50 research outputs found
Low Dimensional Ordering on a Lattice Model
A simple d-dimensional lattice model is proposed, incorporating some degree
of frustration and thus capable of describing some aspects of molecular
orientation in covalently bound molecular solids. For d=2 the model is shown to
be equivalent to the standard two-dimensional Ising model, while for d>2 it
describes a peculiar transition from an isotropic high temperature phase to a
low-dimensional anisotropic low temperature state. A general mean field
analysis is presented and compared to some exact limit properties.Comment: 11 pages, 2 PostScript figures, to appear in Phys. Lett.
The Dark Side of the Propagators: exploring their analytic properties by a massive expansion
Analytical functions for the propagators of QCD, including a set of chiral
quarks, are derived by a one-loop massive expansion in the Landau gauge, and
are studied in Minkowski space, yielding a direct proof of positivity violation
and confinement from first principles. Complex conjugated poles are found for
the gluon propagator.Comment: XIIth Quark Confinement & the Hadron Spectru