Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Centre for Mathematical Sciences, Cambridge CB3 0WA, United Kingdom.
Phys Rev Lett. 2011 Sep 9;107(11):112002. doi: 10.1103/PhysRevLett.107.112002. Epub 2011 Sep 8.
We present the first application of the background field method to nonrelativistic QCD (NRQCD) on the lattice in order to determine the one-loop radiative corrections to the coefficients of the NRQCD action in a manifestly gauge-covariant manner. The coefficients of the σ·B term in the NRQCD action and the four-fermion spin-spin interaction are computed at the one-loop level; the resulting shift of the hyperfine splitting of bottomonium is found to bring the lattice predictions in line with experiment.
我们首次将背景场方法应用于格点上的非相对论性 QCD（NRQCD），以显式协变的方式确定 NRQCD 作用的系数的单圈辐射修正。在 NRQCD 作用中的 σ·B 项和四费米子自旋-自旋相互作用的系数在单圈水平上被计算；得到的底介子精细结构分裂的移动量使格点预测与实验相符。
