Future of Chiral Extrapolations with Domain Wall Fermions

Understand

I discuss the constraints on the lattice spacing, a, the quark masses, m, the box size, L, and particularly the residual mass, m_res, such that one can successfully calculate phenomenologically interesting quantities using Domain Wall fermions (DWF).

• The constraints on a, m, and L are largely common with other improved fermion discretizations, and I emphasize that the improved chiral symmetry of DWF does not remove the need for simulations with a significant range of lattice parameters.
• Concerning m_res, I compare the analysis of chiral symmetry breaking to that with Wilson fermions, emphasizing that DWF are better than simply Wilson fermions with each chiral symmetry breaking effect reduced by a common factor.
• I then discuss the impact of non-zero m_res both on generic hadronic quantities, and on matrix elements which involve mixing with lower dimension operators.