Spectroscopy of Hadrons with b Quarks from Lattice NRQCD

Preliminary results from an extensive lattice calculation of the B, B_c, and \Upsilon spectrum at quenched \beta = 6.0 are presented. The study includes radially and orbitally excited mesons, and baryons containing b quarks. The b quarks are formulated using NRQCD; for light and c quarks, a tadpole-improved clover action is used.Comment: talk given at LATTICE98(heavyqk), 3 pages LaTeX, 2 Postscript figure

Generalized coordinates on the phase space of Yang-Mills theory

We study the suitability of complex Wilson loop variables as (generalized) coordinates on the physical phase space of $SU(2)$-Yang-Mills theory. To this end, we construct a natural one-to-one map from the physical phase space of the Yang-Mills theory with compact gauge group $G$ to a subspace of the physical configuration space of the complex G^\C-Yang-Mills theory. Together with a recent result by Ashtekar and Lewandowski this implies that the complex Wilson loop variables form a complete set of generalized coordinates on the physical phase space of $SU(2)$-Yang-Mills theory. They also form a generalized canonical loop algebra. Implications for both general relativity and gauge theory are discussed.Comment: TeX, 11pp, revised version (minor clarifications added, Comment after (2.9) inserted); to appear in Class. Quant. Grav

An apparatus and method for detecting a tool

The apparatus is adapted to detect a tool based on a 3D image obtained by a 3D ultrasound imaging system. The apparatus comprises an image processing unit, which includes a tool detection module configured to perform a tool detection procedure. The tool detection procedure involves identifying a shadow of the tool in the 3D image and calculating the position of a "tool plane section" of the 3D image in which the entire length of the tool is represented

Threading, Stitching, and Storytelling: Using CBPR and Blackfoot Knowledge and Cultural Practices to Improve Domestic Violence Services for Indigenous Women

This article discusses a community-based participatory research (CBPR) project at two women’s emergency shelters in rural southwestern Alberta. The CBPR project aimed to improve shelter services on and off reserve in our area by engaging the voices of Indigenous women who had experienced domestic violence. The project’s methods were participatory appraisal and arts-based work re-imagined through Blackfoot cultural practices of storytelling and shawl making. The project created a rare safe space where thirteen Blackfoot women emphasised DV services should provide opportunities to connect with family and community and role model Blackfoot knowledge. Role modelling traditional knowledges aids developing life and parenting skills, opening up pathways for Indigenous women to more positive, secure futures. These women’s recommendations impelled this article to challenge the individualized case management model and discourses of cultural competence dominating Canadian DV services, which isolate and marginalize Indigenous women when they seek help. We highlight resources existing in Blackfoot communities to manage and prevent violence by protecting and facilitating Indigenous women’s connections to their communities and cultures, and offer ways to utilize these more effectively in service settings

Canonical General Relativity on a Null Surface with Coordinate and Gauge Fixing

We use the canonical formalism developed together with David Robinson to st= udy the Einstein equations on a null surface. Coordinate and gauge conditions = are introduced to fix the triad and the coordinates on the null surface. Toget= her with the previously found constraints, these form a sufficient number of second class constraints so that the phase space is reduced to one pair of canonically conjugate variables: \Ac_2\and\Sc^2. The formalism is related to both the Bondi-Sachs and the Newman-Penrose methods of studying the gravitational field at null infinity. Asymptotic solutions in the vicinity of null infinity which exclude logarithmic behavior require the connection to fall off like $1/r^3$ after the Minkowski limit. This, of course, gives the previous results of Bondi-Sachs and Newman-Penrose. Introducing terms which fall off more slowly leads to logarithmic behavior which leaves null infinity intact, allows for meaningful gravitational radiation, but the peeling theorem does not extend to $\Psi_1$ in the terminology of Newman-Penrose. The conclusions are in agreement with those of Chrusciel, MacCallum, and Singleton. This work was begun as a preliminary study of a reduced phase space for quantization of general relativity.Comment: magnification set; pagination improved; 20 pages, plain te

Fourth order indirect integration method for black hole perturbations: even modes

On the basis of a recently proposed strategy of finite element integration in time domain for partial differential equations with a singular source term, we present a fourth order algorithm for non-rotating black hole perturbations in the Regge-Wheeler gauge. Herein, we address even perturbations induced by a particle plunging in. The forward time value at the upper node of the $(r^*,t)$ grid cell is obtained by an algebraic sum of i) the preceding node values of the same cell, ii) analytic expressions, related to the jump conditions on the wave function and its derivatives, iii) the values of the wave function at adjacent cells. In this approach, the numerical integration does not deal with the source and potential terms directly, for cells crossed by the particle world line. This scheme has also been applied to circular and eccentric orbits and it will be object of a forthcoming publication.Comment: This series of papers deals with EMRI for LISA. With the respect to the v1 version, the algorithm has been improved; convergence tests and references have been added; v2 is composed by 23 pages, and 6 figures. Paper accepted by Class. Quantum Gravity for the special issue on Theory Meets Data Analysis at Comparable and Extreme Mass Ratios (Capra and NRDA) at Perimeier Institute in June 201

Crushing singularities in spacetimes with spherical, plane and hyperbolic symmetry

It is shown that the initial singularities in spatially compact spacetimes with spherical, plane or hyperbolic symmetry admitting a compact constant mean curvature hypersurface are crushing singularities when the matter content of spacetime is described by the Vlasov equation (collisionless matter) or the wave equation (massless scalar field). In the spherically symmetric case it is further shown that if the spacetime admits a maximal slice then there are crushing singularities both in the past and in the future. The essential properties of the matter models chosen are that their energy-momentum tensors satisfy certain inequalities and that they do not develop singularities in a given regular background spacetime.Comment: 19 page