Liu, CA , Peking Univ, Dept Phys, Beijing 100871, Peoples R China.
Peking Univ, Dept Phys, Beijing 100871, Peoples R China; Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China
We simulate lattice quantum chromodynamics on asymmetric lattices with improved actions, where quenching approximation is used. These lattices have a spatial lattice spacing a. at 0.3 and 0.4 fm, and a temporal lattice spacing at from 0.14 to 0.08 fm. The lattice spacing error due to a, is greatly reduced through improving both quark and gluon actions at a certain level. We find that masses of mesons have weak dependence on both lattice spacings, while the a(s) and a(t) dependence for baryons is more significant. With suitable modelling of these dependences, we are able to obtain the nucleon mass in agreement with the experiment.