We revise the analysis of the bottomonium hyperfine splitting within the lattice nonrelativistic QCD. The Wilson coefficients of the radiatively improved lattice action are evaluated by a semianalytic approach based on the asymptotic expansion about the continuum limit. The nonrelativistic renormalization group is used to estimate the high-order radiative corrections. Our result for the 1S hyperfine splitting is MΥ(1S)−Mηb(1S)=52.9±5.5MeV. It reconciles the predictions of the continuum and lattice QCD and is in very good agreement with the most accurate experimental measurement by Belle collaboration.
@article{arxiv.1504.05979,
title = {Bottomonium Hyperfine Splitting on the Lattice and in the Continuum},
author = {M. Baker and A. A. Penin and D. Seidel and N. Zerf},
journal= {arXiv preprint arXiv:1504.05979},
year = {2015}
}