The CMB Dipole and Circular Galaxy Distribution

The validity of Hubble's law defies the determination of the center of the big bang expansion, even if it exists. Every point in the expanding universe looks like the center from which the rest of the universe flies away. In this article, the author shows that the distribution of apparently circular galaxies is not uniform in the sky and that there exists a special direction in the universe in our neighborhood. The data is consistent with the assumption that the tidal force due to the mass distribution around the universe center causes the deformation of galactic shapes depending on its orientation and location relative to the center and our galaxy. Moreover, the cmb dipole data can also be associated with the center of the universe expansion, if the cmb dipole at the center of our supercluster is assumed to be due to Hubble flow. The location of the center is estimated from the cmb dipole data. The direction to the center from both sets of data is consistent and the distance to the center is computed from the cmb dipole data.Comment: 9 pages, 3 figures (10 figure captions), 1 tabl

Evaluation of the Axial Vector Commutator Sum Rule for Pion-Pion Scattering

We consider the sum rule proposed by one of us (SLA), obtained by taking the expectation value of an axial vector commutator in a state with one pion. The sum rule relates the pion decay constant to integrals of pion-pion cross sections, with one pion off the mass shell. We remark that recent data on pion-pion scattering allow a precise evaluation of the sum rule. We also discuss the related Adler--Weisberger sum rule (obtained by taking the expectation value of the same commutator in a state with one nucleon), especially in connection with the problem of extrapolation of the pion momentum off its mass shell. We find, with current data, that both the pion-pion and pion-nucleon sum rules are satisfied to better than six percent, and we give detailed estimates of the experimental and extrapolation errors in the closure discrepancies.Comment: Plain TeX file;minor changes; version to be published in Pys. Rev. D; corrected refs.12,1

SU(6) isoscalar factors for the product 405×56→56, 70

SU(6) isoscalar factors for the product 405×56→56, 70 are calculated. SU(3) isoscalar factors for the products 27×10→10, 8 and 10×8→8 are also tabulated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69375/2/JMAPAQ-17-4-458-1.pd

Annual progress report to Battelle Pacific Northwest National Laboratories on prediction of phase separation of simulated nuclear waste glasses

The objective of this research is to predict the immiscibility boundaries of multi-component borosilicate glasses, on which many nuclear waste glass compositions are based. The method used is similar to the prediction method of immiscibility boundaries of multi-component silicate glass systems successfully made earlier and is based upon the superposition of immiscibility boundaries of simple systems using an appropriate parameter. This method is possible because many immiscibility boundaries have similar shapes and can be scaled by a parameter. In the alkali and alkaline earth binary silicate systems, for example, the critical temperature and compositions were scaled using the Debye-Hueckel theory. In the present study on borosilicate systems, first, immiscibility boundaries of various binary alkali and alkaline borate glass systems (e.g. BaO-B{sub 2}O{sub 3}) were examined and their critical temperatures were evaluated in terms of Debye-Hueckel theory. The mixing effects of two alkali and alkaline-earth borate systems on the critical temperature were also explored. Next immiscibility boundaries of ternary borosilicate glasses (e.g. Na{sub 2}O-SiO{sub 2}-B{sub 2}O{sub 3}, K{sub 2}O-SiO{sub 2}-B{sub 2}O{sub 3}, Rb{sub 2}O-SiO{sub 2}-B{sub 2}O{sub 3}, and Cs{sub 2}O-SiO{sub 2}-B{sub 2}O{sub 3}) were examined. Their mixing effects are currently under investigation

Characterization of the glass transition in vitreous silica by temperature scanning small-angle X-ray scattering

