Massless Majorana fermion on the domain wall

We study the domain-wall formalism with additional Majorana mass term for the unwanted zero mode, which has recently been proposed for lattice construction of 4D N=1 super Yang-Mills theory without fine-tuning. Switching off the gauge field, we study the dispersion relation of the energy eigenstates numerically, and find that the method works for reasonable values of Majorana mass. We point out, however, that a problem arises for too large Majorana mass, which can be understood in terms of the seesaw mechanism.