nucleon electric and magnetic radii, as well as, the magnetic moment. We compare our results to experiment as well as to other recent lattice QCD calculations.
Nucleon electromagnetic form factors using lattice simulations at the physical point
Energy Technology Data Exchange (ETDEWEB)
Alexandrou, C. [The Cyprus Institute, Nicosia (Cyprus). Computation-based Science and Technology Research Center; Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Constantinou, M. [Temple Univ., Philadelphia, PA (United States). Dept. of Physics; Hadjiyiannakou, K.; Kallidonis, C.; Koutsou, G. [The Cyprus Institute, Nicosia (Cyprus). Computation-based Science and Technology Research Center; Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Vaquero Aviles-Casco, A. [Utah Univ., Salt Lake City, UT (United States). Dept. of Physics and Astronomy
2017-09-20
We present results for the nucleon electromagnetic form factors using an ensemble of maximally twisted mass clover-improved fermions with pion mass of about 130 MeV. We use multiple sink-source separations and three analysis methods to probe ground-state dominance. We evaluate both the connected and disconnected contributions to the nucleon matrix elements. We find that the disconnected quark loop contributions to the isoscalar matrix elements are small giving an upper bound of up to 2% of the connected and smaller than its statistical error. We present results for the isovector and isoscalar electric and magnetic Sachs form factors and the corresponding proton and neutron form factors. By fitting the momentum dependence of the form factors to a dipole form or to the z-expansion we extract the nucleon electric and magnetic radii, as well as, the magnetic moment. We compare our results to experiment as well as to other recent lattice QCD calculations.
Electromagnetic transitions in the atom
International Nuclear Information System (INIS)
Ulehla, I.; Suk, M.; Trka, Z.
1990-01-01
Methods to achieve excitation of atoms are outlined and conditions necessary for the occurrence of electromagnetic transitions in the atomic shell are given. Radiative transitions between the energy states of the atom include stimulated absorption, spontaneous emission, and stimulated emission. Selection rules applying to the majority of observed transitions are given. The parity concept is explained. It is shown how the electromagnetic field and its interaction with the magnetic moment of the atom lead to a disturbance of the energy states of the atom and the occurrence of various electro-optical and magneto-optical phenomena. The Stark effect and electron spin resonance are described. X-rays and X-ray spectra, the Auger effect and the internal photoeffect are also dealt with. The principle of the laser is explained. (M.D.). 22 figs., 1 tab
Protecting the Power Grid From Electromagnetic Pulses
Simpson, Sarah
2004-10-01
A nuclear explosion high in the Earth's atmosphere does no immediate known harm to living things, but the resulting electromagnetic pulse (EMP) from a single detonation could degrade 70 percent or more of the country's electrical service in an instant, warns the Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack, which presented its findings to the U.S. Congress in July.
Experimental evidence for bounds on quantum correlations.
Bovino, F A; Castagnoli, G; Degiovanni, I P; Castelletto, S
2004-02-13
We implemented the experiment proposed by Cabello in the preceding Letter to test the bounds of quantum correlation. As expected from the theory we found that, for certain choices of local observables, Tsirelson's bound of the Clauser-Horne-Shimony-Holt inequality (2 x square root of 2) is not reached by any quantum states.
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
Localization from near-source quasi-static electromagnetic fields
Energy Technology Data Exchange (ETDEWEB)
Mosher, John Compton [Univ. of Southern California, Los Angeles, CA (United States)
1993-09-01
A wide range of research has been published on the problem of estimating the parameters of electromagnetic and acoustical sources from measurements of signals measured at an array of sensors. In the quasi-static electromagnetic cases examined here, the signal variation from a point source is relatively slow with respect to the signal propagation and the spacing of the array of sensors. As such, the location of the point sources can only be determined from the spatial diversity of the received signal across the array. The inverse source localization problem is complicated by unknown model order and strong local minima. The nonlinear optimization problem is posed for solving for the parameters of the quasi-static source model. The transient nature of the sources can be exploited to allow subspace approaches to separate out the signal portion of the spatial correlation matrix. Decomposition techniques are examined for improved processing, and an adaptation of MUtiple SIgnal Characterization (MUSIC) is presented for solving the source localization problem. Recent results on calculating the Cramer-Rao error lower bounds are extended to the multidimensional problem here. This thesis focuses on the problem of source localization in magnetoencephalography (MEG), with a secondary application to thunderstorm source localization. Comparisons are also made between MEG and its electrical equivalent, electroencephalography (EEG). The error lower bounds are examined in detail for several MEG and EEG configurations, as well as localizing thunderstorm cells over Cape Canaveral and Kennedy Space Center. Time-eigenspectrum is introduced as a parsing technique for improving the performance of the optimization problem.
Crystal structure of Na+, K(+)-ATPase in the Na(+)-bound state.
Nyblom, Maria; Poulsen, Hanne; Gourdon, Pontus; Reinhard, Linda; Andersson, Magnus; Lindahl, Erik; Fedosova, Natalya; Nissen, Poul
2013-10-04
The Na(+), K(+)-adenosine triphosphatase (ATPase) maintains the electrochemical gradients of Na(+) and K(+) across the plasma membrane--a prerequisite for electrical excitability and secondary transport. Hitherto, structural information has been limited to K(+)-bound or ouabain-blocked forms. We present the crystal structure of a Na(+)-bound Na(+), K(+)-ATPase as determined at 4.3 Å resolution. Compared with the K(+)-bound form, large conformational changes are observed in the α subunit whereas the β and γ subunit structures are maintained. The locations of the three Na(+) sites are indicated with the unique site III at the recently suggested IIIb, as further supported by electrophysiological studies on leak currents. Extracellular release of the third Na(+) from IIIb through IIIa, followed by exchange of Na(+) for K(+) at sites I and II, is suggested.
International Nuclear Information System (INIS)
Melo, F. de; Aolita, L.; Davidovich, L.; Toscano, F.
2006-01-01
We propose an experimental procedure to directly measure the state of an electromagnetic field inside a resonator, corresponding to a superconducting transmission line, coupled to a Cooper-pair box (CPB). The measurement protocol is based on the use of a dispersive interaction between the field and the CPB, and the coupling to an external classical field that is tuned to resonance with either the field or the CPB. We present a numerical simulation that demonstrates the feasibility of this protocol, which is within reach of present technology
Bounds on the Effect of Progressive Structural Degradation
DEFF Research Database (Denmark)
Achtziger, Wolfgang; Bendsøe, Martin P; Taylor, John E.
1997-01-01
Problem formulations are presented for the evaluation of upper and lower bounds on the effect of progressive structural degradation. For the purposes of this study, degradation effect is measured by an increase in global structural compliance (flexibility). Thus the stated bounds are given simply...
Electric states and magnetic states in a Majorana field. (Part 1: electric states)
International Nuclear Information System (INIS)
Lochak, G.
1987-01-01
It is shown that the Mojarana condition, by which the Dirac equation is reduced to the so-called ''abbreviated'' equation, may be equivalently replaced in a gauge invariant way by the condition that the chiral invariant equals zero. This allows up to give a Lagrangian derivation of the Majorana field. Symmetry laws of this field, interacting with an electromagnetic field, are then investigated. The system is shown to be split (contrary to the Dirac field, but just as the monopole one) into two chiral components. The solution of the equation of such a chiral component is given in the case of a central electric field. It is shown that there are no bounds states but only ionized states which are a special superposition of positive and negative energy states. Finally the geometrical optics approximation is investigated and the Jacobi equation is solved for a chiral component in a central electric field. All the trajectories are hyperbolic but are not of the classical keplerian type. They are divided into two groups respectively corresponding to attractive and repulsive motions, whatever the particle charge may be [fr
Rigorous bounds on the free energy of electron-phonon models
Raedt, Hans De; Michielsen, Kristel
1997-01-01
We present a collection of rigorous upper and lower bounds to the free energy of electron-phonon models with linear electron-phonon interaction. These bounds are used to compare different variational approaches. It is shown rigorously that the ground states corresponding to the sharpest bounds do
Electromagnetic form factors in the light-front dynamics
International Nuclear Information System (INIS)
Karmanov, V.A.; Smirnov, A.V.
1992-01-01
It is shown that the electromagnetic vertex of a nucleus (and of any bound system), expressed through the wave function in the light-front dynamics at relativistic values of momentum transfer, contains a contribution of nonphysical form factors which increases the total number of invariant form factors (for the deuteron from 3 up to 11). This fact explains an ambiguity in the form factors calculated previously. The physical and nonphysical form factors are covariantly separated. Explicit expressions for physical form factors of systems with spin 0, 1/2 and 1 through the vertex functions are obtained. (orig.)
Thorwart, Michael
2018-01-01
Realizing Majorana bound states (MBS) in condensed matter systems is a key challenge on the way toward topological quantum computing. As a promising platform, one-dimensional magnetic chains on conventional superconductors were theoretically predicted to host MBS at the chain ends. We demonstrate a novel approach to design of model-type atomic-scale systems for studying MBS using single-atom manipulation techniques. Our artificially constructed atomic Fe chains on a Re surface exhibit spin spiral states and a remarkable enhancement of the local density of states at zero energy being strongly localized at the chain ends. Moreover, the zero-energy modes at the chain ends are shown to emerge and become stabilized with increasing chain length. Tight-binding model calculations based on parameters obtained from ab initio calculations corroborate that the system resides in the topological phase. Our work opens new pathways to design MBS in atomic-scale hybrid structures as a basis for fault-tolerant topological quantum computing. PMID:29756034
DEFF Research Database (Denmark)
This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis......, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc....
Momentum-energy of the non-radiating electromagnetic field: open problems?
International Nuclear Information System (INIS)
Kholmetskii, Alexander L
2006-01-01
This paper inspects more closely the problem of the momentum and energy of a bound (non-radiative) electromagnetic (EM) field. It has been shown that for an isolating system of non-radiative non-relativistic mechanically free charged particles, a transformation of mechanical to EM momentum and vice versa occurs in accordance with the requirement P-vector G =const, where P-vector G = P-vector M + Σ i N q i A-vector i is the canonical momentum (N>1 is the number of particles, q is the charge, A-vector is the vector potential, P-vector M is the mechanical momentum of the system). Then dP-vector M /dt = -(d/dt)Σq i A-vector i represents the self-force, acting on this isolating system due to violation of Newton's third law in EM interaction. This equation is not applicable to an isolated charged particle, and the problems of its self-action and its own EM momentum have been examined. Analysing the systems of non-radiative particles, where the retardation is not negligible ('dynamical' systems in our definition) it has been found that the total momentum is the same at the initial and final stationary states of such systems, but it varies with time during the dynamical processes. It means a violation of continuous conservation of the total momentum, if the bound EM field spreads at the light velocity c. Finally, the compatibility of the energy conservation law and the Lentz rule for retarded non-radiative EM field has been examined. It has been shown that for dynamical systems the energy conservation law comes into a certain contradiction with the finite (light) spread velocity for the bound EM field
International Nuclear Information System (INIS)
Boutin, D.
