2,988 research outputs found
Quantum Fluctuations of Particles and Fields in Smooth Path Integrals
An approach to evaluation of the smooth Feynman path integrals is developed
for the study of quantum fluctuations of particles and fields in Euclidean
time-space. The paths are described by sum of Gauss functions and are weighted
with exp(-S) by appropriate methods. The weighted smooth paths reproduce
properties of the ground state of the harmonic oscillator in one dimension with
high accuracy. Quantum fluctuations of U(1) and SU(2) gauge fields in four
dimensions are also evaluated in our approach.Comment: 4 pages, 1 figure, talk given at the 12th Asia Pacific Physics
Conference of AAPPS (APPC12), Makuhari, Japan, 14-19 July 201
Framework for non-perturbative analysis of a Z(3)-symmetric effective theory of finite temperature QCD
We study a three dimensional Z(3)-symmetric effective theory of high
temperature QCD. The exact lattice-continuum relations, needed in order to
perform lattice simulations with physical parameters, are computed to order
O(a^0) in lattice perturbation theory. Lattice simulations are performed to
determine the phase structure of a subset of the parameter space.Comment: 28 pages, 11 figures; v3: references rearranged, typos corrected,
figs changed, published versio
Lattice analysis for the energy scale of QCD phenomena
We formulate a new framework in lattice QCD to study the relevant energy
scale of QCD phenomena. By considering the Fourier transformation of link
variable, we can investigate the intrinsic energy scale of a physical quantity
nonperturbatively. This framework is broadly available for all lattice QCD
calculations. We apply this framework for the quark-antiquark potential and
meson masses in quenched lattice QCD. The gluonic energy scale relevant for the
confinement is found to be less than 1 GeV in the Landau or Coulomb gauge.Comment: 4 pages, 4 figure
Classes of confining gauge field configurations
We present a numerical method to compute path integrals in effective SU(2)
Yang-Mills theories. The basic idea is to approximate the Yang-Mills path
integral by summing over all gauge field configurations, which can be
represented as a linear superposition of a small number of localized building
blocks. With a suitable choice of building blocks many essential features of
SU(2) Yang-Mills theory can be reproduced, particularly confinement. The
analysis of our results leads to the conclusion that topological charge as well
as extended structures are essential elements of confining gauge field
configurations.Comment: 18 pages, 16 figures, several sections adde
Lattice energy sum rule and the trace anomaly
We show that the additional contribution to the Michael lattice energy sum rule pointed out recently, can be identified with the contribution to the field energy of a quark-antiquark pair arising from the trace anomaly of the energy momentum tensor
Stability of the pentaquark in a naive string model
The pentaquark is studied in a simple model of confinement where the quarks
and the antiquark are linked by flux tubes of minimal cumulated length, and the
Coulomb-like interaction, the spin-dependent terms and the antisymmetrization
constraints are neglected.. The ground-state is found to be stable against
spontaneous dissociation into a meson and a baryon, both in the case of five
equal-mass constituents and for a static quark or antiquark surrounded by four
equal masses.Comment: 8 pages, 2 figures, minor corrections, references added, to appear in
Phys. Rev.
Lattice oscillator model, scattering theory and a many-body problem
We propose a model for the quantum harmonic oscillator on a discrete lattice
which can be written in supersymmetric form, in contrast with the more direct
discretization of the harmonic oscillator. Its ground state is easily found to
be annihilated by the annihilation operator defined here, and its excitation
spectrum is obtained numerically. The versatility of the model is then used to
calculate, in a simple way, the generalized position-dependent scattering
length for a particle colliding with a single static impurity in a periodic
potential and the exact ground state of an interacting many-body problem in a
one-dimensional ring.Comment: 3 Figures. Version accepted in J. Phys.
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