651 research outputs found
The QCD String Spectrum and Conformal Field Theory
The low energy excitation spectrum of the critical Wilson surface is
discussed between the roughening transition and the continuum limit of lattice
QCD. The fine structure of the spectrum is interpreted within the framework of
two-dimensional conformal field theory.Comment: Lattice2001 (confinement),3 pages,1 figure,uses espcrc2.st
Spin-String Interaction in QCD Strings
I consider the question of the interaction between a QCD string and the spin
of a quark or an antiquark on whose worldline the string terminates. The
problem is analysed from the point of view of a string representation for the
expectation value of a Wilson loop for a spin-half particle. A string
representation of the super Wilson loop is obtained starting from an effective
string representation of a Wilson Loop. The action obtained in this manner is
invariant under a worldline supersymmetry and has a boundary term which
contains the spin-string interaction. For rectangular loops the spin-string
interaction vanishes and there is no spin-spin term in the resulting heavy
quark potential. On the other hand if an allowance is made for the finite
intrinsic thickness of the flux-tube, by assuming that the spin-string
interaction takes place not just at the boundary of the string world-sheet but
extends to a distance of the order of the intrinsic thickness of the flux tube,
then we do obtain a spin-spin interaction which falls as the fifth power of the
distance. Such a term was previously suggested by Kogut and Parisi in the
context of a flux-tube model of confinement.Comment: 19 pages, 1 figure; Published version with added discussion and
references in section
Application of a rule-based knowledge system using CLIPS for the taxonomy of selected Opuntia species
A rule based knowledge system was developed in CLIPS (C Language Integrated Production System) for identifying Opuntia species in the family Cactaceae, which contains approx. 1500 different species. This botanist expert tool system is capable of identifying selected Opuntia plants from the family level down to the species level when given some basic characteristics of the plants. Many plants are becoming of increasing importance because of their nutrition and human health potential, especially in the treatment of diabetes mellitus. The expert tool system described can be extremely useful in an unequivocal identification of many useful Opuntia species
High-Precision Thermodynamics and Hagedorn Density of States
We compute the entropy density of the confined phase of QCD without quarks on
the lattice to very high accuracy. The results are compared to the entropy
density of free glueballs, where we include all the known glueball states below
the two-particle threshold. We find that an excellent, parameter-free
description of the entropy density between 0.7Tc and Tc is obtained by
extending the spectrum with the exponential spectrum of the closed bosonic
string.Comment: 4 pages, 3 figure
Excitations of torelon
The excitations of gluonic flux tube in a periodic lattice are examined.
Monte Carlo simulations from an anisotropic lattice are presented and the
comparison with effective string models is discussed.Comment: Talk at Lattice 2003; 3 pages, 4 figure
IT background of the medium-term storage of Martonvásár Cereal Genebank resources in phytotron cold rooms
Genebanks are storage facilities designed to maintain the plant genetic resources of
crop varieties (and their wild relatives) and to ensure that they are made available and
distributed for use by plant breeders, researchers and farmers. The Martonvásár Cereal
Genebank (MV-CGB) collection evolved from the working collections of local breeders
and consists predominantly of local and regional materials. Established in 1992 by the
Agricultural Research Institute of the Hungarian Academy of Sciences (Bedő, 2009), MVCGB
with its over 10,000 accessions of the major species (Triticum, Aegilops, Agropyron,
Elymus, Thinopyrum, Pseudoroegneria, Secale, Hordeum, Avena, Zea mays), became one
of the approx. 80 cereal germplasm collections that exist globally. In Martonvásár
breeding is underway on a number of cereal species, and large numbers of genotypes are
tested each year in the field and under laboratory conditions. The increasing size of the
research programmes assisted by a modern genebank background involve an enormous
increase in the quantity of data that must be handled during research activities such as
traditional breeding, pre-breeding and organic breeding. A computerized system is of
primary importance to synchronize breeding and genebank activities, to monitor the
quality and quantity of seed accessions in cold storage, to assist the registration of samples,
and to facilitate characterization, regeneration and germplasm distribution
A study of hybrid quarkonium using lattice QCD
The hybrid quarkonium states are studied using the Born-Oppenheimer
expansion. The first step in this expansion is the determination of the energy
levels of the gluons in the presence of a static quark-antiquark pair as a
function of the quark-antiquark separation. The spectrum of such gluonic
excitations is determined from first principles using lattice QCD.Comment: to appear in Proceedings of HADRON97, BNL, August 1997, edited by
S.U. Chung, AIP press; 4 pages, Latex, uses aipproc.sty, 2 postscript figure
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