2005-08-01
The first experimental observation of bound-state beta-decay showed, that due solely to the electron stripping, a stable nuclide, e.g. 163 Dy, became unstable. Also a drastic modification of the half-life of bare 187 Re, from 4.12(2) x 10 10 years down to 32.9(20) years, could be observed. It was mainly due to the possibility for the mother nuclide to decay into a previously inaccessible nuclear level of the daughter nuclide. It was proposed to study a nuclide where this decay mode was competing with continuum-state beta-decay, in order to measure their respective branchings. The ratio β b /β c could also be evaluated for the first time. 207 Tl was chosen due to its high atomic number, and Q-value of about 1.4 MeV, small enough to enhance the β b probability and large enough to allow the use of time-resolved Schottky Mass Spectrometry (SMS) to study the evolution of mother and bound-state beta-decay daughter ions. The decay properties of the ground state and isomeric state of 207 Tl 81+ have been investigated at the GSI accelerator facility in two separate experiments. For the first time β-decay where the electron could go either to a bound state (atomic orbitals) and lead to 207 Pb 81+ as a daughter nuclide, or to a continuum state and lead to 207 Pb 82+ , has been observed. The respective branchings of these two processes could be measured as well. The deduced total nuclear half-life of 255(17) s for 207 Tl 81+ , was slightly modified with respect to the half-life of the neutral atom of 286(2) s. It was nevertheless in very good agreement with calculations based on the assumption that the beta-decay was following an allowed type of transition. The branching β b /β c =0.192(20), was also in very good agreement with the same calculations. The application of stochastic precooling allowed to observe in addition the 1348 keV short-lived isomeric state of 207 Tl. The half-life of this isomeric state was measured as 1.47(32) s, which shows a small deviation
The g-factor of the bound electron in hydrogenic ions
International Nuclear Information System (INIS)
Quint, Wolfgang
2001-01-01
We report on the measurement of the g-factor of the electron bound in an atomic ion. A single hydrogenic ion ( 12 C 5+ ) is stored in a Penning trap. The electronic spin state of the ion is monitored via the continuous Stern-Gerlach effect in a quantum non-demolition measurement. Quantum jumps between the two spin states (spin up and spin down) are induced by a microwave field at the spin precession frequency of the bound electron. The g-factor of the bound electron is obtained by varying the microwave frequency and counting the number of spin flips for a fixed time interval. Applications of the continuous Stern-Gerlach effect include high-accuracy tests of bound-state quantum electrodynamics (QED), the measurement of the atomic mass of the electron, the determination of the fine structure constant α, and the measurement of nuclear g-factors
Adam, Jaroslav; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahmed, Ijaz; Ahn, Sang Un; Aimo, Ilaria; Aiola, Salvatore; Ajaz, Muhammad; Akindinov, Alexander; Alam, Sk Noor; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Armesto Perez, Nestor; Arnaldi, Roberta; Aronsson, Tomas; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Ball, Markus; Baltasar Dos Santos Pedrosa, Fernando; Baral, Rama Chandra; Barbano, Anastasia Maria; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartalini, Paolo; Bartke, Jerzy Gustaw; Bartsch, Esther; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batista Camejo, Arianna; Batyunya, Boris; Batzing, Paul Christoph; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bello Martinez, Hector; Bellwied, Rene; Belmont Iii, Ronald John; Belmont Moreno, Ernesto; Belyaev, Vladimir; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhat, Inayat Rasool; Bhati, Ashok Kumar; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Biswas, Saikat; Bjelogrlic, Sandro; Blanco, Fernando; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Boldizsar, Laszlo; Bombara, Marek; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Borri, Marcello; Bossu, Francesco; Botje, Michiel; Botta, Elena; Boettger, Stefan; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Broker, Theo Alexander; Browning, Tyler Allen; Broz, Michal; Brucken, Erik Jens; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Buxton, Jesse Thomas; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calero Diaz, Liliet; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Carena, Francesco; Carena, Wisla; Castillo Castellanos, Javier Ernesto; Castro, Andrew John; Casula, Ester Anna Rita; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Chartier, Marielle; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chelnokov, Volodymyr; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Chochula, Peter; Choi, Kyungeon; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Connors, Megan Elizabeth; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortes Maldonado, Ismael; Cortese, Pietro; Cosentino, Mauro Rogerio; Costa, Filippo; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dahms, Torsten; Dainese, Andrea; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; De Caro, Annalisa; De Cataldo, Giacinto; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; Deisting, Alexander; Deloff, Andrzej; Denes, Ervin Sandor; D'Erasmo, Ginevra; Di Bari, Domenico; Di Mauro, Antonio; Di Nezza, Pasquale; Diaz Corchero, Miguel Angel; Dietel, Thomas; Dillenseger, Pascal; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni; Domenicis Gimenez, Diogenes; Donigus, Benjamin; Dordic, Olja; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent; Dupieux, Pascal; Ehlers Iii, Raymond James; Elia, Domenico; Engel, Heiko; Erazmus, Barbara Ewa; Erhardt, Filip; Eschweiler, Dominic; Espagnon, Bruno; Estienne, Magali Danielle; Esumi, Shinichi; Evans, David; Evdokimov, Sergey; Eyyubova, Gyulnara; Fabbietti, Laura; Fabris, Daniela; Faivre, Julien; Fantoni, Alessandra; Fasel, Markus; Feldkamp, Linus; Felea, Daniel; Feliciello, Alessandro; Feofilov, Grigorii; Ferencei, Jozef; Fernandez Tellez, Arturo; Gonzalez Ferreiro, Elena; Ferretti, Alessandro; Festanti, Andrea; Figiel, Jan; Araujo Silva Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Fleck, Martin Gabriel; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Francescon, Andrea; Frankenfeld, Ulrich Michael; Fuchs, Ulrich; Furget, Christophe; Furs, Artur; Fusco Girard, Mario; Gaardhoeje, Jens Joergen; Gagliardi, Martino; Gago Medina, Alberto Martin; Gallio, Mauro; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Gao, Chaosong; Garabatos Cuadrado, Jose; Garcia-Solis, Edmundo Javier; Gargiulo, Corrado; Gasik, Piotr Jan; Germain, Marie; Gheata, Andrei George; Gheata, Mihaela; Ghosh, Premomoy; Ghosh, Sanjay Kumar; Gianotti, Paola; Giubellino, Paolo; Giubilato, Piero; Gladysz-Dziadus, Ewa; Glassel, Peter; Gomez Ramirez, Andres; Gonzalez Zamora, Pedro; Gorbunov, Sergey; Gorlich, Lidia Maria; Gotovac, Sven; Grabski, Varlen; Graczykowski, Lukasz Kamil; Grelli, Alessandro; Grigoras, Alina Gabriela; Grigoras, Costin; Grigoryev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grynyov, Borys; Grion, Nevio; Grosse-Oetringhaus, Jan Fiete; Grossiord, Jean-Yves; Grosso, Raffaele; Guber, Fedor; Guernane, Rachid; Guerzoni, Barbara; Gulbrandsen, Kristjan Herlache; Gulkanyan, Hrant; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Haake, Rudiger; Haaland, Oystein Senneset; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Hanratty, Luke David; Hansen, Alexander; Harris, John William; Hartmann, Helvi; Harton, Austin Vincent; Hatzifotiadou, Despina; Hayashi, Shinichi; Heckel, Stefan Thomas; Heide, Markus Ansgar; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Hess, Benjamin Andreas; Hetland, Kristin Fanebust; Hilden, Timo Eero; Hillemanns, Hartmut; Hippolyte, Boris; Hristov, Peter Zahariev; Huang, Meidana; Humanic, Thomas; Hussain, Nur; Hussain, Tahir; Hutter, Dirk; Hwang, Dae Sung; Ilkaev, Radiy; Ilkiv, Iryna; Inaba, Motoi; Ionita, Costin; Ippolitov, Mikhail; Irfan, Muhammad; Ivanov, Marian; Ivanov, Vladimir; Izucheev, Vladimir; Jacholkowski, Adam Wlodzimierz; Jacobs, Peter Martin; Jahnke, Cristiane; Jang, Haeng Jin; Janik, Malgorzata Anna; Pahula Hewage, Sandun; Jena, Chitrasen; Jena, Satyajit; Jimenez Bustamante, Raul Tonatiuh; Jones, Peter Graham; Jung, Hyungtaik; Jusko, Anton; Kalinak, Peter; Kalweit, Alexander Philipp; Kamin, Jason Adrian; Kang, Ju Hwan; Kaplin, Vladimir; Kar, Somnath; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karpechev, Evgeny; Kebschull, Udo Wolfgang; Keidel, Ralf; Keijdener, Darius Laurens; Keil, Markus; Khan, Kamal; Khan, Mohammed Mohisin; Khan, Palash; Khan, Shuaib Ahmad; Khanzadeev, Alexei; Kharlov, Yury; Kileng, Bjarte; Kim, Beomkyu; Kim, Do Won; Kim, Dong Jo; Kim, Hyeonjoong; Kim, Jinsook; Kim, Mimae; Kim, Minwoo; Kim, Se Yong; Kim, Taesoo; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Kiss, Gabor; Klay, Jennifer Lynn; Klein, Carsten; Klein, Jochen; Klein-Boesing, Christian; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Kobayashi, Taiyo; Kobdaj, Chinorat; Kofarago, Monika; Kohler, Markus Konrad; Kollegger, Thorsten; Kolozhvari, Anatoly; Kondratev, Valerii; Kondratyeva, Natalia; Kondratyuk, Evgeny; Konevskikh, Artem; Kouzinopoulos, Charalampos; Kovalenko, Vladimir; Kowalski, Marek; Kox, Serge; Koyithatta Meethaleveedu, Greeshma; Kral, Jiri; Kralik, Ivan; Kravcakova, Adela; Krelina, Michal; Kretz, Matthias; Krivda, Marian; Krizek, Filip; Kryshen, Evgeny; Krzewicki, Mikolaj; Kubera, Andrew Michael; Kucera, Vit; Kucheryaev, Yury; Kugathasan, Thanushan; Kuhn, Christian Claude; Kuijer, Paulus Gerardus; Kulakov, Igor; Kumar, Jitendra; Lokesh, Kumar; Kurashvili, Podist; Kurepin, Alexander; Kurepin, Alexey; Kuryakin, Alexey; Kushpil, Svetlana; Kweon, Min Jung; Kwon, Youngil; La Pointe, Sarah Louise; La Rocca, Paola; Lagana Fernandes, Caio; Lakomov, Igor; Langoy, Rune; Lara Martinez, Camilo Ernesto; Lardeux, Antoine Xavier; Lattuca, Alessandra; Laudi, Elisa; Lea, Ramona; Leardini, Lucia; Lee, Graham Richard; Lee, Seongjoo; Legrand, Iosif; Lehnert, Joerg Walter; Lemmon, Roy Crawford; Lenti, Vito; Leogrande, Emilia; Leon Monzon, Ildefonso; Leoncino, Marco; Levai, Peter; Li, Shuang; Li, Xiaomei; Lien, Jorgen Andre; Lietava, Roman; Lindal, Svein; Lindenstruth, Volker; Lippmann, Christian; Lisa, Michael Annan; Ljunggren, Hans Martin; Lodato, Davide Francesco; Lonne, Per-Ivar; Loggins, Vera Renee; Loginov, Vitaly; Loizides, Constantinos; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lowe, Andrew John; Lu, Xianguo; Luettig, Philipp Johannes; Lunardon, Marcello; Luparello, Grazia; Maevskaya, Alla; Mager, Magnus; Mahajan, Sanjay; Mahmood, Sohail Musa; Maire, Antonin; Majka, Richard Daniel; Malaev, Mikhail; Maldonado Cervantes, Ivonne Alicia; Malinina, Liudmila; Mal'Kevich, Dmitry; Malzacher, Peter; Mamonov, Alexander; Manceau, Loic Henri Antoine; Manko, Vladislav; Manso, Franck; Manzari, Vito; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Margutti, Jacopo; Marin, Ana Maria; Markert, Christina; Marquard, Marco; Martashvili, Irakli; Martin, Nicole Alice; Martin Blanco, Javier; Martinengo, Paolo; Martinez Hernandez, Mario Ivan; Martinez-Garcia, Gines; Martinez Pedreira, Miguel; Martynov, Yevgen; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Massacrier, Laure Marie; Mastroserio, Annalisa; Matyja, Adam Tomasz; Mayer, Christoph; Mazer, Joel Anthony; Mazzoni, Alessandra Maria; Mcdonald, Daniel; Meddi, Franco; Menchaca-Rocha, Arturo Alejandro; Meninno, Elisa; Mercado-Perez, Jorge; Meres, Michal; Miake, Yasuo; Mieskolainen, Matti Mikael; Mikhaylov, Konstantin; Milano, Leonardo; Milosevic, Jovan; Minervini, Lazzaro Manlio; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz Czeslaw; Mitra, Jubin; Mitu, Ciprian Mihai; Mohammadi, Naghmeh; Mohanty, Bedangadas; Molnar, Levente; Montano Zetina, Luis Manuel; Montes Prado, Esther; Morando, Maurizio; Moretto, Sandra; Morreale, Astrid; Morsch, Andreas; Muccifora, Valeria; Mudnic, Eugen; Muhlheim, Daniel Michael; Muhuri, Sanjib; Mukherjee, Maitreyee; Muller, Hans; Mulligan, James Declan; Gameiro Munhoz, Marcelo; Murray, Sean; Musa, Luciano; Musinsky, Jan; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Naru, Muhammad Umair; Nattrass, Christine; Nayak, Kishora; Nayak, Tapan Kumar; Nazarenko, Sergey; Nedosekin, Alexander; Nellen, Lukas; Ng, Fabian; Nicassio, Maria; Niculescu, Mihai; Niedziela, Jeremi; Nielsen, Borge Svane; Nikolaev, Sergey; Nikulin, Sergey; Nikulin, Vladimir; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Norman, Jaime; Nyanin, Alexander; Nystrand, Joakim Ingemar; Oeschler, Helmut Oskar; Oh, Saehanseul; Oh, Sun Kun; Ohlson, Alice Elisabeth; Okatan, Ali; Okubo, Tsubasa; Olah, Laszlo; Oleniacz, Janusz; Oliveira Da Silva, Antonio Carlos; Oliver, Michael Henry; Onderwaater, Jacobus; Oppedisano, Chiara; Ortiz Velasquez, Antonio; Oskarsson, Anders Nils Erik; Otwinowski, Jacek Tomasz; Oyama, Ken; Ozdemir, Mahmut; Pachmayer, Yvonne Chiara; Pagano, Paola; Paic, Guy; Pajares Vales, Carlos; Pal, Susanta Kumar; Pan, Jinjin; Pandey, Ashutosh Kumar; Pant, Divyash; Papikyan, Vardanush; Pappalardo, Giuseppe; Pareek, Pooja; Park, Woojin; Parmar, Sonia; Passfeld, Annika; Paticchio, Vincenzo; Paul, Biswarup; Pawlak, Tomasz Jan; Peitzmann, Thomas; Pereira Da Costa, Hugo Denis Antonio; Pereira De Oliveira Filho, Elienos; Peresunko, Dmitry Yurevich; Perez Lara, Carlos Eugenio; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petrov, Viacheslav; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Pikna, Miroslav; Pillot, Philippe; Pinazza, Ombretta; Pinsky, Lawrence; Piyarathna, Danthasinghe; Ploskon, Mateusz Andrzej; Planinic, Mirko; Pluta, Jan Marian; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Polishchuk, Boris; Poljak, Nikola; Poonsawat, Wanchaloem; Pop, Amalia; Porteboeuf, Sarah Julie; Porter, R Jefferson; Pospisil, Jan; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puccio, Maximiliano; Puddu, Giovanna; Pujahari, Prabhat