400 research outputs found
On the Low-Energy Effective Action of N=2 Supersymmetric Yang-Mills Theory
We investigate the perturbative part of Seiberg's low-energy effective action
of N=2 supersymmetric Yang-Mills theory in Wess-Zumino gauge in the
conventional effective field theory technique. Using the method of constant
field approximation and restricting the effective action with at most two
derivatives and not more than four-fermion couplings, we show some features of
the low-energy effective action given by Seiberg based on anomaly and
non-perturbative -function arguments.Comment: 27 pages, RevTex, no figure
Duality and Non-Commutative Gauge Theory
We study the generalization of S-duality to non-commutative gauge theories.
For rank one theories, we obtain the leading terms of the dual theory by
Legendre transforming the Lagrangian of the non-commutative theory expressed in
terms of a commutative gauge field. The dual description is weakly coupled when
the original theory is strongly coupled if we appropriately scale the
non-commutativity parameter. However, the dual theory appears to be
non-commutative in space-time when the original theory is non-commutative in
space. This suggests that locality in time for non-commutative theories is an
artifact of perturbation theory.Comment: 7 pages, harvmac; a typo fixe
The Dual of Supersymmetric SU(2k) with an Antisymmetric Tensor and Composite Dualities
We suggest a dual to an Susy gauge theory containing an
antisymmetric tensor, \nf fundamentals and \nfb anti-fundamentals. This is
done by expanding the theory into an equivalent description with two gauge
groups and then performing known duality tranformations on each gauge group
separately. Chiral operators, mass perturbations and flat directions are
discussed.Comment: 17 pages, Harvma
Meta-stable Vacuum in Spontaneously Broken N=2 Supersymmetric Gauge Theory
We consider an N=2 supersymmetric SU(2) \times U(1) gauge theory with N_f=2
massless flavors and a Fayet-Iliopoulos (FI) term. In the presence of the FI
term, supersymmetry is spontaneously broken at tree level (on the Coulomb
branch), leaving a pseudo-flat direction in the classical potential. This
vacuum degeneracy is removed once quantum corrections are taken into account.
Due to the SU(2) gauge dynamics, the effective potential exhibits a local
minimum at the dyon point, where not only supersymmetry but also U(1)_R
symmetry is broken, while a supersymmetric vacuum would be realized toward
infinity with the runaway behavior of the potential. This local minimum is
found to be parametrically long-lived. Interestingly, from a phenomenological
point of view, in this meta-stable vacuum the massive hypermultiplets inherent
in the theory play the role of the messenger fields in the gauge mediation
scenario, when the Standard Model gauge group is embedded into their flavor
symmetry.Comment: 27 pages, 11 figures, journal reference added, minor modifications in
the tex
The Vacuum Structure and Spectrum of N=2 Supersymmetric SU(N) Gauge Theory
We present an exact description of the metric on the moduli space of vacua
and the spectrum of massive states for four dimensional N=2 supersymmetric
SU(n) gauge theories. The moduli space of quantum vacua is identified with the
moduli space of a special set of genus n-1 hyperelliptic Riemann surfaces.Comment: 11 pages, Revtex, 2 figures. Reference adde
Monopole and Dyon Bound States in N=2 Supersymmetric Yang-Mills Theories
We study the existence of monopole bound states saturating the BPS bound in
N=2 supersymmetric Yang-Mills theories. We describe how the existence of such
bound states relates to the topology of index bundles over the moduli space of
BPS solutions. Using an index theorem, we prove the existence of certain
BPS states predicted by Seiberg and Witten based on their study of the vacuum
structure of N=2 Yang-Mills theories.Comment: 34 pages, harvma
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