11 Matching Results

Search Results

Advanced search parameters have been applied.

Linking the Gauss-Bonnet-Chern theorem, essential HOPF maps and membrane solitons with exotic spin and statistics

Description: By way of the Gauss-Bonnet-Chern theorem, we present a higher dimensional extension of Polyakov's regularization of Wilson loops of point solitons. Spacetime paths of extended objects become hyper-ribbons with self-linking, twisting and writhing numbers. specifically we discuss the exotic spin and statistical phase entanglements of geometric n-membrane solitons of D-dimensional KP{sub 1} {sigma}-models with an added Hopf-Chern-Simons term where (n, D, K) = (0, 3, C), (2, 7, H), (6, 15, {Omega}). They are uniquely linked to the complex and quaternion and octonion division algebras. 22 refs.
Date: January 1, 1989
Creator: Tze, Chia-Hsiung (Virginia Polytechnic Inst., Blacksburg, VA (USA). Dept. of Physics)
Partner: UNT Libraries Government Documents Department

Dense and dilute instanton-anti-instanton pair configurations

Description: We present a Yang-Mills gauge field configuration which for large values of a separation parameter is an instanton-anti-instanton pair. At a minimum finite separation the field is a pure gauge. The interaction is calculated for large and small separations. According to an approximation algorithm the configuration is the most important quantum fluctuation about the exact solutions. 3 references.
Date: January 1, 1979
Creator: Palmer, W.F. & Pinsky, S.S.
Partner: UNT Libraries Government Documents Department

Rings

Description: The essence of vortex physics is that at certain low-energy scales elementary excitations of a point particle theory can behave like strings rather than particles. Vortices are the resulting string-like solutions; their thickness sets the distance scale beyond which physics is string-like rather than particle-like. String degrees of freedom are massless in the sense that excitations on a string can have an arbitrarily low frequency. Non-string degrees of freedom correspond to massive particles and are absent from the low energy spectrum. This article considers only field theories with vortices at low energies. The possible existence of a class of solitons in these vortex theories will be discussed. They are vortex rings: they are localized and finite in energy, and able to carry the quantum numbers of point particles. Rings are thus particle-like solutions of a vortex theory, which is itself a limit of a point particle field theory.
Date: January 1, 1989
Creator: Davis, R.L.
Partner: UNT Libraries Government Documents Department

Using field theory in hadron physics

Description: Topics are covered on the connection of field theory and hadron physics. The renormalization group and infrared and ultraviolet limits of field theory, in particular quantum chromodynamics, spontaneous mass generation, color confinement, instantons, and the vacuum state in quantum chromodynamics are treated. 21 references. (JFP)
Date: March 1, 1978
Creator: Abarbanel, H.D.I.
Partner: UNT Libraries Government Documents Department

Monte Carlo approaches to effective field theories

Description: In this paper, we explore the application of continuum Monte Carlo methods to effective field theory models. Effective field theories, in this context, are those in which a Fock space decomposition of the state is useful. These problems arise both in nuclear and condensed matter physica. In nuclear physics, much work has been done on effective field theories of mesons and baryons. While the theories are not fundamental, they should be able to describe nuclear properties at low energy and momentum scales. After describing the methods, we solve two simple scalar field theory problems; the polaron and two nucleons interacting through scalar meson exchange. The methods presented here are rather straightforward extensions of methods used to solve quantum mechanics problems. Monte Carlo methods are used to avoid the truncation inherent in a Tamm-Dancoff approach and its associated difficulties. Nevertheless, the methods will be most valuable when the Fock space decomposition of the states is useful. Hence, while they are not intended for ab initio studies of QCD, they may prove valuable in studies of light nuclei, or for systems of interacting electrons and phonons. In these problems a Fock space decomposition can be used to reduce the number of degrees of freedom and to retain the rotational symmetries exactly. The problems we address here are comparatively simple, but offer useful initial tests of the method. We present results for the polaron and two non-relativistic nucleons interacting through scalar meson exchange. In each case, it is possible to integrate out the boson degrees of freedom exactly, and obtain a retarded form of the action that depends only upon the fermion paths. Here we keep the explicit bosons, though, since we would like to retain information about the boson components of the states and it will be necessary to keep these components ...
Date: January 1, 1991
Creator: Carlson, J. (Los Alamos National Lab., NM (United States)) & Schmidt, K.E. (Arizona State Univ., Tempe, AZ (United States). Dept. of Physics)
Partner: UNT Libraries Government Documents Department

Cosmic strings and baryon decay catalysis

Description: Cosmic strings, like monopoles, can catalyze proton decay. For integer charged fermions, the cross section for catalysis is not amplified, unlike in the case of monopoles. We review the catalysis processes both in the free quark and skyrmion pictures and discuss the implications for baryogenesis. We present a computation of the cross section for monopole catalyzed skyrmion decay using classical physics. We also discuss some effects which can screen catalysis processes. 32 refs., 1 fig.
Date: September 1, 1989
Creator: Gregory, R.; Perkins, W.B.; Davis, A.C.; Brandenberger, R.H. (Fermi National Accelerator Lab., Batavia, IL (USA); (UK), Cambridge Univ. & Brown Univ., Providence, RI (USA). Dept. of Physics)
Partner: UNT Libraries Government Documents Department

Elements of quantum chromodynamics

Description: The subject of quantum chromodynamics is discussed at length. The introduction motivates the exposition and points out the analogies between QCD and QED. Then, after some assumptions about the nature of QCD, a description is given of what the solution of the theory should look like for three stages of complexity: pure QCD with no fermions or other sources, introduction of superheavy quarks, introduction of the light quarks (u, d, s) with vacuum polarization and pair creation. Next, canonical quantization of QCD by use of a Hamiltonian formulation (in A/sub 0/ = 0 gauge) is considered; gauge ambiguities, theta vacua, instantons, etc., are encountered. Then the properties of the three stages noted above are discussed in much greater detail. These follow descriptions of the confinement problem and various approaches to it, as well as of more radical alternatives to QCD, such as the string model or the Pati-Salam program. Included in the summary is an assessment of the current situation. 101 references, 23 figures, 2 tables. (RWR)
Date: January 1, 1979
Creator: Bjorken, J.D.
Partner: UNT Libraries Government Documents Department

Some remarkable spin physics with monopoles and fermions

Description: This review will cover the following topics, which follow the historical evolution of the subject: the Dirac monopole; the Kazama-Yang Goldhaber problem in electron-monopole scattering; the 't Hooft-Polyakov monopole and spin from isospin; the Rubakov analysis; monopole catalysis of proton decay the Rubakov-Callan effect; the role of exactly solvable 2-dimensional QFT's and finally observable consequences. 15 references.
Date: January 1, 1984
Creator: Craigie, N.S.
Partner: UNT Libraries Government Documents Department

Chiral field theories as models for hadron substructure

Description: A model for the nucleon as soliton of quarks interacting with classical meson fields is described. The theory, based on the linear sigma model, is renormalizable and capable of including sea quarks straightforwardly. Application to nuclear matter is made in a Wigner-Seitz approximation.
Date: March 1, 1987
Creator: Kahana, S.H.
Partner: UNT Libraries Government Documents Department