6,219 research outputs found
Brown-Rho Scaling in the Strong Coupling Lattice QCD
We examine the Brown-Rho scaling for meson masses in the strong coupling
limit of lattice QCD with one species of staggered fermion. Analytical
expression of meson masses is derived at finite temperature and chemical
potential. We find that meson masses are approximately proportional to the
equilibrium value of the chiral condensate, which evolves as a function of
temperature and chemical potential.Comment: Prepared for Chiral Symmetry in Hadron and Nuclear Physics
(Chiral07), Nov. 13-16, 2007, Osaka, Japa
N=2 Supersymmetric Model with Dirac-Kahler Fermions from Generalized Gauge Theory in Two Dimensions
We investigate the generalized gauge theory which has been proposed
previously and show that in two dimensions the instanton gauge fixing of the
generalized topological Yang-Mills action leads to a twisted N=2 supersymmetric
action. We have found that the R-symmetry of N=2 supersymmetry can be
identified with the flavour symmetry of Dirac-Kahler fermion formulation. Thus
the procedure of twist allows topological ghost fields to be interpreted as the
Dirac-Kahler matter fermions.Comment: 22 pages, LaTe
The bosonic string and superstring models in 26+2 and 10+2 dimensional space--time, and the generalized Chern-Simons action
We have covariantized the Lagrangians of the U(1)_V * U(1)_A models, which
have U(1)_V * U(1)_A gauge symmetry in two dimensions, and studied their
symmetric structures. The special property of the U(1)_V * U(1)_A models is the
fact that all these models have an extra time coordinate in the target
space-time. The U(1)_V * U(1)_A models coupled to two-dimensional gravity are
string models in 26+2 dimensional target space-time for bosonic string and in
10+2 dimensional target space-time for superstring. Both string models have two
time coordinates. In order to construct the covariant Lagrangians of the U(1)_V
* U(1)_A models the generalized Chern-Simons term plays an important role. The
supersymmetric generalized Chern-Simons action is also proposed. The
Green-Schwarz type of U(1)_V * U(1)_A superstring model has another fermionic
local symmetry as well as \kappa-symmetry. The supersymmetry of target
space-time is different from the standard one.Comment: 27 pages, no figure
Generalized Gauge Theories and Weinberg-Salam Model with Dirac-K\"ahler Fermions
We extend previously proposed generalized gauge theory formulation of
Chern-Simons type and topological Yang-Mills type actions into Yang-Mills type
actions. We formulate gauge fields and Dirac-K\"ahler matter fermions by all
degrees of differential forms. The simplest version of the model which includes
only zero and one form gauge fields accommodated with the graded Lie algebra of
supergroup leads Weinberg-Salam model. Thus the Weinberg-Salam model
formulated by noncommutative geometry is a particular example of the present
formulation.Comment: 33 pages, LaTe
Lattice supersymmetry in 1D with two supercharges
A consistent formulation of a fully supersymmetric theory on the lattice has
been a long standing challenge. In recent years there has been a renewed
interest on this problem with different approaches. At the basis of the
formulation we present in the following there is the Dirac-Kahler twisting
procedure, which was proposed in the continuum for a number of theories,
including N=4 SUSY in four dimensions. Following the formalism developed in
recent papers, an exact supersymmetric theory with two supercharges on a one
dimensional lattice is realized using a matrix-based model. The matrix
structure is obtained from the shift and clock matrices used in two dimensional
non-commutative field theories. The matrix structure reproduces on a one
dimensional lattice the expected modified Leibniz rule. Recent claims of
inconsistency of the formalism are discussed and shown not to be relevant.Comment: 14 pages, Presented by SA and AD at the XXV International Symposium
on Lattice Field Theory, July 30 - August 4 2007, Regensburg, German
Dirac-Kaehler fermion with noncommutative differential forms on a lattice
Noncommutativity between a differential form and a function allows us to
define differential operator satisfying Leibniz's rule on a lattice. We propose
a new associative Clifford product defined on the lattice by introducing the
noncommutative differential forms. We show that this Clifford product naturally
leads to the Dirac-K\"ahler fermion on the lattice.Comment: 3 pages, Lattice2003(Theoretical Development
Recursive sampling simulations of 3D gravity coupled to scalar fermions
We study numerically the phase structure of a model of 3D gravity interacting
with scalar fermions. We measure the 3D counterpart of the "string"
susceptibility exponent as a function of the inverse Newton coupling .
We show that there are two phases separated by a critical point around
. The numerical results support the hypothesis that the
phase structures of 3D and 2D simplicial gravity are qualitatively similar, the
inverse Newton coupling in 3D playing the role of the central charge of matter
in 2D.Comment: Latex with 6 figure files, 17 page
Transfer Matrix Formalism for Two-Dimensional Quantum Gravity and Fractal Structures of Space-time
We develop a transfer matrix formalism for two-dimensional pure gravity. By
taking the continuum limit, we obtain a "Hamiltonian formalism'' in which the
geodesic distance plays the role of time. Applying this formalism, we obtain a
universal function which describes the fractal structures of two dimensional
quantum gravity in the continuum limit.Comment: 13 pages, 5 figures, phyzz
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