Stochastic method with low mode substitution for nucleon isovector matrix elements

Abstract

We introduce a stochastic sandwich method with low-mode substitution to evaluate the connected three-point functions. The isovector matrix elements of the nucleon for the axial-vector coupling $g_A^3$, scalar couplings $g_S^3$ and the quark momentum fraction $⟨x{⟩}_{u-d}$ are calculated with overlap fermion on 2+1 flavor domain-wall configurations on a $24^3\times 64$ lattice at $m_{\pi }=330$ MeV with lattice spacing $a=0.114$ fm.

Comments: 15 pages, 13 figures, the version accepted by PRD