Ranjan; Punin, Valery; Putschke, Jorn Henning; Qvigstad, Henrik; Rachevski, Alexandre; Raha, Sibaji; Rajput, Sonia; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Razazi, Vahedeh; Read, Kenneth Francis; Real, Jean-Sebastien; Redlich, Krzysztof; Reed, Rosi Jan; Rehman, Attiq Ur; Reichelt, Patrick Simon; Reicher, Martijn; Reidt, Felix; Ren, Xiaowen; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; Rettig, Felix Vincenz; Revol, Jean-Pierre; Reygers, Klaus Johannes; Riabov, Viktor; Ricci, Renato Angelo; Richert, Tuva Ora Herenui; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Ristea, Catalin-Lucian; Rivetti, Angelo; Rocco, Elena; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roeed, Ketil; Rogochaya, Elena; Rohr, David Michael; Roehrich, Dieter; Romita, Rosa; Ronchetti, Federico; Ronflette, Lucile; Rosnet, Philippe; Rossi, Andrea; Roukoutakis, Filimon; Roy, Ankhi; Roy, Christelle Sophie; Roy, Pradip Kumar; Rubio Montero, Antonio Juan; Rui, Rinaldo; Russo, Riccardo; Ryabinkin, Evgeny; Ryabov, Yury; Rybicki, Andrzej; Sadovskiy, Sergey; Safarik, Karel; Sahlmuller, Baldo; Sahoo, Pragati; Sahoo, Raghunath; Sahoo, Sarita; Sahu, Pradip Kumar; Saini, Jogender; Sakai, Shingo; Saleh, Mohammad Ahmad; Salgado Lopez, Carlos Alberto; Salzwedel, Jai Samuel Nielsen; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sanchez Castro, Xitzel; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Santagati, Gianluca; Sarkar, Debojit; Scapparone, Eugenio; Scarlassara, Fernando; Scharenberg, Rolf Paul; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schuchmann, Simone; Schukraft, Jurgen; Schulc, Martin; Schuster, Tim Robin; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Rebecca Michelle; Seeder, Karin Soraya; Seger, Janet Elizabeth; Sekiguchi, Yuko; Selyuzhenkov, Ilya; Senosi, Kgotlaesele; Seo, Jeewon; Serradilla Rodriguez, Eulogio; Sevcenco, Adrian; Shabanov, Arseniy; Shabetai, Alexandre; Shadura, Oksana; Shahoyan, Ruben; Shangaraev, Artem; Sharma, Ankita; Sharma, Natasha; Shigaki, Kenta; Shtejer Diaz, Katherin; Sibiryak, Yury; Siddhanta, Sabyasachi; Sielewicz, Krzysztof Marek; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Silvestre, Catherine Micaela; Simatovic, Goran; Simonetti, Giuseppe; Singaraju, Rama Narayana; Singh, Ranbir; Singha, Subhash; Singhal, Vikas; Sinha, Bikash; Sarkar - Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Slupecki, Maciej; Smirnov, Nikolai; Snellings, Raimond; Snellman, Tomas Wilhelm; Soegaard, Carsten; Soltz, Ron Ariel; Song, Jihye; Song, Myunggeun; Song, Zixuan; Soramel, Francesca; Sorensen, Soren Pontoppidan; Spacek, Michal; Spiriti, Eleuterio; Sputowska, Iwona Anna; Spyropoulou-Stassinaki, Martha; Srivastava, Brijesh Kumar; Stachel, Johanna; Stan, Ionel; Stefanek, Grzegorz; Steinpreis, Matthew Donald; Stenlund, Evert Anders; Steyn, Gideon Francois; Stiller, Johannes Hendrik; Stocco, Diego; Strmen, Peter; Alarcon Do Passo Suaide, Alexandre; Sugitate, Toru; Suire, Christophe Pierre; Suleymanov, Mais Kazim Oglu; Sultanov, Rishat; Sumbera, Michal; Symons, Timothy; Szabo, Alexander; Szanto De Toledo, Alejandro; Szarka, Imrich; Szczepankiewicz, Adam; Szymanski, Maciej Pawel; Takahashi, Jun; Tanaka, Naoto; Tangaro, Marco-Antonio; Tapia Takaki, Daniel Jesus; Tarantola Peloni, Attilio; Tariq, Mohammad; Tarzila, Madalina-Gabriela; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terasaki, Kohei; Terrevoli, Cristina; Teyssier, Boris; Thaeder, Jochen Mathias; Thomas, Deepa; Tieulent, Raphael Noel; Timmins, Anthony Robert; Toia, Alberica; Trogolo, Stefano; Trubnikov, Victor; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vajzer, Michal; Vala, Martin; Valencia Palomo, Lizardo; Vallero, Sara; Van Der Maarel, Jasper; Van Hoorne, Jacobus Willem; Van Leeuwen, Marco; Vanat, Tomas; Vande Vyvre, Pierre; Varga, Dezso; Diozcora Vargas Trevino, Aurora; Vargyas, Marton; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vauthier, Astrid; Vechernin, Vladimir; Veen, Annelies Marianne; Veldhoen, Misha; Velure, Arild; Venaruzzo, Massimo; Vercellin, Ermanno; Vergara Limon, Sergio; Vernet, Renaud; Verweij, Marta; Vickovic, Linda; Viesti, Giuseppe; Viinikainen, Jussi Samuli; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Vinogradov, Alexander; Vinogradov, Leonid; Vinogradov, Yury; Virgili, Tiziano; Vislavicius, Vytautas; Viyogi, Yogendra; Vodopyanov, Alexander; Volkl, Martin Andreas; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; Von Haller, Barthelemy; Vorobyev, Ivan; Vranic, Danilo; Vrlakova, Janka; Vulpescu, Bogdan; Vyushin, Alexey; Wagner, Boris; Wagner, Jan; Wang, Hongkai; Wang, Mengliang; Wang, Yifei; Watanabe, Daisuke; Weber, Michael; Weber, Steffen Georg; Wessels, Johannes Peter; Westerhoff, Uwe; Wiechula, Jens; Wikne, Jon; Wilde, Martin Rudolf; Wilk, Grzegorz Andrzej; Wilkinson, Jeremy John; Williams, Crispin; Windelband, Bernd Stefan; Winn, Michael Andreas; Yaldo, Chris G; Yamaguchi, Yorito; Yang, Hongyan; Yang, Ping; Yano, Satoshi; Yasnopolskiy, Stanislav; Yin, Zhongbao; Yokoyama, Hiroki; Yoo, In-Kwon; Yurchenko, Volodymyr; Yushmanov, Igor; Zaborowska, Anna; Zaccolo, Valentina; Zaman, Ali; Zampolli, Chiara; Correia Zanoli, Henrique Jose; Zaporozhets, Sergey; Zarochentsev, Andrey; Zavada, Petr; Zavyalov, Nikolay; Zbroszczyk, Hanna Paulina; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Haitao; Zhang, Xiaoming; Zhang, Yonghong; Zhao, Chengxin; Zhigareva, Natalia; Zhou, Daicui; Zhou, You; Zhou, Zhuo; Zhu, Hongsheng; Zhu, Jianhui; Zhu, Xiangrong; Zichichi, Antonino; Zimmermann, Alice; Zimmermann, Markus Bernhard; Zinovjev, Gennady; Zyzak, Maksym
2016-01-10
We present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possible $\\overline{\\Lambda\\mathrm{n}}$ bound state. The search is performed with the ALICE detector in central (0-10%) Pb-Pb collisions at $ \\sqrt{s_{\\rm{NN}}} = 2.76$ TeV, by invariant mass analysis in the decay modes $\\overline{\\Lambda\\mathrm{n}} \\rightarrow \\overline{\\mathrm{d}} \\pi^{+} $ and H-dibaryon $\\rightarrow \\Lambda \\mathrm{p} \\pi^{-}$. No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound states, like the deuteron and the hypertriton.
Surface Andreev Bound States and Odd-Frequency Pairing in Topological Superconductor Junctions
Tanaka, Yukio; Tamura, Shun
2018-04-01
In this review, we summarize the achievement of the physics of surface Andreev bound states (SABS) up to now. The route of this activity has started from the physics of SABS of unconventional superconductors where the pair potential has a sign change on the Fermi surface. It has been established that SABS can be regarded as a topological edge state with topological invariant defined in the bulk Hamiltonian. On the other hand, SABS accompanies odd-frequency pairing like spin-triplet s-wave or spin-singlet p-wave. In a spin-triplet superconductor junction, induced odd-frequency pairing can penetrate into a diffusive normal metal (DN) attached to the superconductor. It causes so called anomalous proximity effect where the local density of states of quasiparticle in DN has a zero energy peak. When bulk pairing symmetry is spin-triplet px-wave, the anomalous proximity effect becomes prominent and the zero bias voltage conductance is always quantized independent of the resistance in DN and interface. Finally, we show that the present anomalous proximity effect is realized in an artificial topological superconducting system, where a nanowire with spin-orbit coupling and Zeeman field is put on the conventional spin-singlet s-wave superconductor.
Current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation
Directory of Open Access Journals (Sweden)
N Hatefi Kargan
2013-09-01
Full Text Available In this paper, current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation has been calculated and compared with the results when there is no electromagnetic radiation. For calculating current -voltage characteristic, it is required to calculate the transmission coefficient of electrons from the well and barrier structures of this device. For calculating the transmission coefficient of electrons at the presence of electromagnetic radiation, Finite Difference Time Domain (FDTD method has been used and when there is no electromagnetic radiation Transfer Matrix Method (TMM and finite diffirence time domain method have been used. The results show that the presence of electromagnetic radiation causes resonant states other than principal resonant state (without presence of electromagnetic radiation to appear on the transmition coefficient curve where they are in distances from the principal peak and from each other. Also, the presence of electromagnetic radiation causes peaks other than principal peak to appear on the current-voltage characteristics of the device. Under electromagnetic radiation, the number of peaks on the current-voltage curve is smaller than the number of peaks on the current-voltage transmission coefficient. This is due to the fact that current-voltage curve is the result of integration on the energy of electrons, Thus, the sharper and low height peaks on the transmission coefficient do not appear on the current-voltage characteristic curve.
Broadband electromagnetic analysis of compacted kaolin
International Nuclear Information System (INIS)
Bore, Thierry; Scheuermann, Alexander; Wagner, Norman; Cai, Caifang
2017-01-01
The mechanical compaction of soil influences not only the mechanical strength and compressibility but also the hydraulic behavior in terms of hydraulic conductivity and soil suction. At the same time, electric and dielectric parameters are increasingly used to characterize soil and to relate them with mechanic and hydraulic parameters. In the presented study electromagnetic soil properties and suction were measured under defined conditions of standardized compaction tests. The impact of external mechanical stress conditions of nearly pure kaolinite was analyzed on soil suction and broadband electromagnetic soil properties. An experimental procedure was developed and validated to simultaneously determine mechanical, hydraulic and broadband (1 MHz–3 GHz) electromagnetic properties of the porous material. The frequency dependent electromagnetic properties were modeled with a classical mixture equation (advanced Lichtenecker and Rother model, ALRM) and a hydraulic-mechanical-electromagnetic coupling approach was introduced considering water saturation, soil structure (bulk density, porosity), soil suction (pore size distribution, water sorption) as well as electrical conductivity of the aqueous pore solution. Moreover, the relaxation behavior was analyzed with a generalized fractional relaxation model concerning a high-frequency water process and two interface processes extended with an apparent direct current conductivity contribution. The different modeling approaches provide a satisfactory agreement with experimental data for the real part. These results show the potential of broadband electromagnetic approaches for quantitative estimation of the hydraulic state of the soil during densification. (paper)
Widmann, E; Curceanu, C; Trento 2006; Trento06
2006-01-01
These are the miniproceedings of the workshop "Exotic hadronic atoms, deeply bound kaonic nuclear states and antihydrogen: present results, future challenges," which was held at the European Centre for Theoretical Nuclear Physics and Related Studies (ECT*), Trento (Italy), June 19-24, 2006. The document includes a short presentation of the topics, the list of participants, and a short contribution from each speaker.
[Dynamics of biomacromolecules in coherent electromagnetic radiation field].
Leshcheniuk, N S; Apanasevich, E E; Tereshenkov, V I
2014-01-01
It is shown that induced oscillations and periodic displacements of the equilibrium positions occur in biomacromolecules in the absence of electromagnetic radiation absorption, due to modulation of interaction potential between atoms and groups of atoms forming the non-valence bonds in macromolecules by the external electromagnetic field. Such "hyperoscillation" state causes inevitably the changes in biochemical properties of macromolecules and conformational transformation times.
DEFF Research Database (Denmark)
Khan, Amir; Connolly, J.A.D.; Olsen, Nils
2006-01-01
We present a general method to constrain planetary composition and thermal state from an inversion of long-period electromagnetic sounding data. As an example of our approach, we reexamine the problem of inverting lunar day-side transfer functions to constrain the internal structure of the Moon. We...... to significantly influence the inversion results. In order to improve future inferences about lunar composition and thermal state, more electrical conductivity measurements are needed especially for minerals appropriate to the Moon, such as pyrope and almandine....
Faddeev-Yakubovsky technique for weakly bound systems
International Nuclear Information System (INIS)
Hadizadeh, M.R.; Yamashita, M.T.; Tomio, Lauro; Delfino, A.
2011-01-01
Nature shows the existence of weakly bound systems in different sectors, ranging from atomic to nuclear physics. Few-body systems with large scattering length exhibit universal features, which are independent of the details of the interaction, and thus are common to nuclear and atomic systems. Very different methods are used to study the properties of few-body systems, from Faddeev methods to diagonalization methods that rely on an expansion of the wave functions in a complete basis set, like e.g. hyper-spherical harmonics and no core shell model. In this talk we present Faddeev-Yakubovsky method to study the three- and four-body bound states in momentum space. To show the efficiency and accuracy of the method we investigate the three- and four-boson weakly bound states in unitary limit (for zero two-body binding) and we present a pretty complete picture of universality. (author)
Inquiry for the conversion of the (π+ - π-) bound state into two π0
International Nuclear Information System (INIS)
Bunatyan, G.G.
