586 research outputs found
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
The Heavy Hybrid Spectrum from NRQCD and the Born-Oppenheimer Approximation
The spectrum of heavy-quark hybrids is studied in the leading
Born-Oppenheimer (LBO) approximation and using leading-order NRQCD simulations
with an improved gluon action on anisotropic lattices. The masses of four
hybrid states are obtained from our simulations for lattice spacings 0.1 fm and
0.2 fm and are compared to the LBO predictions obtained using
previously-determined glue-excited static potentials. The consistency of
results from the two approaches reveals a compelling physical picture for
heavy-quark hybrid states.Comment: LATTICE99(Heavy Quarks),3 pages,2 figures,uses espcrc2.st
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
Coulomb energy and gluon distribution in the presence of static sources
We compute the energy of the ground state and a low lying excitation of the
gluonic field in the presence of static quark -anti-quark (\qq) sources. We
show that for separation between the sources less then a few fm the gluonic
ground state of the static \qq system can be well described in terms of a
mean field wave functional with the excited states corresponding to a single
quasi-particle excitation of the gluon field. We also discuss the role of many
particle excitations relevant for large separation between sources.Comment: 14 pages, 11 figure
[NASA Johnson Space Center Co-Op Student, David Juge, Exit Presentation]
My primary tasks for my second tour here at JSC were working with an Augmented Reality Project and also constructing a Dodecahedron Speaker
Multi-hadron states in Lattice QCD spectroscopy
The ability to reliably measure the energy of an excited hadron in Lattice
QCD simulations hinges on the accurate determination of all lower-lying
energies in the same symmetry channel. These include not only single-particle
energies, but also the energies of multi-hadron states. This talk deals with
the determination of multi-hadron energies in Lattice QCD. The
group-theoretical derivation of lattice interpolating operators that couple
optimally to multi-hadron states is described. We briefly discuss recent
algorithmic developments which allow for the efficient implementation of these
operators in software, and present numerical results from the Hadron Spectrum
Collaboration.Comment: 5 pages, 3 figures, talk given at Hadron 2009, Tallahassee, Florida,
December 1, 200
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