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Jallouli, H.; Sazdjian, H.
Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire1997
Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire1997
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[en] The behavior of the two-particle Green's function in QED is analyzed in the limit when one of the particles becomes infinitely massive. It is found that the dependences of the Green's function on the relative times of the ingoing and outgoing particles factorize and that the bound state spectrum is the same as that of the Dirac equation with the static potential created by the heavy particle. The Bethe-Salpeter wave function is also determined in terms of the Dirac wave function. The present result excludes the existence, in the above limit, of abnormal solutions due to relative time excitations as predicted by the Bethe-Salpeter equation in the ladder approximation. (author)
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Apr 1997; 13 p; 23 refs.
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[en] The recently developed technique of nonlocal regularization is applied to the two dimensional chiral Schwinger model, which is anomalous. It is shown that nonlocal regularization breaks the chiral gauge symmetry of the classical theory. However, the regularized theory belongs to a class of consistent theories considered by Jackiw and Rajaraman. (orig.)
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[en] Electric charge in QED is topological in the sense that the electric current is a curl of a local gauge-invariant field - the dual electromagnetic field strength.Electrically charged particles are then visualized as topological solitons of V corresponding to elements of the homotopy group π (S1) = Z. The quantization of electric charge and the universality of the electromagnetic coupling are thus given a topological interpretation. The low energy physics is described by a 'dual' Lagrangian written in terms of the field V only. The vortex field V is also constructed in non-Abelian gauge theories. Here the solitons of V are identified with the 'constituent' quarks. The dual Lagrangian contains explicit flux-symmetry-breaking terms. As a result the topological solitons (quarks) are linearly confined. In this paper, the authors describe in detail the derivation of the dual Lagrangian and the topological mechanism of confinement in non-Abelian theories with adjoint and fundamental matter. The extension of the above description to the (3 + 1)-dimensional gauge theories is briefly discussed. Several notions are easily generalizable but the picture is far form being complete
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Bagge, E.R.
GKSS-Forschungszentrum Geesthacht GmbH, Geesthacht-Tesperhude (Germany)1992
GKSS-Forschungszentrum Geesthacht GmbH, Geesthacht-Tesperhude (Germany)1992
AbstractAbstract
[en] Very precise investigations of the positron-electron pair production by γ-quanta of 6.13 MeV showed at every single case that the energy sums of the two particles are significantly lower than the energies of the involved quanta. Further on the energy spectra of the positrons and electrons are very different from each other. This is in a direct contradiction to the existing general opinion accepted by nearly all physicists which says that they should be identical. Following own calculations of the author and also the measurements discussed in this paper, we come to the conclusion that the theory of pair creation must be modified, to bring it in a form to include also the above presented new effects. It can be shown, that the well known 'hole theory' of Dirac from 1932 agrees very well with the new results of the observations. Especially the energy deficits of the positrons and electrons and their spectra will be described correctly. (orig.) With 9 figs
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Sehr genaue Untersuchungen zur Erzeugung von Positron-Elektron-Paaren durch Gammaquanten von 6,13 MeV zeigten in jedem Einzelfall, dass die Energiesummen der beiden Teilchen deutlich kleiner sind als die Energien der ausloesenden Quanten. Ausserdem besitzen die Energiespektren von Positron und Elektron zweifelsfrei voellig verschiedene Verlaeufe, die nach heutiger Lehrmeinung eigentlich identisch sein sollten. Nach eigenen Rechnungen des Autors und den hier mitgeteilten Messungen zugleich ergibt sich, dass die urspruenglich von Dirac 1932 vorgeschlagene Theorie der Paarbildung, die sogenannte 'Loechertheorie', eine mit den Beobachtungen am besten uebereinstimmende Deutung des Paarbildungsprozesses darstellt. Sowohl hinsichtlich der Energiedefizite als auch bei den Verlaeufen der Spektren stimmen Theorie und Experiment gut ueberein. (orig.) With 9 figsOriginal Title
Experimente zur Paarerzeugung und ihre Deutung
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1992; 24 p; Available from FIZ Karlsruhe
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ANTILEPTONS, ANTIMATTER, ANTIPARTICLES, ATOM COLLISIONS, BASIC INTERACTIONS, COLLISIONS, ELECTRIC FIELDS, ELECTRODYNAMICS, ELECTROMAGNETIC INTERACTIONS, ELEMENTARY PARTICLES, ELEMENTS, ENERGY RANGE, FERMIONS, FIELD THEORIES, INTERACTIONS, LEPTONS, MATTER, MEV RANGE, NONMETALS, PARTICLE INTERACTIONS, PARTICLE PRODUCTION, PHOTON COLLISIONS, QUANTUM FIELD THEORY, SPECTRA
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[en] We present in a path integral framework a class of gauges for QED that are both temporal and yet do not display the notorious singularity of the naive temporal gauge. These gauges follow from a generalised radiation gauge, where the Coulomb gauge fixing is 'smeared out'. We show that the use of two gauge fixings necessitates the incorporation of gauge dependent Coulomb interactions. The correctness of our theory is demonstrated in two ways: We can reduce to the true degrees of freedom and we show that it reproduces some gaugeinvariant results of perturbation theory. Although Landshoff's α prescription for the temporal gauge can be understood as a limit of our class, extra terms also appear. It is seen that these terms are necessary to obtain the periodic Wilson loop at finite temperature correctly. (orig.)
