2,292,562 research outputs found
Strange particle production in a single-freeze-out model
The transverse-momentum spectra and elliptic flow of strange particles are
calculated in the framework of the single-freeze-out model and compared with
the recent RHIC data. An overall very good agreement between the model
predictions and the data is obtained.Comment: talk presented by WF during the VIIIth Int. Conf. on Strangeness in
Quark Matter, Cape Town, Sept. 15-20, 200
Trions in a periodic potential
The group-theoretical classification of trion states is presented. It is
based on considerations of products of irreducible representations of the 2D
translation group. For a given BvK period N degeneracy of obtained states is
N^2. Trions consist of two identical particles so the symmetrization of states
with respect to particles transposition is considered. Completely antisymmetric
states can be constructed by introducing antisymmetric spin functions. Two
symmetry adapted bases are considered. The third possibility is postponed for
the further investigations.Comment: revtex, 5 p., sub. to Physica
Connecting structure functions on the lattice with phenomenology
We examine the extraction of moments of parton distributions from lattice
data, focusing in particular on the chiral extrapolation as a function of the
quark mass. Inclusion of the correct chiral behavior of the spin-averaged
isovector distribution resolves a long-standing discrepancy between the lattice
moments and experiment. We extract the x-dependence of the valence u-d
distribution from the lowest few lattice moments, and discuss the implications
for the quark mass dependence of meson masses lying on the rho Regge
trajectory. The role of chiral symmetry in spin-dependent distributions, and in
particular the lattice axial vector charge, g_A, is also highlighted.Comment: 8 pages, 5 figures, plenary talk given by W. Melnitchouk at the 3rd
Circum-Pan-Pacific Symposium on High Energy Spin Physics (Beijing, China,
October 2001), to appear in Int. J. Mod. Phys.
Parton distributions from lattice QCD
We extract the x dependence of the nonsinglet u-d distribution function in
the nucleon from the lowest few moments calculated on the lattice, using an
extrapolation formula which ensures the correct behavior in the chiral and
heavy quark limits. We discuss the implications for the quark mass dependence
of meson masses lying on the J(PC)=1(--) Regge trajectory.Comment: 18 pages, 6 figures, minor changes made for publicatio
Deep inelastic scattering from light nuclei
We review recent developments in the study of deep inelastic scattering from
light nuclei, focusing in particular on deuterium, helium, and lithium.
Understanding the nuclear effects in these systems is essential for the
extraction of information on the neutron structure function.Comment: 11 pages, 5 figures; talk given by W. Melnitchouk at the Workshop on
Testing QCD through Spin Observables in Nuclear Targets, University of
Virginia, April 200
1973 Evaluations of Some Pesticide Residues in Food: The Monographs. Food and Agriculture Organization of the United Nations, Rome, 1975. 491 p. Available from Unipub, Box 433, Murray Hill Station, New York, NY 10016. $15.00.
(excerpt)
The evaluations of residues on foodstuffs contained in these monographs were prepared by a joint meeting of an FA0 expert committee and a WHO expert committee on pesticide residues that met in Geneva and produced its report Pesticide Residues in Food published as WHO Technical Report Series No. 545 and FA0 Agricultural Studies No. 92 in 1974. Th
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