Disconnected Quark Loop Contributions to Nucleon Structure

Abstract

We calculate the disconnected contribution to isoscalar nucleon charges for scalar, axial and tensor channels of light and strange quarks. The calculation has been done with the Clover valence quarks on the MILC $N_f=2+1+1$ HISQ lattices whose light quark masses corresponding to the pion masses of 305 MeV and 217 MeV at $a\approx 0.12$ fm and 312 MeV at $a\approx 0.09$ fm. All-mode-averaging technique is used for the evaluation two-point functions. Disconnected quark loops are estimated by using the truncated solver method with Gaussian random noise sources. Contamination from the excited states is removed by fitting the results of various source-sink separations and operator insertions to the formula including up to the first excited state, simultaneously.

arXiv comment7 pages, talk presented at Lattice 2014, PoS (LATTICE2014) 141

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Cited by in corpus (2)

• Effective Field Theory and Time-Reversal Violation in Light Nuclei
• Recent progress in hadron structure from Lattice QCD