Flavor dependence of the hadron spectrum in lattice QCD

We study the dependence of the hadron mass spectrum on the number of light dynamical quarks. We simulated on {dollar}16sp3times Nsb{lcub}t{rcub} (Nsb{lcub}t{rcub}=32{dollar} or 40) lattices with 2 and 4 flavors of dynamical staggered quarks of mass {dollar}ma=0.01{dollar} each and also 0 flavors of quarks, all with large statistics. We adjusted our simulation parameters so that the scales are the same for different number of flavors. Our lattice spacing is about 1.8 GeV and the spatial lattice size is about 1.8 fm.; We have measured the hadron mass spectrum with a variety of valence quark mass combinations. We studied the effects of the size of the source that creates hadron states. We obtain excited state masses from combined analyses of data calculated with different sized sources. We also studied the choice of gauge in hadron mass measurements and found that it is important to use a gauge that is local in time.; We found that between 0 and 2 flavors, the nucleon to the rho mass ratios in the zero valence quark mass limit are not significantly different. However, the 4 flavor ratio is 7% higher than the 2 flavor ratio and this is significant to 2 standard deviations. There is also strong flavor dependence in the whole hadron spectrum as we increase the number of flavors.