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
In this paper,we analyze the dependence of the topological charge density from the overlap operator on the Wilson mass parameter in the overlap kernel by the symmetric multi-probing source(SMP)method.We observe that n...In this paper,we analyze the dependence of the topological charge density from the overlap operator on the Wilson mass parameter in the overlap kernel by the symmetric multi-probing source(SMP)method.We observe that non-trivial topological objects are removed as the Wilson mass is increased.A comparison of topological charge density calculated by the SMP method using the fermionic definition with that of the gluonic definition by the Wilson flow method is shown.A matching procedure for these two methods is used.We find that there is a best match for topological charge density between the gluonic definition with varied Wilson flow time and the fermionic definition with varied Wilson mass.By using the matching procedure,the proper flow time of Wilson flow in the calculation of topological charge density can be estimated.As the lattice spacing a decreases,the proper flow time also decreases,as expected.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.
基金Supported by the National Natural Science Foundation of China(NSFC)(11335001)。
文摘In this paper,we analyze the dependence of the topological charge density from the overlap operator on the Wilson mass parameter in the overlap kernel by the symmetric multi-probing source(SMP)method.We observe that non-trivial topological objects are removed as the Wilson mass is increased.A comparison of topological charge density calculated by the SMP method using the fermionic definition with that of the gluonic definition by the Wilson flow method is shown.A matching procedure for these two methods is used.We find that there is a best match for topological charge density between the gluonic definition with varied Wilson flow time and the fermionic definition with varied Wilson mass.By using the matching procedure,the proper flow time of Wilson flow in the calculation of topological charge density can be estimated.As the lattice spacing a decreases,the proper flow time also decreases,as expected.
