Two-point motional Stark effect diagnostic for Madison Symmetric Torus

A high-precision spectral motional Stark effect (MSE) diagnostic provides internal magnetic field measurements for Madison Symmetric Torus (MST) plasmas. Currently, MST uses two spatial views-on the magnetic axis and on the midminor (off-axis) radius, the latter added recently. A new analysis scheme has been developed to infer both the pitch angle and the magnitude of the magnetic field from MSE spectra. Systematic errors are reduced by using atomic data from atomic data and analysis structure in the fit. Reconstructed current density and safety factor profiles are more strongly and globally constrained with the addition of the off-axis radius measurement than with the on-axis one only

Relative effects on global warming of halogenated methanes and ethanes of social and industrial interest

The relative potential global warming effects for several halocarbons (chlorofluorocarbons (CFC's)-11, 12, 113, 114, and 115; hydrochlorofluorocarbons (HCFC's) 22, 123, 124, 141b, and 142b; and hydrofluorocarbons (HFC's) 125, 134a, 143a, and 152a; carbon tetrachloride; and methyl chloroform) were calculated by two atmospheric modeling groups. These calculations were based on atmospheric chemistry and radiative convective models to determine the chemical profiles and the radiative processes. The resulting relative greenhouse warming when normalized to the effect of CFC-11 agree reasonably well as long as we account for differences between modeled lifetimes. Differences among results are discussed. Sensitivity of relative warming values is determined with respect to trace gas levels assumed. Transient relative global warming effects are analyzed

η→π0γγ\eta \to \pi^0 \gamma \gamma decay within unitarized chiral perturbation theory

We improve the calculations of the $\eta \to \pi^0 \gamma \gamma$ decay within the context of meson chiral lagrangians. We use a chiral unitary approach for the meson-meson interaction, thus generating the $a_0(980)$ resonance and fixing the longstanding sign ambiguity on its contribution. This also allows us to calculate the loops with one vector meson exchange, thus removing a former source of uncertainty. In addition we ensure the consistency of the approach with other processes. First, by using vector meson dominance couplings normalized to agree with radiative vector meson decays. And, second, by checking the consistency of the calculations with the related $\gamma \gamma \to \pi^0 \eta$ reaction. We find an $\eta \to \pi^0 \gamma \gamma$ decay width of $0.47\pm 0.10$ eV, in clear disagreement with published data but in remarkable agreement with the most recent measurement.Comment: 15 pages, 10 figures, published versio

Relative effects on stratospheric ozone of halogenated methanes and ethanes of social and industrial interest

Four atmospheric modeling groups have calculated relative effects of several halocarbons (chlorofluorocarbons (CFC's)-11, 12, 113, 114, and 115; hydrochlorofluorocarbons (HCFC's) 22, 123, 124, 141b, and 142b; hydrofluorocarbons (HFC's) 125, 134a, 143a, and 152a, carbon tetrachloride; and methyl chloroform) on stratospheric ozone. Effects on stratospheric ozone were calculated for each compound and normalized relative to the effect of CFC-11. These models include the representations for homogeneous physical and chemical processes in the middle atmosphere but do no account for either heterogeneous chemistry or polar dynamics which are important in the spring time loss of ozone over Antarctica. Relative calculated effects using a range of models compare reasonably well. Within the limits of the uncertainties of these model results, compounds now under consideration as functional replacements for fully halogenated compounds have modeled stratospheric ozone reductions of 10 percent or less of that of CFC-11. Sensitivity analyses examined the sensitivity of relative calculated effects to levels of other trace gases, assumed transport in the models, and latitudinal and seasonal local dependencies. Relative effects on polar ozone are discussed in the context of evolving information on the special processes affecting ozone, especially during polar winter-springtime. Lastly, the time dependency of relative effects were calculated

Locality, Causality and Noncommutative Geometry

We analyse the causality condition in noncommutative field theory and show that the nonlocality of noncommutative interaction leads to a modification of the light cone to the light wedge. This effect is generic for noncommutative geometry. We also check that the usual form of energy condition is violated and propose that a new form is needed in noncommutative spacetime. On reduction from light cone to light wedge, it looks like the noncommutative dimensions are effectively washed out and suggests a reformulation of noncommutative field theory in terms of lower dimensional degree of freedom. This reduction of dimensions due to noncommutative geometry could play a key role in explaining the holographic property of quantum gravity.Comment: 16 pages, LaTeX, 4 figure

Implications on SUSY breaking mediation mechanisms from observing Bs→μ+μ−B_s \to \mu^+ \mu^- and the muon (g−2)(g-2)

We consider $B_s \to \mu^+ \mu^-$ and the muon $(g-2)_\mu$ in various SUSY breaking mediation mechanisms. If the decay $B_s \to \mu^+ \mu^-$ is observed at Tevatron Run II with a branching ratio larger than $\sim 2 \times 10^{-8}$, the noscale supergravity (including the gaugino mediation), the gauge mediation scenario with small number of messenger fields and low messenger scale, and a class of anomaly mediation scenarios will be excluded, even if they can accommodate a large muon $(g-2)_\mu$. On the other hand, the minimal supergravity scenario and similar mechanisms derived from string models can accommodate this observation.Comment: 4 pages, 3 figure

Automated generation of colluding apps for experimental research

Colluding apps bypass the security measures enforced by sandboxed operating systems such as Android. App collusion can be a real threat in cloud environments as well. Research in detecting and protecting against app collusion requires a variety of colluding apps for experimentation. Presently the number of (real or manually crafted) apps available to researchers is very limited. In this paper we propose a system called Application Collusion Engine (ACE) to automatically generate combinations of colluding and non-colluding Android apps to help researchers fairly evaluate different collusion detection and protection methods. Our initial implementation includes a variety of components that enable the system to create more than 5,000 different colluding and non-colluding app sets. ACE can be extended with more functional components to create even more colluding apps. To show the usefulness of our system, we have applied different risk evaluation and collusion detection methods to the created set of colluding apps

Vertical Structure of the Outer Accretion Disk in Persistent Low-Mass X-Ray Binaries

We have investigated the influence of X-ray irradiation on the vertical structure of the outer accretion disk in low-mass X-ray binaries by performing a self-consistent calculation of the vertical structure and X-ray radiation transfer in the disk. Penetrating deep into the disk, the field of scattered X-ray photons with energy $E\gtrsim10$\,keV exerts a significant influence on the vertical structure of the accretion disk at a distance $R\gtrsim10^{10}$\,cm from the neutron star. At a distance $R\sim10^{11}$\,cm, where the total surface density in the disk reaches $\Sigma_0\sim20$\,g\,cm$^{-2}$, X-ray heating affects all layers of an optically thick disk. The X-ray heating effect is enhanced significantly in the presence of an extended atmospheric layer with a temperature $T_{atm}\sim(2\div3)\times10^6$\,K above the accretion disk. We have derived simple analytic formulas for the disk heating by scattered X-ray photons using an approximate solution of the transfer equation by the Sobolev method. This approximation has a $\gtrsim10$\,% accuracy in the range of X-ray photon energies $E<20$\,keV.Comment: 19 pages, 8 figures, published in Astronomy Letter