2,307 research outputs found
Virtual Supersymmetric Corrections in e^+e^- Annihilation
Depending on their masses, Supersymmetric particles can affect various
measurements in Z decay. Among these are the total width (or consequent
extracted value of ), enhancement or suppression of various flavors,
and left-right and forward-backward asymmetries. The latter depend on squark
mass splittings and are, therefore, a possible test of the Supergravity related
predictions. We calculate leading order corrections for these quantities
considering in particular the case of light photino and gluino where the SUSY
effects are enhanced. In this limit the effect on is appreciable,
the effect on is small, and the effect on the asymmetries is extremely
small.Comment: 11 pages, LaTeX, 3 figures, revised, a reference adde
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Remote sensing of micrometeorological quantities.
This overview of the uses of sodars in meteorological applications categorizes the applications by signal source, specifically amplitude, frequency, or ''visualization'' for example, of vertical time sections of signal amplitude. Examples are shown of data derived from each category. A final section presents the potential for using groups of sodars in networks with other instruments to estimate quantities such as divergence
Gluino Contribution to the 3-loop QCD beta function in the Minimal Supersymmetric Standard Model
We deduce the gluino contribution to the three-loop QCD \beta function within
the minimal supersymmetric Standard Model (MSSM) from its standard QCD
expression. The result is a first step in the computation of the full MSSM
three-loop \beta function. In addition, in the case of a light gluino it
provides the strong three-loop SUSY correction to the extrapolation of the
strong coupling constant from the low energy regime to the Z region and up to
the squark threshold.Comment: 11 pages, RevTex, 4 Postscript figur
Angular dependent vortex pinning mechanisms in YBCO coated conductors and thin films
We present a comparative study of the angular dependent critical current
density in YBa2Cu3O7 films deposited on IBAD MgO and on single crystal MgO and
SrTiO3 substrates. We identify three angular regimes where pinning is dominated
by different types of correlated and uncorrelated defects. We show that those
regimes are present in all cases, indicating that the pinning mechanisms are
the same, but their extension and characteristics are sample dependent,
reflecting the quantitative differences in texture and defect density. In
particular, the more defective nature of the films on IBAD turns into an
advantage as it results in stronger vortex pinning, demonstrating that the
critical current density of the films on single crystals is not an upper limit
for the performance of the IBAD coated conductors.Comment: 14 pages, 3 figures. Submitted to AP
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Development of a volume imaging minisodar
The increased use of phased arrays for transmitting and receiving antennae presents an opportunity to develop and use instruments that allow sampling of a true 3-D volume, for studying the planetary boundary layer. By combining a phase array with independent control of each element, with mutlifrequency techniques and with the use of multiple transmitter-receivers, we are developing an instrument that can accomplish this task on a relatively small scale. Because this instrument is an acoustic device, hardware and software control device costs are modest. In its initial configuration, it has three high-frequency 36-element phased-array antennae with individual control over each of the array elements. A single antenna is being constructed for proof of concept and design changes. If initial tests are successful, two more antennae will follow, and a 3-antennae system may be in operation before the end of the year. Initial deployment outside of Argonne will be at the Argonne Boundary Layer Facility now being built near Wichita KS, within the Atmospheric Radiation Measurement Program`s Southern Great Plains Cloud and Radiation Testbed site
The Woods-Saxon Potential in the Dirac Equation
The two-component approach to the one-dimensional Dirac equation is applied
to the Woods-Saxon potential. The scattering and bound state solutions are
derived and the conditions for a transmission resonance (when the transmission
coefficient is unity) and supercriticality (when the particle bound state is at
E=-m) are then derived. The square potential limit is discussed. The recent
result that a finite-range symmetric potential barrier will have a transmission
resonance of zero-momentum when the corresponding well supports a half-bound
state at E=-m is demonstrated.Comment: 8 pages, 4 figures. Submitted to JPhys
