The variational method is used widely for determining the hadronic spectrum for Wilson and improved Wilson fermions. The method has not been applied to staggered fermions because the hadronic correlation functions in that formalism include terms that oscillate with Euclidean time, and they often include states of both parities. We show that with a simple modification, the variational method can also be applied to staggered fermions. In some cases the method also provides a mechanism for separating the commonly paired parity-partner states. We discuss the extension to staggered fermions and illustrate it by applying it to the calculation of the spectrum of charmed-antistrange mesons consisting of a clover charm quark and a staggered strange antiquark.

• Received 25 November 2014

DOI:https://doi.org/10.1103/PhysRevD.91.034504