3,827 research outputs found
Relativistic effect of spin and pseudospin symmetries
Dirac Hamiltonian is scaled in the atomic units , which allows us
to take the non-relativistic limit by setting the Compton wavelength . The evolutions of the spin and pseudospin symmetries towards
the non-relativistic limit are investigated by solving the Dirac equation with
the parameter . With transformation from the original
Compton wavelength to 0, the spin splittings decrease monotonously in all spin
doublets, and the pseudospin splittings increase in several pseudospin
doublets, no change, or even reduce in several other pseudospin doublets. The
various energy splitting behaviors of both the spin and pseudospin doublets
with are well explained by the perturbation calculations of Dirac
Hamiltonian in the present units. It indicates that the origin of spin symmetry
is entirely due to the relativistic effect, while the origin of pseudospin
symmetry cannot be uniquely attributed to the relativistic effect.Comment: 15 pages, 7 figures, accepted by PR
Investigating the topological structure of quenched lattice QCD with overlap fermions by using multi-probing approximation
The topological charge density and topological susceptibility are determined
by multi-probing approximation using overlap fermions in quenched SU(3) gauge
theory. Then we investigate the topological structure of the quenched QCD
vacuum, and compare it with results from the all-scale topological density, the
results are consistent. Random permuted topological charge density is used to
check whether these structures represent underlying ordered properties.
Pseudoscalar glueball mass is extracted from the two-point correlation function
of the topological charge density. We study ensembles of different lattice
spacing with the same lattice volume , the results are
compatible with the results of all-scale topological charge density, and the
topological structures revealed by multi-probing are much closer to all-scale
topological charge density than that by eigenmode expansion.Comment: 12 pages,34 figure
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