Variance reduction and cluster decomposition

Keh Fei Liu, Jian Liang, Yi Bo Yang

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


It is a common problem in lattice QCD calculation of the mass of the hadron with an annihilation channel that the signal falls off in time while the noise remains constant. In addition, the disconnected insertion calculation of the three-point function and the calculation of the neutron electric dipole moment with the θ term suffer from a noise problem due to the V fluctuation. We identify these problems to have the same origin and the V problem can be overcome by utilizing the cluster decomposition principle. We demonstrate this by considering the calculations of the glueball mass, the strangeness content in the nucleon, and the CP violation angle in the nucleon due to the θ term. It is found that for lattices with physical sizes of 4.5-5.5 fm, the statistical errors of these quantities can be reduced by a factor of 3 to 4. The systematic errors can be estimated from the Akaike information criterion. For the strangeness content, we find that the systematic error is of the same size as that of the statistical one when the cluster decomposition principle is utilized. This results in a 2 to 3 times reduction in the overall error.

Original languageEnglish
Article number034507
JournalPhysical Review D
Issue number3
StatePublished - Feb 1 2018

Bibliographical note

Publisher Copyright:
© 2018 authors.

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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