Studies in covariant soliton dynamics.
Item
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Title
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Studies in covariant soliton dynamics.
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Identifier
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AAI8821065
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identifier
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8821065
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Creator
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Bannur, Vishnu Mayya.
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Contributor
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Adviser: Carl M. Shakin
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Date
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1988
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Language
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English
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Publisher
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City University of New York.
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Subject
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Physics, Nuclear | Physics, Elementary Particles and High Energy
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Abstract
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We have studied various mesons: {dollar}\rho, \rho\sp\prime{dollar}, {dollar}\omega{dollar}, {dollar}\varphi, \varphi\sp\prime{dollar}, charmonium and bottomonium, using covariant soliton dynamics. Both baryons and mesons are described as nontopological solitons in this model, which is a simple, unified, covariant model for the description of the structure of all hadrons. The model describes quarks coupled to a scalar field, which plays the role of an order parameter of the QCD vacuum.;We develop an effective Lagrangian for low-momentum QCD. Various parameters of the model can be related to the dynamics of the gluon condensate. We find that flavor-dependent current quark masses and coupling constants are among the few parameters required to explain all energy levels below the open-flavor threshold. (There are also some high-momentum cutoffs needed in this formalism.).;In order to explain the energy levels above the open-flavor threshold, we have included a covariant model of confinement through the use of a phenomenological form for the quark self-energy. This form results in a quark propagator which has no on-mass-shell poles. (The various spectra we obtained in this extended model are in good agreement with the experimental data.) Recently, we have considered a self-consistent approximation for the self-energy of a quark in the presence of a gluon condensate. We found chiral symmetry breaking and the absence of a fermion pole in the quark propagator. In fact, the self-energy we calculated is in very good agreement with the phenomenological form we have used previously.;We have also studied the wave functions of various mesons. Leptonic widths and radiative transition rates were calculated in a covariant formulation using these wave functions. We have also included "one-gluon-exchange" effects and generally satisfactory results were obtained for decay widths.;Thus far, we have kept one constituent on mass shell, as an approximation. Recently, we have developed a formalism where this approximation is avoided; we have also included a model of confinement in this new formalism. These developments lead to coupled nonlinear equations in two variables. Numerical analysis is underway.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
