Hadronic mass spectrum in pseudofermion lattice QCD.

Abstract

We report on a large-scale calculation of the hadronic mass spectrum in lattice quantum chromodynamics with dynamical quarks using the pseudofermion algorithm. The calculation was carried out on a ${10}^{3}$\ifmmode\times\else\texttimes\fi{}32 lattice, at a gauge coupling of $\ensuremath{\beta}=5.70$, with three flavors of staggered quarks of mass $(\mathrm{ma})=0.05 \mathrm{and} 0.10$ (in lattice units), and with four values of the acceptance: i.e., 60%, 70%, 81%, and 89%. The hadron masses were obtained from propagators calculated at mass $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{m}a=ma$, but also at $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{m}a=0.50 \mathrm{and} 0.02$, in order to study hadronic states with different valence and dynamical quark masses. We also present the results of a calculation on a ${10}^{3}$\ifmmode\times\else\texttimes\fi{}24 lattice at $\ensuremath{\beta}=5.47$ and $ma=0.05$ carried out for comparison with the results obtained by Gottlieb, Liu, Toussaint, Renken, and Sugar using the hybrid algorithm. Finally, we suggest a new parameter for a better estimate of the accuracy of the approximations involved in the pseudofermion algorithm.