TY - JOUR

T1 - Variance reduction and cluster decomposition

AU - Liu, Keh Fei

AU - Liang, Jian

AU - Yang, Yi Bo

N1 - Publisher Copyright:
© 2018 authors.

PY - 2018/2/1

Y1 - 2018/2/1

N2 - 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.

AB - 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.

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U2 - 10.1103/PhysRevD.97.034507

DO - 10.1103/PhysRevD.97.034507

M3 - Article

AN - SCOPUS:85043397478

SN - 2470-0010

VL - 97

JO - Physical Review D

JF - Physical Review D

IS - 3

M1 - 034507

ER -