Charm effects in the MS bottom quark mass from ϒ mesons

We study the shift in the ϒ mass due to a non-zero charm quark mass. This shift affects the value of the MS b-quark mass extracted from the ϒ 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.