7 research outputs found
Vortex content of calorons and deconfinement mechanism
We reveal the center vortex content of SU(2) calorons and ensembles of them.
While one part of the vortex connects the constituent dyons of a single
caloron, another part is predominantly spatial and can be related to the twist
that exists in the caloron gauge field. The latter part depends strongly on the
caloron holonomy and degenerates to a plane between the dyons when the
asymptotic Polyakov loop is traceless. Correspondingly, the spatial vortex in
caloron ensembles is percolating in this case. This finding fits perfectly in
the confinement scenario of vortices and shows that calorons are suitable to
facilitate the vortex (de)confinement mechanism.Comment: talk given by FB at `Quark Confinement And The Hadron Spectrum IX',
Madrid, Sept. 2010; 3 pages; 7 figure
Searching for KvBLL calorons in SU(3) lattice gauge field ensembles
We discuss Kraan - van Baal - Lee - Lu (KvBLL) solutions of the classical
Yang-Mills equations with temperature in the context of SU(3) lattice gauge
theory. We present discretized lattice versions of KvBLL solutions and other
dyonic structures, obtained by cooling in order to understand their variety and
signature. An analysis of the zero modes of the lattice Dirac operator for
different fermionic boundary conditions gives clear evidence for a KvBLL-like
background of finite T lattice subensembles with Q = +/-1. Using APE-smearing
we are able to study the topological charge density q(x) of the configurations
and to corroborate this interpretation.Comment: Presented at LATTICE 2003 (topology) by C. Gattringer and E.M.
Ilgenfritz, 6 page
Dilepton production in proton-proton collisions at BEVALAC energies
The dilepton production in elementary reactions at
BEVALAC energies GeV is investigated. The calculations
include direct decays of the vector mesons , , and , Dalitz decays of the -, -, -, -, and -mesons, and of the baryon resonances
. The subthreshold vector meson production cross sections in
collisions are treated in a way sufficient to avoid double counting with the
inclusive vector meson production. The vector meson dominance model for the
transition form factors of the resonance Dalitz decays is
used in an extended form to ensure correct asymptotics which are in agreement
with the quark counting rules. Such a modification gives an unified and
consistent description of both radiative decays and meson decays.
The effect of multiple pion production on the experimental efficiency for the
detection of the dilepton pairs is studied. We find the dilepton yield in
reasonable agreement with the experimental data for the set of intermediate
energies whereas at the highest energy GeV the number of
dilepton pairs is likely to be overestimated experimentally in the mass range
MeV.Comment: 25 pages (IOP style), 5 figures, revised manuscript accepted for
publication in JP