Nucleon scalar and tensor charges from lattice QCD with light Wilson quarks

Abstract

We present $2+1$ flavor lattice QCD calculations of the nucleon scalar and tensor charges. Using the BMW clover-improved Wilson action with pion masses between 149 and 356 MeV and three source-sink separations between 0.9 and 1.4 fm, we achieve good control over excited-state contamination and extrapolation to the physical pion mass. As a consistency check, we also present results from calculations using unitary domain wall fermions with pion masses between 297 and 403 MeV, and using domain wall valence quarks and staggered sea quarks with pion masses between 293 and 597 MeV.