1,602 research outputs found

    Revisiting the 'LSND anomaly' II: critique of the data analysis

    Full text link
    This paper, together with a preceding paper, questions the so-called 'LSND anomaly': a 3.8 sigma excess of antielectronneutrino interactions over standard backgrounds, observed by the LSND Collaboration in a beam dump experiment with 800 MeV protons. That excess has been interpreted as evidence for the antimuonneutrino to antielectronneutrino oscillation in the \Deltam2 range from 0.2 eV2 to 2 eV2. Such a \Deltam2 range is incompatible with the widely accepted model of oscillations between three light neutrino species and would require the existence of at least one light 'sterile' neutrino. In a preceding paper, it was concluded that the estimates of standard backgrounds must be significantly increased. In this paper, the LSND Collaboration's estimate of the number of antielectronneutrino interactions followed by neutron capture, and of its error, is questioned. The overall conclusion is that the significance of the 'LSND anomaly' is not larger than 2.3 sigma.Comment: 30 pages, 16 figures, 6 table

    Long-range attraction between particles in dusty plasma and partial surface tension of dusty phase boundary

    Full text link
    Effective potential of a charged dusty particle moving in homogeneous plasma has a negative part that provides attraction between similarly charged dusty particles. A depth of this potential well is great enough to ensure both stability of crystal structure of dusty plasma and sizable value of surface tension of a boundary surface of dusty region. The latter depends on the orientation of the surface relative to the counter-ion flow, namely, it is maximal and positive for the surface normal to the flow and minimal and negative for the surface along the flow. For the most cases of dusty plasma in a gas discharge, a value of the first of them is more than sufficient to ensure stability of lenticular dusty phase void oriented across the counter-ion flow.Comment: LATEX, REVTEX4, 7 pages, 6 figure

    Reply to 'Corrections to the HARP-CDP Analysis of the LSND Neutrino Oscillation Backgrounds'

    Full text link
    The alleged mistakes in recent papers that reanalyze the backgrounds to the 'LSND anomaly' do not exist. We maintain our conclusion that the significance of the 'LSND anomaly' is not 3.8 sigma but not larger than 2.3 sigma.Comment: 3 page

    Measurement of air and nitrogen fluorescence light yields induced by electron beam for UHECR experiments

    Get PDF
    Most of the Ultra High Energy Cosmic Ray (UHECR) experiments and projects (HiRes, AUGER, TA, EUSO, TUS,...) use air fluorescence to detect and measure extensive air showers (EAS). The precise knowledge of the Fluorescence Light Yield (FLY) is of paramount importance for the reconstruction of UHECR. The MACFLY - Measurement of Air Cherenkov and Fluorescence Light Yield - experiment has been designed to perform such FLY measurements. In this paper we will present the results of FLY in the 290-440 nm wavelength range for dry air and pure nitrogen, both excited by electrons with energy of 1.5 MeV, 20 GeV and 50 GeV. The experiment uses a 90Sr radioactive source for low energy measurement and a CERN SPS electron beam for high energy. We find that the FLY is proportional to the deposited energy (E_d) in the gas and we show that the air fluorescence properties remain constant independently of the electron energy. At the reference point: atmospheric dry air at 1013 hPa and 23C, the ratio FLY/E_d=17.6 photon/MeV with a systematic error of 13.2%.Comment: 19 pages, 8 figures. Accepted for publication in Astroparticle Physic

    Cross-sections of large-angle hadron production in proton- and pion-nucleus interactions VII: tin nuclei and beam momenta from \pm3 GeV/c to \pm15 GeV/c

    Get PDF
    We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary tin target, of proton and pion beams with momentum from \pm3 GeV/c to \pm15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. Cross-sections on tin nuclei are compared with cross-sections on beryllium, carbon, copper, tantalum and lead nuclei.Comment: 68 pages, 13 figure

