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in subjects: "Three-Body Problem"

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Bag model, the hyperspherical formalism and the heavy baryons

The bag model framework is used to discuss the heavy baryons, triple flavored objects like ccc, cbb, etc. A nonrelativistic picture seems justified. It is insisted that the long-range interaction consist of a genuine three-body force. Once the potential energy of the three quarks is determined, the three-body Schroedinger equation is solved by the method of hyperspherical expansion. 1 table. (RWR)

Date: January 1, 1980

Creator: Richard, J. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Relativistic effects in the atomic and nuclear few-body problems

Relativistic effects in the atomic and nuclear few-body systems are classified and discussed with the emphasis on electromagnetic transitions. The size of relativistic corrections, calculational techniques and ambiguities, and comparison of theory and experiment are considered. 8 figures.

Date: January 1, 1980

Creator: Friar, J.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Few-body binding energy correlations

The effect of strongly linear few-nucleon binding energy correlations under variation of the potential has been found by the authors in the three-nucleon case. Their previous work is sketched as a basis for giving several extensions in the present note. Under realistic conditions there is a weak energy dependence for the kernels of the separable approximated Alt-Grassberger-Sandhas equations. The first-order correction E/sub T//sup 1/ is smaller for the Gauss potential than for the Yamaguchi; t… more

Date: January 1, 1980

Creator: Kroeger, H. & Perne, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Analyzing-power formalism for three-body final states

Various relations important for extraction of analyzing powers from data on reactions involving three particles in the final state were derived. Several of the results pertinent for spin-1/2 and spin-1 polarized beams are presented here. These may be used in analysis of the /sup 1/H(d-vector,pp)n reaction. 3 figures. (RWR)

Date: January 1, 1980

Creator: Ohlsen, G.G.; Brown, R.E.; Correll, F.D. & Hardekopf, R.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Three lectures on effective interaction in nuclei

The first lecture discusses the origins of the density dependence of the effective interaction. The significance of effective interactions in nuclei is noted. The lowest-order treatment of the short-range repulsion in the nucleon-nucleon interaction (the separation method) and an improved treatment including some of the effect of the nuclear medium on the interaction (dispersion effect) are reviewed. Density dependence and effective three-body interactions and also isospin asymmetry effects are… more

Date: May 1, 1980

Creator: Moszkowski, S.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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(p,2p) study of high-momentum components at 2. 1 GeV

A (p,2p) experiment designed to isolate interactions with small numbers of fast nuclear constituents is described. Special attention is paid to the experimental manifestation and description of a correlated pair of nucleons in the nucleus. Phase space calculations are presented for the proton-pair three-body final state and for final states with larger number of particles. The Two Armed Spectrometer System (TASS) is described in detail. The data suggest the possibility of isolating an interacti… more

Date: July 1, 1982

Creator: Treuhaft, R.N.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Chaos in the lowest Landau level

The problem of a few electrons in the lowest Landau level is discussed. Low-lying states of the three-and four-electron problems are constructed. In the classical limit, the three-body problem is integrable but there is numerical evidence of chaotic motion in the four-body problem. Consequences of classical chaos for the statistics of energy levels are described and the possibility of carrying out relevant experiments in semiconductor heterostructures is discussed. 9 refs.

Date: January 1, 1991

Creator: Emery, V.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Cluster separability in front-form particle dynamics

In relativistic quantum dynamics, the group structure demands that some transformations other than the time evolutions depend on dynamics. It is possible to choose the representation of a kinematic subgroup to be independent of the dynamics, leading to different ''forms of dynamics'' which are unitarily equivalen. In the ''front-form'' dynamics the kinematic subgroup leaves the light front invariant, and the rotations about any transverse axis are dynamical transformations. In the front form th… more

Date: January 1, 1986

Creator: Coester, F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Configuration space methods in the three-nucleon problem