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Zeitschrift fuer Physik. C, Particles and Fields; ISSN 0170-9739;
; CODEN ZPCFD2; v. 59(2); p. 351-356

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[en] We show that discontinuities in the vacuum polarisation give rise to charge screening effects which are large and result in a lower bound Δ with -m<Δ
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ANNIHILATION OPERATORS, BOUND STATE, CHARGE DENSITY, COULOMB FIELD, CREATION OPERATORS, EIGENSTATES, EIGENVALUES, ELECTRONIC STRUCTURE, ELECTRONS, ENERGY LEVELS, EXCITED STATES, GROUND STATES, HAMILTONIANS, HILBERT SPACE, LIMITING VALUES, OCCUPATION NUMBER, POLARIZATION, QUANTUM ELECTRODYNAMICS, SINGULARITY, SPINOR FIELDS, TIME DEPENDENCE, VACUUM POLARIZATION, VACUUM STATES
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[en] I present a new method of deriving under some mild assumptions the most general options for the B.R.S.T. transformation, without having recourse either to Lagrange or Feynman's integral-over-all-paths formalisms. It turns out that these different variants can be reduced eventually to two cases, from which one encompasses the conventional B.R.S.T. transformation. 10 refs. (author)
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B.R.S.T.- Becchi, Rouet, Stora, Tyutin
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30. Cracow school of theoretical physics; Zakopane (Poland); 2-12 Jun 1990
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[en] In this paper, motivated by evidence for a chiral phase transition in strong coupling lattice QED, the authors calculate the two-particle spectrum of the broken QED phase. This is done in the framework of a Nambu and Jona-Lasinio model with U(1) symmetry including chiral symmetry and symmetry breaking properties of QED. The second order chiral phase transition behavior in our model and in lattice QED are in excellent agreement. The authors then present a detailed analysis of the spectra of the e+e- modes in the broken phase. The authors examine whether these modes have any possible relationship to the narrow e+e- resonances found in soft heavy ion collisions at GSL. The authors' answer is negative
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[en] In this paper, the authors evaluate the one-loop vacuum polarization tensor for three dimensional quantum electrodynamics (QED), using an analytic regularization technique, implemented in a gauge-invariant way. The authors show thus that a gauge boson mass is generated at this level of radiative correction to the photon propagator. The authors also point out in their conclusions that the generalization for the non Abelian case is straightforward
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[en] In this paper, the author considers the geometric version of the Schwinger Model (GSM) (two dimensional QED with massless fermions) in continuum Euclidean space time
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Dodonov, V.V.; Man; ko, V.I; 274 p; ISBN 1-56072-037-9;
; 1991; p. 73-76; Nova Science Publishers, Inc; Commack, NY (United States); 18. international colloquium on group theoretical methods in physics; Moscow (USSR); 4-9 Jun 1990; CONF-9006272--; Nova Science Publishers, Inc., 6080 Jericho Turnpike, Suite 207, Commack, NY 11725 (United States)

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