1,313 research outputs found

    A review of dieback - a disorder of the papaw (Carica papaya L.) in Queensland

    Get PDF
    Dieback is a disorder of the pawpaw which causes annual losses in southern sub-tropical Queensland. Tree deaths in plantations may be as high as 100%. This paper collates available information relating to dieback since it was first reported in 1922. It includes origin and production areas, symptoms and occurrence with respect to plant characteristics and cultivars, soils, weather and localities

    A Bayesian technique for improving the sensitivity of the atmospheric neutrino L/E analysis

    Full text link
    This paper outlines a method for improving the precision of atmospheric neutrino oscillation measurements. One experimental signature for these oscillations is an observed deficit in the rate of νμ\nu_{\mu} charged-current interactions with an oscillatory dependence on Lν/EνL_{\nu}/E_{\nu}, where LνL_{\nu} is the neutrino propagation distance, and EνE_{\nu} is the neutrino energy. For contained-vertex atmospheric neutrino interactions, the Lν/EνL_{\nu}/E_{\nu} resolution varies significantly from event to event. The precision of the oscillation measurement can be improved by incorporating information on Lν/EνL_{\nu}/E_{\nu} resolution into the oscillation analysis. In the analysis presented here, a Bayesian technique is used to estimate the Lν/EνL_{\nu}/E_{\nu} resolution of observed atmospheric neutrinos on an event-by-event basis. By separating the events into bins of Lν/EνL_{\nu}/E_{\nu} resolution in the oscillation analysis, a significant improvement in oscillation sensitivity can be achieved.Comment: 12 pages, 7 figures, submitted to Nucl. Instrum. Methods A, accompanies arXiv:1208.2915 [hep-ex

    Comparison of space-time evolutions of hot/dense matter in sNN\sqrt{s_{NN}}=17 and 130 GeV relativistic heavy ion collisions based on a hydrodynamical model

    Full text link
    Based on a hydrodynamical model, we compare 130 GeV/AA Au+Au collisions at RHIC and 17 GeV/AA Pb+Pb collisions at SPS. The model well reproduces the single-particle distributions of both RHIC and SPS. The numerical solution indicates that huge amount of collision energy in RHIC is mainly used to produce a large extent of hot fluid rather than to make a high temperature matter; longitudinal extent of the hot fluid in RHIC is much larger than that of SPS and initial energy density of the fluid is only 5% higher than the one in SPS. The solution well describes the HBT radii at SPS energy but shows some deviations from the ones at RHIC.Comment: 28 pages, 21 figures, REVTeX4, one figure is added and some figures are replace

    Hydrodynamical analysis of hadronic spectra in the 130 GeV/nucleon Au+Au collisions

    Get PDF
    We study one-particle spectra and a two-particle correlation function in the 130 GeV/nucleon Au+Au collisions at RHIC by making use of a hydrodynamical model. We calculate the one-particle hadronic spectra and present the first analysis of Bose-Einstein correlation functions based on the numerical solution of the hydrodynamical equations which takes both longitudinal and transverse expansion into account appropriately. The hydrodynamical model provides excellent agreement with the experimental data in the pseudorapidity and the transverse momentum spectra of charged hadrons, the rapidity dependence of anti-proton to proton ratio, and almost consistent result for the pion Bose-Einstein correlation functions. Our numerical solution with simple freeze-out picture suggests the formation of the quark-gluon plasma with large volume and low net-baryon density.Comment: 7 pages, 8 figures, REVTeX4. Numerical results and figures are correcte

    General Relativistic Mean Field Theory for Rotating Nuclei

    Full text link
    We formulate a general relativistic mean field theory for rotating nuclei starting from the special relativistic σω\sigma - \omega model Lagrangian. The tetrad formalism is adopted to generalize the model to the accelerated frame.Comment: 13 pages, REVTeX, no figures, submitted to Phys. Rev. Lett., the word `curved' is replaced by `non-inertial' or `accelerated' in several places to clarify the physical situation interested, some references are added, more detail discussions are given with omitting some redundant sentence

    Hydrodynamical analysis of symmetric nucleus-nucleus collisions at CERN/SPS energies

