1,440 research outputs found

    Neutrino-photon Scattering in a Magnetic Field

    Get PDF
    Previous calculations of photon-neutrino scattering in a constant background magnetic field are extended and corrected.Comment: Corrections to the labeling of the entries in Table

    Neutrino-photon reactions for energies above mem_e

    Get PDF
    We show that neutrino-photon reactions above mem_e are dominated by the reaction νγνe+e\nu \gamma \to \nu e^+ e^-. We calculate its cross-section and see that it is larger by several orders of magnitude than the cross-sections of other neutrino-photon processes, for energies above mem_e. We also discuss potential astrophysical and cosmological consequences.Comment: 7 pages, 2 figure

    Angular momentum content of a virtual graviton

    Full text link
    We show that a virtual graviton has a J=0 component, which serves to cancel the J=2, J_z=0 component when the graviton is on shell. In contrast, a massive graviton has no J=0 component either on or off shell. This difference is responsible for the van Dam-Veltman-Zakharov discontinuity.Comment: 5 pages. Reference adde

    Signals of a superlight gravitino at hadron colliders when the other superparticles are heavy

    Get PDF
    If the gravitino (G) is very light and all the other supersymmetric particles are above threshold, supersymmetry may still be found at colliders, by looking at processes with only gravitinos and ordinary particles in the final state. We compute here the cross-sections for some distinctive signals at hadron colliders: photon plus missing energy, induced by (q antiquark -> G G photon), and jet plus missing energy, induced by (q antiquark -> G G g), (q g -> G G q), and (g g -> G G g). From the present Tevatron data, we estimate the bound m_{3/2} > 2.3 10^-5 eV on the gravitino mass, corresponding to the bound sqrt{F} > 310 GeV on the supersymmetry-breaking scale. We foresee that the upgraded Tevatron and the LHC will be sensitive to values of m_{3/2} up to 4.0 10^-5 eV and 6.2 10^-4 eV, corresponding to sqrt{F} up to 410 GeV and 1.6 TeV, respectively.Comment: 19 pages, Latex, epsfig, 13 figures This revised version supersedes that published in Nucl. Phys. B526 (1998) 136, and contains important changes. The correction of a sign error modifies the relevant partonic cross-sections. The sensitivity to the supersymmetry-breaking scale (gravitino mass) is only slightly weakene

    Synthesis of blade flutter vibratory patterns using stationary transducers

    Get PDF
    Flutter frequency was determined and rotor vibratory amplitude and phase distributions during flutter were reconstructed from stationary aerodynamic type measurements. A previously reported optical method for measuring blade-tip displacement during flutter was extended by means of digital analysis. Displacement amplitudes and phase angles were determined based on this method. For selected blades, spectral results were also obtained from strain gage measurements. The results from these three types of measurement were compared and critically evaluated

    Computer program to generate engine inlet flow contour maps and distortion parameters

    Get PDF
    Program generates inlet contour maps with choice of mapping parameters. Contour maps are represented by symbols on picture produced by line printer. Program also generates variety of simple circumferential and radial distortion parameters that enable calculation of almost any specific distortion parameter

    Calculation of the decay {\bm H\bm\to\bm e\bar{\bm e}\bm\ga}

    Full text link
    We revisit an earlier calculation of the decay H\to e\,\bar{e}\ga using the recently reported mass value of the Higgs boson candidate observed in the ATLAS and CMS experiments together with cuts that are appropriate for experimental analyzes.Comment: 4 pages, 5 figure

    Searching for the Higgs Bosons of Minimal Supersymmetry with Muon Pairs and Bottom Quarks

    Full text link
    The prospects for the discovery of neutral Higgs bosons (phi^0 = H^0, h^0, A^0) produced with bottom quarks via Higgs decays into muon pairs (pp --> b b-bar phi^0 --> b b-bar mu mu-bar +X) at the CERN LHC are investigated in the minimal supersymmetric model. The complete physics background from the production of b b-bar mu mu-bar, b b-bar W^+ W^- (including t t-bar) and jj mu mu-bar, j = g, u, d, s, c in the Standard Model is calculated with realistic acceptance cuts. This discovery mode has a simple production mechanism from gg --> b b-bar phi^0 with its cross section proportional to 1/cos^2(beta) and could provide an opportunity to measure tan(beta) and the b b-bar phi^0 couplings. In addition, we compare the associated discovery mode above with the inclusive discovery channel pp --> phi^0 --> mu mu-bar +X. Promising results are found for the CP-odd pseudoscalar (A^0) and the heavier CP-even scalar (H^0) Higgs bosons for tan(beta) equivalent to v_2/v_1 >~ 14 and m_A,m_H <~ 325 GeV.Comment: 12 pages, REVTeX, 4 Figure
    corecore