    Soft X-ray resonant scattering study of single-crystal LaSr2_2Mn2_2O7_7

    Full text link
    Soft X-ray resonant scattering studies at the Mn LII, IIIL_{\texttt{II, III}}- and the La MIV, VM_{\texttt{IV, V}}- edges of single-crystal LaSr2_2Mn2_2O7_7 are reported. At low temperatures, below TN160T_\texttt{N} \approx 160 K, energy scans with a fixed momentum transfer at the \emph{A}-type antiferromagnetic (0 0 1) reflection around the Mn LII, IIIL_{\texttt{II, III}}-edges with incident linear σ\sigma and π\pi polarizations show strong resonant enhancements. The splitting of the energy spectra around the Mn LII, IIIL_{\texttt{II, III}}-edges may indicate the presence of a mixed valence state, e.g., Mn3+^{3+}/Mn4+^{4+}. The relative intensities of the resonance and the clear shoulder-feature as well as the strong incident σ\sigma and π\pi polarization dependences strongly indicate its complex electronic origin. Unexpected enhancement of the charge Bragg (0 0 2) reflection at the La MIV, VM_{\texttt{IV, V}}-edges with σ\sigma polarization has been observed up to 300 K, with an anomaly appearing around the orbital-ordering transition temperature, TOO220T_{\texttt{OO}} \approx 220 K, suggesting a strong coupling (competition) between them.Comment: Accepted by European Physical Journal

    Pad equalization and dE/dx in the HARP TPC

    Get PDF
    In the HARP TPC, the specific ionization dE/dx depends critically on the pad equalization, which in turn depends on the crosstalk correction. We discuss the TPC pad equalization algorithm and its performance in terms of average and resolution of dE/dx of negative pions with an average active track length of 300 mm. The observed dE/dx of pions and protons agrees satisfactorily with the theoretical expectation, the resolution for a minimum-ionizing track length of 300 mm is 16%

    Interacting circular nanomagnets

    Full text link
    Regular 2D rectangular lattices of permalloy nanoparticles (40 nm in diameter) were prepared by the method of the electron lithography. The magnetization curves were studied by Hall magnetometry with the compensation technique for different external field orientations at 4.2K and 77K. The shape of hysteresis curves indicates that there is magnetostatic interaction between the particles. The main peculiarity is the existence of remanent magnetization perpendicular to easy plain. By numerical simulation it is shown, that the character of the magnetization reversal is a result of the interplay of the interparticle interaction and the magnetization distribution within the particles (vortex or uniform).Comment: 16 pages, 8 figure

    Comparative investigation of dimephosphon, actovegin and trental influence on survival potention of skin-fascial autograft in arterial blood insufficiency and venous stasis

    Get PDF
    It has been demonstrated that dimephosphon as well as actovegin and trental taken for the comparison in conditions of the «normal» (АВВА) arterialvenous permeability, «separated» (АВВА and АВВА; the underlined letters here and further denote the ligation of arteries and veins in different variants) and «mixed» (АВВА, АВВА, АВВА и АВВА) arterial and venous insuffieciency of the constrained skin-fascial autograft (on two feeding cruses with preserved skin sensitive nerves) increase its survival potential. On intensity of dermaprotective action (DPA) dimephosfon and reference preparations can be situated as following: АВВА - trental > dimephosphon = actovegin; АВВА - dimephosphon = trental > actovegin; АВВА - actovegin = dimephosphon, trental is not effective; АВВА - dimephosphon = actovegin = trental; АВВА - all these preparations are not effective; АВВА - trental > dimephosphon = actovegin. The DPA mechanism of dimephosphon depends on its ability to join in the different links of homeostasis and mediately to provide the functional correction of violated local (myogenic and metabolic) and remote neurohormonal mechanisms that regulate blood flow to the skin

    Fraction of muons in the T9 pion beams

    Get PDF
    In the T9 beam line, the beam instrumentation does not permit the separation of pions from muons. For a correct pion interaction cross-section, the flux of beam muons must be subtracted from the flux of pion-like particles incident on the target. In this memo, data from the beam instrumentation and the beam-muon identifier in 'empty-target' runs are analyzed in order to measure the fraction of beam muons incident on the target, in the pion beams from 3 to 15 GeV/c
    corecore