1998-01-01
In the work presented, the decay of the pionium, that is the (π + π - ) bound state, into two π 0 is studied, the ππ-interaction causing this transition being described by the underlying Weinberg Lagrangian. The calculation with such a ππ-Lagrangian being carried out, the π-meson size r 0 emerges to be allowed for, and this quantity occurs in the final result. The bound (π + π - )-system itself is presumed to be due to the instantaneous Coulomb interaction and is treated consistently nonrelativistically, the Bethe-Salpeter equation being utilized. When calculating, the terms to the lowest order in the fine structure constant α and the terms ∼ ln (r 0 ) are retained. The obtained pionium lifetime τ is thought to be compatible with the conceivable future experimental data. The dependence of the results on the effective Lagrangian parameters is visualized. The investigation carried out persuades us that it is just the complete form of the genuine ππ-interaction that determines the pionium lifetime , but not much simply the ππ scattering lengths. The inquiry into pionium decaying promotes to specify the validity of the various ππ-interaction descriptions
Observable gravitational and electromagnetic orbits and trajectories in discrete physics
International Nuclear Information System (INIS)
Noyes, H.P.; McGoveran, D.O.
1988-01-01
Our discrete and finite version of relativistic quantum mechanics provides an elementary particle physics consistent with the standard model of quarks and leptons. Our recent relativistic calculation of the bound state spectrum of hydrogen has allowed us to make a combinatorial correction to the first order estimate of 1/α = /Dirac h/c/e 2 = 137 derived from the combinatorial hierarchy and achieve agreement with experiment up to terms of order α 3 . The same theory requires that to first order /Dirac h/c/Gm/sub p/ 2 = 2 127 + 136 ≅ 1.7 /times/ 10 38 . Using the emission and absorption of spin 1 photons and spin 2 gravitons in this framework, we try to show that we can meet the three additional tests of general relativity---solar red shift, solar bending of light, and precession of the perihelion of Mercury. We predict that a macroscopic electromagnetic orbit would have four times the Sommerfeld precession for basically the same reason that Mercury has six times the Sommerfeld precession. 20 refs
The Biological Effects of Weak Electromagnetic Fields
International Nuclear Information System (INIS)
Algattawi, A.; Elshyrih, H.
2010-01-01
Many studies investigated that weak electromagnetic fields remove calcium ions bound to the membranes of living cells, making them more likely to tear,. There is an enzyme that destroys DNA this enzyme leaking through the membranes of lysosomes explains the fragmentation of DNA. This case was seen in cells exposed to mobile phone signals. When this occurs in the germ line it reduces fertility and predicts genetic damage in future generations. Although leakage of calcium ions into the cytosol (the main part of the cell) accelerates the growth, but it also promotes the growth of tumors. Leakage of calcium ions into neurons (brain cells) makes nerve impulses accounting for pain and other neurological symptoms in electro sensitive. It also reduces the signal to noise ratio of the brain making it less likely to respond. This may be partially responsible for the increased accident rate of drivers using mobile phones. More details for the molecular mechanisms to explain characteristics of electromagnetic exposure are needed, e.g. I) why weak fields are more effective than strong ones, II) why some frequencies such as 16 Hz are especially potent and III) why pulsed fields do more damage
Bound states via Higgs exchanging and heavy resonant di-Higgs
Directory of Open Access Journals (Sweden)
Zhaofeng Kang
2017-08-01
Full Text Available The existence of Higgs boson h predicted by the standard model (SM was established and hunting for clues to new physics (NP hidden in h has become the top priority in particle physics. In this paper we explore an intriguing phenomenon that prevails in NP associated with h, bound state (Bh, referring to the ground state only of relatively heavy particles ϕ out of NP via interchanging h. This is well-motivated due to the intrinsic properties of h: It has zero spin and light mass, capable of mediating Yukawa interactions; moreover, it may be strongly coupled to ϕ in several important contexts, from addressing the naturalness problem by compositeness/supersymmetry (SUSY/classical scale invariance to understanding neutrino mass origin radiatively and matter asymmetry by electroweak baryogensis. The new resonance Bh, being a neutral scalar boson, has important implications to the large hadron collider (LHC di-Higgs search because it yields a clear resonant di-Higgs signature at the high mass region (≳1 TeV. In other words, searching for Bh offers a new avenue to probe the hidden sector with a Higgs-portal. For illustration in this paper we concentrate on two examples, the stop sector in SUSY and an inert Higgs doublet from a radiative neutrino model. In particular, h-mediation opens a new and wide window to probe the conventional stoponium and the current date begins to have sensitivity to stoponium around TeV.
Bound states via Higgs exchanging and heavy resonant di-Higgs
Kang, Zhaofeng
2017-08-01
The existence of Higgs boson h predicted by the standard model (SM) was established and hunting for clues to new physics (NP) hidden in h has become the top priority in particle physics. In this paper we explore an intriguing phenomenon that prevails in NP associated with h, bound state (Bh, referring to the ground state only) of relatively heavy particles ϕ out of NP via interchanging h. This is well-motivated due to the intrinsic properties of h: It has zero spin and light mass, capable of mediating Yukawa interactions; moreover, it may be strongly coupled to ϕ in several important contexts, from addressing the naturalness problem by compositeness/supersymmetry (SUSY)/classical scale invariance to understanding neutrino mass origin radiatively and matter asymmetry by electroweak baryogensis. The new resonance Bh, being a neutral scalar boson, has important implications to the large hadron collider (LHC) di-Higgs search because it yields a clear resonant di-Higgs signature at the high mass region (≳ 1 TeV). In other words, searching for Bh offers a new avenue to probe the hidden sector with a Higgs-portal. For illustration in this paper we concentrate on two examples, the stop sector in SUSY and an inert Higgs doublet from a radiative neutrino model. In particular, h-mediation opens a new and wide window to probe the conventional stoponium and the current date begins to have sensitivity to stoponium around TeV.
Electroweak-charged bound states as LHC probes of hidden forces
Li, Lingfeng; Salvioni, Ennio; Tsai, Yuhsin; Zheng, Rui
2018-01-01
We explore the LHC reach on beyond-the-standard model (BSM) particles X associated with a new strong force in a hidden sector. We focus on the motivated scenario where the SM and hidden sectors are connected by fermionic mediators ψ+,0 that carry SM electroweak charges. The most promising signal is the Drell-Yan production of a ψ±ψ¯ 0 pair, which forms an electrically charged vector bound state ϒ± due to the hidden force and later undergoes resonant annihilation into W±X . We analyze this final state in detail in the cases where X is a real scalar ϕ that decays to b b ¯, or a dark photon γd that decays to dileptons. For prompt X decays, we show that the corresponding signatures can be efficiently probed by extending the existing ATLAS and CMS diboson searches to include heavy resonance decays into BSM particles. For long-lived X , we propose new searches where the requirement of a prompt hard lepton originating from the W boson ensures triggering and essentially removes any SM backgrounds. To illustrate the potential of our results, we interpret them within two explicit models that contain strong hidden forces and electroweak-charged mediators, namely λ -supersymmetry (SUSY) and non-SUSY ultraviolet extensions of the twin Higgs model. The resonant nature of the signals allows for the reconstruction of the mass of both ϒ± and X , thus providing a wealth of information about the hidden sector.
Exact spinor-scalar bound states in a quantum field theory with scalar interactions
International Nuclear Information System (INIS)
Shpytko, Volodymyr; Darewych, Jurij
2001-01-01
We study two-particle systems in a model quantum field theory in which scalar particles and spinor particles interact via a mediating scalar field. The Lagrangian of the model is reformulated by using covariant Green's functions to solve for the mediating field in terms of the particle fields. This results in a Hamiltonian in which the mediating-field propagator appears directly in the interaction term. It is shown that exact two-particle eigenstates of the Hamiltonian can be determined. The resulting relativistic fermion-boson equation is shown to have Dirac and Klein-Gordon one-particle limits. Analytical solutions for the bound state energy spectrum are obtained for the case of massless mediating fields
Energy Technology Data Exchange (ETDEWEB)
Anaguano, L.
2005-07-01
According to the theory of Quantum Electrodynamics (QED) the vacuum state will change in the presence of very strong electromagnetic fields. If the external field (in the simplest case purely electrostatic) exceeds a certain critical value the creation of electron-positron pairs will ensue, resulting the the formation of a charged vacuum. This process is characterized by the emergence of electron states with a binding energy larger than twice the electron rest mass. The effect up to now usually was studied for spherically symmetric systems, in particular for the Coulomb potential of a heavy nucleus. In the present thesis we investigate, how this phenomenon changes when passing from spherical to cylindrical geometry. For this, we derive the solutions of the Dirac equation for electrons in the electrostatic potential of a long, thin charged cylinder (a ''charged string'') and study the ensuing supercritical effects. Since the logarithmic potential of an infinitely long string rises indefinitely with growing distance, all electron states should be supercritical (i.e., electrons should be able to tunnel through the particle-antiparticle gap of the Dirac equation). Therefore on may expect that the central charge will surround itself with an oppositely charged sheath of vacuum electrons, leading to neutralization of the string. To develop a quantitative description of this process, we investigate the solutions of the Poisson equation and the Dirac equation in cylindrical symmetry. In the first step a series expansion of the electrostatic potential in the central plane of a homogeneously charge cylinder of finite length and finite radius is derived. Subsequently, we employ the tetrad (vierbein) formalism to separate the Dirac equation in cylindrical coordinates. The resulting radial Dirac equation is transformed to Schroedinger type. The bound states are evaluated using the method of uniform approximation (a version of the WKB approximation). We study
Terrestrial propagation of long electromagnetic waves
Galejs, Janis; Fock, V A
2013-01-01
Terrestrial Propagation of Long Electromagnetic Waves deals with the propagation of long electromagnetic waves confined principally to the shell between the earth and the ionosphere, known as the terrestrial waveguide. The discussion is limited to steady-state solutions in a waveguide that is uniform in the direction of propagation. Wave propagation is characterized almost exclusively by mode theory. The mathematics are developed only for sources at the ground surface or within the waveguide, including artificial sources as well as lightning discharges. This volume is comprised of nine chapte
Quasiparticle Scattering off Defects and Possible Bound States in Charge-Ordered YBa_{2}Cu_{3}O_{y}.
Zhou, R; Hirata, M; Wu, T; Vinograd, I; Mayaffre, H; Krämer, S; Horvatić, M; Berthier, C; Reyes, A P; Kuhns, P L; Liang, R; Hardy, W N; Bonn, D A; Julien, M-H
2017-01-06
We report the NMR observation of a skewed distribution of ^{17}O Knight shifts when a magnetic field quenches superconductivity and induces long-range charge-density-wave (CDW) order in YBa_{2}Cu_{3}O_{y}. This distribution is explained by an inhomogeneous pattern of the local density of states N(E_{F}) arising from quasiparticle scattering off, yet unidentified, defects in the CDW state. We argue that the effect is most likely related to the formation of quasiparticle bound states, as is known to occur, under specific circumstances, in some metals and superconductors (but not in the CDW state, in general, except for very few cases in 1D materials). These observations should provide insight into the microscopic nature of the CDW, especially regarding the reconstructed band structure and the sensitivity to disorder.
Energy Technology Data Exchange (ETDEWEB)
Acheson, S.A.; Bell, J.B.; Jones, M.E.; Wolfenden, R. (Univ. of North Carolina School of Medicine, Chapel Hill (USA))
1990-04-03
The enzymatic decarboxylation of orotidine 5'-monophosphate may proceed by an addition-elimination mechanism involving a covalently bound intermediate or by elimination of CO2 to generate a nitrogen ylide. In an attempt to distinguish between these two alternatives, 1-(phosphoribosyl)barbituric acid was synthesized with 13C at the 5-position. Interaction of this potential transition-state analogue inhibitor with yeast orotidine-5'-monophosphate decarboxylase resulted in a small (0.6 ppm) downfield displacement of the C-5 resonance, indicating no rehybridization of the kind that might have been expected to accompany 5,6-addition of an enzyme nucleophile. When the substrate orotidine 5'-monophosphate was synthesized with deuterium at C-5, no significant change in kcat (H/D = 0.99 +/- 0.06) or kcat/KM (H/D = 1.00 +/- 0.06) was found to result, suggesting that C-5 does not undergo significant changes in geometry before or during the step that determines the rate of the catalytic process. These results are consistent with a nitrogen ylide mechanism and offer no support for the intervention of covalently bound intermediates in the catalytic process.
Grant, Ian S
1990-01-01
The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw the Physics of Stars Second Edition A. C. Phillips Computing for Scient
Bounds and enhancements for negative scattering time delays
International Nuclear Information System (INIS)
Muga, J.G.; Egusquiza, I.L.; Damborenea, J.A.; Delgado, F.
2002-01-01
The time of passage of the transmitted wave packet in a tunneling collision of a quantum particle with a square potential barrier becomes independent of the barrier width in a range of barrier thickness. This is the Hartman effect, which has been frequently associated with 'superluminality'. A fundamental limitation on the effect is set by nonrelativistic 'causality conditions'. We demonstrate first that the causality conditions impose more restrictive bounds on the negative time delays (time advancements) when no bound states are present. These restrictive bounds are in agreement with a naive, and generally false, causality argument based on the positivity of the 'extrapolated phase time', one of the quantities proposed to characterize the duration of the barrier's traversal. Nevertheless, square wells may in fact lead to much larger advancements than square barriers. We point out that close to the thresholds of new bound states, the time advancement increases considerably, while, at the same time, the transmission probability is large, which facilitates the possible observation of the enhanced time advancement
Electromagnetic fields mediate efficient cell reprogramming into a pluripotent state.
Baek, Soonbong; Quan, Xiaoyuan; Kim, Soochan; Lengner, Christopher; Park, Jung-Keug; Kim, Jongpil
2014-10-28
Life on Earth is constantly exposed to natural electromagnetic fields (EMFs), and it is generally accepted that EMFs may exert a variety of effects on biological systems. Particularly, extremely low-frequency electromagnetic fields (EL-EMFs) affect biological processes such as cell development and differentiation; however, the fundamental mechanisms by which EMFs influence these processes remain unclear. Here we show that EMF exposure induces epigenetic changes that promote efficient somatic cell reprogramming to pluripotency. These epigenetic changes resulted from EMF-induced activation of the histone lysine methyltransferase Mll2. Remarkably, an EMF-free system that eliminates Earth's naturally occurring magnetic field abrogates these epigenetic changes, resulting in a failure to undergo reprogramming. Therefore, our results reveal that EMF directly regulates dynamic epigenetic changes through Mll2, providing an efficient tool for epigenetic reprogramming including the acquisition of pluripotency.
