Domain-wall induced quark masses in topologically nontrivial backgrounds -art. no. 074508

In the domain-wall formulation of chiral fermions, the finite separation be tween domain walls (L-s) induces an effective quark mass (m(eff)) which com plicates the chiral limit. In this work we study the size of the effective mass as a function of L-s and the domain-wall height m(o) by calculating th e smallest eigenvalue of the Hermitian domain-wail Dirac operator in the to pologically nontrivial background fields. We find that,just as in the free case, m(eff) decreases exponentially in L-s with a rate depending on m(o). However, quantum fluctuations amplify the wall effects significantly. Our n umerical result is consistent with a previous study of the effective mass f rom the Gell-Mann-Oakes-Renner relation.