Numerical simulation tests with light dynamical quarks

Abstract. Two degenerate flavors of quarks are simulated with small masses down to about one fifth of the strange quark mass by using the two-step multi-boson (TSMB) algorithm. The lattice size is $8^3 \times 16$ with lattice spacing about $a \simeq 0.27 {\mathrm {fm}}$ which is not far from the Nt=4 thermodynamical cross-over line. Autocorrelations of different physical quantities are estimated as a function of the quark mass. The eigenvalue spectra of the Wilson-Dirac operator are investigated.