Soil Bacterial Diversity and Potential Functions Are Regulated by Long-Term Conservation Tillage and Straw Mulching
Soil physiochemical properties are regulated by cropping practices, but little is known
about how tillage influences soil microbial community diversity and functions. Here, we assessed
soil bacterial community assembly and functional profiles in relation to tillage. Soils, collected in
2018 from a 17âyear field experiment in northwestern China, were analyzed using highâthroughput
sequencing and the PICRUSt approach. The taxonomic diversity of bacterial communities was
dominated primarily by the phyla Proteobacteria (32â56%), Bacteroidetes (12â33%), and Actinobacteria
(17â27%). Alpha diversity (Chao1, Shannon, Simpson, and operational taxonomic unit (OTU)
richness) was highest under noâtillage with crop residue removed (NT). Crop residue retention on
the soil surface (NTS) or incorporated into soil (TS) promoted the abundance of Proteobacteria by 16
to 74% as compared to conventional tillage (T). Tillage practices mainly affected the pathways of
soil metabolism, genetic information processing, and environmental information processing. Soil
organic C and NH4âN were the principal contributors to the diversity and composition of soil
microbiota, whereas soil pH, total nitrogen, total P, and moisture had little effect. Our results
suggest that longâterm conservation practices with noâtillage and crop residue retention shape soil
bacterial community composition through modifying soil physicochemical properties and
promoting the metabolic function of soil microbiomes
emiT: an apparatus to test time reversal invariance in polarized neutron decay
We describe an apparatus used to measure the triple-correlation term (\D
\hat{\sigma}_n\cdot p_e\times p_\nu) in the beta-decay of polarized neutrons.
The \D-coefficient is sensitive to possible violations of time reversal
invariance. The detector has an octagonal symmetry that optimizes
electron-proton coincidence rates and reduces systematic effects. A beam of
longitudinally polarized cold neutrons passes through the detector chamber,
where a small fraction beta-decay. The final-state protons are accelerated and
focused onto arrays of cooled semiconductor diodes, while the coincident
electrons are detected using panels of plastic scintillator. Details regarding
the design and performance of the proton detectors, beta detectors and the
electronics used in the data collection system are presented. The neutron beam
characteristics, the spin-transport magnetic fields, and polarization
measurements are also described.Comment: 15 pages, 13 figure
The Otterbein Miscellany - Spring 1985
https://digitalcommons.otterbein.edu/miscellany/1010/thumbnail.jp
Conservation Tillage Increases Water Use Efficiency of Spring Wheat by Optimizing Water Transfer in a Semi-Arid Environment
Water availability is a major constraint for crop production in semiarid environments.
The impact of tillage practices on water potential gradient, water transfer resistance, yield, and water
use eïżœciency (WUEg) of spring wheat was determined on the western Loess Plateau. Six tillage
practices implemented in 2001 and their eïżœects were determined in 2016 and 2017 including
conventional tillage with no straw (T), no-till with straw cover (NTS), no-till with no straw (NT),
conventional tillage with straw incorporated (TS), conventional tillage with plastic mulch (TP),
and no-till with plastic mulch (NTP). No-till with straw cover, TP, and NTP significantly improved
soil water potential at the seedling stage by 42, 47, and 57%, respectively; root water potential at the
seedling stage by 34, 35, and 51%, respectively; leaf water potential at the seedling stage by 37, 48,
and 42%, respectively; tillering stage by 21, 24, and 30%, respectively; jointing stage by 28, 32, and 36%,
respectively; and flowering stage by 10, 26, and 16%, respectively, compared to T. These treatments
also significantly reduced the soilâleaf water potential gradient at the 0â10 cm soil depth at the
seedling stage by 35, 48, and 35%, respectively, and at the 30â50 cm soil depth at flowering by 62,
46, and 65%, respectively, compared to T. Thus, NTS, TP, and NTP reduced soilâleaf water transfer
resistance and enhanced transpiration. Compared to T, the NTS, TP, and NTP practices increased
biomass yield by 18, 36, and 40%; grain yield by 28, 22, and 24%; and WUEg by 24, 26, and 24%,
respectively. These results demonstrate that no-till with straw mulch and plastic mulching with
either no-till or conventional tillage decrease the soilâleaf water potential gradient and soilâleaf water
transfer resistance and enhance sustainable intensification of wheat production in semi-arid areas
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