The Heavy Quarkonium Spectrum at Order $m{\alpha }_s^5\ln {\alpha }_s$

Abstract

We compute the complete leading-log terms of the next-to-next-to-next-to-leading-order corrections to potential NRQCD. As a by-product we obtain the leading logs at $O(m{\alpha }_s^5)$ in the heavy quarkonium spectrum. These leading logs, when ${\Lambda }_{QCD}\ll m{\alpha }_s^2$, give the complete $O(m{\alpha }_s^5\ln {\alpha }_s)$ corrections to the heavy quarkonium spectrum.

Comments: 12 pages, LaTeX, 1 figure. Journal version. Minor explanatory remarks added