  In recent years, many investigations of confining Yang Mills gauge theories
near the edge of the conformal window have been carried out using lattice
techniques. These studies have revealed that the spectrum of hadrons in nearly
conformal ("walking") gauge theories differs significantly from the QCD
spectrum. In particular, a light flavorsinglet scalar appears in the spectrum
which is nearly degenerate with the pseudo-NambuGoldstone bosons (PNGBs) at the
lightest currently accessible quark masses. This state is a viable candidate
for a composite Higgs boson. Presently, an acceptable effective field theory
(EFT) description of the light states in walking theories has not been
established. Such an EFT would be useful for performing chiral extrapolations
of lattice data and for serving as a bridge between lattice calculations and
phenomenology. It has been shown that the chiral Lagrangian fails to describe
the IR dynamics of a theory near the edge of the conformal window. Here we
assess a linear sigma model as an alternate EFT description by performing
explicit chiral fits to lattice data. Our model provides an acceptable combined
fit to the PNGB mass and decay constant, reducing the $\chi^2$/d.o.f. by more
than an order of magnitude compared to next-to-leading order chiral
perturbation theory.
