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[en] The interaction between the fluctuations that can be excited in a magnetically confined plasma and the high-energy-particle population produced by fusion reactions is analyzed in view of its relevance to the process of thermonuclear ignition. The spectrum of the perturbations that, in the absence of fusion reaction products, would be described by the incompressible ideal magnetohydrodynamic approximation is studied considering finite value of the plasma pressure relative ot the magnetic pressure. The combined effects of the magnetic field curvature and shear are taken into account and the relevant spectrum is shown to consist of a continuous portion, that could be identified as a mixture of shear-Alfven and interchange oscillations, and a discrete unstable part corresponding to the so-called ballooning modes. The rate of diffusion of the fusion reaction products induced by oscillations in the continuous part of the spectrum, as estimated from the appropriate quasi-linear theory, is found to be significantly smaller than could be expected if normal modes (i.e., nonconvective solutions) were excited. However, a relatively wide intermediate region is identified where opalescent fluctuations, capable of achieving significant amplitudes and corresponding to a quasi-discrete spectrum, can be excited

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Annals of Physics (New York); ISSN 0003-4916; ; v. 134 p. 376-410

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[en] The validity of the leptodermous expansion of the binding energy of nuclear systems is studied. First, a soluble model, in the one dimensional case, which is suitable for the study of such effects is briefly recalled and subsequently generalized to allow for variable nuclear compressibility. A mass formula with exponential terms which are necessary for the description of light systems is introduced. We show that the determination of its parameters does not require any new fits. They are completely determined once one allows for breakdown of the leptodermous expansion for very small systems

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Annals of Physics (New York); ISSN 0003-4916; ; v. 139(1); p. 1-13

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[en] The interference of electromagnetic and weak production mechanisms for lepton pair production may give rise to several effects which violate parity and charge symmetry. These effects are generally of the order of 1% for dilepton masses of 10 GeV. The theoretical calculations presented here show that experimental studies of these asymmetries may be useful. In particular, measurements of these asymmetries in collisions of pions with polarized protons may lead to a greatly enhanced understanding of the polarization distribution of quarks in a polarized proton. The polarization structure of d quark is shown to be of the special interest. Measurement of the parity-violating asymmetries in proton-polarized proton collisions may prove to be a sensitive probe of the flavor symmetry of the proton antiquark sea. Analysis of the parity conserving charge asymmetry (which is predicted to occur in collisions of unpolarized hadrons) allows a unique further test of the Dree--Yan model for lepton pair production, as well as of our understanding of weak interactions

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Annals of Physics (New York); ISSN 0003-4916; ; v. 144(2); p. 282-344

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ANNIHILATION, ASYMMETRY, CROSS SECTIONS, GLUONS, HELICITY, LEPTONS, P INVARIANCE, PAIR PRODUCTION, PARTON MODEL, PERTURBATION THEORY, PION-PROTON INTERACTIONS, POLARIZATION, POLARIZED TARGETS, PROTON-PROTON INTERACTIONS, QUANTUM CHROMODYNAMICS, QUARK-ANTIQUARK INTERACTIONS, QUARKS, SINGULARITY, TRANSVERSE MOMENTUM

BARYON-BARYON INTERACTIONS, COMPOSITE MODELS, ELEMENTARY PARTICLES, FERMIONS, FIELD THEORIES, HADRON-HADRON INTERACTIONS, INTERACTIONS, INVARIANCE PRINCIPLES, LINEAR MOMENTUM, MATHEMATICAL MODELS, MESON-BARYON INTERACTIONS, MESON-NUCLEON INTERACTIONS, NUCLEON-NUCLEON INTERACTIONS, PARTICLE INTERACTIONS, PARTICLE MODELS, PARTICLE PRODUCTION, PARTICLE PROPERTIES, PION-NUCLEON INTERACTIONS, POSTULATED PARTICLES, QUANTUM FIELD THEORY, TARGETS

