Captures of Hot and Warm Sterile Antineutrino Dark Matter on EC-decaying Ho-163 Nuclei

Capturing low-energy electron antineutrinos on radioactive Ho-163 nuclei, which decay into Dy-163 via electron capture (EC), is a noteworthy opportunity to detect relic sterile antineutrinos. Such hypothetical particles are more or less implied by current experimental and cosmological data, and they might be a part of hot dark matter or a candidate for warm dark matter in the Universe. Using the isotope Ho-163 as a target and assuming reasonable active-sterile antineutrino mixing angles, we calculate the capture rate of relic electron antineutrinos against the corresponding EC-decay background in the presence of sterile antineutrinos at the sub-eV or keV mass scale. We show that the signature of hot or warm sterile antineutrino dark matter should in principle be observable, provided the target is big enough and the energy resolution is good enough.Comment: 16 pages, 6 figures, more discussions and references added. To appear in JCA

Numerical study of parametric pumping current in mesoscopic systems in the presence of a magnetic field

We numerically study the parametric pumped current when magnetic field is applied both in the adiabatic and nonadiabatic regimes. In particular, we investigate the nature of pumped current for systems with resonance as well as antiresonance. It is found that, in the adiabatic regime, the pumped current changes sign across the sharp resonance with long lifetime, while the nonadiabatic pumped current at finite frequency does not. When the lifetime of the resonant level is short, the behaviors of the adiabatic and nonadiabatic pumped currents are similar with sign changes. Our results show that, at the energy where complete transmission occurs, the adiabatic pumped current is zero, while the nonadiabatic pumped current is nonzero. Different from the resonant case, both the adiabatic and nonadiabatic pumped currents are zero at antiresonance with complete reflection. We also investigate the pumped current when the other system parameters such as magnetic field, pumped frequency, and pumping potentials are varied. Interesting behaviors are revealed. Finally, we study the symmetry relation of the pumped current for several systems with different spatial symmetries upon reversal of magnetic field. Different from the previous theoretical prediction, we find that a system with general inversion symmetry can pump out a finite current in both the adiabatic and nonadiabatic regimes with an approximate relation I(B)I(-B) at small magnetic field. It has been shown theoretically that for systems with reflection symmetry, the pumped current satisfies the relation I(B)=I(-B) in the adiabatic regime. Our results show that even for systems evolving from the inversion to reflection symmetry, the pumped current still obeys the relation I(B)=I(-B) in the adiabatic regime at small magnetic field. © 2011 American Physical Society.published_or_final_versio

Endogenous structural transformation in economic development

This paper proposes a framework to model how a country develops its economy by endogenous structural transformation and efficient resource allocation in a market mechanism. To achieve this goal, the paper first summarizes three attributes of economic structures from the literature, namely, structurality, durationality, and transformality, and discuss their implications for methods of economic modeling. Then, with the common knowledge assumption, the paper studies a Ramsey growth model with endogenous structural transformation in which the social planner chooses the optimal industrial structure, recource allocation with the chosen structure, and consumption to maximize the representative household's total utility subject to the resource constraint. The paper next establishes the mathematical underpinning of the static, dynamic, and structural equilibria. The Ramsey growth model and its equilibria are then extended to economies with complicated economic structures consisting of hierarchical production, composite consumption, technology adoption and innovation, infrastructure, and economic and political institutions. The paper concludes with a brief discussion of applications of the proposed methodology to economic development problems in other scenarios.Comment: 43 pages, 0 figure

More Straightforward Extraction of the Fundamental Lepton Mixing Parameters from Long-Baseline Neutrino Oscillations

We point out the simple reversibility between the fundamental neutrino mixing parameters in vacuum and their effective counterparts in matter. The former can therefore be expressed in terms of the latter, allowing more straightforward extraction of the genuine lepton mixing quantities from a variety of long-baseline neutrino oscillation experiments. In addition to the parametrization-independent results, we present the formulas based on the standard parametrization of the lepton flavor mixing matrix and give a typical numerical illustration.Comment: RevTex 10 pages. Minor changes. Phys. Rev. D in printin

Exponential asymptotics for time-space Hamiltonians

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Can the Lepton Flavor Mixing Matrix Be Symmetric?

Current neutrino oscillation data indicate that the 3x3 lepton flavor mixing matrix V is likely to be symmetric about its V_{e3}-V_{\mu 2}-V_{\tau 1} axis. This off-diagonal symmetry corresponds to three pairs of {\it congruent} unitarity triangles in the complex plane. Terrestrial matter effects can substantially modify the genuine CP-violating parameter and off-diagonal asymmetries of V in realistic long-baseline experiments of neutrino oscillations.Comment: RexTex 14 pages (4 PS figures). More discussions adde