Calculation of disconnected quark loops in lattice QCD is very time consuming.Stochastic noise methods are generally used to estimate these loops.However,stochastic estimation gives large errors in the calculations of...Calculation of disconnected quark loops in lattice QCD is very time consuming.Stochastic noise methods are generally used to estimate these loops.However,stochastic estimation gives large errors in the calculations of disconnected diagrams.We use the symmetric multi-probing source(SMP)method to estimate the disconnected quark loops,and compare the results with the Z(2)noise method and the spin-color explicit(SCE)method on a quenched lattice QCD ensemble with lattice volume 12^3×24 and lattice spacing a≈0.1 fm.The results show that the SMP method is very suitable for the calculation of pseudoscalar disconnected quark loops.However,the SMP and SCE methods do not have an obvious advantage over the Z(2)noise method in the evaluation of the scalar disconnected loops.展开更多
基金Supported by National Natural Science Foundation of China(11335001)
文摘Calculation of disconnected quark loops in lattice QCD is very time consuming.Stochastic noise methods are generally used to estimate these loops.However,stochastic estimation gives large errors in the calculations of disconnected diagrams.We use the symmetric multi-probing source(SMP)method to estimate the disconnected quark loops,and compare the results with the Z(2)noise method and the spin-color explicit(SCE)method on a quenched lattice QCD ensemble with lattice volume 12^3×24 and lattice spacing a≈0.1 fm.The results show that the SMP method is very suitable for the calculation of pseudoscalar disconnected quark loops.However,the SMP and SCE methods do not have an obvious advantage over the Z(2)noise method in the evaluation of the scalar disconnected loops.
