Article,
QCD and dimensional deconstruction
(Feb 14, 2004)
Abstract
Motivated by phenomenological models of hidden local symmetries and the ideas
of dimensional deconstruction and gauge/gravity duality, we consider the model
of an öpen moose". Such a model has a large number K of hidden gauge groups as
well as a global chiral symmetry. In the continuum limit K->infinity the model
becomes a 4+1 dimensional theory of a gauge field propagating in a dilaton
background and an external space-time metric with two boundaries. We show that
the model reproduces several well known phenomenological and theoretical
aspects of low-energy hadron dynamics. We derive the general formulas for the
mass spectrum, the decay constants of the pion and vector mesons, and the
couplings between mesons. We then consider two simple realizations, one with a
flat metric and another with a "cosh" metric interpolating between two AdS
boundaries. For the pion form-factor, the single pole rho-meson dominance is
exact in the latter case and approximate in the former case. We discover that
an AdS/CFT-like prescription emerges in the computation of current-current
correlators. We speculate on the role of the model in the theory dual to QCD.
