  The Lattice Strong Dynamics collaboration is investigating the properties of
a SU(3) gauge theory with $N_f = 8$ light fermions on the lattice. We measure
the masses of the lightest pseudoscalar, scalar and vector states using
simulations with the nHYP staggered-fermion action on large volumes and at
small fermion masses, reaching $M_{\rho}/M_{\pi} \approx 2.2$. The axial-vector
meson and the nucleon are also studied for the same range of fermion masses.
One of the interesting features of this theory is the dynamical presence of a
light flavor-singlet scalar state with $0^{++}$ quantum numbers that is lighter
than the vector resonance and has a mass consistent with the one of the
pseudoscalar state for the whole fermion mass range explored. We comment on the
existence of such state emerging from our lattice simulations and on the
challenges of its analysis. Moreover we highlight the difficulties in pursuing
simulations in the chiral regime of this theory using large volumes.