The assumptions underlying the formulation and solution of the Schroedinger equation for three nucleons in configuration space are reviewed. Those qualitative aspects of the two-nucleon problem which play an important role in the trinucleon are discussed. The geometrical aspects of the problem are developed, and the importance of the angular momentum barrier is demonstrated. The Faddeev-Noyes formulation of the Schroedinger equation is motivated, and the boundary conditions for various three-bo… more

Date: January 1, 1985

Creator: Friar, J.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The trinucleons: Physical observables and model properties

Our progress in understanding the properties of {sup 3}H and {sup 3}He in terms of a nonrelativistic Hamiltonian picture employing realistic nuclear forces is reviewed. Trinucleon model properties are summarized for a number of contemporary force models, and predictions for physical observables are presented. Disagreement between theoretical model results and experimental results are highlighted.

Date: January 1, 1992

Creator: Gibson, B. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Three-nucleon problem: trinucleon bound states and trinucleon interactions

The assumptions underlying the formulation and solution of the Schroedinger equation for three nucleons in configuration space are reviewed, in conjunction with those qualitative aspects of the two-nucleon problem which are important. The geometrical features of the problem and the crucial role of the angular momentum barrier are developed. The boundary conditions for scattering are discussed qualitatively, and the Faddeev-Noyes equation is motivated. The method of splines and orthogonal colloc… more

Date: January 1, 1985

Creator: Friar, J.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Three-nucleon forces and the trinucleon bound states

A summary of the bound-state working group session of the ''International Symposium on the Three-Body Force in the Three-Nucleon System'' is presented. The paper includes a discussion of presently used calculational techniques, experimental evidence for three-nucleon forces in trinucleon ground states, future directions in theoretical research and future experimental research. (DWL)

Date: January 1, 1986

Creator: Friar, J.L. & Frois, B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Relativistic effects in the binding energies of few-body nuclei

We have examined the consequences of Poincare invariance for the binding-energy calculations of few-body nuclei. Nonrelativistic Hamiltonians have been considered in an attempt to fit simultaneously the binding energies of 2-, 3-, 4-body nuclei and that of nuclear matter. Even with reasonable three-body forces it appears to be difficult to simultaneously fit the binding energies of 3- and 4-body nuclei. The size of the discrepancy is of the order of possible relativistic effects. After eliminat… more

Date: January 1, 1983

Creator: Coester, F. & Wiringa, R.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Resonance capture and Saturn's rings

We have assigned the resonances apparently responsible for the stabilization of the Saturn's shepherd satellites and for the substructure seen in the F-ring and the ringlets in the C-ring. We show that Saturn's narrow ringlets have a substructure determined by three-body resonances with Saturn's ringmoons and the sun. We believe such resonances have important implications to satellite formation. 17 refs., 1 fig., 1 tab.

Date: May 1, 1986

Creator: Patterson, C.W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Nucleon-nucleon scattering contribution to the triton binding energy

We conjectured in 1972 that much of the dynamics of a few nucleon systems could be computed from the on-shell nucleon-nucleon scatterings provided that a consistent few body theory using this input could be constructed. Such a Zero Range Scattering Theory has been shown to lead to unitary three and four particle scattering amplitudes provided only the two particle amplitudes have no singularities other than bound state poles when continued to negative energies, which restricts the theory to Cas… more

Date: April 1, 1983

Creator: Noyes, H. Pierre

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Three-body forces mandated by Poincare invariance

Poincare invariant models for the three-nucleon system are examined which have the same heuristic relation to field theories as the nonrelativistic nuclear models. The generators of the infinitesimal dynamical transformations can be obtained as functions of the kinematic generators, the invariant mass operator of the interacting system, and additional operators. These additional operators are the components of the Newton-Wigner position operator in the instant form, and the transverse component… more

Date: January 1, 1986

Creator: Coester, F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Recent results in the theory of the three-nucleon systems

