Bound states in the three-dimensional Ising and $\phi^4$ models.
Michele Caselle
Abstract
We discuss the spectrum of the three dimensional Ising and
$\phi^4$ theory in the broken symmetry phase. In this phase the effective
potential between the elementary quanta of the model is attractive and
bound states of two or more of them may exist. We give theoretical and
numerical evidence for the existence of these bound states. Looking in
particular at the Ising model realization of the $\phi^4$ theory we show,
by using duality, that
these bound states are in one-to-one correspondence with the glueball states of
the gauge Ising model. We discuss some interesting consequences of this
identification [1,2].
[1] M.Caselle, M.Hasenbusch and P.Provero,
Nucl. Phys. {\bf B556} (1999) 575.
[2] M.Caselle, M.Hasenbusch, P.Provero and K. Zarembo,
Phys. Rev. {\bf D62} (2000) 017901.
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