Structure of the Nucleon and Roper Resonance with Diquark Correlations

We investigate the electric form factors of the nucleon and Roper resonance using a quark-diquark model. We find that the charge radii of the nucleon and Roper resonance are almost the same in size.Comment: To appear in the proceedings of Chiral 07, Osaka, Japan, November 13-16, 2007. 4pages, 4figure

Structure of the nuclear force in a chiral quark-diquark model

We discuss the structure of the nuclear force using a lagrangian derived from hadronization of a chiral quark and diquark model. A generalized trace log formula including meson and nucleon fields is expanded to the order in which relevant terms emerge. It is shown that the nuclear force is composed of long and medium range parts of chiral meson exchanges and short range parts of quark-diquark exchanges. The ranges of the scalar and vector interactions coincide well with those of sigma ($\sigma$) and omega ($\omega$) meson exchanges if the size of the nucleon core of a quark-diquark bound state is adjusted appropriately.Comment: 12 pages, 9 figure

Nucleon axial couplings and [(1/2,0) + (0,1/2)]-[(1,1/2) + (1/2,1)] chiral multiplet mixing

Three-quark nucleon interpolating fields in QCD have well-defined SU_L(2) x SU_R(2) and U_A(1) chiral transformation properties. Mixing of the [(1,1/2) + (1/2,1)] chiral multiplet with one of [(1/2,0) + (0,1/2)] or [(0,1/2) + (1/2,0)] representation can be used to fit the isovector axial coupling g_A(1) and thus predict the isoscalar axial coupling g_A(0) of the nucleon, in reasonable agreement with experiment. We also use a chiral meson-baryon interaction to calculate the masses and one-pion-interaction terms of J=1/2 baryons belonging to the [(0,1/2) + (1/2,0)] and [(1,1/2) + (1/2,1)] chiral multiplets and fit two of the diagonalized masses to the lowest-lying nucleon resonances thus predicting the third J=1/2 resonance at 2030 MeV, not far from the (one-star PDG) state Delta(2150).Comment: To appear in Modern Physics Letters

Reconstruction of the primordial fluctuation spectrum from the five-year WMAP data by the cosmic inversion method with band-power decorrelation analysis

The primordial curvature fluctuation spectrum is reconstructed by the cosmic inversion method using the five-year WMAP data of the cosmic microwave background temperature anisotropy. We apply the covariance matrix analysis and decompose the reconstructed spectrum into statistically independent band-powers. The statistically significant deviation from a simple power-law spectrum suggested by the analysis of the first-year data is not found in the five-year data except possibly at one point near the border of the wavenumber domain where accurate reconstruction is possible.Comment: 9page

A Lagrangian for the Chiral (1/2,0) + (0,1/2) Quartet Nucleon Resonances

We study the nucleon and three N* resonances' properties in an effective linear realization chiral SU_L(2) x SU_R(2) and U_A(1) symmetric Lagrangian. We place the nucleon fields into the so-called "naive" (1/2,0) + (0, 1/2) and "mirror" (0, 1/2) + (1/2,0) (fundamental) representations of SU_L(2) x SU_R(2), two of each -distinguished by their U_A(1) chiral properties, as defined by an explicit construction of the nucleon interpolating fields in terms of three quark (Dirac) fields. We construct the most general one-meson-baryon chiral interaction Lagrangian assuming various parities of these four nucleon fields. We show that the observed masses of the four lowest lying nucleon states can be well reproduced with the effective Lagrangian, after spontaneous symmetry breakdown, without explicit breaking of U_A(1) symmetry. This does not mean that explicit U_A(1) symmetry breaking does not occur in baryons, but rather that it does not have a unique mass prediction signature that exists e.g. in the case of spinless mesons. We also consider briefly the axial couplings with chiral representation mixing.Comment: Published in International Journal of Modern Physics

Reversion phenomena of Cu-Cr alloys

Cu-Cr alloys which were given various aging and reversion treatments were investigated in terms of electrical resistivity and hardness. Transmission electron microscopy was one technique employed. Some results obtained are as follows: the increment of electrical resistivity after the reversion at a constant temperature decreases as the aging temperature rises. In a constant aging condition, the increment of electrical resistivity after the reversion increases, and the time required for a maximum reversion becomes shorter as the reversion temperature rises. The reversion phenomena can be repeated, but its amount decreases rapidly by repetition. At first, the amount of reversion increases with aging time and reaches its maximum, and then tends to decrease again. Hardness changes by the reversion are very small, but the hardness tends to soften slightly. Any changes in transmission electron micrographs by the reversion treatment cannot be detected

Dynamic and tribological analysis of a toroidal CVT

The continuously variable transmission investigated in this paper works with contacts in the elastohydrodynamic regime of lubrication, thus the tangential forces are transmitted between elements through the shearing the lubricant film. The behavior of the lubricant film when subjected to shear depends of the nature of the lubricant and the relative motion between the contacting surfaces. In this paper a non-Newtonian behavior is assumed for the lubricant while the relative motion is determined for every point on the contact area by kinematic methods. The net tractive force in the sliding direction, and the spin torque are evaluated and from these the power losses in the contacts are calculated. The dynamic behavior of the device is evaluated taking into account the rheological behavior of the lubricant

Reactivation of contraction in detergent-lysed teleost retinal cones.

Teleost retinal cones contract in the light and elongate in the dark. In the green sunfish, Lepomis cyanellus, the necklike myoid region of the cone contracts from as much as 120 micrometers (midnight dark-adapted) to 6 micrometers in fully light-adapted state. When dark-adapted fish are exposed to light (1.4 lux), cone myoids contract with a linear rate of 1.5 +/- 0.1 micrometers/min. We report here that detergent-lysed motile models of teleost retinal cones exhibit calcium- and ATP-dependent reactivated contraction, with morphology and rate comparable to that observed in vivo. For reactivation studies isolated dark-adapted retinas were lysed with nonionic detergent Brij-58 (0.1-1.0%). In reactivation medium containing 10(-5) M free calcium and 4 mM ATP, the lysed cones contracted with normal morphology at in vivo rates (1.4 +/- 1 micrometer/min). Little contraction was observed if ATP or detergent was deleted from the medium or if free calcium levels were less than 10(-8) M. Ultrastructural examination of cone models lysed with 1% Brij-58 revealed that, in spite of extensive extraction of the cytoplasmic matrix, cytoskeletal components (thin filaments, intermediate filaments, microtubules) were still present. Thus we have produced extensively extracted motile models of teleost retinal cones which undergo calcium- and ATP-dependent reactivated contraction with normal morphology at physiological rate