Improving the kinetic couplings in lattice nonrelativistic QCD

We improve the nonrelativistic QCD (NRQCD) action by comparing the dispersion relation to that of the continuum through O(p6) in perturbation theory. The one-loop matching coefficients of the O(p4) kinetic operators are determined, as well as the scale at which to evaluate αs in the V-scheme for each quantity. We utilize automated lattice perturbation theory using twisted boundary conditions as an infrared regulator. The one-loop radiative corrections to the mass renormalization, zero-point energy and overall energy-shift of an NRQCD b-quark are also found. We also explore how a Fat3-smeared NRQCD action and changes of the stability parameter n affect the coefficients. Finally, we use gluon field ensembles at multiple lattice spacing values, all of which include u, d, s and c quark vacuum polarization, to test how the improvements affect the nonperturbatively determined ϒ(1S) and ηb(1S) kinetic masses, and the tuning of the b quark mass.