Recently the full O(αS5m, α S5 log αS) correction to the heavy quarkonium 1S energy level has been computed (except the a3 term in the QCD potential). We point out that the full correction (including the log αS term) is approximated well by the large-β0 approximation. Based on the assumption that this feature holds up to higher orders, we discuss why the top quark pole mass cannot be determined to better than O(ΛQCD) accuracy at a future e+e- collider, while the modified minimal-subtraction (MS̄) mass can be determined to about 40 MeV accuracy (provided the 4-loop MS̄-pole mass relation will be computed in due time).
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)