7,747 research outputs found

    Study of high resolution wind measuring systems. phase ii- analysis

    Get PDF
    Comparative analysis of high resolution wind measuring system

    The Name "Iowa"

    Get PDF

    The Name "Iowa"

    Get PDF

    Scattering and absorption of gravitational plane waves by rotating black holes

    Full text link
    This is a study of the scattering and absorption of planar gravitational waves by a Kerr black hole in vacuum. We apply the partial wave method to compute cross sections for the special case of radiation incident along the rotation axis. A catalogue of numerically-accurate cross sections is presented, for a range of incident wavelengths Mω4M\omega \le 4 and rotation rates a0.999Ma \le 0.999M. Three effects are studied in detail: polarization, helicity-reversal and glory scattering. First, a new approximation to the polarization in the long-wavelength limit is derived. We show that black hole rotation distinguishes between co- and counter-rotating wave helicities, leading to a term in the cross section proportional to aωa\omega. Second, we confirm that helicity is not conserved by the scattering process, and show that superradiance amplifies the effect. For certain wavelengths, the back-scattered flux is enhanced by as much as 35\sim 35 times for a rapidly-rotating hole (e.g. for a=0.999Ma = 0.999M at Mω=0.945M\omega = 0.945). Third, we observe regular glory and spiral scattering peaks in the numerically-determined cross sections. We show that the angular width and intensity of the peaks may be estimated via a semi-classical approximation. We conclude with a discussion of the observable implications of our results.Comment: 43 pages, 17 figures. To match published versio

    Physics Opportunities of e+e- Linear Colliders

    Get PDF
    We describe the anticipated experimental program of an e+e- linear collider in the energy range 500 GeV -- 1.5 TeV. We begin with a description of current collider designs and the expected experimental environment. We then discuss precision studies of the W boson and top quark. Finally, we review the range of models proposed to explain the physics of electroweak symmetry breaking and show, for each case, the central role that the linear collider experiments will play in elucidating this physics. (to appear in Annual Reviews of Nuclear and Particle Science)Comment: 93 pages, latex + 23 figures; typos corrections + 1 reference adde

    A Search for Jet Handedness in Hadronic Z0Z^0 Decays

    Get PDF
    We have searched for signatures of polarization in hadronic jets from Z0qqˉZ^0 \to q \bar{q} decays using the ``jet handedness'' method. The polar angle asymmetry induced by the high SLC electron-beam polarization was used to separate quark jets from antiquark jets, expected to be left- and right-polarized, respectively. We find no evidence for jet handedness in our global sample or in a sample of light quark jets and we set upper limits at the 95% C.L. of 0.063 and 0.099 respectively on the magnitude of the analyzing power of the method proposed by Efremov {\it et al.}Comment: Revtex, 8 pages, 2 figure

    Testing the Higgs boson gluonic couplings at LHC

    Get PDF
    We study Higgs + jet production at hadron colliders in order to look for new physics residual effects possibly described by the dim=6dim=6 operators {\O}_{GG} and {\widetilde\O}_{GG} which induce anomalous HggHgg and HgggHggg couplings. Two ways for constraining these operators at LHC may be ~useful. The first is based on the total Higgs boson production rate induced by gluon-gluon fusion, in which the main cause of limitations are due to theoretical uncertainties leading to sensitivities of dG3.×104|d_G|\simeq 3.\times 10^{-4} and d~G1.4×103|\widetilde{d}_G|\simeq 1.4\times 10^{-3} for the corresponding anomalous couplings, in the mass range 100 GeV \lsim \mh \lsim 2~00 GeV. These results imply sensitivity to new physics scales of 51 and 24 TeV respectively. The second way investigated here concerns the shape of the Higgs transverse momentum; for which the theoretical uncertainties are less severe and the limitations are mainly induced by statistics. A simple analysis, based on the ratio of the number of events at large and low pTp_T at LHC, leads to similar sensitivities, if only the HγγH\to \gamma \gamma decay mode is used. But the sensitivities can now be improved by a factor 2 to 10, depending on the Higgs mass, if the Higgs decay modes to WWWW^*, ZZZZ^*, WWWW, ZZZZ are also used.Comment: 23 pages and 7 figures, version to appear in Phys.ReV.D. e-mail: [email protected]

    Search for R-parity Violating Supersymmetry in Dimuon and Four-Jets Channel

    Get PDF
    We present results of a search for R-parity-violating decay of the neutralino chi_1^0, taken to be the Lightest Supersymmetric Particle. It is assumed that this decay proceeds through one of the lepton-number violating couplings lambda-prime_2jk (j=1,2; k=1,2,3). This search is based on 77.5 pb-1 of data, collected by the D0 experiment at the Fermilab Tevatron in ppbar collisions at a center of mass energy of 1.8 TeV in 1992-1995.Comment: 10 pages, 3 figure
    corecore