Charm Effects in the $\overline{MS}$ Bottom Quark Mass from ${\rm Y}$ Mesons

Abstract

We study the shift in the ${\rm Y}$ mass due to a non-zero charm quark mass. This shift affects the value of the $\overline{\mathrm{MS}}$ $b$-quark mass extracted from the ${\rm Y}$ system by about -20 MeV, due to an incomplete cancellation of terms that are non-analytic in the charm quark mass. The precise size of the shift depends on unknown higher order corrections, and might have a considerable uncertainty if they are large.

Comments: 7 pages, revtex, 2 postscript figures