Chiral Lagrangian for Karsten-Wilczek Minimally Doubled Fermions

Abstract

Lattice chiral perturbation theory is developed for Karsten-Wilczek fermions, a variant of minimally doubled fermions. As a first step, we consider the n\"aive fermionic field on lattice without its doubler. Once the symmetries of the action, the Symanzik effective theory and the spurion structure are established for the single fermion, we extend our study to include the doubler. Symanzik effective actions are considered up to five-dimensional operators in both cases. The two fermionic tastes are realized by point-splitting the quark wavefunction in the coordinate space. Spurion analysis is used to construct the chiral lagrangians for Karsten-Wilczek fermions from the Symanzik actions. In this work, we have not included a pion that is massive in the continuum limit.