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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] P. A. M. Dirac took the matrix square root of the Klein-Gordon equation to obtain his relativistic wave equation for a single spin-one-half particle. In this paper, we use Dirac's constraint mechanics and supersymmetry to perform the same operation on the relativistic description of two spinless particles to obtain consistent descriptions of two interacting particles, either or both of which may have spin one-half. The resulting coupled quantum wave equations correctly incorporate relativistic kinematics as well as heavy-particle limits to one-body Dirac or Klein-Gordon equations. The 16-component wave equations for the system of two spin one-half particles separate exactly into four decoupled four-component equations for the analogs of ''upper'' and ''lower'' components of the Dirac equation. Perturbative treatment of our equations through O(α

^{4}) automatically reproduces the appropriate fine structure. Furthermore, like the decoupled forms of Dirac's equation, the two-body versions have spin-dependent pieces that make non-perturbating quantum-mechanical sense. This feature eliminates the need for extra smoothing parameters in the potential or finite particle size in phenomenological applicationsPrimary Subject

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Annals of Physics (New York); ISSN 0003-4916; ; v. 148(1); p. 57-94

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[en] The nonsymmetric Kaluza-Klein theory unifying Moffat's theory of gravitation, the Yang-Mills' field and the Higgs' fields are constructed in a geometric manner. Spontaneous symmetry breaking, the Higg's mechanism and mass generation in the theory are discussed. The connection between R/sub +/ invariance (dilatation on the space-time) from Moffat's theory of gravitation and U(1)/sub F/ from GUts, is proposed within the framework of fermion number conservation

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Annals of Physics (New York); ISSN 0003-4916; ; v. 148(1); p. 214-253

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[en] We present an approach to quantum gauge theories formulated entirely on a superspace. We show that at the classical level the field equations are the same as in the usual Minkowski space approach. In particular the a-flatness conditions, which represent the BRS and anti-BRS covariance in the usual approach, appear as field equations. We show that the theory is renormalizable and the a-flatness conditions are stable under renormalization. We speculate about the relevance of this approach to the confinement problem

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Annals of Physics (New York); ISSN 0003-4916; ; v. 144(1); p. 15-33

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[en] Existence of the Moller wave operators and unitarity of the S operator is proved for quantum-mechanical scattering potentials for V (r) = (sin r)/r/sup b/, 1/2< b< or =3/4

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Annals of Physics (New York); ISSN 0003-4916; ; v. 121(1); p. 415-431

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[en] A systematic procedure for calculating semiclassical expansions of physically interesting quantities is presented. The method is based on the Wigner transform of operators. It is applied specifically to the case of fermions governed by a one-body Hamiltonian. Expansions up to fourth order in h of the density matrix for various spin-indenpendent potentials are derived. Expressions of the kinetic energy density in terms of the matter density are given, which are of particular interest for nuclear structure calculations

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Annals of Physics (New York); ISSN 0003-4916; ; v. 123(2); p. 359-380

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[en] In Rosen's ''bimetric'' theory of gravity the (local) speed of gravitational radiation ν/sub g/ is determined by the combined effects of cosmological boundary values and nearby concentrations of matter. It is possible for ν/sub g/ to be less than the speed of light. I show here that emission of gravitational radiation prevents particles of nonzero rest mass from exceeding the speed of gravitational radiation. Observations of relativistic particles place limits on ν/sub s/ and the cosmological boundary values today, and observations of synchrotron radiation from compact radio sources place limits on the cosmological boundary values in the past

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Annals of Physics (New York); ISSN 0003-4916; ; v. 125(1); p. 35-52

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[en] The compact open four-dimensional manifold CP

^{2}, with Euclidean metric, has recently attracted attention as an example of a spacetime in which fields of half-integral spin cannot be defined in the absence of additional structure (such as an electromagnetic background). In this note we identify the specific topological anomaly responsible for this phenomenon: CP^{2}contains a class of two-dimensional spheres-''complex lines'': in small neighborhoods of each of which the two transverse degrees of freedom are forced to ''twist'' in a characteristic way. It is shown in detail how the twists force vierbeins: tetrads of orthonormal vector fields that play a central role in the theory of spinors: to have singularities on every complex line. As an aid to visualization we construct an example of a vierbein with, loosely speaking, the smallest possible set of singularities: It is ill-defined at every point of some one complex line and smooth everywhere else. The behavior of such a vierbein near any one of its singular points is characterized explicitly. The structure of the minimally singular vierbein is used to illuminate the observation of Hawking and Pope that in the presence of an appropriate electromagnetic background, fields of any spin can exist on CP^{2}as long as their electric charges are correctly quantized, but that the charge values available to half-integral-spin fields differ from those available to integral-spin fieldsPrimary Subject

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Annals of Physics (New York); ISSN 0003-4916; ; v. 126(1); p. 123-134

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[en] The three-dimensional Schroedinger equation with an effective mass is solved for a new class of angular momentum dependent potentials with varying depths and shapes. The energy eigenvalues and resonances are given in algebraic form as a function of the effective mass and depth and shape of the potential. The eigenfunctions, scattering function, and Green's function are given in closed form in terms of known special functions. The charge density of

^{208}Pb is calculated using eigenfunctions of a potential and this charge density is compared to the measured charge densityPrimary Subject

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Annals of Physics (New York); ISSN 0003-4916; ; v. 159(2); p. 467-480

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