90 research outputs found

    Astrophysical Uncertainties in the Cosmic Ray Electron and Positron Spectrum From Annihilating Dark Matter

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    In recent years, a number of experiments have been conducted with the goal of studying cosmic rays at GeV to TeV energies. This is a particularly interesting regime from the perspective of indirect dark matter detection. To draw reliable conclusions regarding dark matter from cosmic ray measurements, however, it is important to first understand the propagation of cosmic rays through the magnetic and radiation fields of the Milky Way. In this paper, we constrain the characteristics of the cosmic ray propagation model through comparison with observational inputs, including recent data from the CREAM experiment, and use these constraints to estimate the corresponding uncertainties in the spectrum of cosmic ray electrons and positrons from dark matter particles annihilating in the halo of the Milky Way.Comment: 21 pages, 9 figure

    On the trace identity in a model with broken symmetry

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    Considering the simple chiral fermion meson model when the chiral symmetry is explicitly broken, we show the validity of a trace identity -- to all orders of perturbation theory -- playing the role of a Callan-Symanzik equation and which allows us to identify directly the breaking of dilatations with the trace of the energy-momentum tensor. More precisely, by coupling the quantum field theory considered to a classical curved space background, represented by the non-propagating external vielbein field, we can express the conservation of the energy-momentum tensor through the Ward identity which characterizes the invariance of the theory under the diffeomorphisms. Our ``Callan-Symanzik equation'' then is the anomalous Ward identity for the trace of the energy-momentum tensor, the so-called ``trace identity''.Comment: 11 pages, Revtex file, final version to appear in Phys.Rev.

    Symmetries of topological field theories in the BV-framework

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    Topological field theories of Schwarz-type generally admit symmetries whose algebra does not close off-shell, e.g. the basic symmetries of BF models or vector supersymmetry of the gauge-fixed action for Chern-Simons theory (this symmetry being at the origin of the perturbative finiteness of the theory). We present a detailed discussion of all these symmetries within the algebraic approach to the Batalin-Vilkovisky formalism. Moreover, we discuss the general algebraic construction of topological models of both Schwarz- and Witten-type.Comment: 30 page

    Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory

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    Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius AA. Also the events detected simultaneously by the surface and fluorescence detectors (the `hybrid' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.Comment: Matches published versio

    Measurement of (anti)deuteron and (anti)proton production in DIS at HERA

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    The first observation of (anti)deuterons in deep inelastic scattering at HERA has been made with the ZEUS detector at a centre-of-mass energy of 300--318 GeV using an integrated luminosity of 120 pb-1. The measurement was performed in the central rapidity region for transverse momentum per unit of mass in the range 0.3<p_T/M<0.7. The particle rates have been extracted and interpreted in terms of the coalescence model. The (anti)deuteron production yield is smaller than the (anti)proton yield by approximately three orders of magnitude, consistent with the world measurements.Comment: 26 pages, 9 figures, 5 tables, submitted to Nucl. Phys.

    ARIA 2016: Care pathways implementing emerging technologies for predictive medicine in rhinitis and asthma across the life cycle

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    The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative commenced during a World Health Organization workshop in 1999. The initial goals were (1) to propose a new allergic rhinitis classification, (2) to promote the concept of multi-morbidity in asthma a

    Effect of date of harvest on the nutritional quality of native grass hay

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    Native grass hay meadows in three Kansas Flint Hills counties were sampled at 2-week intervals during the growing season to determine the effect of harvest date on forage quality. Each sample was analyzed for crude protein (CP), acid detergent fiber (ADF), and phosphorus (PHOS). CP and PHOS contents declined, and ADF increased as harvest date progressed into the growing season. Both CP and ADF were related highly to harvest date. PHOS content was associated only moderately with harvest date. Harvest date of native grass hay can significantly influence supplemental protein needs for beef cows

    Effect of date of harvest on the yield and nutritional quality of native grass hay

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    Native grass hay meadows in three Kansas Flint Hills counties were sampled at 2-week intervals during the 1997 and 1998 growing seasons to determine the effect of harvest date on forage quality and dry matter (DM) yield. Each sample was weighed and analyzed for crude protein (CP), acid detergent fiber (ADF), and phosphorus (PHOS). The CP and PHOS contents declined, whereas ADF and DM yield increased as harvest date progressed. Although CP, ADF and DM yield were related highly to harvest date, the association for PHOS content was only moderate. Because harvest date of native grass hay can significantly influence supplemental protein needs for beef cows, mid-July harvesting appears to be the best compromise between yield and forage quality

    Effects of spring pasture burning, pasture deworming, and grain supplementation on performance of stocker steers grazing native Flinthills pasture

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    A grazing study was conducted using 445 crossbred beef steers (496 lb) to determine the benefits of feeding a grain-based supplementon burned and unburned native pasture, with and without a Safe-Guard (fenbendazole) treatment while on pasture. Treatments consisted of mineral only, mineral with Safe-Guard treatment at day 29, and a supplement based on dry-rolled corn with a Safe-Guard treatment on day 29. All three treatments provided GainPro to the steers. Twelve pastures were used, six that were burned and six that were not burned during the month before the start of the trial. The control pastures were stocked at 272 lb per acre; the pastures with cattle receiving supplements were stocked at 312 lb per acre, 15% more than controls. Cattle grazing burned pastures had greater daily gains (1.81 vs. 1.65 lb/day; P=0.05) and gained 9 lb more per acre (85 vs. 76 lb/acre; P=0.03) than those grazing unburned pastures. Supplementation with grain mix improved the pounds of gain per acre, compared with cattle not receiving supplement (95 vs. 76 lb/acre; P<0.01). Steers treated with Safe-Guard while on pasture tended to have greater daily gains (1.73 vs. 1.61; P=0.17) and gained slightly more weight per acre, but this increase was not significant (P=0.24). Analysis of fecal samples indicated that deworming while on pasture did not reduce the average number of eggs shed per animal, but did increase the percentage of steers shedding no eggs
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