Brownian motion in Robertson-Walker spacetimes from electromagnetic vacuum fluctuations
International Nuclear Information System (INIS)
Bessa, Carlos H. G.; Bezerra, V. B.; Ford, L. H.
2009-01-01
We consider the effects of the vacuum fluctuations of a quantized electromagnetic field on particles in an expanding universe. We find that these particles typically undergo Brownian motion and acquire a nonzero mean squared velocity that depends on the scale factor of the universe. This Brownian motion can be interpreted as due to noncancellation of anticorrelated vacuum fluctuations in the time-dependent background spacetime. Alternatively, one can interpret this effect as the particles acquiring energy from the background spacetime geometry, a phenomenon that cannot occur in a static spacetime. We treat several types of coupling between the electromagnetic field and the particles and several model universes. We also consider both free particles, which, on the average, move on geodesics, and particles in bound systems. There are significant differences between these two cases, which illustrates that nongeodesic motion alters the effects of the vacuum fluctuations. We discuss the possible applications of this Brownian motion effect to cosmological scenarios.
International Nuclear Information System (INIS)
Cai Xun-Ming
2015-01-01
Electromagnetically induced transparency and absorption of a monochromatic light controlled by a radio frequency field in the cold multi-Zeeman-sublevel atoms are theoretically investigated. These Zeeman sublevels are coupled by a radio frequency (RF) field. Both electromagnetically induced transparency and electromagnetically induced absorption can be obtained by tuning the frequency of RF field for both the linear polarization and elliptical polarization monochromatic lights. When the transfer of coherence via spontaneous emission from the excited state to the ground state is considered, electromagnetically induced absorption can be changed into electromagnetically induced transparency with the change of intensity of radio field. The transparency windows controlled by the RF field can have potential applications in the magnetic-field measurement and quantum information processing. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Bound and scattering wave functions for a velocity-dependent Kisslinger potential for l>0
International Nuclear Information System (INIS)
Jaghoub, M.I.
2002-01-01
Using formal scattering theory, the scattering wave functions are extrapolated to negative energies corresponding to bound-state poles. It is shown that the ratio of the normalized scattering and the corresponding bound-state wave functions, at a bound-state pole, is uniquely determined by the bound-state binding energy. This simple relation is proved analytically for an arbitrary angular momentum quantum number l>0, in the presence of a velocity-dependent Kisslinger potential. The extrapolation relation is tested analytically by solving the Schroedinger equation in the p-wave case exactly for the scattering and the corresponding bound-state wave functions when the Kisslinger potential has the form of a square well. A numerical resolution of the Schroedinger equation in the p-wave case and of a square-well Kisslinger potential is carried out to investigate the range of validity of the extrapolated connection. It is found that the derived relation is satisfied best at low energies and short distances. (orig.)
Calculation of electromagnetic force in electromagnetic forming process of metal sheet
International Nuclear Information System (INIS)
Xu Da; Liu Xuesong; Fang Kun; Fang Hongyuan
2010-01-01
Electromagnetic forming (EMF) is a forming process that relies on the inductive electromagnetic force to deform metallic workpiece at high speed. Calculation of the electromagnetic force is essential to understand the EMF process. However, accurate calculation requires complex numerical solution, in which the coupling between the electromagnetic process and the deformation of workpiece needs be considered. In this paper, an appropriate formula has been developed to calculate the electromagnetic force in metal work-piece in the sheet EMF process. The effects of the geometric size of coil, the material properties, and the parameters of discharge circuit on electromagnetic force are taken into consideration. Through the formula, the electromagnetic force at different time and in different positions of the workpiece can be predicted. The calculated electromagnetic force and magnetic field are in good agreement with the numerical and experimental results. The accurate prediction of the electromagnetic force provides an insight into the physical process of the EMF and a powerful tool to design optimum EMF systems.
Braneworld black holes and entropy bounds
Directory of Open Access Journals (Sweden)
Y. Heydarzade
2018-01-01
Full Text Available The Bousso's D-bound entropy for the various possible black hole solutions on a 4-dimensional brane is checked. It is found that the D-bound entropy here is apparently different from that of obtained for the 4-dimensional black hole solutions. This difference is interpreted as the extra loss of information, associated to the extra dimension, when an extra-dimensional black hole is moved outward the observer's cosmological horizon. Also, it is discussed that N-bound entropy is hold for the possible solutions here. Finally, by adopting the recent Bohr-like approach to black hole quantum physics for the excited black holes, the obtained results are written also in terms of the black hole excited states.
Electromagnetic wave analogue of an electronic diode
International Nuclear Information System (INIS)
Shadrivov, Ilya V; Powell, David A; Kivshar, Yuri S; Fedotov, Vassili A; Zheludev, Nikolay I
2011-01-01
An electronic diode is a nonlinear semiconductor circuit component that allows conduction of electrical current in one direction only. A component with similar functionality for electromagnetic waves, an electromagnetic isolator, is based on the Faraday effect of rotation of the polarization state and is also a key component in optical and microwave systems. Here we demonstrate a chiral electromagnetic diode, which is a direct analogue of an electronic diode: its functionality is underpinned by an extraordinarily strong nonlinear wave propagation effect in the same way as the electronic diode function is provided by the nonlinear current characteristic of a semiconductor junction. The effect exploited in this new electromagnetic diode is an intensity-dependent polarization change in an artificial chiral metamolecule. This microwave effect exceeds a similar optical effect previously observed in natural crystals by more than 12 orders of magnitude and a direction-dependent transmission that differs by a factor of 65.
Energy Technology Data Exchange (ETDEWEB)
Sturm, Sven
2012-09-06
This thesis describes the ultra-precise determination of the g-factor of the electron bound to hydrogenlike {sup 28}Si{sup 13+}. The experiment is based on the simultaneous determination of the cyclotron- and Larmor frequency of a single ion, which is stored in a triple Penning-trap setup. The continuous Stern-Gerlach effect is used to couple the spin of the bound electron to the motional frequencies of the ion via a magnetic bottle, which allows the non-destructive determination of the spin state. To this end, a highly sensitive, cryogenic detection system was developed, which allowed the direct, non-destructive detection of the eigenfrequencies with the required precision. The development of a novel, phase sensitive detection technique finally allowed the determination of the g-factor with a relative accuracy of 4 . 10{sup -11}, which was previously inconceivable. The comparison of the hereby determined value with the value predicted by quantumelectrodynamics (QED) allows the verification of the validity of this fundamental theory under the extreme conditions of the strong binding potential of a highly charged ion. The exact agreement of theory and experiment is an impressive demonstration of the exactness of QED. The experimental possibilities created in this work will allow in the near future not only further tests of theory, but also the determination of the mass of the electron with a precision that exceeds the current literature value by more than an order of magnitude.
International Nuclear Information System (INIS)
Verlan, E.M.
2003-01-01
A two-level atom interacting with a field mode is considered. The field frequency is assumed to be equal to the atom transition frequency. The relaxation equations of the atom - field system are written in the basis of dressed states of the Jaynes - Cummings model taking into account quasi-resonant pumping. Their solutions are derived for a stationary regime. The average amplitude of a coherent electromagnetic field is found
Electron-electron bound states in Maxwell-Chern-Simons-Proca QED{sub 3}
Energy Technology Data Exchange (ETDEWEB)
Belich, H.; Helayel-Neto, J.A. [Grupo de Fisica Teorica Jose Leite Lopes, Petropolis, RJ (Brazil)]|[Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Teoria de Campos e Particulas]. E-mail: belich@cbpf.br; helayel@gft.ucp.br; Del Cima, O.M. [Grupo de Fisica Teorica Jose Leite Lopes, Petropolis, RJ (Brazil)]. E-mail: delcima@gft.ucp.br; Ferreira, M.M. Jr. [Grupo de Fisica Teorica Jose Leite Lopes, Petropolis, RJ (Brazil)]|[Maranhao Univ., Sao Luis, MA (Brazil). Dept. de Fisica]. E-mail: manojr@cbpf.br
2002-10-01
We start from a parity-breaking MCS QED{sub 3} model with spontaneous breaking of the gauge symmetry as a framework for evaluation of the electron-electron interaction potential and for attainment of numerical values for the e{sup -}e{sup -} - bound state. Three expressions (V{sub eff{down_arrow}}{sub {down_arrow}}, V{sub eff{down_arrow}}{sub {up_arrow}}, V{sub eff{down_arrow}}{sub {down_arrow}}) are obtained according to the polarization state of the scattered electrons. In an energy scale compatible with condensed matter electronic excitations, these potentials become degenerated. The resulting potential is implemented in the Schroedinger equation and the variational method is applied to carry out the electronic binding energy. The resulting binding energies in the scale of 10-100 meV and a correlation length in the scale of 10 - 30 Angstrom are possible indications that the MCS-QED{sub 3} model adopted may be suitable to address an eventual case of e{sup -}e{sup -} pairing in the presence of parity-symmetry breakdown. The data analyzed here suggest an energy scale of 10-100 meV to fix the breaking of the U(1)-symmetry. (author)
Properties of a Bound Polaron under a Perpendicular Magnetic Field
International Nuclear Information System (INIS)
Liu Jia; Chen Ziyu; Xiao Jinglin; Huo Shufen
2007-01-01
We investigate the influence of a perpendicular magnetic field on a bound polaron near the interface of a polar-polar semiconductor with Rashba effect. The external magnetic field strongly changes the ground state binding energy of the polaron and the Rashba spin-orbit (SO) interaction originating from the inversion asymmetry in the heterostructure splits the ground state binding energy of the bound polaron. In this paper, we have shown how the ground state binding energy will be with the change of the external magnetic field, the location of a single impurity, the wave vector of the electron and the electron areal density, taking into account the SO coupling. Due to the presence of the phonons, whose energy gives negative contribution to the polaron's, the spin-splitting states of the bound polaron are more stable, and we find that in the condition of week magnetic field, the Zeeaman effect can be neglected.
Electromagnetically shielded building
Energy Technology Data Exchange (ETDEWEB)
Takahashi, T; Nakamura, M; Yabana, Y; Ishikawa, T; Nagata, K
1992-04-21
This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs.
Electromagnetically shielded building
International Nuclear Information System (INIS)
Takahashi, T.; Nakamura, M.; Yabana, Y.; Ishikawa, T.; Nagata, K.
1992-01-01
This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs
Mitchell, Tarissa; Lee, Deborah; Weinberg, Michelle; Phares, Christina; James, Nicola; Amornpaisarnloet, Kittisak; Aumpipat, Lalita; Cooley, Gretchen; Davies, Anita; Tin Shwe, Valerie Daw; Gajdadziev, Vasil; Gorbacheva, Olga; Khwan-Niam, Chutharat; Klosovsky, Alexander; Madilokkowit, Waritorn; Martin, Diana; Htun Myint, Naing Zaw; Yen Nguyen, Thi Ngoc; Nutman, Thomas B; O'Connell, Elise M; Ortega, Luis; Prayadsab, Sugunya; Srimanee, Chetdanai; Supakunatom, Wasant; Vesessmith, Vattanachai; Stauffer, William M
2018-03-01
With an unprecedented number of displaced persons worldwide, strategies for improving the health of migrating populations are critical. United States-bound refugees undergo a required overseas medical examination to identify inadmissible conditions (e.g., tuberculosis) 2-6 months before resettlement, but it is limited in scope and may miss important, preventable infectious, chronic, or nutritional causes of morbidity. We sought to evaluate the feasibility and health impact of diagnosis and management of such conditions before travel. We offered voluntary testing for intestinal parasites, anemia, and hepatitis B virus infection, to U.S.-bound refugees from three Thailand-Burma border camps. Treatment and preventive measures (e.g., anemia and parasite treatment, vaccination) were initiated before resettlement. United States refugee health partners received overseas results and provided post-arrival medical examination findings. During July 9, 2012 to November 29, 2013, 2,004 refugees aged 0.5-89 years enrolled. Among 463 participants screened for seven intestinal parasites overseas and after arrival, helminthic infections decreased from 67% to 12%. Among 118 with positive Strongyloides -specific antibody responses, the median fluorescent intensity decreased by an average of 81% after treatment. The prevalence of moderate-to-severe anemia (hemoglobin migration process to improve the health of refugees before resettlement. With more than 250 million migrants globally, this model may offer insights into healthier migration strategies.
Universal bounds in even-spin CFTs
Energy Technology Data Exchange (ETDEWEB)
Qualls, Joshua D. [Department of Physics, National Taiwan University,Taipei, Taiwan (China)
2015-12-01
We prove using invariance under the modular S− and ST−transformations that every unitary two-dimensional conformal field theory (CFT) having only even-spin primary operators (with no extended chiral algebra and with right- and left-central charges c,c̃>1) contains a primary operator with dimension Δ{sub 1} satisfying 0<Δ{sub 1}<((c+c̃)/24)+0.09280…. After deriving both analytical and numerical bounds, we discuss how to extend our methods to bound higher conformal dimensions before deriving lower and upper bounds on the number of primary operators in a given energy range. Using the AdS{sub 3}/CFT{sub 2} dictionary, the bound on Δ{sub 1} proves the lightest massive excitation in appropriate theories of 3D matter and gravity with cosmological constant Λ<0 can be no heavier than 1/8G{sub N}+O(√(−Λ)); the bounds on the number of operators are related via AdS/CFT to the entropy of states in the dual gravitational theory. In the flat-space approximation, the limiting mass is exactly that of the lightest BTZ black hole.
