### Speaker

Dr
YIBO Yang
(university of Kentucky)

### Description

We employ dimension 4 operators to improve the local vector and axial vector currents, as the leading order approximation of the lattice conserved current, and then calculate the nucleon iso-vector axial coupling $g^3_A$ using overlap valence on Domain Wall Fermion sea. Using the equality of $g^3_A$ from $A_i$ and $A_4$ components of the axial-vector current as a normalization condition in addition to
axial Ward identity, we find two to three percent increase of $g^3_A$ towards the experimental value. The excited state contamination has been taken into account with three time separations between the source and sink.
The improved axial charges $g_A^{IM}(24I)=1.188(7)$, $g_A^{IM}(32I)=1.177(9)$ are obtained on $24^3\times 64$ and $32^3\times 64$ lattices at the unitary point where the pion masses are $330$ MeV and $300$ MeV respectively.

### Primary author

Dr
Jian Liang
(University of Kentucky)

### Co-authors

Prof.
Andrei Alexandru
(The George Washington University)
Prof.
Keh-Fei Liu
(University of Kentucky)
Raza Sufian
(University of Kentucky, United States)
Prof.
Terrence Draper
(University of Kentucky)
Dr
YIBO Yang
(university of Kentucky)