Nucleon average quark momentum fraction with $N_{\mathrm{f}}=2+1$ Wilson fermions

Abstract

We report on an analysis of the average quark momentum fraction of the nucleon and related quantities using $N_{\mathrm{f}}=2+1$ Wilson fermions. Computations are performed on four CLS ensembles covering three values of the lattice spacing at pion masses down to $M_{\pi }\approx 200\mathrm{MeV}$. Several source-sink separations ($\sim 1.0\mathrm{fm}$ to $\sim 1.4\mathrm{fm}$) are used to assess the excited-state contamination. To gain further insight, the generalized pencil-of-functions approach has been implemented to reduce the excited-state contamination in the relevant two- and three-point functions. Preliminary results are shown for the isovector nucleon charges from vector, axial vector and tensor derivative (twist-2) operators.

Comments: 8 pages, 3 figures, 2 tables. Talk presented at the 35th International Symposium on Lattice Field Theory, 18-24 June 2017, Granada, Spain