Energy Technology Data Exchange (ETDEWEB)
Halligan, Matthew
2017-11-01
Radiated power calculation approaches for practical scenarios of incomplete high- density interface characterization information and incomplete incident power information are presented. The suggested approaches build upon a method that characterizes power losses through the definition of power loss constant matrices. Potential radiated power estimates include using total power loss information, partial radiated power loss information, worst case analysis, and statistical bounding analysis. A method is also proposed to calculate radiated power when incident power information is not fully known for non-periodic signals at the interface. Incident data signals are modeled from a two-state Markov chain where bit state probabilities are derived. The total spectrum for windowed signals is postulated as the superposition of spectra from individual pulses in a data sequence. Statistical bounding methods are proposed as a basis for the radiated power calculation due to the statistical calculation complexity to find a radiated power probability density function.
Gallium Electromagnetic (GEM) Thrustor Concept and Design
Polzin, Kurt A.; Markusic, Thomas E.
2006-01-01
We describe the design of a new type of two-stage pulsed electromagnetic accelerator, the gallium electromagnetic (GEM) thruster. A schematic illustration of the GEM thruster concept is given in Fig. 1. In this concept, liquid gallium propellant is pumped into the first stage through a porous metal electrode using an electromagneticpump[l]. At a designated time, a pulsed discharge (approx.10-50 J) is initiated in the first stage, ablating the liquid gallium from the porous electrode surface and ejecting a dense thermal gallium plasma into the second state. The presence of the gallium plasma in the second stage serves to trigger the high-energy (approx.500 I), send-stage puke which provides the primary electromagnetic (j x B) acceleration.
International Nuclear Information System (INIS)
Rao, N.N.
1998-01-01
A systematic analysis of the stationary propagation of nonlinearly coupled electromagnetic and ion-acoustic waves in an unmagnetized plasma via the ponderomotive force is carried out. For small but finite amplitudes, the governing equations have a Hamiltonian structure, but with a kinetic energy term that is not positive definite. The Hamiltonian is similar to the well-known Hacute enon endash Heiles Hamiltonian of nonlinear dynamics, and is completely integrable in three regimes of the allowed parameter space. The corresponding second invariants of motion are also explicitly obtained. The integrable parameter regimes correspond to supersonic values of the Mach number, which characterizes the propagation speed of the coupled waves. On the other hand, in the sub- as well as near-sonic regimes, the coupled mode equations admit different types of exact analytical solutions, which represent nonlinear localized eigenstates of the electromagnetic field trapped in the density cavity due to the ponderomotive potential. While the density cavity has always a single-dip structure, for larger amplitudes it can support higher-order modes having a larger number of nodes in the electromagnetic field. In particular, we show the existence of a new type of localized electromagnetic wave whose field intensity has a triple-hump structure. For typical parameter values, the triple-hump solitons propagate with larger Mach numbers that are closer to the sonic limit than the single- as well as the double-hump solitons, but carry a lesser amount of the electromagnetic field energy. A comparison between the different types of solutions is carried out. The possibility of the existence of trapped electromagnetic modes having a larger number of humps is also discussed. copyright 1998 American Institute of Physics
The Pressure and Magnetic Flux Density Analysis of Helical-Type DC Electromagnetic Pump
International Nuclear Information System (INIS)
Lee, Geun Hyeong; Kim, Hee Reyoung
2016-01-01
The developed pressure was made by only electromagnetic force eliminating probability of impurities contact, therefore the high reactivity materials such as alkali were best match to electromagnetic pump. The heavy ion accelerator facility by Rare Isotope Science Project (RISP) in Korea is trying to construct accelerator using liquid lithium for high efficiency of acceleration by decreasing charge state. The helical-type DC electromagnetic pump was employed to make a charge stripper that decrease charge state of heavy ion. The specification of electromagnetic pump was developed pressure of 15 bar with flowrate of 6 cc/s in the condition of 200℃. The pressure of DC electromagnetic pump was analyzed in the aspects of current and number of duct turns. The developed pressure was almost proportional to input current because relatively low flowrate made negligible of the electromotive force and hydraulic pressure drop. The pressure and magnetic flux density of helical-type DC electromagnetic pump were analyzed. The pressure was proportion to input current and number of duct turns, and magnetic flux density was higher when ferromagnet was applied at electromagnetic pump. It seems that number of duct turns could be increase and ferromagnet could be applied in order to increase pressure of DC electromagnetic pump with constant input current
International Nuclear Information System (INIS)
Alinejad, H.; Robinson, P. A.; Cairns, I. H.; Skjaeraasen, O.; Sobhanian, S.
2007-01-01
Nucleating and collapsing wave packets relevant to electromagnetic strong plasma turbulence are studied theoretically in two dimensions. Model collapsing Langmuir and transverse potentials are constructed as superpositions of approximate eigenstates of a spherically symmetric density well. Electrostatic and electromagnetic potentials containing only components with azimuthal quantum numbers m=0, 1, 2 are found to give a good representation of the electric fields of nucleating collapsing wave packets in turbulence simulations. The length scales of these trapped states are related to the electron thermal speed v e and the length scale of the density well. It is shown analytically that the electromagnetic trapped states change with v e and that for v e e > or approx. 0.17c, the Langmuir and transverse modes remain coupled during collapse, with autocorrelation lengths in a constant ratio. An investigation of energy transfer to packets localized in density wells shows that the strongest power transfer to the nucleating state occurs for Langmuir waves. Energy transitions between different trapped and free states for collapsing wave packets are studied, and the transition rate from trapped Langmuir to free plane electromagnetic waves is calculated and related to the emission of electromagnetic waves at the plasma frequency
Electromagnetic properties of the three-nucleon ground state
International Nuclear Information System (INIS)
Strueve, W.
1985-01-01
The electromagnetic form factors of the three-nucleon ground state are calculated on the base of an exact solution of the Faddeev equations. In a Hilbert space of nucleons and a possible Δ-isobar the effects of a non-perturbative description of the Δ-isobar on the magnetic form factors are studied. Pure nucleonic current operators with two- and three-particle character can be described in the extended Hilbert space by simpler one-body operators. Additionally nonrelativistic meson-exchange corrections due to π and ρ exchange are calculated consistently with the requirements of current conservation. Further relativistic corrections are estimated on selected examples. The calculations yield a total magnetic contribution of the Δ-isobar which is smaller than hitherto assumed, a static approximation of the Δ propagation is proved as inadmissible and must be rejected. Together with the meson-exchange corrections a well agreement with the experimental data at low momentum transfers results. Especially the magnetic moments and magnetization radii can be explained. For higher momentum transfers the results show the importance of further corrections. The regard of selected relativistic corrections leads to a good description of the experimental magnetic form factors. Also by this way the position of the minimum and the height of the second maximum in the 3 He charge form factor can be explained. The comparison with the latest experimental results reveals furthermore unresolved problems in the description of the 3 H charge form factor. (orig.) [de
International Nuclear Information System (INIS)
Bosanac, Slobodan Danko
2016-01-01
This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.
Exact S-matrices for dn+1(2) affine Toda solitons and their bound states
International Nuclear Information System (INIS)
Gandenberger, G.M.; MacKay, N.J.
1995-01-01
We conjecture an exact S-matrix for the scattering of solitons in d n+1 (2) affine Toda field theory in terms of the R-matrix of the quantum group U q (c n (1) ). From this we construct the scattering amplitudes for all scalar bound states (breathers) of the theory. This S-matrix conjecture is justified by detailed examination of its pole structure. We show that a breather-particle identification holds by comparing the S-matrix elements for the lowest breathers with the S-matrix for the quantum particles in real affine Toda field theory, and discuss the implications for various forms of duality. (orig.)
International Nuclear Information System (INIS)
2009-01-01
The investigating committee aimed at research on electromagnetic fields in functional devices and X-ray fibers for efficient coherent X-ray generation and their material science, high-precision manufacturing, X-ray microscope, application to medical and information communication technologies, such as interaction between material and nanometer electromagnetic waves of radiated light and X-ray, interaction between microwaves and particle beams, theory and design of high-frequency waveguides for resonator and accelerator, from January 2003 to December 2005. In this report, we describe our research results, in particular, on the topics of synchrotron radiation and Cherenkov radiation, Kyushu synchrotron light source and its technology, nanometer electromagnetic fields in optical region, process of interaction between evanescent waves and near-field light, orthogonal relation of electromagnetic fields including evanescent waves in dispersive dielectrics, optical amplification using electron beam, nanometer electromagnetic fields in focusing waveguide lens device with curved facets, electromagnetic fields in nanometer photonic crystal waveguide consisting of atoms, X-ray scattering and absorption I bio-material for image diagnosis. (author)
Bone Mineral 31P and Matrix-Bound Water Densities Measured by Solid-State 1H and 31P MRI
Seifert, Alan C.; Li, Cheng; Rajapakse, Chamith S.; Bashoor- Zadeh, Mahdieh; Bhagat, Yusuf A.; Wright, Alexander C.; Zemel, Babette S.; Zavaliangos, Antonios; Wehrli, Felix W.
2014-01-01
Bone is a composite material consisting of mineral and hydrated collagen fractions. MRI of bone is challenging due to extremely short transverse relaxation times, but solid-state imaging sequences exist that can acquire the short-lived signal from bone tissue. Previous work to quantify bone density via MRI used powerful experimental scanners. This work seeks to establish the feasibility of MRI-based measurement on clinical scanners of bone mineral and collagen-bound water densities, the latter as a surrogate of matrix density, and to examine the associations of these parameters with porosity and donors’ age. Mineral and matrix-bound water images of reference phantoms and cortical bone from 16 human donors, ages 27-97 years, were acquired by zero-echo-time 31P and 1H MRI on whole body 7T and 3T scanners, respectively. Images were corrected for relaxation and RF inhomogeneity to obtain density maps. Cortical porosity was measured by micro-CT, and apparent mineral density by pQCT. MRI-derived densities were compared to x-ray-based measurements by least-squares regression. Mean bone mineral 31P density was 6.74±1.22 mol/L (corresponding to 1129±204 mg/cc mineral), and mean bound water 1H density was 31.3±4.2 mol/L (corresponding to 28.3±3.7 %v/v). Both 31P and bound water (BW) densities were correlated negatively with porosity (31P: R2 = 0.32, p bone mineralization ratio (expressed here as the ratio of 31P density to bound water density), which is proportional to true bone mineralization, was found to be uncorrelated with porosity, age, or pQCT density. This work establishes the feasibility of image-based quantification of bone mineral and bound water densities using clinical hardware. PMID:24846186
On the role of anti-bound states in the RPA description of the giant monopole resonance
International Nuclear Information System (INIS)
Vertse, T.; Bang, J.
1989-01-01
The limit of the applicability of the resonant Random Phase Approximation (RPA) method is tested by calculating escape widths in the giant monopole resonance of 16 O and comparing them to the results of a time dependent Hartree-Fock calculation. Though the widths of the narrow s-wave component agree reasonably well, the broad p-wave component shows large disagreement, which cannot be cured by complementing the basis with anti-bound states in the RPA calculation. (author) 18 refs.; 3 tabs
International Nuclear Information System (INIS)
Zhukov, V.V.; Osovskij, V.D.; Ptushnikov, Yu.G.; Sukretnyj, V.G.; Chujkov, B.A.
1986-01-01
A molecular beam technique with an effusion source operating at T=200 K is used to study the adsorption interaction of oxygen with W(100) and (110) faces in the range of the simple temperatures from 5 to 340 K. Three weakly-bound adsorption states of oxygen are detected corresponding to adsorption in the second, third and forth monolayer. These states are characterized by adsorption energies of 0.13, 0.08 and 0.07 eV and desorption temperatures of 45, 27 and 25 K, respectively. The kinetics of filling of these states is almost similar for both faces, whereas the adsorption kinetics in the first monolayer is essentially different. A dissociative nature of adsorption at T >or approx. 5 K and a jump migration mechanism of the admolecules in the precursor state to the stationary adsorption sites are suggested
Lorentz invariance violation and simultaneous emission of electromagnetic and gravitational waves
Directory of Open Access Journals (Sweden)
E. Passos
2017-09-01
Full Text Available In this work, we compute some phenomenological bounds for the electromagnetic and massive gravitational high-derivative extensions supposing that it is possible to have an astrophysical process that generates simultaneously gravitational and electromagnetic waves. We present Lorentz invariance violating (LIV higher-order derivative models, following the Myers–Pospelov approach, to electrodynamics and massive gravitational waves. We compute the corrected equation of motion of these models, their dispersion relations and the velocities. The LIV parameters for the gravitational and electromagnetic sectors, ξg and ξγ, respectively, were also obtained for three different approaches: luminal photons, time delay of flight and the difference of graviton and photon velocities. These LIV parameters depend on the mass scales where the LIV-terms become relevant, M for the electromagnetic sector and M1 for the gravitational one. We obtain, using the values for M and M1 found in the literature, that ξg∼10−2, which is expected to be phenomenologically relevant and ξγ∼103, which cannot be suitable for an effective LIV theory. However, we show that ξγ can be interesting in a phenomenological point of view if M≫M1. Finally the relation between the variation of the velocities of the photon and the graviton in relation to the speed of light was calculated and resulted in Δvg/Δvγ≲1.82×10−3.
International Nuclear Information System (INIS)
Zeppenfeld, D.
1984-01-01
The present thesis deals with the construction and the analysis of mesonic bound states in SU(N) gauge theories in a two-dimensional space-time. The based field theory can thereby be considered as a simplified version of the QCD, the theory of the strong interactions. After an extensive discussion of the quantization in the temporal gauge and after the Poincare invariance of the theory has been shown mesonic bound states and the meson spectrum for different ranges of the free parameters of the theory (quark mass, coupling constant, and index N of the gauge group) are treated. The spectrum is given by a boundary value problem which in the perturbative limit is solved analytically. For massless quarks gauge-invariant annihilation operators are constructed which permit an exact solution of the energy eigenvalue equation. The energy eigenstates so found described massive interacting mesons which are surrounded by a cloud of massless free particles. (orig.) [de
On the problem of bound states of pions and neutrons
International Nuclear Information System (INIS)
Gudima, K.K.; Karnaukhov, V.A.
