Taste non-Goldstone, flavor-charged pseudo-Goldstone boson masses in staggered chiral perturbation theory

Understand

We calculate the masses of taste non-Goldstone pions and kaons in staggered chiral perturbation theory through next-to-leading order in the standard power counting.

• The results can be used to quantitatively understand taste violations in existing lattice data generated with staggered fermions and to extract the $u$, $d$, and $s$ quark masses and Gasser-Leutwyler parameters from the experimentally observed spectrum.
• The expressions for the non-Goldstone masses contain low-energy couplings unique to the non-Goldstone sector.
• With two exceptions these enter as coefficients of analytic terms; all the new couplings can be fixed by performing spectrum calculations.