Diffractive production of high pt photons at HERA

We study the diffractive production of high pt photons at HERA. We have implemented the process as a new hard sub-process in the HERWIG event generator in order to prepare the ground for a future measurement.Comment: 4 pages, 4 figures. Contribution to the 1999 UK Phenomenology Workshop on Collider Physics, Durham, U

Learning in Game Jams: A Case Study of the GLASS Summer School

Game jams provide exciting opportunities for education and research. In this session we describe the GLASS Summer School, sharing videos where students talk about their experiences, and sharing results from our learning survey. We discuss questions such as what are optimal conditions for game jams? How can we measure learning

An Archaeological Survey for Asylum Creek and No Name Creek Channel Rectification Project, Bexar County, Texas

During August of 1992, staff archaeologists from the Center for Archaeological Research (CAR) at the University of Texas at San Antonio (UTSA) conducted surface survey, mapping, and subsurface testing adjacent to Asylum and No-Name Creeks under contract with the San Antonio River Authority in conjunction with a channel rectification project. Particular attention was given to locating cultural materials associated with the nearby San Juan Acequia. No significant cultural resources were located at either location

Measurements of vector magnetic field using multiple electromagnetically induced transparency resonances in Rb vapor

We study intensity distribution of transmission resonances under the conditions of electromagnetically induced transparency (EIT) with lin||lin configuration in 87Rb vapor. We demonstrate that for various orientations of the external magnetic field all seven resolved EIT resonances exhibit maxima or minima at certain directions of the linear polarization of the laser field. This effect can be used for development of a high-precision vector EIT magnetometer.Comment: 4 pages, 4 figure

Statistics of quantum transmission in one dimension with broad disorder

We study the statistics of quantum transmission through a one-dimensional disordered system modelled by a sequence of independent scattering units. Each unit is characterized by its length and by its action, which is proportional to the logarithm of the transmission probability through this unit. Unit actions and lengths are independent random variables, with a common distribution that is either narrow or broad. This investigation is motivated by results on disordered systems with non-stationary random potentials whose fluctuations grow with distance. In the statistical ensemble at fixed total sample length four phases can be distinguished, according to the values of the indices characterizing the distribution of the unit actions and lengths. The sample action, which is proportional to the logarithm of the conductance across the sample, is found to obey a fluctuating scaling law, and therefore to be non-self-averaging, in three of the four phases. According to the values of the two above mentioned indices, the sample action may typically grow less rapidly than linearly with the sample length (underlocalization), more rapidly than linearly (superlocalization), or linearly but with non-trivial sample-to-sample fluctuations (fluctuating localization).Comment: 26 pages, 4 figures, 1 tabl

Reconstruction of tomographic images of dry aqueous foams

WOS:000328011500007International audienceX-ray tomography offers the possibility to examine the local changes in the structure of a three-dimensional aqueous foam as it flows, allowing a better fundamental understanding of foam rheology and the validation of models. We present an automated algorithm that reconstructs a dry aqueous foam from such images. Our algorithm uses ImageJ to extract from an image the topology of the network of Plateau borders in the foam, and then analyses this network to re-create the films and then the bubbles, and equilibrates the structure in Surface Evolver. We validate our algorithm and demonstrate its precision by applying it to simulated foam structures and analysing the topology and geometry obtained. We then apply our algorithm to a sequence of images from an experiment in which a spherical bead falls under its own weight through a polydisperse dry foam. This allows us to describe the evolution of the foam's bubble volumes with time as well as the distribution of bubble pressure and the forces exerted on a falling sphere. (C) 2013 Elsevier B.V. All rights reserved

The beta function of the multichannel Kondo model

The beta function of the multichannel Kondo model is calculated exactly in the limit of large spin N and channel number M=gamma*N, with constant gamma. There are no corrections in any finite order of 1/N. One zero is found at a finite coupling strength, showing directly the Non--Fermi liquid behavior of the model. This renormalization group flow allows to introduce a variational principle for the entropy, to obtain the low temperature thermodynamics. Such in particular the low temperature thermodynamics of the non--crossing approximation to the Kondo model becomes accessible.Comment: 4 page

Scaling analysis of the magnetic monopole mass and condensate in the pure U(1) lattice gauge theory

We observe the power law scaling behavior of the monopole mass and condensate in the pure compact U(1) gauge theory with the Villain action. In the Coulomb phase the monopole mass scales with the exponent \nu_m=0.49(4). In the confinement phase the behavior of the monopole condensate is described with remarkable accuracy by the exponent \beta_{exp}=0.197(3). Possible implications of these phenomena for a construction of a strongly coupled continuum U(1) gauge theory are discussed.Comment: Added references [1