1992-01-01
The problem of existence of the bound states of negative pions and neutrons has been widely discussed for the last years. It is considered possibilities of the experimental observation of pion-neutron clusters, if they do exist, in nucleus-nucleus collisions. The yields of exotic fragments π -Z n A in the interactions of 12 C and 56 Fe with 208 Pb at the energies from 0.3 to 3.7 GeV per nucleon are calculated. For 40 Ar+ 238 U and 139 La+ 238 U collisions the calculations were performed at the energied of 1.8 GeV and 1.3 GeV per nucleon, respectively. These calculations were performed in the framework of the coalescence mechanism with the differential cross sections for pion and neutron production generated by firestreak model. The differential cross sections for production of π -1 n -2 , π -2 N 2 , π - n 4 , π -4 n 6 , and π -12 n 6 were calculated. It is shown that the use of very heavy projectiles like 56 Fe and 139 La has a great advantage in the experimental search for the exotic clusters. 20 refs.; 8 figs
Detecting Majorana bound states coupling with an Aharonov-Bohm interferometer
Orellana, Pedro; Ramos Andrade, Juan Pablo; Ulloa, Sergio
In this work we consider a quantum dot (QD) connected to current leads arranged to mediate the interaction between two topological nanowires, both hosting Majorana bound states (MBS) at their ends. In an interesting system geometry, one nanowire has both ends coupled with the QD, forming an Aharonov-Bohm (AB) interferometer, while the other is placed nearby such that two MBS belonging to different nanowires can interact. We model the system using an effective low energy Hamiltonian, considering that the QD is embedded between metallic leads. Using a Green's function formalism via the equation of motion procedure, we find that the conductance across the leads can show MBS signatures, i.e. half-maximum conductance at zero-energy, when both topological nanowires are connected, independent of the AB flux phase. This system may be used as a detector of the effective connections between independent MBS by monitoring the conductance while tuning the AB phase. J.P.R.-A. acknowledge support from scholarship CONICYT-Chile No.21141034. P.A.O. acknowledges support from FONDECYT Grant No. 1140571 and S.E.U. acknowledge support from NSF Grant No. DMR 1508325.
Electromagnetic properties of neutrinos
International Nuclear Information System (INIS)
Ould-Saada, F.
1996-01-01
Electromagnetic properties of neutrinos and their implications are discussed, and the experimental situation summarised. Spin precession in solar magnetic fields presents a solution of the solar neutrino problem. A magnetic moment, μ ν , of the order of 10 -11 μ B would be needed. In the simplest extension of the standard model, with no-vanishing neutrino masses, dipole moment interactions are allowed through higher order processes. A neutrino mass of ≅10 eV would give μ ν ≅10 -18 μ B , much smaller than the present experimental upper limit of 2x10 -10 μ B . Although model-dependent, upper bounds on dipole moments from astrophysics and cosmology are 10 to 100 times more stringent. Any values of μ ν , larger than the SM predictions, would then signal the onset of new physics. Among the processes sensitive to the magnetic moment, νe - scattering presents two advantages: it is a pure weak, theoretically well understood process, and the recoil electron can be easily measured. A hypothetical electromagnetic contribution to the cross-section would dominate at low energies. A low background detector, MUNU, being built at the Bugey nuclear reactor is presented.It is based on a gas TPC, surrounded by a scintillator. The threshold on the electron recoil energy can be set very low, around 500 keV, giving the experiment a good sensitivity to the magnetic moment of the ν e , extending down to 2x10 -11 μ B . (author) 15 figs., 5 tabs., 96 refs
Energy Technology Data Exchange (ETDEWEB)
Zheng, Rui [School of Mathematics and Information Science, North China University of Water Resources and Electric Power, Zhengzhou (China); Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan (China); Li, Song, E-mail: lsong@yangtzeu.edu.cn [School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou (China); Chen, Shan-Jun; Chen, Yan [School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou (China); Zheng, Li-Min [Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan (China)
2015-09-08
Highlights: • A two-dimensional potential for Ar–BrCl is constructed at the CCSD(T) level. • The PES is characterized by three minima and two saddle points between them. • Bound state calculations were carried out for the complex. - Abstract: The intermolecular potential energy surface (PES) of the ground electronic state for the Ar–BrCl dimer is constructed at the CCSD(T) level with the aug-cc-pVQZ basis set and mid-bond functions. The PES is characterized by three minima and two saddle points. The global minimum corresponding to a collinear Ar–BrCl configuration, which has been observed experimentally, is located at R = 4.10 Å and θ = 2.5° with a well depth of −285.207 cm{sup −1}. A nearly T-shaped structure and an anti-linear Ar–ClBr geometry is also predicted. The bound state calculations are preformed to study intermolecular vibrational modes, rotational levels and average structures for the complex. Our transition frequencies, spectroscopic constants and average structures for all isotopomers of the collinear isomer agree well with experimental data. We have also provided pure rotational transitional frequencies for both nearly T-shaped and anti-linear isomers. These results are significant for further experimental investigations of the Ar–BrCl dimer.
Suzuki, Shu-Ichiro; Kawaguchi, Yuki; Tanaka, Yukio
2018-04-01
We study quasiparticle states on a surface of a topological insulator (TI) with proximity-induced superconductivity under an external magnetic field. An applied magnetic field creates two Majorana bound states: a vortex Majorana state localized inside a vortex core and an exterior Majorana state localized along a circle centered at the vortex core. We calculate the spin-resolved local density of states (LDOS) and demonstrate that the shrinking of the radius of the exterior Majorana state, predicted in R. S. Akzyanov et al., Phys. Rev. B 94, 125428 (2016), 10.1103/PhysRevB.94.125428, under a strong magnetic field can be seen in LDOS without smeared out by nonzero-energy states. The spin-resolved LDOS further reveals that the spin of the exterior Majorana state is strongly spin-polarized. Accordingly, the induced odd-frequency spin-triplet pairs are found to be spin-polarized as well. In order to detect the exterior Majorana states, however, the Fermi energy should be closed to the Dirac point to avoid contributions from continuum levels. We also study a different two-dimensional topological-superconducting system where a two-dimensional electron gas with the spin-orbit coupling is sandwiched between an s -wave superconductor and a ferromagnetic insulator. We show that the radius of an exterior Majorana state can be tuned by an applied magnetic field. However, on the contrary to the results at a TI surface, neither the exterior Majorana state nor the induced odd-frequency spin-triplet pairs are spin-polarized. We conclude that the spin polarization of the Majorana state is attributed to the spin-polarized Landau level, which is characteristic for systems with the Dirac-like dispersion.
Shell closures, loosely bound structures, and halos in exotic nuclei
International Nuclear Information System (INIS)
Saxena, G.; Singh, D.
2013-01-01
Inspired by the recent experiments indicating doubly magic nuclei that lie near the drip-line and encouraged by the success of our relativistic mean-field (RMF) plus state-dependent BCS approach to the description of the ground-state properties of drip-line nuclei, we develop this approach further, across the entire periodic table, to explore magic nuclei, loosely bound structures, and halo formation in exotic nuclei. In our RMF+BCS approach, the single-particle continuum corresponding to the RMF is replaced by a set of discrete positive-energy states for the calculations of pairing energy. Detailed analysis of the single-particle spectrum, pairing energies, and densities of the nuclei predict the unusual proton shell closures at proton numbers Z = 6, 14, 16, 34, and unusual neutron shell closures at neutron numbers N = 6, 14, 16, 34, 40, 70, 112. Further, in several nuclei like the neutron-rich isotopes of Ca, Zr, Mo, etc., the gradual filling of lowlying single-particle resonant state together with weakly bound single-particle states lying close to the continuum threshold helps accommodate more neutrons but with an extremely small increase in the binding energy. This gives rise to the occurrence of loosely bound systems of neutron-rich nuclei with a large neutron-to-proton ratio. In general, the halo-like formation, irrespective of the existence of any resonant state, is seen to be due to the large spatial extension of the wave functions for the weakly bound single-particle states with low orbital angular momentum having very small or no centrifugal barriers.
Shell closures, loosely bound structures, and halos in exotic nuclei
Energy Technology Data Exchange (ETDEWEB)
Saxena, G., E-mail: gauravphy@gmail.com [Govt. Women Engineering College, Department of Physics (India); Singh, D. [University of Rajasthan, Department of Physics (India)
2013-04-15
Inspired by the recent experiments indicating doubly magic nuclei that lie near the drip-line and encouraged by the success of our relativistic mean-field (RMF) plus state-dependent BCS approach to the description of the ground-state properties of drip-line nuclei, we develop this approach further, across the entire periodic table, to explore magic nuclei, loosely bound structures, and halo formation in exotic nuclei. In our RMF+BCS approach, the single-particle continuum corresponding to the RMF is replaced by a set of discrete positive-energy states for the calculations of pairing energy. Detailed analysis of the single-particle spectrum, pairing energies, and densities of the nuclei predict the unusual proton shell closures at proton numbers Z = 6, 14, 16, 34, and unusual neutron shell closures at neutron numbers N = 6, 14, 16, 34, 40, 70, 112. Further, in several nuclei like the neutron-rich isotopes of Ca, Zr, Mo, etc., the gradual filling of lowlying single-particle resonant state together with weakly bound single-particle states lying close to the continuum threshold helps accommodate more neutrons but with an extremely small increase in the binding energy. This gives rise to the occurrence of loosely bound systems of neutron-rich nuclei with a large neutron-to-proton ratio. In general, the halo-like formation, irrespective of the existence of any resonant state, is seen to be due to the large spatial extension of the wave functions for the weakly bound single-particle states with low orbital angular momentum having very small or no centrifugal barriers.
Frolov, Alexei M.
2018-03-01
The universal variational expansion for the non-relativistic three-body systems is explicitly constructed. This universal expansion can be used to perform highly accurate numerical computations of the bound state spectra in various three-body systems, including Coulomb three-body systems with arbitrary particle masses and electric charges. Our main interest is related to the adiabatic three-body systems which contain one bound electron and two heavy nuclei of hydrogen isotopes: the protium p, deuterium d and tritium t. We also consider the analogous (model) hydrogen ion ∞H2+ with the two infinitely heavy nuclei.
Equivalence principles and electromagnetism
Ni, W.-T.
1977-01-01
The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.
Excitations and possible bound states in the S = 1/2 alternating chain compound (VO)2P2O7
International Nuclear Information System (INIS)
Tennant, D.A.; Nagler, S.E.; Sales, B.C.
1997-01-01
Magnetic excitations in an array of (VO) 2 P 2 O 7 single crystals have been measured using inelastic neutron scattering. Until now, (VO) 2 P 2 O 7 has been thought of as a two-leg antiferromagnetic Heisenberg spin ladder with chains running in the a-direction. The present results show unequivocally that (VO) 2 P 2 O 7 is best described as an alternating spin-chain directed along the crystallographic b-direction. In addition to the expected magnon with magnetic zone-center energy gap Δ = 3.1 meV, a second excitation is observed at an energy just below 2Δ. The higher mode may be a triplet two-magnon bound state. Numerical results in support of bound modes are presented
International Nuclear Information System (INIS)
Nielsen, Joseph; Tokuhiro, Akira; Khatry, Jivan; Hiromoto, Robert
2014-01-01
Traditional probabilistic risk assessment (PRA) methods have been developed to evaluate risk associated with complex systems; however, PRA methods lack the capability to evaluate complex dynamic systems. In these systems, time and energy scales associated with transient events may vary as a function of transition times and energies to arrive at a different physical state. Dynamic PRA (DPRA) methods provide a more rigorous analysis of complex dynamic systems. Unfortunately DPRA methods introduce issues associated with combinatorial explosion of states. In order to address this combinatorial complexity, a branch-and-bound optimization technique is applied to the DPRA formalism to control the combinatorial state explosion. In addition, a new characteristic scaling metric (LENDIT – length, energy, number, distribution, information and time) is proposed as linear constraints that are used to guide the branch-and-bound algorithm to limit the number of possible states to be analyzed. The LENDIT characterization is divided into four groups or sets – 'state, system, resource and response' (S2R2) – describing reactor operations (normal and off-normal). In this paper we introduce the branch-and-bound DPRA approach and the application of LENDIT scales and S2R2 sets to a station blackout (SBO) transient. (author)
Circuit lower bounds in bounded arithmetics
Czech Academy of Sciences Publication Activity Database
Pich, Ján
2015-01-01
Roč. 166, č. 1 (2015), s. 29-45 ISSN 0168-0072 R&D Projects: GA AV ČR IAA100190902 Keywords : bounded arithmetic * circuit lower bounds Subject RIV: BA - General Mathematics Impact factor: 0.582, year: 2015 http://www.sciencedirect.com/science/article/pii/S0168007214000888
Bottom and charm mass determinations from global fits to Q\\overline{Q} bound states at N3LO
Mateu, Vicent; Ortega, Pablo G.