The temperature dependence of the x-ray scattering in the region below the first sharp diffraction peak was measured for silica glasses with low and high OH content (GE-124 and Corning 7980). Data were obtained upon scanning the temperature at 10, 40 and 80 K/min between 400 K and 1820 K. The measurements resolve, for the first time, the hysteresis between heating and cooling through the glass transition for silica glass, and the data have a better signal to noise ratio than previous light scattering and differential thermal analysis data. For the glass with the higher hydroxyl concentration the glass transition is broader and at a lower temperature. Fits of the data to the Adam-Gibbs-Fulcher equation provide updated kinetic parameters for this very strong glass. The temperature derivative of the observed X-ray scattering matches that of light scattering to within 14%.Comment: EurophysicsLetters, in pres

Relativistic O(q4)O(q^4) two-pion exchange nucleon-nucleon potential: configuration space

We have recently performed a relativistic $O(q^4)$ chiral expansion of the two-pion exchange $NN$ potential, and here we explore its configuration space content. Interactions are determined by three families of diagrams, two of which involve just $g_A$ and $f_{\pi}$, whereas the third one depends on empirical coefficients fixed by subthreshold $\pi N$ data. In this sense, the calculation has no adjusted parameters and gives rise to predictions, which are tested against phenomenological potentials. The dynamical structure of the eight leading non-relativistic components of the interaction is investigated and, in most cases, found to be clearly dominated by a well defined class of diagrams. In particular, the central isovector and spin-orbit, spin-spin, and tensor isoscalar terms are almost completely fixed by just $g_A$ and $f_{\pi}$. The convergence of the chiral series in powers of the ratio (pion mass/nucleon mass) is studied as a function of the internucleon distance and, for $r>$ 1 fm, found to be adequate for most components of the potential. An important exception is the dominant central isoscalar term, where the convergence is evident only for $r>$ 2.5 fm. Finally, we compare the spatial behavior of the functions that enter the relativistic and heavy baryon formulations of the interaction and find that, in the region of physical interest, they differ by about 5%.Comment: 27 pages, 33 figure

The in-medium isovector pi N amplitude from low energy pion scattering

Differential cross sections for elastic scattering of 21.5 MeV positive and negative pions by Si, Ca, Ni and Zr have been measured as part of a study of the pion-nucleus potential across threshold. The `anomalous' repulsion in the s-wave term was observed, as is the case with pionic atoms. The extra repulsion can be accounted for by a chiral-motivated model where the pion decay constant is modified in the medium. Unlike in pionic atoms, the anomaly cannot be removed by merely introducing an empirical on-shell energy dependence.Comment: 9 pages, 2 figures. Minor changes, to appear in PR

Quasinormal distributions and expansion at the mode

The Gram-Charlier series of type A is discussed in terms of deviants which are related to moments in a way similar to the way Hermite polynomials are related to the powers. Distribution functions are also expressed in terms of the mode and moments (cumulants or deviants), which are useful expansions when the distributions are approximately normal. It is shown that such expansions as well as the Gram-Charlier series are valid asymptotically for discrete distributions defined on the semiinfinite interval [0, ∞].Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45129/1/10955_2005_Article_BF01010217.pd

Precision spectroscopy of pionic 1s states of Sn nuclei and evidence for partial restoration of chiral symmetry in the nuclear medium

Deeply bound 1s states of $\pi^-$ in $^{115,119,123}$Sn were preferentially observed using the Sn($d$,$^3$He) pion-transfer reaction under the recoil-free condition. The 1s binding energies and widths were precisely determined, and were used to deduce the isovector parameter of the s-wave pion-nucleus potential to be $b_1 =-0.115\pm 0.007 ~m_{\pi}^{-1}$. The observed enhancement of $|b_1|$ over the free $\pi N$ value ($b_1^{\rm free}/b_1 = 0.78 \pm 0.05$) indicates a reduction of the chiral order parameter, $f^{*}_{\pi} (\rho)^2/f_{\pi}^2 \approx 0.64$, at the normal nuclear density, $\rho = \rho_0$.Comment: 4 pages including 3 postscript figures, RevTeX 4 with multirow.sty, submitted to Physical Review Letter