17,687 research outputs found
Improved limit on electron neutrino charge radius through a new evaluation of the weak mixing angle
We have obtained a new limit on the electron neutrino effective charge radius
from a new evaluation of the weak mixing angle by a combined fit of all
electron-(anti)neutrino electron elastic scattering measurements. Weak mixing
angle is found to be sin^2 theta_W=0.259 \pm 0.025 in the low energy regime
below 100 MeV. The electron neutrino charge radius squared is bounded to be in
the range -0.13 10^-32 cm^2 < r^2 < 3.32 10^-32 cm^2 at 90 % C.L. Both results
improve previously published analyses. We also discuss perspectives of future
experiments to improve these constraints.Comment: 10 pages, 2 figures. Final published versio
Global constraints on muon-neutrino non-standard interactions
The search for new interactions of neutrinos beyond those of the Standard
Model may help to elucidate the mechanism responsible for neutrino masses. Here
we combine existing accelerator neutrino data with restrictions coming from a
recent atmospheric neutrino data analysis in order to lift parameter
degeneracies and improve limits on new interactions of muon neutrinos with
quarks. In particular we re-consider the results of the NuTeV experiment in
view of a new evaluation of its systematic uncertainties. We find that,
although constraints for muon neutrinos are better than those applicable to tau
or electron neutrinos, they lie at the few level, not as
strong as previously believed. We briefly discuss prospects for further
improvement.Comment: 10 pages, 5 figures, 2 table
Invisible decays of ultra-high energy neutrinos
Gamma-ray bursts (GRBs) are expected to provide a source of ultra high energy
cosmic rays, accompanied with potentially detectable neutrinos at neutrino
telescopes. Recently, IceCube has set an upper bound on this neutrino flux well
below theoretical expectation. We investigate whether this mismatch between
expectation and observation can be due to neutrino decay. We demosntrate the
phenomenological consistency and theoretical plausibility of the neutrino decay
hypothesis. A potential implication is the observability of majoron-emitting
neutrinoless double beta decay.Comment: 11 pages, 3 figures. To appear in Frontiers High Energy Physic
WHEAT BUFFER STOCKS AND TRADE IN AN EFFICIENT GLOBAL ECONOMY
This study assesses storage and trade of wheat in an integrated global economy. Domestic and international linkages are analyzed using a dynamic rational expectations model of the world wheat market. The results of this study demonstrate the importance of endogenizing both storage and trade in studying commodity markets. Results suggest an optimal US buffer stock level of 150 million bushel. Results indicate that past government stockholdings have not followed efficient market outcomes. Private markets likely would perform better in the absence of government market distortions. Results indicate that elimination of the Export Enhancement Program by the US and of export restitution payments by the EU is unlikely to have a major impact on wheat exports from the two regions, but will save millions of tax dollars in both regions.Crop Production/Industries, International Relations/Trade,
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