7,129 research outputs found
Taxonomy and Ecology of the Inconnu, Stenodus Leucichthys Nelma, in Alaska
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
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
Three charged particles in the continuum. Astrophysical examples
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 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 which take place as a step of
-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
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
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
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
- …
