EFFECTS OF SPATIAL SIZE, LATTICE DOUBLING, AND SOURCE OPERATORS ON THE HADRON SPECTRUM WITH DYNAMICAL STAGGERED QUARKS AT 6/G(2) = 5.6

We have extended our previous study of the lattice QCD spectrum with two flavors of staggered dynamical quarks at 6/g2=5.6 and am(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 is-proportional-to m(q), and f(pi) is estimated. Use of undoubled lattices removes the 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 am(q)=0.01 when we increased the spatial size from 12 to 16. No such effect is observed at the larger quark mass, am(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.