Quark Condensate in Massless QCD from Planar Equivalence

A previous estimate of the quark condensate in one-flavour massless QCD from the known value of the gluino condensate in super Yang-Mills (SYM) theory is extended to Nf >1 by considering the large-N limit of an SU(N) gauge theory with one flavour in the antisymmetric representation and nf = Nf -1 extra flavours in the fundamental representation. We argue that, even at nf> 0, suitably chosen correlators in this theory can be mapped to those of SYM as N–> infinity. We give arguments why this correspondence should be particularly good for Nf =3 and compare our prediction with available (real and Monte Carlo) data.