3,495 research outputs found
A description of n-ary semigroups polynomial-derived from integral domains
We provide a complete classification of the n-ary semigroup structures
defined by polynomial functions over infinite commutative integral domains with
identity, thus generalizing G{\l}azek and Gleichgewicht's classification of the
corresponding ternary semigroups
Squeezed correlations of strange particle-antiparticles
Squeezed correlations of hadron-antihadron pairs are predicted to appear if
their masses are modified in the hot and dense medium formed in high energy
heavy ion collisions. If discovered experimentally, they would be an
unequivocal evidence of in-medium mass shift found by means of hadronic probes.
We discuss a method proposed to search for this novel type of correlation,
illustrating it by means of D_s-mesons with in-medium shifted masses. These
particles are expected to be more easily detected and identified in future
upgrades at RHIC.Comment: 6 pages, 3 figures with parts a) and b), SQM 2009 contribution; added
acknowledgmen
Solid weak BCC-algebras
We characterize weak BCC-algebras in which the identity is
satisfied only in the case when elements belong to the same branch
Scattering processes and resonances from lattice QCD
The vast majority of hadrons observed in nature are not stable under the
strong interaction, rather they are resonances whose existence is deduced from
enhancements in the energy dependence of scattering amplitudes. The study of
hadron resonances offers a window into the workings of quantum chromodynamics
(QCD) in the low-energy non-perturbative region, and in addition, many probes
of the limits of the electroweak sector of the Standard Model consider
processes which feature hadron resonances. From a theoretical standpoint, this
is a challenging field: the same dynamics that binds quarks and gluons into
hadron resonances also controls their decay into lighter hadrons, so a complete
approach to QCD is required. Presently, lattice QCD is the only available tool
that provides the required non-perturbative evaluation of hadron observables.
In this article, we review progress in the study of few-hadron reactions in
which resonances and bound-states appear using lattice QCD techniques. We
describe the leading approach which takes advantage of the periodic finite
spatial volume used in lattice QCD calculations to extract scattering
amplitudes from the discrete spectrum of QCD eigenstates in a box. We explain
how from explicit lattice QCD calculations, one can rigorously garner
information about a variety of resonance properties, including their masses,
widths, decay couplings, and form factors. The challenges which currently limit
the field are discussed along with the steps being taken to resolve them
Representations of -semigroups by multiplace functions
We describe the representations of -semigroups, i.e. groupoids with
binary associative operations, by partial -place functions and prove
that any such representation is a union of some family of representations
induced by Schein's determining pairs.Comment: 17 page
Time-odd components in the rotating mean field and identical bands
A systematic construction of the energy-density functional within the local density approximation is presented. The Hartree-Fock equations corresponding to such a functional are solved in case of rotating superdeformed nuclei. The identical bands in ^{152}Dy, ^{151}Tb, and ^{150}Gd are investigated and the time-odd components in the rotating mean field are analyzed
Representations of Menger -semigroups by multiplace functions
Investigation of partial multiplace functions by algebraic methods plays an
important role in modern mathematics were we consider various operations on
sets of functions, which are naturally defined. The basic operation for
-place functions is an -ary superposition , but there are some
other naturally defined operations, which are also worth of consideration. In
this paper we consider binary Mann's compositions \op{1},...,\op{n} for
partial -place functions, which have many important applications for the
study of binary and -ary operations. We present methods of representations
of such algebras by -place functions and find an abstract characterization
of the set of -place functions closed with respect to the set-theoretic
inclusion
Experimental Status of Exotic Mesons and the GlueX Experiment
One of the unanswered and most fundamental questions in physics regards the
nature of the confinement mechanism of quarks and gluons in QCD. Exotic hybrid
mesons manifest gluonic degrees of freedom and their spectroscopy will provide
the data necessary to test assumptions in lattice QCD and the specific
phenomenology leading to confinement. Within the past two decades a number of
experiments have put forth tantalizing evidence for the existence of exotic
hybrid mesons in the mass range below 2 GeV. This talk represents an overview
of the available data and what has been learned. In looking toward the future,
the GlueX experiment at Jefferson Laboratory represents a new initiative that
will perform detailed spectroscopy of the light-quark meson spectrum. This
experiment and its capabilities will be reviewed.Comment: 10 pages, 8 figures, 2nd Meeting of the APS Topical Group on Hadron
Physics GHP06, Nashville, TN (10/22-10/24/06
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