Effects of spatial size, lattice doubling and source operator on the hadron spectrum with dynamical staggered quarks

Abstract

We have extended our previous study of the lattice QCD spectrum with 2 flavors of staggered dynamical quarks at $6/g^2=5.6$ and $a{m}_q=0.025$ and 0.01 to larger lattices, with better statistics and with additional sources for the propagators. The additional sources allowed us to estimate the $\Delta$ mass and to measure the masses of all mesons whose operators are local in time. These mesons show good evidence for flavor symmetry restoration, except for the masses of the Goldstone and non-Goldstone pions. PCAC is observed in that $m_{\pi }^2\propto m_q$, and $f_{\pi }$ is estimated. Use of undoubled lattices removes problems with the pion propagator found in our earlier work. Previously we found a large change in the nucleon mass at a quark mass of $a{m}_q=0.01$ when we increased the spatial size from 12 to 16. No such effect is observed at the larger quark mass, $a{m}_q=0.025$. Two kinds of wall source were used, and we have found difficulties in getting consistent results for the nucleon mass between the two sources.

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References in corpus (3)

• Hadron Spectrum in QCD with Valence Wilson Fermions and Dynamical Staggered Fermions at $6/g^2=5.6
• Simple Hadronic Matrix Elements with Wilson Valence Quarks and Dynamical Staggered Fermions at $6/{\mathbf{g}}^2=5.6$
• Comparison of Lattice Coulomb Gauge Wave Functions in Quenched Approximation and with Dynamical Fermions

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