7,591 research outputs found
Phase structure of Abelian Chern-Simons gauge theories
We study the effect of a Chern-Simons (CS) term in the phase structure of two
different Abelian gauge theories. For the compact Maxwell-Chern-Simons theory,
we obtain that for values of the CS coupling with ,
the theory is equivalent to a gas of closed loops with contact interaction,
exhibiting a phase transition in the universality class. We also employ
Monte Carlo simulations to study the noncompact U(1) Abelian Higgs model with a
CS term. Finite size scaling of the third moment of the action yields critical
exponents and that vary continuously with the strength of the CS
term, and a comparison with available analytical results is made.Comment: RevTex4, 4 pages, 1 figure; v3: improvements and corrections made in
the first part of the paper; references added. To be published in Europhysics
Letter
Compact U(1) gauge theories in 2+1 dimensions and the physics of low dimensional insulating materials
Compact abelian gauge theories in dimensions arise often as an
effective field-theoretic description of models of quantum insulators. In this
paper we review some recent results about the compact abelian Higgs model in
in that context.Comment: 5 pages, 3 figures; based on talk by F.S. Nogueira in the Aachen
HEP2003 conferenc
Ground State of the Hydrogen Atom via Dirac Equation in a Minimal Length Scenario
In this work we calculate the correction to the ground state energy of the
hydrogen atom due to contributions arising from the presence of a minimal
length. The minimal length scenario is introduced by means of modifying the
Dirac equation through a deformed Heisenberg algebra (kempf algebra). With the
introduction of the Coulomb potential in the new Dirac energy operator, we
calculate the energy shift of the ground state of the hydrogen atom in first
order of the parameter related to the minimal length via perturbation theory.Comment: 11 page
Solving the three-body bound-state Bethe-Salpeter equation in Minkowski space
The scalar three-body Bethe-Salpeter equation, with zero-range interaction,
is solved in Minkowski space by direct integration of the four-dimensional
integral equation. The singularities appearing in the propagators are treated
properly by standard analytical and numerical methods, without relying on any
ansatz or assumption. The results for the binding energies and transverse
amplitudes are compared with the results computed in Euclidean space. A fair
agreement between the calculations is found.Comment: 10 pages, 2 figures, version accepted for publication in Phys. Lett.
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