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[en] Radiative effects on classical nonrelativistic charged particles are discussed in complete analogy with those arising in quantum electrodynamics. The effects originate in the interaction of the particle with its own electromagnetic fields. In particular, we derive an expression for the anomalous magnetic moment which provides both an intuitively appealing explanation of its origin and a reasonable relation to experimental values

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Annals of Physics (New York); ISSN 0003-4916; ; v. 142(2); p. 284-298

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[en] We first review the unitarity properties of the first order optical potential theory which arise from the one-body nature of both the single scattering approximation and of the single particle model for the nucleus. We construct optical potentials relaxing either the independent particle guided by the requirement of incorporating the minimal unitary of the first order theory and extending it to more complex situations. Our investigation of the effects of nucleon-nucleon residual interaction results in a description of the quasifree mechanism modified by final state unitarity requires the inclusion of all possible scattering processes on a given pair of target nucleons. This naturally leads to a formation of the optical potential in terms of three-body rather than two-body amplitudes. We discuss various approximation which make, in combination with phenomenological ingredients, an evaluation of these optical potentials feasible

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Annals of Physics (New York); ISSN 0003-4916; ; v. 143(1); p. 84-126

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[en] From the assumption that the collective Hamiltonian be invariant under the orthogonal group O(A-1, R) it is concluded that classical collective dynamics can be formulated on a sympletic manifold. This manifold is shown to be a coset space of the sympletic group Sh(6, R) of dimension 12, 16 or 18. The first case corresponds to the dequantization of closed-shell collective dynamics and is described in terms of six complex s- and d-quasiparticles. In the limit A>>1 it is shown that a transformation leads to interacting s- and d-bosons with the symmetry group U(6) in the collective phase space

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Annals of Physics (New York); ISSN 0003-4916; ; v. 141(2); p. 254-268

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[en] The equivalence between a D-dimensional classical field theory coupled to an external random source having Gaussian correlations and its D-2 dimensional quantum counterpart was established. Utilizing this equivalence, a regularization procedure for scalar theories is developed. The regularization amounts to a compactification of the extra two dimensions. The regularization scheme is interpreted in terms of superpropagator modifications

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Annals of Physics (New York); ISSN 0003-4916; ; v. 140(2); p. 247-265

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[en] Approximations to the Schroedinger time evolution in a highly truncated subspace are studied as an alternative to the time-dependent Hartree-Fock approximation. We derive a differential equation of second order in time, that involves the subspace matrix elements of the square of the Hamiltonian. The equation is completely defined and soluble within an arbitrarily truncated subspace. The solutions are non-unitary and allow for a flux of probability between the subspace and the excluded space. The accuracy of the approximation is studied in a number of examples

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Annals of Physics (New York); ISSN 0003-4916; ; v. 141(1); p. 179-198

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[en] We derive duality relations for the generating functional of correlation-functions for disordered (''frustrated'') lattice Higgs and gauge models with arbitrary locally compact abelian symmetry groups. We examine the effects on duality of nontrivial lattice topology and of configurational boundary conditions. Technically, we employ some elementary concepts borrowed from algebraic topology. Combined with Fourier expansions on groups, they provide tools to handle functions on lattices in a very efficient way. For convenience, these concepts are described in some detail in the first part of the paper

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Annals of Physics (New York); ISSN 0003-4916; ; v. 141(2); p. 225-253

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[en] In the temporal gauge formalism, in order to make a distinction between the global limit of local gauge transformations and global ones a non-local operator, theta, is introduced. It is claimed that what kind of theta is used is equivalent to what kind of gauge-fixing schemes is chosen. Along this idea, in non-abelian theories the coulomb, axial and unitary gauges have been investigated. In the unitary gauge spontaneous breakdown of global gauge symmetry has been found to be reduced to a problem of the boundary condition for the Higgs field and the occurrence of symmetry breaking has been calculated

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Annals of Physics (New York); ISSN 0003-4916; ; v. 141(2); p. 290-315

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