Residual chiral symmetry breaking in domain-wall fermions

We study the effective quark mass induced by the finite separation of the d omain walls in the domain-wall formulation of chiral fermion as the functio n of the size of the fifth dimension (L-s), the gauge coupling (beta) and t he physical volume (V). We measure the mass by calculating the small eigenv alues of the hermitian domain-wall Dirac operator (H-DWF(m(0) = 1.8)) in th e topologically-nontrivial quenched SU(3) gauge configurations. We find tha t the induced quark mass is nearly independent of the physical volume, deca ys exponentially as a function of L-s, and has a strong dependence on the s ize of quantum fluctuations controlled by beta. The effect of the choice of the lattice gluon action is also studied.