14,944 research outputs found
Multi-phases in gauge theories on non-simply connected spaces
It is pointed out that phase structures of gauge theories compactified on
non-simply connected spaces are not trivial. As a demonstration, an SU(2) gauge
model on is studied and is shown to possess three phases:
Hosotani, Higgs and coexisting phases. The critical radius and the order of the
phase transitions are explicitly determined. A general discussion about phase
structures for small and large scales of compactified spaces is given. The
appearance of phase transitions suggests a GUT scenario in which the gauge
hierarchy problem is replaced by a dynamical problem of how to stabilize a
radius of a compactified space in close vicinity to a critical radius.Comment: 12 pages, 1 figur
A New Mechanism of Spontaneous SUSY Breaking
We propose a new mechanism of spontaneous supersymmetry breaking. The
existence of extra dimensions with nontrivial topology plays an important role.
We investigate new features resulted from the mechanism in two simple
supersymmetric Z_2 and U(1) models. One of remarkable features is that there
exists a phase in which the translational invariance for the compactified
directions is broken spontaneously, accompanying the breakdown of the
supersymmetry. The mass spectrum of the models appeared in reduced dimensions
is a full of variety, reflecting the highly nontrivial vacuum structure of the
models. The Nambu-Goldstone bosons (fermions) associated with breakdown of
symmetries are found in the mass spectrum. Our mechanism also yields quite
different vacuum structures if models have different global symmetries.Comment: 43 pages, 3 figure
Quantum Scattering in Two Black Hole Moduli Space
We discuss the quantum scattering process in the moduli space consisting of
two maximally charged dilaton black holes. The black hole moduli space geometry
has different structures for arbitrary dimensions and various values of dilaton
coupling. We study the quantum effects of the different moduli space geometries
with scattering process. Then, it is found that there is a resonance state on
certain moduli spaces.Comment: 15 pages, 19 figures, RevTeX 3.
Renormalization group for the probability distribution of magnetic impurities in a random-field model
Extending the usual Ginzburg-Landau theory for the random-field Ising model,
the possibility of dimensional reduction is reconsidered. A renormalization
group for the probability distribution of magnetic impurities is applied. New
parameters corresponding to the extra coupling constants in the
replica Hamiltonian are introduced. Although they do not affect the critical
phenomena near the upper critical dimension, they can when dimensions are
lowered.Comment: 16 pages, 11 figures, revte
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