Search for nucleon resonances of mass up to 8.5 GeV

Missing mass spectra were obtained by measuring recoil protons from the reaction p+p→p+X in the Jacobian peak region. Data were taken during the acceleration ramp of the Fermilab machine using an internal hydrogen gas jet target. We observe the well known N¹(1688) and N¹(2190) resonances but no significant structures at higher mass.     

The 110Pd, 116Cd(p,p'γ) reactions

The possibility of extending our knowledge about higher-energy collective-type states among the vibrational nuclei by observing γ-rays from states excited by inelastically scattered protons has been examined. Gamma rays from ¹¹⁰Pd and ¹¹⁶Cd were detected in coincidence with inelastically scattered protons; the incident protons had energies of 12 and 13 MeV. Gamma rays, most of them previously unreported, were observed from 17 levels in ¹¹⁰Pd and 14 levels in ¹¹⁶Cd below ≈ 2.5 MeV. The results are compared to predictions of a phonon- model interpretation of the levels. Evidence is shown for the existence of the three-quadrupole phonon quintet in ¹¹⁰Pd.     

The stereochemical dependence of one-bond carbon-carbon coupling constants

Spin-spin coupling constants for carbon-carbon single bonds vary with the orientation of lone pairs on adjacent nitrogen atoms and of adjacent carbonyl groups.     

Return to equilibrium

The problem of return to equilibrium is phrased in terms of aC*-algebraU, and two one-parameter groups of automorphisms , ^P corresponding to the unperturbed and locally perturbed evolutions. The asymptotic evolution, under , of ^P -invariant, and ^P -K.M.S., states is considered. This study is a generalization of scattering theory and results concerning the existence of limit states are obtained by techniques similar to those used to prove the existence, and intertwining properties, of wave-operators. Conditions of asymptotic abelianness provide the necessary dispersive properties for the return to equilibrium. It is demonstrated that the ^P -equilibrium states and their limit states are coupled by automorphisms with a quasi-local property; they are not necessarily normal with respect to one another. An application to theX–Y model is given which extends previously known results and other applications, and examples, are given for the Fermi gas.     

A nonlinear test case for the finite element method in two-phase flow

The ability of the finite element method to compute the motion of sharp interfaces in two-phase flow is examined by applying it to a test problem for which an analytical solution can be found. The problem is one of imbibition, the nonlinear diffusion of a fixed amount of water into an oil filled porous medium and can be solved exactly by similarity and the separation of variables method used by Boyer. The finite element program used was of the Galerkin type and employed a self-adaptive time stepping algorithm with both linear and quadratic isoparametric triangular elements. Results are presented for both elements and show that there is little difficulty in this type of diffusion problem in following the oil-water interface to accuracies of 2 or 3 percent.     

Molecular orientation in poly(vinyl chloride) studied by Raman spectroscopy and birefringence measurements

The ratios of the intensities of Raman scattering in the C? CI stretching region for eight combinations of sample orientation and directions of polarization of incident and scattered light have been measured for 15 samples of poly(vinyl chloride) (PVC) containing 0, 5, 10, 15 or 20 pph dioctyl sebacate (DOS) plasticizer which had been drawn uniaxially at 22, 70, 75, 80, or 90°C to draw ratios in the range 1–4.5. The birefringences of the samples were also measured. The Raman data were analyzed to give 〈P₂(cosθ)〉_cryst and 〈P₄(cosθ)〉_cryst, the values of the second- and fourth-order Legendre polynomials in cosθ averaged over the distribution of orientations of the crystallites, where θ is the angle between the c axis of a typical crystallite and the draw direction. Comparison of 〈P₂(cosθ)〉_cryst with the birefrigence showed that the crystallites are more highly oriented than the noncrystalline material in samples containing the higher amounts of plasticizer drawn at the higher temperatures. A value of 13.0 × 10^?3 was deduced for the birefringence of fully oriented PVC. The values of 〈P₄(cosθ)〉_cryst for a given 〈P₂(cosθ)〉_cryst were found to be higher than predicted by calculations based on two simple models, the pseudoaffine rigid-rod rotation model and the affine rubber elasticity model.