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

We study the shift in the $\mathrm{{\rm Y}}$ mass due to a non-zero charm quark mass. This shift affects the value of the $\overline{\mathrm{M}\mathrm{S}}$ $b$-quark mass extracted from the $\mathrm{{\rm Y}}$ 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.