9,340 research outputs found
Implications of the SNO and the Homestake Results for the BOREXINO Experiment
Using the recent result of the SNO solar neutrino experiment, we have
demonstrated in a model independent way that the contribution of Be-7 and other
medium energy neutrinos to the event rate of the Homestake experiment is 4
sigma smaller than the BP2000 SSM prediction. We have considered the
implications of this result for the future BOREXINO experiment.Comment: 9 pages, no figure
Human Capital and Economic Growth : Dynamic Implications of Insider-outsider Problem for Macroeconomics
This paper considers a dynamic model with human capital accumulation, for which both firm-specific skills and general skills are sources of growth. We analyze how the existence of firm-specific skills changes the effects of productivity shocks on economic growth. It is well known that the insider-outsider problem can cause employment inertia in the macro economy because workers with firm-specific skills (insiders) face the hold up problem. However, most previous studies have been static in nature, so that they have paid little attention to dynamic interactions between firm-specific skills and general skills during the adjustment to the new steady state. This paper considers dynamic models that involve creation of human capital from both firm-specific skills and general skills. We show that the insider-outsider problem that is generated through the creation of firm-specific skills can cause a dramatic decline in the youth labor force during a transition path to the steady state. We also show that the problem may result in a temporary economic downturn even if the shock is positive. In Japan, since the mid-1990s, there has been a dramatic increase in the unemployment rate and a substantial decrease in the working population ratio together with increased irregular employment among young people. By analyzing firm-specific human capital as an engine of economic growth, this paper shows that these trends are consistent with our dynamic model. It also demonstrates that the productivity shocks might explain recent dramatic declines in youth employment and temporary declines in growth rates.firm-specific human capital, labor markets, insider-outsider problem
Searching for Oscillations with Extragalactic Neutrinos
We propose a novel approach for studying oscillations
with extragalactic neutrinos. Active Galactic Nuclei and Gamma Ray Bursts are
believed to be sources of ultrahigh energy muon neutrinos. With distances of
100 Mpc or more, they provide an unusually long baseline for possible detection
of with mixing parameters down to
eV, many orders of magnitude below the current accelerator
experiments. By solving the coupled transport equations, we show that
high-energy 's, as they propagate through the earth, cascade down in
energy, producing the enhancement of the incoming flux in the low
energy region, in contrast to the high-energy 's, which get absorbed.
For an AGN quasar model we find the flux to be a factor of 2 to 2.5
larger than the incoming flux in the energy range between GeV and
GeV, while for a GRB fireball model, the enhancement is 10%-27% in the same
energy range and for zero nadir angle. This enhancement decreases with larger
nadir angle, thus providing a novel way to search for appearance by
measuring the angular dependence of the muons. To illustrate how the cascade
effect and the final flux depend on the steepness of the incoming
, we show the energy and angular distributions for several generic
cases of the incoming tau neutrino flux, for n=1,2 and
3.6. We show that for the incoming flux that is not too steep, the signal for
the appearance of high-energy is the enhanced production of lower
energy and their distinctive angular dependence, due to the contribution
from the decay into just below the detector.Comment: 11 pages, including 4 color figure
Positivity constraints for lepton polarization in neutrino deep inelastic scattering
We consider the spin polarization of leptons produced in neutrino and
antineutrino nucleon deep inelastic scattering, via charged currents, and we
study the positivity constraints on the spin components in a model independent
way. These results are very important, in particular in the case of
leptons, because the polarization information is crucial in all
future neutrino oscillation experiments.Comment: 14 pages, 4 figure
Using transcranial direct-current stimulation (tDCS) to understand cognitive processing
Noninvasive brain stimulation methods are becoming increasingly common tools in the kit of the cognitive scientist. In particular, transcranial direct-current stimulation (tDCS) is showing great promise as a tool to causally manipulate the brain and understand how information is processed. The popularity of this method of brain stimulation is based on the fact that it is safe, inexpensive, its effects are long lasting, and you can increase the likelihood that neurons will fire near one electrode and decrease the likelihood that neurons will fire near another. However, this method of manipulating the brain to draw causal inferences is not without complication. Because tDCS methods continue to be refined and are not yet standardized, there are reports in the literature that show some striking inconsistencies. Primary among the complications of the technique is that the tDCS method uses two or more electrodes to pass current and all of these electrodes will have effects on the tissue underneath them. In this tutorial, we will share what we have learned about using tDCS to manipulate how the brain perceives, attends, remembers, and responds to information from our environment. Our goal is to provide a starting point for new users of tDCS and spur discussion of the standardization of methods to enhance replicability.The authors declare that they had no conflicts of interest with respect to their authorship or the publication of this article. This work was supported by grants from the National Institutes of Health (R01-EY019882, R01-EY025272, P30-EY08126, F31-MH102042, and T32-EY007135). (R01-EY019882 - National Institutes of Health; R01-EY025272 - National Institutes of Health; P30-EY08126 - National Institutes of Health; F31-MH102042 - National Institutes of Health; T32-EY007135 - National Institutes of Health)Accepted manuscrip
Prospects for observations of high-energy cosmic tau neutrinos
We study prospects for the observations of high-energy cosmic tau neutrinos
(E \geq 10^6 GeV) originating from proton acceleration in the cores of active
galactic nuclei. We consider the possibility that vacuum flavor neutrino
oscillations induce a tau to muon neutrino flux ratio greatly exceeding the
rather small value expected from intrinsic production. The criterias and event
rates for under water/ice light Cerenkov neutrino telescopes are given by
considering the possible detection of downgoing high-energy cosmic tau
neutrinos through characteristic double shower events.Comment: 10 pages, Revtex, 3 figures included with eps
Measuring Technology Achievement of Nations and the Capacity to Participate in the Network Age
human development, democracy
Symplectic Symmetry of the Neutrino Mass and the See-Saw Mechanism
We investigate the algebraic structure of the most general neutrino mass
Hamiltonian and place the see-saw mechanism in an algebraic framework. We show
that this Hamiltonian can be written in terms of the generators of an Sp(4)
algebra. The Pauli-Gursey transformation is an SU(2) rotation which is embedded
in this Sp(4) group. This SU(2) also generates the see-saw mechanism.Comment: 11 pages, REVTE
- …