This paper concentrates on calculational results obtained by the Los Alamos-Iowa Faddeev group and on related calculations. Most of the interest of this group has centered on the Helium 3 and Hydrogen 3 ground states, including the effects of the Coulomb interactions between the two protons in Helium 3. Recent progress in treating the alpha particle is reported and zero energy n-d and p-d scattering and an improved understanding of the scattering lengths for these systems are also discussed. Si… more

Date: June 1, 1987

Creator: Friar, J.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Three-body force in the three-nucleon system

A brief summary of the symposium is presented. Three-nucleon force models are discussed, including the two-pion exchange potential, NN-..delta..N coupled-channels model, and phenomenological parametrization. Relevant experimental data and model calculations are discussed including form factors, binding energies, charge radii, and charge density for /sup 3/H and /sup 3/He. A calculation of the EMC effect for /sup 3/He is also made using Sasakawa's wave function and compared to experimental data … more

Date: January 1, 1986

Creator: Gibson, B. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Minimal relativistic three-particle equations

A minimal self-consistent set of covariant and unitary three-particle equations is presented. Numerical results are obtained for three-particle bound states, elastic scattering and rearrangement of bound pairs with a third particle, and amplitudes for breakup into states of three free particles. The mathematical form of the three-particle bound state equations is explored; constraints are set upon the range of eigenvalues and number of eigenstates of these one parameter equations. The behavior … more

Date: July 1, 1981

Creator: Lindesay, J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Three-body forces and the trinucleons

Three-body forces are discussed in the context of classical, atomic, solid-state and nuclear physics. The basic theoretical ingredients used in the construction of such forces are reviewed. Experimental evidence for three-nucleon forces and an overview of the three-nucleon bound states are presented. 53 refs., 9 figs.

Date: January 1, 1987

Creator: Friar, J.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Physics of few-body lambda hypernuclei

The energies of the particle-stable states in few-body ..lambda.. hypernuclei are summarized. Other topics reviewed include: the role of the hypertriton in determining the spin dependence of the ..lambda..N force, the role of the hypertriton in three-body force investigations, the effect of medium modifications upon ..lambda..N-..sigma..N coupling in the ..lambda..-4 isodoublet and the spin dependence of the ..lambda..N force, the importance of exact equation formalisms in interpreting precisio… more

Date: January 1, 1987

Creator: Gibson, B. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Applied Nuclear Science Research and Development progress report, June 1, 1984-May 31, 1985

This progress report describes the activities of the Los Alamos Applied Nuclear Science Group for June 1, 1984 through May 31, 1985. The topical content includes the theory and evaluation of nuclear cross sections; neutron cross section processing and testing; neutron activation, fission products and actinides; and core neutronics code development and application. 70 refs., 31 figs., 15 tabs. (WRF)

Date: September 1, 1985

Creator: Arthur, E. D. & Mutschlecner, A. D. (comps.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Minimal unitary (covariant) scattering theory

In the minimal three particle equations developed by Lindesay the two body input amplitude was an on shell relativistic generalization of the non-relativistic scattering model characterized by a single mass parameter ..mu.. which in the two body (m + m) system looks like an s-channel bound state (..mu.. < 2m) or virtual state (..mu.. > 2m). Using this driving term in covariant Faddeev equations generates a rich covariant and unitary three particle dynamics. However, the simplest way of writing … more

Date: June 1, 1983

Creator: Lindesay, J.V. & Markevich, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Nuclear structure theory. Annual technical progress report, October 1, 1978-September 30, 1979. [Summaries of research activities at Univ. of Rochester]

This report summarizes progress during the past year in the following areas of nuclear structure and reaction theory: Statistical spectroscopy, including: Random matrix methods, with applications to fluctuations in spectra and in strength distributions, and to problems of ergodicity; Group symmetries in spectral-distribution theory; Electromagnetic and ..beta.. transitions. Meson scattering and absorption by nuclei, including: general scattering theory with absorption, multiple scattering theor… more

Date: January 1, 1979

Creator: French, J. B. & Koltun, D. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department