Detecting atmospheric neutrino oscillations in the ATLAS detector at CERN

We discuss the possibility to study oscillations of atmospheric neutrinos in the ATLAS experiment at CERN. Due to the large total detector mass, a significant number of events is expected, and during the shutdown phases of the LHC, reconstruction of these events will be possible with very good energy and angular resolutions, and with charge identification. We argue that 500 live days of neutrino running could be achieved, and that a total of ~160 contained \nu_\mu events and ~360 upward going muons could be collected during this time. Despite the low statistics, the excellent detector resolution will allow for an unambiguous confirmation of atmospheric neutrino oscillations and for measurements of the leading oscillation parameters. Though our detailed simulations show that the sensitivity of ATLAS is worse than that of dedicated neutrino experiments, we demonstrate that more sophisticated detectors, e.g. at the ILC, could be highly competitive with upcoming superbeam experiments, and might even give indications for the mass hierarchy and for the value of theta-13.Comment: 8 pages, 4 figures, 2 tables, RevTeX 4; modified treatment of upward going muons, results unchanged; matches published versio

ATS-6 flight accelerometers

Five accelerometers mounted near the adapter base of the Titan 3-C launch vehicle and three on the hub of the ATS-F spacecraft provided (1) data for verifying basic spacecraft mode shapes and frequencies during powered flight while attached to the launch vehicle; (2) failure mode detection and diagnostic information on in-flight anomalies; and (3) data to be used in the design of future spacecraft to be flown on the Titan 3-C. Because data from the instruments mounted on the spacecraft hub passed through an in-flight disconnect at the separation plane between the transtage and ATS-F, the moment this connector was broken, the signal to the telemetry system showed a step function change. By monitoring these telemetry traces on the ground at appropriate times during flight sequences, a positive indication of spacecraft separation was obtained. Flight data showing dynamic response at spacecraft launch vehicle interface and at the top of ATS spacecraft during significant launch events are presented in tables

W(h)ither the Fed’s balance sheet?

Federal Reserve policymakers have expressed their support for ultimately shrinking the Fed’s balance sheet and returning the composition of its portfolio to only Treasury securities. Policymakers also favor returning to a fed-funds-rate-targeting procedure or something quite similar. While Fed holdings of some asset classes have been diminishing naturally, the orderly reduction of others could involve special tools that the Fed has been putting in place for a while. An ongoing issue will be to determine an optimal sequence of appropriate actions.Monetary policy - United States ; Federal Reserve System ; Financial crises

Exploiting the directional sensitivity of the Double Chooz near detector

In scintillator detectors, the forward displacement of the neutron in the reaction $\bar\nu_e+p\to e^++n$ provides neutrino directional information as demonstrated by the CHOOZ reactor experiment with 2,500 events. The near detector of the forthcoming Double Chooz experiment will collect $1.6\times10^5$ events per year, enough to determine the average neutrino direction with a $1 \sigma$ half-cone aperture of $2.3^\circ$ in one year. It is more difficult to separate the two Chooz reactors that are viewed at a separation angle $\phi=30^\circ$. If their strengths are known and approximately equal, the azimuthal location of each reactor is obtained with $\pm6^\circ$ ($1 \sigma$) and the probability of confusing them with a single source is less than 11%. Five year's data reduce this ``confusion probability'' to less than 0.3%, i.e., a $3 \sigma$ separation is possible. All of these numbers improve rapidly with increasing angular separation of the sources. For a setup with $\phi=90^\circ$ and one year's data, the azimuthal $1 \sigma$ uncertainty for each source decreases to $\pm3.2^\circ$. Of course, for Double Chooz the two reactor locations are known, allowing one instead to measure their individual one-year integrated power output to $\pm11$ ($1 \sigma$), and their five-year integrated output to $\pm4.8$ ($1 \sigma$).Comment: 7 pages, 10 figure

Condition number estimates for combined potential boundary integral operators in acoustic scattering

We study the classical combined field integral equation formulations for time-harmonic acoustic scattering by a sound soft bounded obstacle, namely the indirect formulation due to Brakhage-Werner/Leis/Panic, and the direct formulation associated with the names of Burton and Miller. We obtain lower and upper bounds on the condition numbers for these formulations, emphasising dependence on the frequency, the geometry of the scatterer, and the coupling parameter. Of independent interest we also obtain upper and lower bounds on the norms of two oscillatory integral operators, namely the classical acoustic single- and double-layer potential operators

Signatures of axion-like particles in the spectra of TeV gamma-ray sources

One interpretation of the unexplained signature observed in the PVLAS experiment invokes a new axion-like particle (ALP) with a two-photon vertex, allowing for photon-ALP oscillations in the presence of magnetic fields. In the range of masses and couplings suggested by PVLAS, the same effect would lead to a peculiar dimming of high-energy photon sources. For typical parameters of the turbulent magnetic field in the galaxy, the effect sets in at E_gamma >~ 10 TeV, providing an ALP signature in the spectra of TeV gamma sources that can be probed with Cherenkov telescopes. A dedicated search will be strongly motivated if the ongoing photon regeneration experiments confirm the PVLAS particle interpretation.Comment: 8 pages, 1 eps figure; typos corrected, matches published versio

Störungen des Natriumhaushalts beim Notfallpatienten: Salz in der Suppe der Notfallmedizin

Zusammenfassung: Elektrolytstörungen sind beim Notfallpatienten häufig und können potenziell lebensbedrohlich sein. So weisen z.B. knapp 20 % aller Notfallpatienten eine Hypo- oder Hypernatriämie auf. In den letzten Jahren konnte gezeigt werden, dass Störungen des Natriumhaushalts nicht nur Ausdruck der Schwere der Grunderkrankung, sondern unabhängige Prädiktoren für das Outcome des Patienten darstellen. Die Patienten berichten häufig unspezifische Symptome wie Gang- und Konzentrationsstörungen oder werden nach Sturz bei erhöhter Falltendenz der zentralen Notaufnahme zugeführt. Umso wichtiger ist es, Dysnatriämien beim Notfallpatienten rechtzeitig zu erkennen und eine adäquate Korrektur einzuleiten. Hierfür ist die Kenntnis der Mechanismen der Entstehung von Hypo- [Diuretikatherapie, Syndrom der inadäquaten Vasopressin(ADH)-Sekretion (SIADH), Herzinsuffizienz, Leberzirrhose etc.] und Hypernatriämien (Dehydration, Infusionen, Diuretikatherapie, osmotische Diurese etc.) zu berücksichtigen. Akute, symptomatische Dysnatriämien sind rasch mithilfe der Gabe von 3 %iger Kochsalz(NaCl)-Lösung im Fall einer Hyponatriämie und mithilfe der Gabe von 5 %iger Glucoselösung im Fall einer Hypernatriämie zu therapieren. Unter allen Umständen ist während der Korrektur einer Hypo- oder Hypernatriämie das engmaschige Monitoring der Serumnatriumkonzentration essenziell, um eine zu rasche Korrektur und daraus resultierende Folgeschäden zu vermeiden. Der vorliegende Beitrag erläutert Epidemiologie und Ätiologie der Hypo- sowie Hypernatriämie auf Basis der aktuellen Studienlage unter spezieller Berücksichtigung notfallmedizinischer Aspekte und gibt Empfehlungen zur Therapie der Elektrolytstörunge