2018-01-01
The bottomonium spectrum up to n = 3 is studied within Non-Relativistic Quantum Chromodynamics up to N3LO. We consider finite charm quark mass effects both in the QCD potential and the \\overline{MS} -pole mass relation up to third order in the Y-scheme counting. The u = 1 /2 renormalon of the static potential is canceled by expressing the bottom quark pole mass in terms of the MSR mass. A careful investigation of scale variation reveals that, while n = 1 , 2 states are well behaved within perturbation theory, n = 3 bound states are no longer reliable. We carry out our analysis in the n ℓ = 3 and n ℓ = 4 schemes and conclude that, as long as finite m c effects are smoothly incorporated in the MSR mass definition, the difference between the two schemes is rather small. Performing a fit to b\\overline{b} bound states we find {\\overline{m}}_b({\\overline{m}}_b) = 4 .216 ± 0 .039 GeV. We extend our analysis to the lowest lying charmonium states finding {\\overline{m}}_c({\\overline{m}}_c) = 1 .273 ± 0 .054 GeV. Finally, we perform simultaneous fits for {\\overline{m}}_b and α s finding {α}_s^{({n}_f=5)}({m}_Z)=0.1178± 0.0051 . Additionally, using a modified version of the MSR mass with lighter massive quarks we are able to predict the uncalculated O({α}_s^4) virtual massive quark corrections to the relation between the \\overline{MS} and pole masses.
Rovibrational bound states of SO2 isotopologues. I: Total angular momentum J = 0-10
Kumar, Praveen; Ellis, Joseph; Poirier, Bill
2015-04-01
Isotopic variation of the rovibrational bound states of SO2 for the four stable sulfur isotopes 32-34,36S is investigated in comprehensive detail. In a two-part series, we compute the low-lying energy levels for all values of total angular momentum in the range J = 0-20. All rovibrational levels are computed, to an extremely high level of numerical convergence. The calculations have been carried out using the ScalIT suite of parallel codes. The present study (Paper I) examines the J = 0-10 rovibrational levels, providing unambiguous symmetry and rovibrational label assignments for each computed state. The calculated vibrational energy levels exhibit very good agreement with previously reported experimental and theoretical data. Rovibrational energy levels, calculated without any Coriolis approximations, are reported here for the first time. Among other potential ramifications, this data will facilitate understanding of the origin of mass-independent fractionation of sulfur isotopes in the Archean rock record-of great relevance for understanding the "oxygen revolution".
7th conference on ultra-wideband, short-pulse electromagnetics
Schenk, Uwe; Nitsch, Daniel; Sabath, Frank; Ultra-Wideband, Short-Pulse Electromagnetics 7; UWBSP7
2007-01-01
Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-Wideband Short-Pulse Electromagnetics 7 presents selected papers of deep technical content and high scientific quality from the UWB-SP7 Conference, including wide-ranging contributions on electromagnetic theory, scattering, UWB antennas, UWB systems, ground penetrating radar (GPR), UWB communications, pulsed-power generation, time-domain computational electromagnetics, UWB compatibility, target detection and discrimination, propagation through dispersive media, and wavelet and multi-res...
On the atomic-state dressing effect by an intense electromagnetic radiation
Energy Technology Data Exchange (ETDEWEB)
Gonzalez-Diaz, P.F.; Garcia-Fernandez, P.
1985-11-01
Perturbation of the atomic energy levels by an intense electromagnetic field is theoretically investigated. A dressing interaction Hamiltonian is constructed in the second-quantization formalism and the correct transitional Hamiltonian formulated. (orig.).
Electromagnetic Properties Analysis on Hybrid-driven System of Electromagnetic Motor
Zhao, Jingbo; Han, Bingyuan; Bei, Shaoyi
2018-01-01
The hybrid-driven system made of permanent-and electromagnets applied in the electromagnetic motor was analyzed, equivalent magnetic circuit was used to establish the mathematical models of hybrid-driven system, based on the models of hybrid-driven system, the air gap flux, air-gap magnetic flux density, electromagnetic force was proposed. Taking the air-gap magnetic flux density and electromagnetic force as main research object, the hybrid-driven system was researched. Electromagnetic properties of hybrid-driven system with different working current modes is studied preliminary. The results shown that analysis based on hybrid-driven system can improve the air-gap magnetic flux density and electromagnetic force more effectively and can also guarantee the output stability, the effectiveness and feasibility of the hybrid-driven system are verified, which proved theoretical basis for the design of hybrid-driven system.
The ground state energy of a bound polaron in the presence of a magnetic field
Energy Technology Data Exchange (ETDEWEB)
Zorkani, I [International Centre for Theoretical Physics, Trieste (Italy); Belhissi, R [Faculte des Sciences Dhar Mahraz, Fes (Morocco). Dept. de Physique
1995-09-01
A theoretical calculation for the ground state energy of a bound polaron as a function of the magnetic field is presented. The theory is based on a variational approach using a trial wave function proposed by Devreese et al. in the absence of the magnetic field. It was shown that his function is adequate for all electron - phonon coupling {alpha} and all parameter {gamma}{sub 0} which is the ratio between the L.O. phonon energy and the Colombian one. Analytical results are obtained in the weak coupling limit. (author). 27 refs, 4 figs, 1 tab.
Big-bang nucleosynthesis through bound-state effects with a long-lived slepton in the NMSSM
Kohri, Kazunori; Koike, Masafumi; Konishi, Yasufumi; Ohta, Shingo; Sato, Joe; Shimomura, Takashi; Sugai, Kenichi; Yamanaka, Masato
2014-08-01
We show that the Li problems can be solved in the next-to-minimal supersymmetric standard model where the slepton as the next-to-lightest supersymmetric (SUSY) particle is very long lived. Such a long-lived slepton induces exotic nuclear reactions in big-bang nucleosynthesis, and destroys and produces the Li7 and Li6 nuclei via bound state formation. We study cases where the lightest SUSY particle is singlino-like neutralino and bino-like neutralino to present allowed regions in the parameter space, which is consistent with the observations on the dark matter and the Higgs mass.
Bounds on the moment of inertia of nonrotating neutron stars
International Nuclear Information System (INIS)
Sabbadini, A.G.; Hartle, J.B.
1977-01-01
Upper and lower bounds are placed on the moments of inertia of relativistic, spherical, perfect fluid neutron stars assuming that the pressure p and density p are positive and that (dp/drho) is positive. Bounds are obtained (a) for the moment of inertia of a star with given mass and radius, (b) for the moment of inertia of neutron stars for which the equation of state is known below a given density rho/sub omicron/and (c) for the mass-moment of inertia relation for stars whose equation of state is known below a given density rho/sub omicron/The bounds are optimum ones in the sense that there always exists a configuration consistent with the assumptions having a moment of inertia equal to that of the bound. The implications of the results for the maximum mass of slowly rotating neutron stars are discussed
Klatt, Michael A.; Torquato, Salvatore
2018-01-01
In the first two papers of this series, we characterized the structure of maximally random jammed (MRJ) sphere packings across length scales by computing a variety of different correlation functions, spectral functions, hole probabilities, and local density fluctuations. From the remarkable structural features of the MRJ packings, especially its disordered hyperuniformity, exceptional physical properties can be expected. Here we employ these structural descriptors to estimate effective transport and electromagnetic properties via rigorous bounds, exact expansions, and accurate analytical approximation formulas. These property formulas include interfacial bounds as well as universal scaling laws for the mean survival time and the fluid permeability. We also estimate the principal relaxation time associated with Brownian motion among perfectly absorbing traps. For the propagation of electromagnetic waves in the long-wavelength limit, we show that a dispersion of dielectric MRJ spheres within a matrix of another dielectric material forms, to a very good approximation, a dissipationless disordered and isotropic two-phase medium for any phase dielectric contrast ratio. We compare the effective properties of the MRJ sphere packings to those of overlapping spheres, equilibrium hard-sphere packings, and lattices of hard spheres. Moreover, we generalize results to micro- and macroscopically anisotropic packings of spheroids with tensorial effective properties. The analytic bounds predict the qualitative trend in the physical properties associated with these structures, which provides guidance to more time-consuming simulations and experiments. They especially provide impetus for experiments to design materials with unique bulk properties resulting from hyperuniformity, including structural-color and color-sensing applications.
Experimental Testing of a Van De Graaff Generator as an Electromagnetic Pulse Generator
2016-07-01
EXPERIMENTAL TESTING OF A VAN DE GRAAFF GENERATOR AS AN ELECTROMAGNETIC PULSE GENERATOR THESIS...protection in the United States AFIT-ENP-MS-16-S-075 EXPERIMENTAL TESTING OF A VAN DE GRAAFF GENERATOR AS AN ELECTROMAGNETIC PULSE GENERATOR...RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENP-MS-16-S-075 EXPERIMENTAL TESTING OF A VAN DE GRAAFF GENERATOR AS AN ELECTROMAGNETIC PULSE GENERATOR
Electromagnetic Gowdy universe
International Nuclear Information System (INIS)
Charach, C.
1979-01-01
Following Gowdy and Berger we construct an inhomogeneous closed electromagnetic universe with three-torus topology. This model is obtained as a result of the homogeneity breaking in the electromagnetic Bianchi type-I universe and contains interacting gravitational and electromagnetic waves. This cosmological solution provides an exactly solvable model for the study of the nonlinear fully relativistic regime of coupled electromagnetic and gravitational fields in the early universe. The asymptotic behavior is considered (i) in the vicinity of the initial singularity and (ii) in the high-frequency limit. It is shown that the effects of coupling between electromagnetic and gravitational waves cause an evolution which is significantly different from that of the vacuum model. The influence of the primordial homogeneous electromagnetic field on the dynamics of the model is also discussed
Theory of electromagnetic fluctuations for magnetized multi-species plasmas
Energy Technology Data Exchange (ETDEWEB)
Navarro, Roberto E., E-mail: roberto.navarro@ug.uchile.cl; Muñoz, Víctor [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Araneda, Jaime [Departamento de Física, Universidad de Concepción, Concepción 4070386 (Chile); Moya, Pablo S. [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, Maryland 20771 (United States); Department of Physics, Catholic University of America, Washington, D. C. 20064 (United States); Viñas, Adolfo F. [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, Maryland 20771 (United States); Valdivia, Juan A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Centro de Estudios Interdisciplinarios Básicos y Aplicados en Complejidad, CEIBA complejidad, Bogotá (Colombia)
2014-09-15
Analysis of electromagnetic fluctuations in plasma provides relevant information about the plasma state and its macroscopic properties. In particular, the solar wind persistently sustains a small but detectable level of magnetic fluctuation power even near thermal equilibrium. These fluctuations may be related to spontaneous electromagnetic fluctuations arising from the discreteness of charged particles. Here, we derive general expressions for the plasma fluctuations in a multi-species plasma following arbitrary distribution functions. This formalism, which generalizes and includes previous works on the subject, is then applied to the generation of electromagnetic fluctuations propagating along a background magnetic field in a plasma of two proton populations described by drifting bi-Maxwellians.
Electromagnetic waves in optical fibres in a magnetic field
International Nuclear Information System (INIS)
Gorelik, V S; Burdanova, M G
2016-01-01
A new method is reported of recording the secondary radiation of luminescent substances based on the use of capillary fibres of great length. Theoretical analysis of the dispersion curves of electromagnetic radiation in capillary fibres doped with erbium ions Er 3+ has been established. The Lorentz model is used for describing the dispersion properties of electromagnetic waves in a homogeneous medium doped with rare-earth ions. The dispersion dependencies of polariton and axion–polariton waves in erbium nitrate hydrate are determined on the basis of the model of the interaction between electromagnetic waves and the resonance electronic states of erbium ions in the absence and presence of a magnetic field. (paper)
Multiphoton ionization of the hydrogen atom by a circularly polarized electromagnetic field
International Nuclear Information System (INIS)
Prepelitsa, O.B.
1999-01-01
This paper examines the multiphoton ionization of the ground state of the hydrogen atom in the field of a circularly polarized intense electromagnetic wave. To describe the states of photoelectrons, quasiclassical wave functions are introduced that partially allow for the effect of an intense electromagnetic wave and that of the Coulomb potential. Expressions are derived for the angular and energy distributions of photoelectrons with energies much lower than the ionization potential of an unperturbed atom. It is found that, due to allowance for the Coulomb potential in the wave function of the final electron states, the transition probability near the ionization threshold tends to a finite value. In addition, the well-known selection rules for multiphoton transitions in a circularly polarized electromagnetic field are derived in a natural way. Finally, the results are compared with those obtained in the Keldysh-Faisal-Reiss approximation
International Nuclear Information System (INIS)
Yusa, Noritaka; Hashizume, Hidetoshi; Uchimoto, Tetsuya; Takagi, Toshiyuki
2011-01-01
This study proposes a method to fabricate an artificial defect that is almost identical to stress corrosion cracking from the viewpoint of electromagnetic nondestructive evaluations. The key idea is to realize a region having electrical resistance embedded inside a conductive materials using solid state bonding. A rough region is introduced into the surface of the materials to be bonded so that the region is partially bonded to realize electrical resistance. Experimental demonstrations are carried out using type 316L austenitic stainless steels. Eddy current tests and subsequent numerical evaluations are conducted to discuss the validity of the proposed method. (author)
The origin of electromagnetically induced absorption
International Nuclear Information System (INIS)
Park, Jong Dae; Hwang, Sung Tae; Lee, Ho Seong; Park, Sung Jong; Cho, Hyuck; Choi, Won Sik
2000-01-01
Recently, there have been a lot of interests in the coherence superposition of atomic states which are formed by laser fields. Coherent population trapping(CTP), electromagnetically induced transparency(EIT), enhancement of the refractive index without absorption, lasing without inversion(LWI), and electromagnetically induced absorption(EIA) are the examples where coherence effects are important. Previously, the spontaneous transfer of the light-induced coherence from the excited level to the ground one was emphasized for the essential ingredient for electromagnetically induced absorption. In this paper, we have considered a case where linearly polarized coupling laser and probe laser are applied to the same degenerated ground and excited levels. We have solved the master equations for density matrix using time varying Hamiltonian and studied the absorption spectra at various conditions. We demonstrate that EIA can be observed without spontaneous transfer of the light-induced coherence in F g = 1 -> F e = 2 D2 transitions of Hydrogen atoms