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Title: Overlap valence on 2+1 flavor domain wall fermion configurations with deflation and low-mode substitution

Journal Article · · Physical Review. D, Particles Fields
 [1]; ;  [2];  [3];  [4]; ; ; ; ;  [5];  [6];  [7];  [8];  [9]
  1. Department of Physics, Duke University, Durham, North Carolina 27708 (United States)
  2. Department of Physics, George Washington University, Washington, D.C. 20052 (United States)
  3. Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049 (China)
  4. Graduate School of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan)
  5. Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States)
  6. Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States)
  7. Department of Theoretical Physics, Tata Institute of Fundamental Research, Mumbai 40005 (India)
  8. Institute for Theoretical Physics, University of Regensburg, 93040 Regensburg (Germany)
  9. ZIMP and Department of Physics, Zhejiang University, Hangzhou, Zhejiang 310027 (China)

The overlap fermion propagator is calculated on 2+1 flavor domain-wall fermion gauge configurations on 16{sup 3}x32, 24{sup 3}x64 and 32{sup 3}x64 lattices. With hyper-cubic (HYP) smearing and low eigenmode deflation, it is shown that the inversion of the overlap operator can be expedited by {approx}20 times for the 16{sup 3}x32 lattice and {approx}80 times for the 32{sup 3}x64 lattice. The overhead cost for calculating eigenmodes ranges from 4.5 to 7.9 propagators for the above lattices. Through the study of hyperfine splitting, we found that the O(m{sup 2}a{sup 2}) error is small and these dynamical fermion lattices can adequately accommodate quark mass up to the charm quark. A preliminary calculation of the low-energy constant {Delta}{sub mix} which characterizes the discretization error of the pion made up of a pair of sea and valence quarks in this mixed-action approach is carried out via the scalar correlator with periodic and antiperiodic boundary conditions. It is found to be small which shifts a 300 MeV pion mass by {approx}10 to 19 MeV on these sets of lattices. We have studied the signal-to-noise issue of the noise source for the meson and baryon. We introduce a new algorithm with Z{sub 3} grid source and low eigenmode substitution to study the many-to-all meson and baryon correlators. It is found to be efficient in reducing errors for the correlators of both mesons and baryons. With 64-point Z{sub 3} grid source and low-mode substitution, it can reduce the statistical errors of the light quark (m{sub {pi}{approx}2}00-300 MeV) meson and nucleon correlators by a factor of {approx}3-4 as compared to the point source. The Z{sub 3} grid source itself can reduce the errors of the charmonium correlators by a factor of {approx}3.

OSTI ID:
21503716
Journal Information:
Physical Review. D, Particles Fields, Vol. 82, Issue 11; Other Information: DOI: 10.1103/PhysRevD.82.114501; (c) 2010 American Institute of Physics; ISSN 0556-2821
Country of Publication:
United States
Language:
English