Prospects for t¯tH at the LHC

The search for the Higgs boson is a major focus for the ATLAS and CMS experiments at the Large Hadron Collider. If the Higgs boson has a low mass (mH < 130 GeV) then its production in association with a top quark pair could be observed. Searching for t¯tH signals is very challenging due to a small signal cross section, large backgrounds, and a high number of jets in the final state. Here we review previous simulation studies of t¯tH(H → b¯b). We show the current status of the major background measurement, t¯t+jets. We outline recent improvements in theoretical predictions, Monte Carlo generators and jet reconstruction techniques that will enable us to perform this search in the near future

Control of the switching behavior of ferromagnetic nanowires using magnetostatic interactions

Magnetostatic interactions between two end-to-end Permalloy (Ni80Fe20) nanowires have been studied as a function of their separation, end shape, and width. The change in switching field increases as the wires become closer, with deviations from the switching field of an isolated wire of up to 40% observed. The sign of the change depends on the relative magnetization orientation of the two wires, with higher fields for parallel magnetization and lower fields for antiparallel magnetization. A wire end shape has a strong influence, with larger field variations being seen for flat-ended wires than wires with tapered ends. The micromagnetic modeling and experiments performed here were in good qualitative agreement. The experimental control of switching behavior of one nanowire with another was also demonstrated using magnetostatic interactions

Enhanced longitudinal magnetooptic Kerr effect contrast in nanomagnetic structures

We report on enhanced longitudinal magnetooptic Kerr effect signal contrast in thin-film nanomagnetic disks with in-plane magnetization when combined with dielectric layers that provide impedance matching to the structure and the underlying substrate. Kerr signals can increase by a factor of three, while substrate reflectance is almost completely suppressed. This leads to an increase in Kerr ellipticity relative to the background intensity and a subsequent improvement in the measured signal-to-noise ratio. Measurements using a beam focused on opaque 400-nm Ni disks yield contrast improvements of a factor of 8. Arrays of nanodisks demonstrate more complex behavior due to diffraction effects

Tickling Java with a Feather

Fragments of mainstream programming languages are formalised in order to show desirable properties of their static semantics. We ask if said formalisms could also be used to define a test suite for the mainstream programming language in question, and what the utility of such a suite would be. In this work, we present our findings from testing Java with Featherweight Java (FJ). We take the syntax and binding structure of FJ to define an instance space of non-isomorphic test programs and implementations of FJ type checkers to provide oracles for our tests, to ensure the mainstream implementation conforms with the expectations of FJ. Using these, we evaluate (using code coverage techniques) how much of the Sun OpenJDK javac can be tested by FJ. © 2009 Elsevier B.V. All rights reserved

Strengthening the Zipper

The zipper is a well known design pattern for providing a cursor-like interface to a data structure. However, the classic treatise by Huet only scratches the surface of some of its potential applications. In this paper we take inspiration from Huet, and describe a library suitable as an underpinning for structured editors. We consider a zipper structure that is suitable for traversing heterogeneous data types, encoding routes to other places in the tree (for bookmark or quick-jump functionality), expressing lexically bound information using contexts, and traversals for rendering a program indicating where the cursor is currently focused

Letter from Martin S. Allwood to Hubert Creekmore

Allwood writes from Hobart and William Smith Colleges in a document titled, Outline of An International College in Sweden. He discusses the founding of the Marston Hill Intercultural Center for Quality of Life and the Anglo-American Center there by founders Charles S. Allwood and C. S. Fearenside. Allwood discusses the summer school for Anglo-American students and explains the finances and resources that the school needs. Includes envelope.https://egrove.olemiss.edu/creekmore/1039/thumbnail.jp

Higgsless electroweak symmetry breaking at the LHC

While the Higgs model is the best studied scenario of electroweak symmetry breaking, a number strongly-coupled models exist, predicting new signatures. Recent studies of WW and WZ final states at the ATLAS and CMS experiments are summarized and expected sensitivities are presented within the frameworks of the technicolor straw-man model and the electroweak chiral Lagrangian.Comment: Proceedings for the EPS HEP 2007 conference, Manchester, U.K., on behalf of the ATLAS and CMS Collaboration