Topological susceptibility in full QCD with Ginsparg–Wilson fermions

AbstractWe show that, if the formula for the topological charge density operator suggested by the use of fermions obeying the Ginsparg–Wilson relation is employed, it is possible to give a precise and unambiguous definition of the topological susceptibility in full QCD, χfulltL, for finite quark masses on the lattice. The lattice expression of χfulltL looks like the formal continuum one, in the sense that no power divergent subtractions are needed for its proper definition. As a consequence, the small mass behaviour of χfulltL leads directly to a multiplicative renormalizable definition of the chiral condensate that does not require any power divergent subtraction