857 research outputs found
Evaluating fuzzy inequalities and solving fully fuzzified linear fractional programs
In our earlier articles, we proposed two methods for solving the fully fuzzified linear fractional programming (FFLFP) problems. In this paper, we introduce a different approach of evaluating fuzzy inequalities between two triangular fuzzy numbers and solving FFLFP problems. First, using the Charnes-Cooper method, we transform the linear fractional programming problem into a linear one. Second, the problem of maximizing a function with triangular fuzzy value is transformed into a problem of deterministic multiple objective linear programming. Illustrative numerical examples are given to clarify the developed theory and the proposed algorithm
k-String tensions and the 1/N expansion
We address the question of whether the large-N expansion in pure SU(N) gauge
theories requires that k-string tensions must have a power series expansion in
1/N^2, as in the sine law, or whether 1/N contributions are also allowable, as
in Casimir scaling. We find that k-string tensions may, in fact, have 1/N
corrections, and consistency with the large-N expansion in the open-string
sector depends crucially on an exact cancellation, which we will prove, among
terms involving odd powers of 1/N in particular combinations of Wilson loops.
It is shown how these cancellations are fulfilled, and consistency with the
large-N expansion achieved, in a concrete example, namely, strong-coupling
lattice gauge theory with the heat-kernel action. This is a model which has
both a 1/N^2 expansion and Casimir scaling of the k-string tensions. Analysis
of the closed string channel in this model confirms our conclusions, and
provides further insights into the large-N dependence of energy eigenstates and
eigenvalues.Comment: RevTeX4, 21 pages. Typos corrected, references added, some
discussions expanded; conclusions unchanged. Version to appear on PR
On a three-body confinement force in hadron spectroscopy
Recently it has been argued that a three-body colour confinement interaction
can affect the stability condition of a three-quark system and the spectrum of
a tetraquark described by any constituent quark model. Here we discuss the role
of a three-body colour confinement interaction in a simple quark model and
present some of its implications for the spectra of baryons, tetraquarks and
six-quark systems.Comment: 19 pages (RevTeX), addition of new material regarding the NN
interaction, more accurate discussion of the baryonic case, accepted for
publication in Phys. Rev.
Pentaquarks in string dynamics
The masses of , , and pentaquarks are
evaluated in a framework of both the Effective Hamiltonian approach to QCD and
spinless Salpeter using the Jaffe-Wilczek diquark approximation and the string
interaction for the diquark-diquark-antiquark system. The masses of the light
pentaquarks are found to be in the region above 2 GeV. The similar calculations
yield the mass of pentaquark 3250 MeV and
pentaquark 6509 MeV.Comment: 5 pages. Based on talk by I.M.Narodetskii at BEACH 2004, 6th
International Conference on Hyperons, Charm and Beauty Hadrons, Illionois
Institute of Technology, Chicago, June. 27 - July 3, 2004. Typos correcte
A (p/E) Calculation of Strong Pionic Decays of Baryons
Strong pionic decays of baryons are studied in a non-relativistic quark model
framework via a convergent (p/E) expansion of the transition operator. Results
are compared to the ones obtained within a more conventional (p/m) expansion.Comment: 16 pages, LaTeX, using amssymb.st
Determinants of meal satisfaction in a workplace environment
To access publisher's full text version of this article click on the hyperlink at the bottom of the pageWorkplace lunches are recurrent meal occasions that can contribute to the general well-being of employees. The objective of our research was to study which factors influence consumers' satisfaction with these meals by exploring the relative role of food-related, personal, situational factors. Using a longitudinal approach, we monitored a total of 71 participants compiled and experienced 519 meals from their workplace canteen buffet during a three-month period; in addition the composed lunches were photographed. Before and after the lunch choice period respondents filled in a questionnaire on several meal-related variables. A mixed modelling approach was used to analyse the data. Meal satisfaction was directly associated with a positive ambience and a positive evaluation of both the quality of the food eaten and the buffet assortment, whereas the meal's energy content did not contribute to meal satisfaction. Additionally, meal satisfaction was associated with a more positive mood, lower hunger level as well as feeling less busy and stressed after lunch. The buffet assortment, a more positive mood before lunch and mindful eating contributed to the perceived food quality, but not associated with the hunger level before lunch. Time available, mindful eating and eating with close colleagues were positively associated with perceived ambience. The results indicate that consumers' satisfaction with workplace meals can be increased by putting emphasis on the quality of food served, but equally important is the ambience in the lunch situation. Most of the ambience factors were related to available time and mental resources of the participants and the possibility to share the meal with close colleagues. These are factors that can be facilitated by the service provider, but not directly influenced.Senswell project, Innovation Fund Denmark/0603-00418
Charmed Exotics in Heavy Ion Collisions
Based on the color-spin interaction in diquarks, we argue that charmed
multiquark hadrons are likely to exist. Because of the appreciable number of
charm quarks produced in central nucleus-nucleus collisions at
ultrarelativistic energies, production of charmed multiquark hadrons is
expected to be enhanced in these collisions. Using both the quark coalescence
model and the statistical hadronization model, we estimate the yield of charmed
tetraquark meson and pentaquark baryon in heavy ion
collisions at RHIC and LHC. We further discuss the decay modes of these charmed
exotic hadrons in order to facilitate their detections in experiments
MiniBooNE
The physics motivations, design, and status of the Booster Neutrino
Experiment at Fermilab, MiniBooNE, are briefly discussed. Particular emphasis
is given on the ongoing preparatory work that is needed for the MiniBooNE muon
neutrino to electron neutrino oscillation appearance search. This search aims
to confirm or refute in a definitive and independent way the evidence for
neutrino oscillations reported by the LSND experiment.Comment: 3 pages, no figures, to appear in the proceedings of the 9th
International Conference on Astroparticle and Underground Physics (TAUP
2005), Zaragoza, Spain, 10-14 Sep 200
Hysteretic properties of a magnetic particle with strong surface anisotropy
We study the influence of surface anisotropy on the zero-temperature
hysteretic properties of a small single-domain magnetic particle, and give an
estimation of the anisotropy constant for which deviations from the
Stoner-Wohlfarth model are observed due to non-uniform reversal of the
particle's magnetisation. For this purpose, we consider a spherical particle
with simple cubic crystalline structure, a uniaxial anisotropy for core spins
and radial anisotropy on the surface. The hysteresis loop is obtained by
solving the local (coupled) Landau-Lifschitz equations for classical spin
vectors. We find that when the surface anisotropy constant is at least of the
order of the exchange coupling, large deviations are observed with respect to
the Stoner-Wohlfarth model in the hysteresis loop and thereby the
limit-of-metastability curve, since in this case the magnetisation reverses its
direction in a non-uniform manner via a progressive switching of spin clusters.
In this case the critical field, as a function of the particle's size, behaves
as observed in experiments.Comment: 12 pages, 15 eps figure
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