Lattice regularization for chiral perturbation theory

Abstract

The SU(3) chiral lagrangian for the lightest octets of mesons and baryons is constructed on a spacetime lattice. The lattice spacing acts as an ultraviolet momentum cutoff which appears directly in the Lagrangian so chiral symmetry remains explicit. As the lattice spacing vanishes, Feynman loop diagrams typically become divergent due to inverse powers of the lattice spacing, and these divergences get absorbed into counterterms such that the standard results of dimensional regularization are obtained. One advantage of lattice regularization is that power divergences are seen explicitly. In the present work, the octet meson masses, the octet baryon masses and the pion-nucleon sigma term are all computed explicitly to one loop order.