7,129 research outputs found

    Taxonomy and Ecology of the Inconnu, Stenodus Leucichthys Nelma, in Alaska

    Get PDF
    A taxonomic and life history study of the inconnu was carried out on populations from the Kobuk, Chatanika, and upper Yukon Rivers, and Selawik, Alaska. Data on 24 morphological measurements and 11 meristic counts show little difference among: 1) males and females; 2) young and older inconnu; and 3) fish from the upper Yukon River, Chatanika River, Selawik, and Kobuk River in Alaska and the Ob River, USSR. Based on close agreement of these counts and measurements, the inconnu in Alaska is designated as Stenodus leufifhthys nelma (Pallas). For arctic fish, the inconnu exhibits a rapid growth rate. Growth rates for males and females are similar, but females live longer than males. Alaskan inconnu become sexually mature quite late in life (for Selawik males, 9 years; females, 10 years). Spawning behavior is described. Spawning occurred in the Kobuk River above Kobuk the last days of September at water temperatures betwen 1/4 and 4.6 C. Older inconnu are mainly piscivorous while the younger fish feed on invertebrates and fish. The least cisco, Coregonus sardinella, was the main food item of the Selawik inconnu. The estimated catch in Northwest Alaska in 1965 was between 34,200 and 37,000 fish, 85% of which were taken for subsistence

    New results from fluctuation analysis in NA49 at the CERN SPS

    Full text link
    The exploration of the phase diagram of strongly interacting matter, particularly the study of the phase transition from hadronic to partonic matter and the search for a hypothetical critical endpoint of the first order transition line, is one of the most challenging tasks in present heavy ion physics. In this talk new results on chemical (particle ratio), transverse momentum, multiplicity and azimuthal angle fluctuations will be presented. We also discuss their connection to the onset of deconfinement and to the critical endpoint.Comment: The Proceedings of the International Conference "Critical Point and Onset of Deconfinement - CPOD 2011", Wuhan, November 7-11, 201

    Benchmarks and implementation of the ALICE high level trigger

    Get PDF

    Three charged particles in the continuum. Astrophysical examples

    Full text link
    We suggest a new adiabatic approach for description of three charged particles in the continuum. This approach is based on the Coulomb-Fourier transformation (CFT) of three body Hamiltonian, which allows to develop a scheme, alternative to Born-Oppenheimer one. The approach appears as an expansion of the kernels of corresponding integral transformations in terms of small mass-ratio parameter. To be specific, the results are presented for the system ppeppe in the continuum. The wave function of a such system is compared with that one which is used for estimation of the rate for triple reaction p+p+ed+ν, p+p+e\to d+\nu, which take place as a step of pppp-cycle in the center of the Sun. The problem of microscopic screening for this particular reaction is discussed

    Possible formulations for three-charged particles correlations in terms of Coulomb wave functions

    Full text link
    The recent data for Bose-Einstein Correlations (BEC) of three-charged particles obtained by NA44 Collaboration have been analysed using theoretical formula with Coulomb wave functions. It has been recently proposed by Alt et al. It turns out that there are discrepancies between these data and the respective theoretical values. To resolve this problem we seek a possibly modified theoretical formulation of this problem by introducing the degree of coherence for the exchange effect due to the BEC between two-identical bosons. As a result we obtain a modified formulation for the BEC of three-charged particles showing good agreement with the data. Moreover, we investigate physical connection between our modified formulation and the core-halo model proposed by Csorgo et al. Our study indicates that the interaction region estimated by the BEC of three-charged particles in the S + Pb collisions at 200 GeV/c per nucleon is equal to about 1.5 fm~1.8 fm.Comment: 15 pages, 7 postscript figures, with addendu

    System Size Dependence of Particle Production at the SPS

    Full text link
    Recent results on the system size dependence of net-baryon and hyperon production as measured at the CERN SPS are discussed. The observed Npart dependences of yields, but also of dynamical properties, such as average transverse momenta, can be described in the context of the core corona approach. Other observables, such as antiproton yields and net-protons at forward rapidities, do not follow the predictions of this model. Possible implications for a search for a critical point in the QCD phase diagram are discussed. Event-by-event fluctuations of the relative core to corona source contributions might influence fluctuation observables (e.g. multiplicity fluctuations). The magnitude of this effect is investigated.Comment: 10 pages, 4 figurs. Proceedings of the 6th International Workshop on Critical Point and Onset of Deconfinement in Dubna, Aug. 201

    Bose Einstein Condensate in a Box

    Full text link
    Bose-Einstein condensates have been produced in an optical box trap. This novel optical trap type has strong confinement in two directions comparable to that which is possible in an optical lattice, yet produces individual condensates rather than the thousands typical of a lattice. The box trap is integrated with single atom detection capability, paving the way for studies of quantum atom statistics.Comment: 4 pages, 5 figure
    corecore