Note on Anomalous Higgs-Boson Couplings in Effective Field Theory

We propose a parametrization of anomalous Higgs-boson couplings that is both systematic and practical. It is based on the electroweak chiral Lagrangian, including a light Higgs boson, as the effective field theory (EFT) at the electroweak scale $v$. This is the appropriate framework for the case of sizeable deviations in the Higgs couplings of order $10\%$ from the Standard Model, considered to be parametrically larger than new-physics effects in the sector of electroweak gauge interactions. The role of power counting in identifying the relevant parameters is emphasized. The three relevant scales, $v$, the scale of new Higgs dynamics $f$, and the cut-off $\Lambda=4\pi f$, admit expansions in $\xi=v^2/f^2$ and $f^2/\Lambda^2$. The former corresponds to an organization of operators by their canonical dimension, the latter by their loop order or chiral dimension. In full generality the EFT is thus organized as a double expansion. However, as long as $\xi\gg 1/16\pi^2$ the EFT systematics is closer to the chiral counting. The leading effects in the consistent approximation provided by the EFT, relevant for the presently most important processes of Higgs production and decay, are given by a few (typically six) couplings. These parameters allow us to describe the properties of the Higgs boson in a general and systematic way, and with a precision adequate for the measurements to be performed at the LHC. The framework can be systematically extended to include loop corrections and higher-order terms in the EFT.Comment: 7 pages, no figures; typos corrected; references adde

Complete One-Loop Renormalization of the Higgs-Electroweak Chiral Lagrangian

Employing background-field method and super-heat-kernel expansion, we compute the complete one-loop renormalization of the electroweak chiral Lagrangian with a light Higgs boson. Earlier results from purely scalar fluctuations are confirmed as a special case. We also recover the one-loop renormalization of the conventional Standard Model in the appropriate limit.Comment: 15 pages, no figures; v2: reference and comments added, typos fixed, matches published versio

Intrinsic peculiarities of real material realizations of a spin-1/2 kagome lattice

Spin-1/2 magnets with kagome geometry, being for years a generic object of theoretical investigations, have few real material realizations. Recently, a DFT-based microscopic model for two such materials, kapellasite Cu3Zn(OH)6Cl2 and haydeeite Cu3Mg(OH)6Cl2, was presented [O. Janson, J. Richter and H. Rosner, arXiv:0806.1592]. Here, we focus on the intrinsic properties of real spin-1/2 kagome materials having influence on the magnetic ground state and the low-temperature excitations. We find that the values of exchange integrals are strongly dependent on O--H distance inside the hydroxyl groups, present in most spin-1/2 kagome compounds up to date. Besides the original kagome model, considering only the nearest neighbour exchange, we emphasize the crucial role of the exchange along the diagonals of the kagome lattice.Comment: 4 pages, 4 figures. A paper for the proceedings of the HFM 2008 conferenc

Spatial analysis of campylobacter infection in the Canadian province of Manitoba

BACKGROUND: The study describes population level variations in campylobacter incidence within the Canadian province of Manitoba, and the relationship to sociodemographic and landscape related characteristics. Using data derived from the Manitoba Health Public Health Branch communicable disease surveillance database, the study applied a number of spatial and ecological techniques to visualize, explore and model campylobacter incidence for the years 1996 to 2004. Analytical techniques used in the study included spatial smoothing, the spatial scan statistic, the Gini coefficient, and Poisson regression analysis. RESULTS: The study demonstrated marked and statistically significant geographic variability in the rates of campylobacter incidence in Manitoba.. The incidence of campylobacter was observed to be significantly higher in populations living in rural and agricultural areas of the province, with the highest rates occurring in populations living in proximity to high densities of farm animals (cows, pigs, chickens). The study also observed that the age specific pattern of campylobacter incidence in rural Manitoba was very different than the urban pattern, with the incidence rate in the 0–4 year age group seven times higher in rural Manitoba than in the City of Winnipeg. CONCLUSION: The study demonstrates the value of a deploying a diverse set of spatial techniques to better understand the dynamics of an enteric disease such as campylobacter infection. The study concludes that there may be three distinct mechanisms for the transmission of campylobacter in Manitoba which are operating simultaneously. These include broad population exposure to a centralized food system endemically infected with the campylobacter organism, exposure to local level factors such as farm animals or contaminated water, and exposure to campylobacter infection through foreign travel

MicroRNA-34a promotes genomic instability by a broad suppression of genome maintenance mechanisms downstream of the oncogene KSHV-vGPCR

The Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded chemokine receptor vGPCR acts as an oncogene in Kaposi's sarcomagenesis. Until now, the molecular mechanisms by which the vGPCR contributes to tumor development remain incompletely understood. Here, we show that the KSHV-vGPCR contributes to tumor progression through microRNA (miR)-34a-mediated induction of genomic instability. Large-scale analyses on the DNA, gene and protein level of cell lines derived from a mouse model of vGPCR-driven tumorigenesis revealed that a vGPCR-induced upregulation of miR-34a resulted in a broad suppression of genome maintenance genes. A knockdown of either the vGPCR or miR-34a largely restored the expression of these genes and confirmed miR-34a as a downstream effector of the KSHV-vGPCR that compromises genome maintenance mechanisms. This novel, protumorigenic role of miR-34a questions the use of miR-34a mimetics in cancer therapy as they could impair genome stability

Rapid Profiling of Marine Notches Using a Handheld Laser Distance Meter

A rapid, single-user profiling method for rocky shores is described. The Leica Disto D8 handheld laser distance meter measures distance up to 100 m and inclination in 360 degrees. It automatically calculates horizontal distance and vertical elevation. Memory storage accommodates data for 30 measurement points, allowing easy plotting of shore profiles. This technique allows even inaccessible, dangerous, and overhanging cliff faces to be evaluated faithfully and within minutes. It is a major improvement over standard methods that often involve risky coasteering and climbing. Examples are given from marine notches in Thailand

Direct strain and elastic energy evaluation in rolled-up semiconductor tubes by x-ray micro-diffraction

We depict the use of x-ray diffraction as a tool to directly probe the strain status in rolled-up semiconductor tubes. By employing continuum elasticity theory and a simple model we are able to simulate quantitatively the strain relaxation in perfect crystalline III-V semiconductor bi- and multilayers as well as in rolled-up layers with dislocations. The reduction in the local elastic energy is evaluated for each case. Limitations of the technique and theoretical model are discussed in detail.Comment: 32 pages (single column), 9 figures, 39 reference

Partial Cross-Sections And Photoelectron Angular-Distributions In The Region Of The 4S- 5P And 5S- 6P Resonances In Krypton And Xenon

Using synchrotron radiation and photoelectron spectrometry, we have examined the 4s4p (6)5p resonance region in krypton and the 5s5p (6)6p resonance region in xenon. We have obtained partial and total cross sections, intensity ratios, and photoelectron angular distribution parameters for the energy regions 20.6-21.5 eV in xenon and 24.6-25.3 eV in krypton. We also report Shore parameters for all cross-section data taken. In addition to the anticipated single-electron transition, we clearly resolve features attributable to two-electron transitions in both species. Characteristics of these autoionizing states may differ considerably in the two available exit channels