2,043 research outputs found
Confining properties of 2-color QCD at finite density
We study the confining properties of QCD with two colors across the finite
density phase transition. A disorder parameter detecting dual superconductivity
of the QCD vacuum is used as a probe for the confinement/deconfinement phase
transition.Comment: 7 pages, 3 figures, talk presented at Lattice 2006 (High Temperature
and Density
Topological susceptibility at zero and finite in SU(3) Yang-Mills theory
We determine the topological susceptibility at T=0 in pure SU(3) gauge
theory and its behaviour at finite across the deconfining transition. We
use an improved topological charge density operator. drops sharply by
one order of magnitude at the deconfining temperature .Comment: Recently appeared erratum added as an "Appendix" to the original
pape
Order, Disorder and Confinement
Studying the order of the chiral transition for is of fundamental
importance to understand the mechanism of color confinement. We present results
of a numerical investigation on the order of the transition by use of a novel
strategy in finite size scaling analysis. The specific heat and a number of
susceptibilities are compared with the possible critical behaviours. A second
order transition in the O(4) and O(2) universality classes are excluded.
Substantial evidence emerges for a first order transition. Results are in
agreement with those found by studying the scaling properties of a disorder
parameter related to the dual superconductivity mechanism of color confinement.Comment: 7 pages, 11 figures. Talk given at the International Workshop on
Quantum Chromodynamics: QCD@Work 2005, Conversano, Italy, 16-20 June 200
Hie-Isolde High Beta Cavity Study and Measurements
The upgrade of the ISOLDE machine at CERN foresees a superconducting linac
based on two gap independently phased Nb sputtered Quarter Wave Resonators
(QWRs) working at 101.28MHz and producing an accelerating field of 6MV/m on
axis. A careful study of the fields in the cavity has been carried out in order
to pin down the crucial e-m parameters of the structure such as peak fields,
quality factor and e-m power dissipated on the cavity wall. A tuning system
with about 200kHz frequency range has been developed in order to cope with
fabrication tolerances. In this paper we will report on the cavity simulations.
The tuning plate design will be described. Finally the frequency measurements
on a cavity prototype at room temperature will be presented.Comment: 5 pages, SRF09 Conference in Berli
Topological susceptibility through the deconfining phase transition
We present a measurement of the topological susceptibility in SU(3)
Yang-Mills theory through the deconfinement phase transition. An improved
operator is used for the topological charge density. A drop by an order of
magnitude is observed from the confined to the deconfined phase.Comment: Talk presented at LATTICE96(topology). 3 pages, 2 postscript figures,
uses espcrc2.sty include
QCD, monopoles on the Lattice and gauge invariance
The number and the location of the monopoles observed on the lattice in QCD
configurations happens to depend strongly on the choice of the gauge used to
expose them, in contrast to the physical expectation that monopoles be gauge
invariant objects. It is proved by use of the non abelian Bianchi identities
(NABI) that monopoles are indeed gauge invariant, but the method used to detect
them depends, in a controllable way, on the choice of the abelian projection.
Numerical checks are presented.Comment: 3 pages, 1 figure. Presented at the Conference QUARK CONFINEMENT AND
THE HADRON SPECTRUM IX, Madrid Aug.30-Sept.3 201
The chiral transition in two-flavor QCD
QCD with N_f=2 is a specially interesting system to investigate the chiral
transition. The order of the transition has still not been established. We
report the results of an in-depth numerical investigation performed with
staggered fermions on lattices with L_t=4 and L_s=12,16,20,24,32 and quark
masses am_q ranging from 0.01335 to 0.307036. Using finite-size techniques we
compare the scaling behavior of a number of thermodynamical susceptibilities
with the expectations of O(4) and O(2) universality classes. Clear disagreement
is observed. Indications of a first order transition are found.Comment: 6 pages, 4 figures, PoS style. Talk presented at Lattice 2005
(Nonzero temperature and density), Dublin, Ireland, July 25-3
Topological properties of QCD with two dynamical fermions
We investigate the topological susceptibility of the QCD vacuum with two
flavours of dynamical staggered fermions on the lattice both at zero and finite
temperature. At zero temperature we study the dependence of the signal on the
fermion mass and at finite temperature we analyze the behaviour across the
phase transition.Comment: LATTICE99(finite temperature and density). 3 pages, contains
espcrc2.sty fil
Analytical continuation from imaginary to real chemical potential in 2-color QCD under scrutiny
The method of analytical continuation from imaginary to real chemical
potential is tested in 2-color QCD. In comparison to previous studies in the
same theory, an exact updating algorithm is used and simulations are performed
closer to the thermodynamic limit. It is shown that the method considerably
improves if suitable functions are used to interpolate data with imaginary
chemical potential.Comment: 7 pages, 5 figures, Lattice 2006 (High Temperature and Density
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