11,885 research outputs found

    A new method of creating high intensity neutron source

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    We propose a new scheme of producing intense neutron beam whose yields exceed those of existing facilities by many orders of magnitude. This scheme uses the recently proposed photon beam extracted from circulating quantum ions, which is directed to a deuteron target for photo-disintegration. The calculated neutron energy spectrum is nearly flat down to neV range, except a threshold rise and its adjacent wide structure. Hence, there exists a possibility of directly using sub-eV neutrons without a moderator. We shall have brief comments on promising particle physics applications using this large yield of neutron.Comment: A bug in numerical computation is corrected. 9 pages, 5 figure

    Unbinding Transition Induced by Osmotic Pressure in Relation to Unilamellar Vesicle Formation

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    Small-angle X-ray scattering and phase-contrast microscopy experiments were performed to investigate the effect of the osmotic pressure on vesicle formation in a dioleoylphosphatidylcholine (DOPC)/water/NaI system. Multi-lamellar vesicles were formed when a pure lipid film was hydrated with an aqueous solution of NaI. On the other hand, uni-lamellar vesicles (ULVs) were formed when a lipid film mixed with an enough amount of NaI was hydrated. To confirm the effect of the osmotic pressure due to NaI, a free-energy calculation was performed. This result showed that the osmotic pressure induced an unbinding transition on the hydration process, which resulted in ULV formation

    Parity violating observables in radiative neutrino pair emission from metastable atoms

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    We report on a possibility of measuring parity violating effects in radiative neutrino pair emission from metastable atoms; asymmetric angular distribution of emitted photons from oriented atoms and emergent circular polarization. Their observation, along with the continuous photon energy spectrum which has 6 thresholds, may be interpreted as events being a combined weak and QED process, emission of γνiνj\gamma \nu_i \nu_j in the final state. The method may greatly help to perform neutrino mass spectroscopy using atoms, a systematic determination of the neutrino mass matrix.Comment: 9 pages, 4 figure

    Double inflation in supergravity and the primordial black hole formation

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    We study a double inflation model (a hybrid inflation + a new inflation) in supergravity and discuss the formation of primordial black holes (PBHs) with mass \sim 10^{-20}-10^{5}M_{\odot}. We find that in a wide range of parameter space, we obtain PBHs which amount to \Omega \simeq 1, i.e., PBH dark matter. Also, we find a set of inflation parameters which produces PBHs evaporating now. Those PBHs may be responsible for antiproton fluxes observed by the BESS experiment.Comment: 14 pages, 2 figures (RevTeX file
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