    Full text link
    We present a coherent theoretical study of ultrarelativistic heavy-ion data obtained at the CERN/SPS by the NA35/NA49 Collaborations using 3+1-dimensional relativistic hydrodynamics. We find excellent agreement with the rapidity spectra of negative hadrons and protons and with the correlation measurements in two experiments: S+SS+S at 200 AGeVAGeV and Pb+PbPb+Pb at 160 AGeVAGeV (preliminary results). Within our model this implies that for Pb+PbPb+Pb (S+SS+S) a quark-gluon-plasma of initial volume 174 fm3fm^3 (24 fm3fm^3) with a lifetime 3.4 fm/cfm/c (1.5 fm/cfm/c) was formed. It is found that the Bose-Einstein correlation measurements do not determine the maximal effective radii of the hadron sources because of the large contributions from resonance decay at small momenta. Also within this study we present an NA49 acceptance corrected two-pion Bose-Einstein correlation function in the invariant variable, QinvQ_{inv}.Comment: 21 pages, 11 Postscript figures (1 File, 775654 Bytes, has to be requested for submission via e.mail from [email protected]

    Hadronic freeze-out following a first order hadronization phase transition in ultrarelativistic heavy-ion collisions

    Get PDF
    We analyze the hadronic freeze-out in ultra-relativistic heavy ion collisions at RHIC in a transport approach which combines hydrodynamics for the early, dense, deconfined stage of the reaction with a microscopic non-equilibrium model for the later hadronic stage at which the hydrodynamic equilibrium assumptions are not valid. With this ansatz we are able to self-consistently calculate the freeze-out of the system and determine space-time hypersurfaces for individual hadron species. The space-time domains of the freeze-out for several hadron species are found to be actually four-dimensional, and differ drastically for the individual hadrons species. Freeze-out radii distributions are similar in width for most hadron species, even though the Omega-baryon is found to be emitted rather close to the phase boundary and shows the smallest freeze-out radii and times among all baryon species. The total lifetime of the system does not change by more than 10% when going from SPS to RHIC energies.Comment: 11 pages, 4 eps-figures included, revised versio

    Properties of Ly-alpha and Gamma Ray Burst selected starbursts at high redshifts

    Full text link
    Selection of starbursts through either deep narrow band imaging of redshifted Ly-alpha emitters, or localisation of host galaxies of gamma-ray bursts both give access to starburst galaxies that are significantly fainter than what is currently available from selection techniques based on the continuum (such as Lyman-break selection). We here present results from a survey for Ly-alpha emitters at z=3, conducted at the European Southern Observatory's Very Large Telescope. Furthermore, we briefly describe the properties of host galaxies of gamma-ray bursts at z>2. The majority of both Ly-alpha and gamma-ray burst selected starbursts are fainter than the flux limit of the Lyman-break galaxy sample, suggesting that a significant fraction of the integrated star formation at z~3 is located in galaxies at the faint end of the luminosity function.Comment: invited talk, 6 pages, 3 figures, to appear in ``Starbursts from 30 Doradus to Lyman Break Galaxies'', eds. R. de Grijs, R. M. Gonzalez Delgado, Astrophysics & Space Science Library Series, Kluwer (in press

    Spin, charge and orbital ordering in ferrimagnetic insulator YBaMn2_2O5_5

    Full text link
    The oxygen-deficient (double) perovskite YBaMn2_2O5_5, containing corner-linked MnO5_5 square pyramids, is found to exhibit ferrimagnetic ordering in its ground state. In the present work we report generalized-gradient-corrected, relativistic first-principles full-potential density-functional calculations performed on YBaMn2_2O5_5 in the nonmagnetic, ferromagnetic and ferrimagnetic states. The charge, orbital and spin orderings are explained with site-, angular momentum- and orbital-projected density of states, charge-density plots, electronic structure and total energy studies. YBaMn2_2O5_5 is found to stabilize in a G-type ferrimagnetic state in accordance with experimental results. The experimentally observed insulating behavior appears only when we include ferrimagnetic ordering in our calculation. We observed significant optical anisotropy in this material originating from the combined effect of ferrimagnetic ordering and crystal field splitting. In order to gain knowledge about the presence of different valence states for Mn in YBaMn2_2O5_5 we have calculated KK-edge x-ray absorption near-edge spectra for the Mn and O atoms. The presence of the different valence states for Mn is clearly established from the x-ray absorption near-edge spectra, hyperfine field parameters and the magnetic properties study. Among the experimentally proposed structures, the recently reported description based on PP4/nmmnmm is found to represent the stable structure
    corecore