Isovector and flavor-diagonal charges of the nucleon

Abstract

We present an update on the status of the calculations of isovector and flavor-diagonal charges of the nucleon. The calculations of the isovector charges are being done using ten $2+1+1$-flavor HISQ ensembles generated by the MILC collaboration covering the range of lattice spacings $a\approx$ 0.12, 0.09, 0.06 fm and pion masses $M_{\pi }\approx$ 310, 220, 130 MeV. Excited-states contamination is controlled by using four-state fits to two-point correlators and three-states fits to the three-point correlators. The calculations of the disconnected diagrams needed to estimate flavor-diagonal charges are being done on a subset of six ensembles using the stocastic method. Final results are obtained using a simultaneous fit in $M_{\pi }^2$, the lattice spacing $a$ and the finite volume parameter $M_{\pi }L$ keeping only the leading order corrections.

Comments: 8 pages and 3 figures