  This paper continues the investigation of the modified Sakai-Sugimoto model
proposed in arXiv:0708.3233. Here we discuss in detail numerical solutions to
the classical equations for the brane profile and the tachyon condensate. An
ultraviolet cut-off turns out to be essential because the numerical solutions
tend to rapidly diverge from the desired asymptotic solutions, beyond a
sufficiently large value of the holographic coordinate. The required cut-off is
determined by the non-normalizable part of the tachyon and is parametrically
far smaller than that dictated by consistency of a description in terms of
10-dimensional bulk gravity. In arXiv:0708.3233 we had argued that the solution
in which the tachyon field goes to infinity at the point where the brane and
antibrane meet has only one free parameter, which may be taken to be the
asymptotic brane-antibrane separation. Here we present numerical evidence in
favour of this observation. We also present evidence that the non-normalizable
part of the asymptotic tachyon solution, which is identified with quark mass in
the QCD-like boundary theory, is determined by this parameter. We show that the
normalizable part of the asymptotic tachyon solution determines the quark
condensate, but this requires holographic renormalization of the on-shell
boundary brane action because of the presence of infinite cut-off dependent
terms. Our renormalization scheme gives an exponential dependence on the
cut-off to the quark mass. We also discuss meson spectra in detail and show
that the pion mass is nonzero and satisfies the Gell-Mann-Oakes-Renner relation
when a small quark mass is switched on.
